IDWeek 2013

SAN FRANCISCO – The incidence of invasive pneumococcal disease among children is declining in the wake of the 2010 introduction of the 13-valent pneumococcal conjugate vaccine, surveillance data suggest.

In New York City during 2011-2012, for example, the incidence of invasive pneumococcal disease (IPD) declined among children under age 5 across all age categories and race/ethnicity groups, Andrea Farnham of the New York City Department of Health and Mental Hygiene reported in a poster at an annual scientific meeting on infectious diseases.

The decline was driven by a reduction in 13-valent pneumococcal conjugate vaccine (PCV13)-type IPD and was temporally associated with the introduction and increased uptake of PCV13 vaccine, she said.

IPD incidence decreased by 70% (from 21.0 to 6.4 cases/100,000) between 2007-2009 and 2011-2012, and PCV13-type IPD incidence decreased 82% (from 15.3 to 2.7 cases/100,000) in that same time period.

The greatest decrease (80%) occurred in children under age 12 months. Decreases were 68% and 62.1% in those aged 12-35 months and 36-59 months, respectively, Ms. Farnham noted.

Another study presented at the meeting showed that 89% of PCV13 serotype disease in Ontario during the second year after the implementation of PCV13 vaccine (2012-2013) occurred in unvaccinated children. Half of the cases (14 of 28) were in children who were not eligible for vaccination, and of the remaining 14, 1 child was unvaccinated, 3 had missed doses, 7 had appropriately received PCV7 vaccine but missed the PCV13 catch-up dose, and 2 received PCV13 vaccine at ages 2 and 4 months but developed IPD at ages 10 and 11 months, respectively, Karen Green, an epidemiologist at Mount Sinai Hospital, Toronto, also reported in a poster.

One apparently healthy 5-year-old developed empyema from serotype 5 disease after receiving age-appropriate vaccination, she noted at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

The findings suggest that PCV13 vaccination is having a substantial effect on rates of IPD – an effect that could be improved upon with increased vaccine coverage.

A third study suggested that children over age 2 years, in particular, may not be vaccinated appropriately.

In that study, John M. McLaughlin, Ph.D., of Pfizer Specialty Care Medicines Development Group, Collegeville, Penn, showed that although children up to age 1 year had significant reductions in all 13 serotypes covered by the PCV13 vaccine, those aged 2-17 years did not experience a reduction in serotype 19A disease.

Overall, among children aged 0-17 years, the proportion of IPD caused by serotype 19A decreased from 37% in 2008-2009 to 28% in 2010-2011, and the proportion caused by the other 12 serotypes in the PCV13 vaccine decreased from 66% to 48% during the same period.

However, while there was a 44% relative reduction in the proportion of IPD caused by serotypes in the PCV13 vaccine among those aged 0-1 years, there was only a 17% relative reduction in those aged 2-17 years.

"The difference in these two age groups was driven largely by the difference in reduction of the proportion of IPD caused by serotype 19A," he said, explaining that there was a 36% relative reduction in the proportion of IPD caused by serotype 19A among those aged 0-1 years, but no decrease in those aged 2-17 years.

No difference was seen between the 0- to 1-year age group and the 2- to 17-year age group for the remaining serotypes (32% for both groups).

This could be a result of a lack of early indirect effect of vaccination or of the virulence of 19A, or it could be caused by more comorbid disease in the older age group. Comorbidities increased significantly with increasing age, Dr. McLaughlin said, noting that 27% of those aged less than 1 year had comorbid conditions, compared with 32% of those aged 1-2 years, 45% of those aged 3-5 years, and 60% of those aged 6-17 years.

Low PCV13 vaccination rates in older children may also be a factor; in this study, only two children aged 11 years and over had received PCV13 vaccination.

IPD cases in Dr. McLaughlin’s study were identified from eight geographically dispersed children’s hospitals in the U.S. Pediatric Multicenter Pneumococcal Surveillance Study Group. The findings support the Jan. 25, 2013, decision by the Food and Drug Administration to expand the age indication for PCV13 vaccination in children and teens to those aged 6-17 years for prevention of vaccine-type IPD, he concluded (AAP News 2013 March 6 [doi: 10.1542/aapnews.20130306-2]).

Ms. Farnham stressed the importance of vaccination.

"Given the potential of PCV13 to reduce IPD incidence and racial/ethnic disparities, efforts should be focused on increasing coverage of PCV13 and ensuring patients receive all the recommended doses of PCV13," she concluded.

Ms. Green reported working as a grant investigator for, and receiving educational and/or research support from, Pfizer and GlaxoSmithKline. Dr. McLaughlin reported that he is an employee and shareholder of Pfizer. Ms. Farnham reported having no disclosures.

SAN FRANCISCO – The incidence of invasive pneumococcal disease among children is declining in the wake of the 2010 introduction of the 13-valent pneumococcal conjugate vaccine, surveillance data suggest.

In New York City during 2011-2012, for example, the incidence of invasive pneumococcal disease (IPD) declined among children under age 5 across all age categories and race/ethnicity groups, Andrea Farnham of the New York City Department of Health and Mental Hygiene reported in a poster at an annual scientific meeting on infectious diseases.

The decline was driven by a reduction in 13-valent pneumococcal conjugate vaccine (PCV13)-type IPD and was temporally associated with the introduction and increased uptake of PCV13 vaccine, she said.

IPD incidence decreased by 70% (from 21.0 to 6.4 cases/100,000) between 2007-2009 and 2011-2012, and PCV13-type IPD incidence decreased 82% (from 15.3 to 2.7 cases/100,000) in that same time period.

The greatest decrease (80%) occurred in children under age 12 months. Decreases were 68% and 62.1% in those aged 12-35 months and 36-59 months, respectively, Ms. Farnham noted.

Another study presented at the meeting showed that 89% of PCV13 serotype disease in Ontario during the second year after the implementation of PCV13 vaccine (2012-2013) occurred in unvaccinated children. Half of the cases (14 of 28) were in children who were not eligible for vaccination, and of the remaining 14, 1 child was unvaccinated, 3 had missed doses, 7 had appropriately received PCV7 vaccine but missed the PCV13 catch-up dose, and 2 received PCV13 vaccine at ages 2 and 4 months but developed IPD at ages 10 and 11 months, respectively, Karen Green, an epidemiologist at Mount Sinai Hospital, Toronto, also reported in a poster.

One apparently healthy 5-year-old developed empyema from serotype 5 disease after receiving age-appropriate vaccination, she noted at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

The findings suggest that PCV13 vaccination is having a substantial effect on rates of IPD – an effect that could be improved upon with increased vaccine coverage.

A third study suggested that children over age 2 years, in particular, may not be vaccinated appropriately.

In that study, John M. McLaughlin, Ph.D., of Pfizer Specialty Care Medicines Development Group, Collegeville, Penn, showed that although children up to age 1 year had significant reductions in all 13 serotypes covered by the PCV13 vaccine, those aged 2-17 years did not experience a reduction in serotype 19A disease.

Overall, among children aged 0-17 years, the proportion of IPD caused by serotype 19A decreased from 37% in 2008-2009 to 28% in 2010-2011, and the proportion caused by the other 12 serotypes in the PCV13 vaccine decreased from 66% to 48% during the same period.

However, while there was a 44% relative reduction in the proportion of IPD caused by serotypes in the PCV13 vaccine among those aged 0-1 years, there was only a 17% relative reduction in those aged 2-17 years.

"The difference in these two age groups was driven largely by the difference in reduction of the proportion of IPD caused by serotype 19A," he said, explaining that there was a 36% relative reduction in the proportion of IPD caused by serotype 19A among those aged 0-1 years, but no decrease in those aged 2-17 years.

No difference was seen between the 0- to 1-year age group and the 2- to 17-year age group for the remaining serotypes (32% for both groups).

This could be a result of a lack of early indirect effect of vaccination or of the virulence of 19A, or it could be caused by more comorbid disease in the older age group. Comorbidities increased significantly with increasing age, Dr. McLaughlin said, noting that 27% of those aged less than 1 year had comorbid conditions, compared with 32% of those aged 1-2 years, 45% of those aged 3-5 years, and 60% of those aged 6-17 years.

Low PCV13 vaccination rates in older children may also be a factor; in this study, only two children aged 11 years and over had received PCV13 vaccination.

IPD cases in Dr. McLaughlin’s study were identified from eight geographically dispersed children’s hospitals in the U.S. Pediatric Multicenter Pneumococcal Surveillance Study Group. The findings support the Jan. 25, 2013, decision by the Food and Drug Administration to expand the age indication for PCV13 vaccination in children and teens to those aged 6-17 years for prevention of vaccine-type IPD, he concluded (AAP News 2013 March 6 [doi: 10.1542/aapnews.20130306-2]).

Ms. Farnham stressed the importance of vaccination.

"Given the potential of PCV13 to reduce IPD incidence and racial/ethnic disparities, efforts should be focused on increasing coverage of PCV13 and ensuring patients receive all the recommended doses of PCV13," she concluded.

Ms. Green reported working as a grant investigator for, and receiving educational and/or research support from, Pfizer and GlaxoSmithKline. Dr. McLaughlin reported that he is an employee and shareholder of Pfizer. Ms. Farnham reported having no disclosures.

SAN FRANCISCO – The incidence of invasive pneumococcal disease among children is declining in the wake of the 2010 introduction of the 13-valent pneumococcal conjugate vaccine, surveillance data suggest.

In New York City during 2011-2012, for example, the incidence of invasive pneumococcal disease (IPD) declined among children under age 5 across all age categories and race/ethnicity groups, Andrea Farnham of the New York City Department of Health and Mental Hygiene reported in a poster at an annual scientific meeting on infectious diseases.

The decline was driven by a reduction in 13-valent pneumococcal conjugate vaccine (PCV13)-type IPD and was temporally associated with the introduction and increased uptake of PCV13 vaccine, she said.

IPD incidence decreased by 70% (from 21.0 to 6.4 cases/100,000) between 2007-2009 and 2011-2012, and PCV13-type IPD incidence decreased 82% (from 15.3 to 2.7 cases/100,000) in that same time period.

The greatest decrease (80%) occurred in children under age 12 months. Decreases were 68% and 62.1% in those aged 12-35 months and 36-59 months, respectively, Ms. Farnham noted.

Another study presented at the meeting showed that 89% of PCV13 serotype disease in Ontario during the second year after the implementation of PCV13 vaccine (2012-2013) occurred in unvaccinated children. Half of the cases (14 of 28) were in children who were not eligible for vaccination, and of the remaining 14, 1 child was unvaccinated, 3 had missed doses, 7 had appropriately received PCV7 vaccine but missed the PCV13 catch-up dose, and 2 received PCV13 vaccine at ages 2 and 4 months but developed IPD at ages 10 and 11 months, respectively, Karen Green, an epidemiologist at Mount Sinai Hospital, Toronto, also reported in a poster.

One apparently healthy 5-year-old developed empyema from serotype 5 disease after receiving age-appropriate vaccination, she noted at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

The findings suggest that PCV13 vaccination is having a substantial effect on rates of IPD – an effect that could be improved upon with increased vaccine coverage.

A third study suggested that children over age 2 years, in particular, may not be vaccinated appropriately.

In that study, John M. McLaughlin, Ph.D., of Pfizer Specialty Care Medicines Development Group, Collegeville, Penn, showed that although children up to age 1 year had significant reductions in all 13 serotypes covered by the PCV13 vaccine, those aged 2-17 years did not experience a reduction in serotype 19A disease.

Overall, among children aged 0-17 years, the proportion of IPD caused by serotype 19A decreased from 37% in 2008-2009 to 28% in 2010-2011, and the proportion caused by the other 12 serotypes in the PCV13 vaccine decreased from 66% to 48% during the same period.

However, while there was a 44% relative reduction in the proportion of IPD caused by serotypes in the PCV13 vaccine among those aged 0-1 years, there was only a 17% relative reduction in those aged 2-17 years.

"The difference in these two age groups was driven largely by the difference in reduction of the proportion of IPD caused by serotype 19A," he said, explaining that there was a 36% relative reduction in the proportion of IPD caused by serotype 19A among those aged 0-1 years, but no decrease in those aged 2-17 years.

No difference was seen between the 0- to 1-year age group and the 2- to 17-year age group for the remaining serotypes (32% for both groups).

This could be a result of a lack of early indirect effect of vaccination or of the virulence of 19A, or it could be caused by more comorbid disease in the older age group. Comorbidities increased significantly with increasing age, Dr. McLaughlin said, noting that 27% of those aged less than 1 year had comorbid conditions, compared with 32% of those aged 1-2 years, 45% of those aged 3-5 years, and 60% of those aged 6-17 years.

Low PCV13 vaccination rates in older children may also be a factor; in this study, only two children aged 11 years and over had received PCV13 vaccination.

IPD cases in Dr. McLaughlin’s study were identified from eight geographically dispersed children’s hospitals in the U.S. Pediatric Multicenter Pneumococcal Surveillance Study Group. The findings support the Jan. 25, 2013, decision by the Food and Drug Administration to expand the age indication for PCV13 vaccination in children and teens to those aged 6-17 years for prevention of vaccine-type IPD, he concluded (AAP News 2013 March 6 [doi: 10.1542/aapnews.20130306-2]).

Ms. Farnham stressed the importance of vaccination.

"Given the potential of PCV13 to reduce IPD incidence and racial/ethnic disparities, efforts should be focused on increasing coverage of PCV13 and ensuring patients receive all the recommended doses of PCV13," she concluded.

Ms. Green reported working as a grant investigator for, and receiving educational and/or research support from, Pfizer and GlaxoSmithKline. Dr. McLaughlin reported that he is an employee and shareholder of Pfizer. Ms. Farnham reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Cefazolin was better tolerated than nafcillin for the outpatient treatment of methicillin-sensitive Staphylococcus aureus among clinic patients included in a retrospective cohort study.

A number of drug-related adverse events occurred more often in 366 patients who received outpatient parenteral antimicrobial therapy (OPAT) with nafcillin, compared with 119 patients treated with cefazolin, including rash (13.9% vs. 4.2%), renal dysfunction (11.4% vs. 3.3%), and transaminitis (8.1% vs. 1.6%), Dr. Ilan Youngster reported at an annual scientific meeting on infectious diseases.

The patients in this study were adults with a mean age of 57 years in the nafcillin group and 56 years in the cefazolin group.

Furthermore, neutropenia developed in 8.4% of nafcillin patients, compared with 3.3% of cefazolin patients, and Clostridium difficile colitis developed in 2.4% vs. 0.8% of the nafcillin and cefazolin patients, respectively, said Dr. Youngster, a research fellow at Boston Children’s Hospital and Massachusetts General Hospital, Boston.

The discontinuation rate was significantly higher in the nafcillin group than in the cefazolin group, with 34% and 7% of patients in the groups, respectively, failing to complete the prespecified treatment course, he said. Nine patients who discontinued nafcillin switched over to cefazolin and completed treatment without any further drug-related adverse events.

The findings have implications for treatment of methicillin-sensitive Staphylococcus aureus (MSSA), which is a major pathogen in both community and health care–acquired infection, and one of the most common infections requiring prolonged antimicrobial administration.

Both nafcillin and cefazolin are considered first-line options for therapy for most MSSA infections, and recent studies suggest that the two beta-lactam antibiotics have similar efficacy, Dr. Youngster explained.

In addition to cost and efficacy, the differences in tolerability between these two drugs should be considered when deciding on long-term intravenous treatment for MSSA in the OPAT setting, he said. A failure to tolerate treatment will result in exposure to a partially treated infection should treatment be discontinued prematurely, or to the inconvenience of returning for another evaluation and a change of treatment.

Although the current study did not compare the efficacy of the two drugs, a clinical data collection system now in place will allow for such assessments going forward, he said.

IDWeek is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Dr. Youngster reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

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Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

©AvailableLight/istockphoto.com

Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

©AvailableLight/istockphoto.com

Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

©AvailableLight/istockphoto.com

Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

©AvailableLight/istockphoto.com

Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Influenza vaccination during pregnancy was associated with significantly lower odds of delivering a preterm or small for gestational age infant during a period of widespread influenza activity, but the effects varied based on maternal characteristics, according to findings from a large retrospective cohort study.

A highly significant overall association was seen between maternal vaccination with trivalent inactivated influenza vaccine and reduced odds of preterm birth among all 8,393 women with live births between Jan. 1, 2005, and Dec. 31, 2008, who were included in the study (odds ratio, 0.39). However, vaccination was most protective against preterm birth among white women (OR, 0.34) and women of higher socioeconomic status (OR, 0.30), Dr. Saad Omer of Emory University, Atlanta, reported an annual scientific meeting on infectious diseases.

©AvailableLight/istockphoto.com

Vaccination protected against small for gestational age birth only among those at higher risk for influenza-related morbidity, including those enrolled in the WIC (Women, Infant, and Children) program (OR, 0.20) and black women (OR, 0.15), Dr. Omer said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

Data for this study were derived from the Georgia pregnancy risk assessment and monitoring system, as well as from hospital discharges and birth certificates. A number of prior studies have demonstrated beneficial effects of maternal immunization on maternal outcomes, and a 2011 study by Dr. Omer was the first to demonstrate overall beneficial effects on fetal outcomes following maternal influenza vaccine.

In that study, maternal vaccination was associated with reduced odds of preterm birth during local, regional, and widespread periods of influenza activity (OR, 0.44, 0.41, and 0.28, respectively), and with reduced odds of delivering a small for gestational age infant during the widespread activity period (OR, 0.31), he said (PLoS Med. 2011;8:e1000441). These findings have been replicated in subsequent studies.

But this is a complex process, and there is increasing recognition that inflammation and other factors play a role in preterm birth, he explained, noting: "There is substantial epidemiological and biological evidence that maternal characteristics are associated with adverse birth outcomes."

The current study is the first to look at fetal outcomes stratified by some of these maternal characteristics, he noted.

The outcomes were similar in magnitude to those in his 2011 study – but were restricted to the period of widespread influenza activity.

"And essentially, we had restriction of effect by race," he added, noting that there also was heterogeneity among the two outcomes (preterm birth and small for gestational age birth).

"So the bottom line is, yes, we saw – especially during the period of widespread influenza activity – that there was reduction of odds in both preterm birth and small for gestational age, but there’s more to this story. There is heterogeneity, perhaps based on underlying risk factors and mechanisms through which these extraneous factors have an impact on birth outcome," he said.

Currently, three international trials looking at some of these outcomes are underway, he said, adding: One hopes that from these trials "we’ll have a little bit more clarity both in terms of the actual clinical effect of these interventions, but also in terms of biologic pathways that are involved."

Dr. Omer reported having no disclosures.

SAN FRANCISCO – Colonization with a methicillin-resistant Staphylococcus aureus strain carrying the gene for staphylococcal enterotoxin P was highly correlated with development of MRSA bacteremia among intensive care unit patients in a nested case-control study.

From among 8,203 adults with 11,528 intensive care unit admissions, staff collected 1,578 MRSA isolates from 492 patients – either at ICU admission or readmission, ICU discharge, or during weekly MRSA surveillance screening. Case subjects were 33 colonized patients who developed MRSA bacteremia; controls were 132 colonized patients (four controls for each case patient) who did not develop bacteremia, Dr. Michael S. Calderwood, an infectious disease specialist at Brigham and Women’s Hospital, Boston, reported at an annual scientific meeting on infectious diseases.

Full genome sequencing of collected MRSA strains was performed for all cases and for 127 controls. In particular, the investigators evaluated the isolates for the presence of 30 MRSA genes potentially associated with virulence and invasion. After controlling for host factors, they assessed the association between these genes and the development of bacteremia, Dr. Calderwood said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

"We all know that MRSA colonization is increasing in U.S. hospitals, and that colonization with MRSA is a predictor of later infection," Dr. Calderwood said, noting that more than 80% of bacteremia cases involve an identical strain in the patient’s nares and blood.

While both host and pathogen factors play a role in MRSA infection, the two are typically looked at separately; their interaction hasn’t been assessed, he said.

"We looked at combined host-pathogen risk factors in a prospective cohort with the hope of successfully identifying genomic determinants of virulence," he said, noting that identifying risk-adjusted genomic determinant of virulence may improve the ability to predict invasive disease and suggest new targets for therapeutic intervention.

Cases and controls for the current study were identified from samples from eight ICUs, banked between Sept. 1, 2003 and April 30, 2005.

Host factors considered in this study included comorbidities, wounds or recent surgeries, device use (such as a central venous catheter or intubation), recent health care exposures, antibiotic use, and lab values. Pathogen factors included Panton-Valentine leukocidin (LukS and LukF), other leukocidins (LukD and LukE), staphylococcal enterotoxins A-U, chemotaxis inhibitory protein of S. aureus, staphylococcal complement inhibitor protein family, staphylokinase, toxic shock syndrome toxin, staphylococcal cassette chromosome mec type, accessory gene regulator locus group, single-nucleotide polymorphisms (SNPs) in gene for phenol-soluble modulins, and SNPs in gene for alpha-hemolysin.

Hazard ratios were calculated for each of these factors, and those with a P value of 0.2 or less were entered into a multivariable model.

On multivariate analysis, significant risk factors for bacteremia among colonized patients included staphylococcal enterotoxin P, known as SEP (HR, 26.7), cancer (HR, 3.1), presence of a central venous catheter (HR, 2.9), and hyperglycemia (HR, 0.9). Treatment with an anti-MRSA antibiotic had a protective effect (HR, 0.5). An interaction effect was found for SEP and treatment with an anti-MRSA antibiotic (HR, 1.5), Dr. Calderwood said.

The presence of SEP – which is carried by a bacteriophage along with other genes encoding proteins that help S. aureus evade the host’s innate immune response – has been linked previously to higher mortality in S. aureus bacteremia, and lower antibody levels of S. aureus enterotoxins have been linked to bacteremia, he said, adding that the findings have potential implications for predicting and preventing MRSA bacteremia; they suggest SEP as a possible target for immunotherapeutics or vaccine development, he said.

This study was supported by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases/National Institutes of Health. Dr. Calderwood reported having no disclosures.

SAN FRANCISCO – Colonization with a methicillin-resistant Staphylococcus aureus strain carrying the gene for staphylococcal enterotoxin P was highly correlated with development of MRSA bacteremia among intensive care unit patients in a nested case-control study.

From among 8,203 adults with 11,528 intensive care unit admissions, staff collected 1,578 MRSA isolates from 492 patients – either at ICU admission or readmission, ICU discharge, or during weekly MRSA surveillance screening. Case subjects were 33 colonized patients who developed MRSA bacteremia; controls were 132 colonized patients (four controls for each case patient) who did not develop bacteremia, Dr. Michael S. Calderwood, an infectious disease specialist at Brigham and Women’s Hospital, Boston, reported at an annual scientific meeting on infectious diseases.

Full genome sequencing of collected MRSA strains was performed for all cases and for 127 controls. In particular, the investigators evaluated the isolates for the presence of 30 MRSA genes potentially associated with virulence and invasion. After controlling for host factors, they assessed the association between these genes and the development of bacteremia, Dr. Calderwood said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

"We all know that MRSA colonization is increasing in U.S. hospitals, and that colonization with MRSA is a predictor of later infection," Dr. Calderwood said, noting that more than 80% of bacteremia cases involve an identical strain in the patient’s nares and blood.

While both host and pathogen factors play a role in MRSA infection, the two are typically looked at separately; their interaction hasn’t been assessed, he said.

"We looked at combined host-pathogen risk factors in a prospective cohort with the hope of successfully identifying genomic determinants of virulence," he said, noting that identifying risk-adjusted genomic determinant of virulence may improve the ability to predict invasive disease and suggest new targets for therapeutic intervention.

Cases and controls for the current study were identified from samples from eight ICUs, banked between Sept. 1, 2003 and April 30, 2005.

Host factors considered in this study included comorbidities, wounds or recent surgeries, device use (such as a central venous catheter or intubation), recent health care exposures, antibiotic use, and lab values. Pathogen factors included Panton-Valentine leukocidin (LukS and LukF), other leukocidins (LukD and LukE), staphylococcal enterotoxins A-U, chemotaxis inhibitory protein of S. aureus, staphylococcal complement inhibitor protein family, staphylokinase, toxic shock syndrome toxin, staphylococcal cassette chromosome mec type, accessory gene regulator locus group, single-nucleotide polymorphisms (SNPs) in gene for phenol-soluble modulins, and SNPs in gene for alpha-hemolysin.

Hazard ratios were calculated for each of these factors, and those with a P value of 0.2 or less were entered into a multivariable model.

On multivariate analysis, significant risk factors for bacteremia among colonized patients included staphylococcal enterotoxin P, known as SEP (HR, 26.7), cancer (HR, 3.1), presence of a central venous catheter (HR, 2.9), and hyperglycemia (HR, 0.9). Treatment with an anti-MRSA antibiotic had a protective effect (HR, 0.5). An interaction effect was found for SEP and treatment with an anti-MRSA antibiotic (HR, 1.5), Dr. Calderwood said.

The presence of SEP – which is carried by a bacteriophage along with other genes encoding proteins that help S. aureus evade the host’s innate immune response – has been linked previously to higher mortality in S. aureus bacteremia, and lower antibody levels of S. aureus enterotoxins have been linked to bacteremia, he said, adding that the findings have potential implications for predicting and preventing MRSA bacteremia; they suggest SEP as a possible target for immunotherapeutics or vaccine development, he said.

This study was supported by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases/National Institutes of Health. Dr. Calderwood reported having no disclosures.

SAN FRANCISCO – Colonization with a methicillin-resistant Staphylococcus aureus strain carrying the gene for staphylococcal enterotoxin P was highly correlated with development of MRSA bacteremia among intensive care unit patients in a nested case-control study.

From among 8,203 adults with 11,528 intensive care unit admissions, staff collected 1,578 MRSA isolates from 492 patients – either at ICU admission or readmission, ICU discharge, or during weekly MRSA surveillance screening. Case subjects were 33 colonized patients who developed MRSA bacteremia; controls were 132 colonized patients (four controls for each case patient) who did not develop bacteremia, Dr. Michael S. Calderwood, an infectious disease specialist at Brigham and Women’s Hospital, Boston, reported at an annual scientific meeting on infectious diseases.

Full genome sequencing of collected MRSA strains was performed for all cases and for 127 controls. In particular, the investigators evaluated the isolates for the presence of 30 MRSA genes potentially associated with virulence and invasion. After controlling for host factors, they assessed the association between these genes and the development of bacteremia, Dr. Calderwood said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

"We all know that MRSA colonization is increasing in U.S. hospitals, and that colonization with MRSA is a predictor of later infection," Dr. Calderwood said, noting that more than 80% of bacteremia cases involve an identical strain in the patient’s nares and blood.

While both host and pathogen factors play a role in MRSA infection, the two are typically looked at separately; their interaction hasn’t been assessed, he said.

"We looked at combined host-pathogen risk factors in a prospective cohort with the hope of successfully identifying genomic determinants of virulence," he said, noting that identifying risk-adjusted genomic determinant of virulence may improve the ability to predict invasive disease and suggest new targets for therapeutic intervention.

Cases and controls for the current study were identified from samples from eight ICUs, banked between Sept. 1, 2003 and April 30, 2005.

Host factors considered in this study included comorbidities, wounds or recent surgeries, device use (such as a central venous catheter or intubation), recent health care exposures, antibiotic use, and lab values. Pathogen factors included Panton-Valentine leukocidin (LukS and LukF), other leukocidins (LukD and LukE), staphylococcal enterotoxins A-U, chemotaxis inhibitory protein of S. aureus, staphylococcal complement inhibitor protein family, staphylokinase, toxic shock syndrome toxin, staphylococcal cassette chromosome mec type, accessory gene regulator locus group, single-nucleotide polymorphisms (SNPs) in gene for phenol-soluble modulins, and SNPs in gene for alpha-hemolysin.

Hazard ratios were calculated for each of these factors, and those with a P value of 0.2 or less were entered into a multivariable model.

On multivariate analysis, significant risk factors for bacteremia among colonized patients included staphylococcal enterotoxin P, known as SEP (HR, 26.7), cancer (HR, 3.1), presence of a central venous catheter (HR, 2.9), and hyperglycemia (HR, 0.9). Treatment with an anti-MRSA antibiotic had a protective effect (HR, 0.5). An interaction effect was found for SEP and treatment with an anti-MRSA antibiotic (HR, 1.5), Dr. Calderwood said.

The presence of SEP – which is carried by a bacteriophage along with other genes encoding proteins that help S. aureus evade the host’s innate immune response – has been linked previously to higher mortality in S. aureus bacteremia, and lower antibody levels of S. aureus enterotoxins have been linked to bacteremia, he said, adding that the findings have potential implications for predicting and preventing MRSA bacteremia; they suggest SEP as a possible target for immunotherapeutics or vaccine development, he said.

This study was supported by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases/National Institutes of Health. Dr. Calderwood reported having no disclosures.

SAN FRANCISCO – Black children were less likely than nonblack children to receive an otitis media diagnosis and, when treated for otitis media, were less likely to receive a broad-spectrum antibiotic, national survey data showed.

Overall, there were no significant differences in the rate of outpatient visits for respiratory illness and otitis media (OM) between black children and nonblack children aged 0-14 years who participated in the National Ambulatory Care Survey and the National Hospital Ambulatory Medical Care Survey during 2008-2010 (1,175 vs. 1,150 per 1,000 population for respiratory visits; 253 vs. 324 per 1,000 population for OM visits), but the percentage of all visits resulting in an OM diagnosis was significantly lower among black children (7% vs. 10%), Dr. Katherine E. Fleming-Dutra of Emory University and the Centers for Disease Control and Prevention, Atlanta, reported in a poster at an annual scientific meeting on infectious diseases.

Furthermore, while the percentage of OM visits leading to an antibiotic prescription did not differ significantly between black and nonblack children, (81% vs. 76%), among those who did receive antibiotics, black children were significantly less likely than nonblack children to receive broad-spectrum antibiotics (42% vs. 52%), Dr. Fleming-Dutra reported at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

After adjustment for potential confounders, black race remained a significant protective factor against prescription of a broad-spectrum antibiotic (adjusted odds ratio, 0.59), she noted.

The findings support those from a prior regional study that also showed a lower rate of OM diagnosis and lower broad-spectrum antibiotic use in black children, and suggest these racial differences in diagnosis and prescribing also occur at the national level, Dr. Fleming-Dutra said, noting that race-based differences in physician and parental preferences may contribute to inappropriate antibiotic prescribing for nonblack children.

"Reducing antibiotic prescriptions and broad-spectrum antibiotic prescribing is a major public health goal. ... National guidelines recommend that not all patients with OM require antibiotics, and when they do, amoxicillin is recommended for most children with OM," she said.

Providers may be tailoring the diagnosis to justify an antibiotic prescription in nonblack children, she added.

"Provider education campaigns should target appropriate communication with parents regarding the need for and use of antibiotics, and how to determine and manage parental expectations," she concluded.

Dr. Fleming-Dutra reported having no relevant financial conflicts.

SAN FRANCISCO – Black children were less likely than nonblack children to receive an otitis media diagnosis and, when treated for otitis media, were less likely to receive a broad-spectrum antibiotic, national survey data showed.

Overall, there were no significant differences in the rate of outpatient visits for respiratory illness and otitis media (OM) between black children and nonblack children aged 0-14 years who participated in the National Ambulatory Care Survey and the National Hospital Ambulatory Medical Care Survey during 2008-2010 (1,175 vs. 1,150 per 1,000 population for respiratory visits; 253 vs. 324 per 1,000 population for OM visits), but the percentage of all visits resulting in an OM diagnosis was significantly lower among black children (7% vs. 10%), Dr. Katherine E. Fleming-Dutra of Emory University and the Centers for Disease Control and Prevention, Atlanta, reported in a poster at an annual scientific meeting on infectious diseases.

Furthermore, while the percentage of OM visits leading to an antibiotic prescription did not differ significantly between black and nonblack children, (81% vs. 76%), among those who did receive antibiotics, black children were significantly less likely than nonblack children to receive broad-spectrum antibiotics (42% vs. 52%), Dr. Fleming-Dutra reported at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

After adjustment for potential confounders, black race remained a significant protective factor against prescription of a broad-spectrum antibiotic (adjusted odds ratio, 0.59), she noted.

The findings support those from a prior regional study that also showed a lower rate of OM diagnosis and lower broad-spectrum antibiotic use in black children, and suggest these racial differences in diagnosis and prescribing also occur at the national level, Dr. Fleming-Dutra said, noting that race-based differences in physician and parental preferences may contribute to inappropriate antibiotic prescribing for nonblack children.

"Reducing antibiotic prescriptions and broad-spectrum antibiotic prescribing is a major public health goal. ... National guidelines recommend that not all patients with OM require antibiotics, and when they do, amoxicillin is recommended for most children with OM," she said.

Providers may be tailoring the diagnosis to justify an antibiotic prescription in nonblack children, she added.

"Provider education campaigns should target appropriate communication with parents regarding the need for and use of antibiotics, and how to determine and manage parental expectations," she concluded.

Dr. Fleming-Dutra reported having no relevant financial conflicts.

SAN FRANCISCO – Black children were less likely than nonblack children to receive an otitis media diagnosis and, when treated for otitis media, were less likely to receive a broad-spectrum antibiotic, national survey data showed.

Overall, there were no significant differences in the rate of outpatient visits for respiratory illness and otitis media (OM) between black children and nonblack children aged 0-14 years who participated in the National Ambulatory Care Survey and the National Hospital Ambulatory Medical Care Survey during 2008-2010 (1,175 vs. 1,150 per 1,000 population for respiratory visits; 253 vs. 324 per 1,000 population for OM visits), but the percentage of all visits resulting in an OM diagnosis was significantly lower among black children (7% vs. 10%), Dr. Katherine E. Fleming-Dutra of Emory University and the Centers for Disease Control and Prevention, Atlanta, reported in a poster at an annual scientific meeting on infectious diseases.

Furthermore, while the percentage of OM visits leading to an antibiotic prescription did not differ significantly between black and nonblack children, (81% vs. 76%), among those who did receive antibiotics, black children were significantly less likely than nonblack children to receive broad-spectrum antibiotics (42% vs. 52%), Dr. Fleming-Dutra reported at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

After adjustment for potential confounders, black race remained a significant protective factor against prescription of a broad-spectrum antibiotic (adjusted odds ratio, 0.59), she noted.

The findings support those from a prior regional study that also showed a lower rate of OM diagnosis and lower broad-spectrum antibiotic use in black children, and suggest these racial differences in diagnosis and prescribing also occur at the national level, Dr. Fleming-Dutra said, noting that race-based differences in physician and parental preferences may contribute to inappropriate antibiotic prescribing for nonblack children.

"Reducing antibiotic prescriptions and broad-spectrum antibiotic prescribing is a major public health goal. ... National guidelines recommend that not all patients with OM require antibiotics, and when they do, amoxicillin is recommended for most children with OM," she said.

Providers may be tailoring the diagnosis to justify an antibiotic prescription in nonblack children, she added.

"Provider education campaigns should target appropriate communication with parents regarding the need for and use of antibiotics, and how to determine and manage parental expectations," she concluded.

Dr. Fleming-Dutra reported having no relevant financial conflicts.

SAN FRANCISCO – Treatment of Shiga toxin–producing Escherichia coli 0157 infection with beta-lactams is associated with increased risk for postdiarrheal hemolytic uremic syndrome in both children and adults, according to findings from a population-based study.

Beta-lactam antibiotics are particularly troublesome in this setting, the findings suggest.

Among 1,308 patients with the infection, known as STEC 0157 – the leading cause of postdiarrheal hemolytic uremic syndrome (HUS) in the United States – 137 had HUS, and 44 had partial HUS, Dr. Melissa Tobin-D’Angelo reported at an annual scientific meeting on infectious diseases.

Up to 15% of patients with STEC 0157 diarrhea develop HUS, which comprises microangiopathic hemolytic anemia, acute azotemia, and thrombocytopenia, said Dr. Tobin-D’Angelo of the Georgia Department of Public Health, Atlanta.

Generally in this observational study, antibiotic treatment was used more commonly and HUS occurred less frequently with increasing age quartile. Among those under age 5 years, 12% received antibiotics and 22% had HUS; among those aged 5-14 years, 11% received antibiotics and 11% had HUS; among those aged 15-39 years, 45% received antibiotics and 5% had HUS; and among those aged 40 years or older, 52% received antibiotics and 4% had HUS.

Adults aged 40 and older were more likely than were those in all other age groups to receive beta-lactam antibiotics (8% vs. 4%) or metronidazole (31% vs. 11%), while children under age 15 years were more likely than were others to receive sulfonamides (5% vs. 1%), Dr. Tobin-D’Angelo reported at the conference, the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

No overall association was seen between antibiotic treatment and HUS, but among children aged 5-14 years, treatment with any antibiotic and treatment with metronidazole were significantly associated with HUS (odds ratios, 2.6 and 4.0, respectively). Also, among all subjects, beta-lactam antibiotics and sulfonamides were associated with at least partial HUS (odds ratios, 2.9 and 2.2, respectively), she noted.

Study subjects were patients with STEC 0157 identified through active, population-based surveillance in 10 states during 2006-2010. Patients or caregivers were interviewed, and data were extracted from medical records. Only antibiotic exposures during the first 7 days of illness or before HUS onset were included in the analysis.

"Controversy remains regarding antibiotic treatment of STEC 0157 and its possible association with an increased risk of HUS; antibiotics increase Shiga toxin production and release in vitro, but this varies by antibiotic class and dose, and it has varied by study," Dr. Tobin-D’Angelo said. Although observational studies have suggested that antibiotics increase the risk for HUS, those studies included only children and were limited by difficulties in controlling for the confounding effects of illness severity, she added.

The only randomized controlled trial was limited to trimethoprim-sulfamethoxazole, she noted.

The findings of the current study suggest that adults are considerably more likely than are children to receive antibiotics for the treatment of STEC 0157 diarrhea, and – as with prior findings in children – suggest that treatment with beta-lactams is associated with increased HUS risk in both children and adults, she said.

"We recommend that beta-lactams should not be prescribed to any patient of any age with known STEC 0157 infection and that clinicians should consider the risk of HUS when prescribing beta-lactams to any patients with diarrhea that could be caused by STEC 0157," she said. It is also prudent to avoid the use of other antibiotics for the treatment of STEC 0157 diarrhea because of evidence of increased HUS risk from other studies, and because of the lack of data demonstrating any therapeutic benefit, she added.

The conference was the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. Dr. Tobin-D’Angelo reported having no disclosures.

SAN FRANCISCO – Treatment of Shiga toxin–producing Escherichia coli 0157 infection with beta-lactams is associated with increased risk for postdiarrheal hemolytic uremic syndrome in both children and adults, according to findings from a population-based study.

Beta-lactam antibiotics are particularly troublesome in this setting, the findings suggest.

Among 1,308 patients with the infection, known as STEC 0157 – the leading cause of postdiarrheal hemolytic uremic syndrome (HUS) in the United States – 137 had HUS, and 44 had partial HUS, Dr. Melissa Tobin-D’Angelo reported at an annual scientific meeting on infectious diseases.

Up to 15% of patients with STEC 0157 diarrhea develop HUS, which comprises microangiopathic hemolytic anemia, acute azotemia, and thrombocytopenia, said Dr. Tobin-D’Angelo of the Georgia Department of Public Health, Atlanta.

Generally in this observational study, antibiotic treatment was used more commonly and HUS occurred less frequently with increasing age quartile. Among those under age 5 years, 12% received antibiotics and 22% had HUS; among those aged 5-14 years, 11% received antibiotics and 11% had HUS; among those aged 15-39 years, 45% received antibiotics and 5% had HUS; and among those aged 40 years or older, 52% received antibiotics and 4% had HUS.

Adults aged 40 and older were more likely than were those in all other age groups to receive beta-lactam antibiotics (8% vs. 4%) or metronidazole (31% vs. 11%), while children under age 15 years were more likely than were others to receive sulfonamides (5% vs. 1%), Dr. Tobin-D’Angelo reported at the conference, the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

No overall association was seen between antibiotic treatment and HUS, but among children aged 5-14 years, treatment with any antibiotic and treatment with metronidazole were significantly associated with HUS (odds ratios, 2.6 and 4.0, respectively). Also, among all subjects, beta-lactam antibiotics and sulfonamides were associated with at least partial HUS (odds ratios, 2.9 and 2.2, respectively), she noted.

Study subjects were patients with STEC 0157 identified through active, population-based surveillance in 10 states during 2006-2010. Patients or caregivers were interviewed, and data were extracted from medical records. Only antibiotic exposures during the first 7 days of illness or before HUS onset were included in the analysis.

"Controversy remains regarding antibiotic treatment of STEC 0157 and its possible association with an increased risk of HUS; antibiotics increase Shiga toxin production and release in vitro, but this varies by antibiotic class and dose, and it has varied by study," Dr. Tobin-D’Angelo said. Although observational studies have suggested that antibiotics increase the risk for HUS, those studies included only children and were limited by difficulties in controlling for the confounding effects of illness severity, she added.

The only randomized controlled trial was limited to trimethoprim-sulfamethoxazole, she noted.

The findings of the current study suggest that adults are considerably more likely than are children to receive antibiotics for the treatment of STEC 0157 diarrhea, and – as with prior findings in children – suggest that treatment with beta-lactams is associated with increased HUS risk in both children and adults, she said.

"We recommend that beta-lactams should not be prescribed to any patient of any age with known STEC 0157 infection and that clinicians should consider the risk of HUS when prescribing beta-lactams to any patients with diarrhea that could be caused by STEC 0157," she said. It is also prudent to avoid the use of other antibiotics for the treatment of STEC 0157 diarrhea because of evidence of increased HUS risk from other studies, and because of the lack of data demonstrating any therapeutic benefit, she added.

The conference was the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. Dr. Tobin-D’Angelo reported having no disclosures.

SAN FRANCISCO – Treatment of Shiga toxin–producing Escherichia coli 0157 infection with beta-lactams is associated with increased risk for postdiarrheal hemolytic uremic syndrome in both children and adults, according to findings from a population-based study.

Beta-lactam antibiotics are particularly troublesome in this setting, the findings suggest.

Among 1,308 patients with the infection, known as STEC 0157 – the leading cause of postdiarrheal hemolytic uremic syndrome (HUS) in the United States – 137 had HUS, and 44 had partial HUS, Dr. Melissa Tobin-D’Angelo reported at an annual scientific meeting on infectious diseases.

Up to 15% of patients with STEC 0157 diarrhea develop HUS, which comprises microangiopathic hemolytic anemia, acute azotemia, and thrombocytopenia, said Dr. Tobin-D’Angelo of the Georgia Department of Public Health, Atlanta.

Generally in this observational study, antibiotic treatment was used more commonly and HUS occurred less frequently with increasing age quartile. Among those under age 5 years, 12% received antibiotics and 22% had HUS; among those aged 5-14 years, 11% received antibiotics and 11% had HUS; among those aged 15-39 years, 45% received antibiotics and 5% had HUS; and among those aged 40 years or older, 52% received antibiotics and 4% had HUS.

Adults aged 40 and older were more likely than were those in all other age groups to receive beta-lactam antibiotics (8% vs. 4%) or metronidazole (31% vs. 11%), while children under age 15 years were more likely than were others to receive sulfonamides (5% vs. 1%), Dr. Tobin-D’Angelo reported at the conference, the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

No overall association was seen between antibiotic treatment and HUS, but among children aged 5-14 years, treatment with any antibiotic and treatment with metronidazole were significantly associated with HUS (odds ratios, 2.6 and 4.0, respectively). Also, among all subjects, beta-lactam antibiotics and sulfonamides were associated with at least partial HUS (odds ratios, 2.9 and 2.2, respectively), she noted.

Study subjects were patients with STEC 0157 identified through active, population-based surveillance in 10 states during 2006-2010. Patients or caregivers were interviewed, and data were extracted from medical records. Only antibiotic exposures during the first 7 days of illness or before HUS onset were included in the analysis.

"Controversy remains regarding antibiotic treatment of STEC 0157 and its possible association with an increased risk of HUS; antibiotics increase Shiga toxin production and release in vitro, but this varies by antibiotic class and dose, and it has varied by study," Dr. Tobin-D’Angelo said. Although observational studies have suggested that antibiotics increase the risk for HUS, those studies included only children and were limited by difficulties in controlling for the confounding effects of illness severity, she added.

The only randomized controlled trial was limited to trimethoprim-sulfamethoxazole, she noted.

The findings of the current study suggest that adults are considerably more likely than are children to receive antibiotics for the treatment of STEC 0157 diarrhea, and – as with prior findings in children – suggest that treatment with beta-lactams is associated with increased HUS risk in both children and adults, she said.

"We recommend that beta-lactams should not be prescribed to any patient of any age with known STEC 0157 infection and that clinicians should consider the risk of HUS when prescribing beta-lactams to any patients with diarrhea that could be caused by STEC 0157," she said. It is also prudent to avoid the use of other antibiotics for the treatment of STEC 0157 diarrhea because of evidence of increased HUS risk from other studies, and because of the lack of data demonstrating any therapeutic benefit, she added.

The conference was the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. Dr. Tobin-D’Angelo reported having no disclosures.

SAN FRANCISCO – Influenza vaccination was associated with a substantial reduction in the risk of life-threatening influenza illness among children during the 2010-2011 and 2011-2012 influenza seasons, according to findings from a case-control study.

However, vaccine coverage was low in this study, even among children with comorbidities that increased their risk of severe influenza-related complications, Dr. Ed Belangia reported at an annual scientific meeting on infectious diseases.

Cases included 44 children with life-threatening confirmed influenza illness, 172 pediatric intensive care unit (PICU) control patients without influenza, and 93 community controls without influenza. Only 18% of cases and 31% of the PICU controls were fully vaccinated, compared with 50% of community controls; those who were fully vaccinated were 74% less likely to be admitted to a PICU for influenza-related illness, said Dr. Belangia of the Marshfield (Wis.) Clinic Research Foundation, who presented that data on behalf of study author Jill Ferdinands, Ph.D., of the Centers for Disease Control and Prevention.

© Yarinca/istockphoto.com

Of the cases, 15 (34%) had conditions that put them at high risk of influenza-related complications, and of the PICU controls and community controls, 89 (51%) and 35 (37%), respectively, had such conditions; 20% of the PICU patients had three or more comorbidities, compared with 3% of community controls, said Dr. Belangia.

After the investigators adjusted for factors including age, sex, date of onset, medical conditions, and – among PICU patients – illness severity and days from illness onset to influenza testing, the vaccine efficacy rate was 77%.

Of note, the receipt of one vaccine dose by children in whom two doses were recommended did not appear to provide protection in this study.

Children in the study, who were aged 6 months to 17 years during the 2010-2011 and 2011-2012 influenza seasons, were recruited within 7 days of symptom onset from 21 U.S. PICUs in the Pediatric Acute Lung Injury and Sepsis Investigators Network. Cases included those with acute severe respiratory illness who tested positive for influenza by reverse-transcription polymerase chain reaction; controls were PICU patients who tested negative for influenza, and children from the community who were matched for comorbidities and geographic region and who had no recent history of an influenza-related hospitalization.

Vaccine status was verified by medical record review, except in the community controls, whose vaccine status was based on parent report.

The low vaccine coverage in this study population, even among those at increased risk for influenza-related complications, is troubling, he said.

Although numerous studies have looked at flu vaccine efficacy in children, this study is among the first to look at the effects on severe influenza-related illness in children, he said, noting that about 1-7/10,000 children are hospitalized with influenza every year, which translates to 8,000-54,000 children per year.

"So that’s substantial morbidity – and of those, about 4%-24% require ICU admission," he said.

The results highlight the value of increasing the use of influenza vaccine among children, he concluded.

Dr. Ferdinand and her coauthors reported having no relevant financial disclosures. Dr. Belangia was not involved in the study.

SAN FRANCISCO – Influenza vaccination was associated with a substantial reduction in the risk of life-threatening influenza illness among children during the 2010-2011 and 2011-2012 influenza seasons, according to findings from a case-control study.

However, vaccine coverage was low in this study, even among children with comorbidities that increased their risk of severe influenza-related complications, Dr. Ed Belangia reported at an annual scientific meeting on infectious diseases.

Cases included 44 children with life-threatening confirmed influenza illness, 172 pediatric intensive care unit (PICU) control patients without influenza, and 93 community controls without influenza. Only 18% of cases and 31% of the PICU controls were fully vaccinated, compared with 50% of community controls; those who were fully vaccinated were 74% less likely to be admitted to a PICU for influenza-related illness, said Dr. Belangia of the Marshfield (Wis.) Clinic Research Foundation, who presented that data on behalf of study author Jill Ferdinands, Ph.D., of the Centers for Disease Control and Prevention.

© Yarinca/istockphoto.com

Of the cases, 15 (34%) had conditions that put them at high risk of influenza-related complications, and of the PICU controls and community controls, 89 (51%) and 35 (37%), respectively, had such conditions; 20% of the PICU patients had three or more comorbidities, compared with 3% of community controls, said Dr. Belangia.

After the investigators adjusted for factors including age, sex, date of onset, medical conditions, and – among PICU patients – illness severity and days from illness onset to influenza testing, the vaccine efficacy rate was 77%.

Of note, the receipt of one vaccine dose by children in whom two doses were recommended did not appear to provide protection in this study.

Children in the study, who were aged 6 months to 17 years during the 2010-2011 and 2011-2012 influenza seasons, were recruited within 7 days of symptom onset from 21 U.S. PICUs in the Pediatric Acute Lung Injury and Sepsis Investigators Network. Cases included those with acute severe respiratory illness who tested positive for influenza by reverse-transcription polymerase chain reaction; controls were PICU patients who tested negative for influenza, and children from the community who were matched for comorbidities and geographic region and who had no recent history of an influenza-related hospitalization.

Vaccine status was verified by medical record review, except in the community controls, whose vaccine status was based on parent report.

The low vaccine coverage in this study population, even among those at increased risk for influenza-related complications, is troubling, he said.

Although numerous studies have looked at flu vaccine efficacy in children, this study is among the first to look at the effects on severe influenza-related illness in children, he said, noting that about 1-7/10,000 children are hospitalized with influenza every year, which translates to 8,000-54,000 children per year.

"So that’s substantial morbidity – and of those, about 4%-24% require ICU admission," he said.

The results highlight the value of increasing the use of influenza vaccine among children, he concluded.

Dr. Ferdinand and her coauthors reported having no relevant financial disclosures. Dr. Belangia was not involved in the study.

SAN FRANCISCO – Influenza vaccination was associated with a substantial reduction in the risk of life-threatening influenza illness among children during the 2010-2011 and 2011-2012 influenza seasons, according to findings from a case-control study.

However, vaccine coverage was low in this study, even among children with comorbidities that increased their risk of severe influenza-related complications, Dr. Ed Belangia reported at an annual scientific meeting on infectious diseases.

Cases included 44 children with life-threatening confirmed influenza illness, 172 pediatric intensive care unit (PICU) control patients without influenza, and 93 community controls without influenza. Only 18% of cases and 31% of the PICU controls were fully vaccinated, compared with 50% of community controls; those who were fully vaccinated were 74% less likely to be admitted to a PICU for influenza-related illness, said Dr. Belangia of the Marshfield (Wis.) Clinic Research Foundation, who presented that data on behalf of study author Jill Ferdinands, Ph.D., of the Centers for Disease Control and Prevention.

© Yarinca/istockphoto.com

Of the cases, 15 (34%) had conditions that put them at high risk of influenza-related complications, and of the PICU controls and community controls, 89 (51%) and 35 (37%), respectively, had such conditions; 20% of the PICU patients had three or more comorbidities, compared with 3% of community controls, said Dr. Belangia.

After the investigators adjusted for factors including age, sex, date of onset, medical conditions, and – among PICU patients – illness severity and days from illness onset to influenza testing, the vaccine efficacy rate was 77%.

Of note, the receipt of one vaccine dose by children in whom two doses were recommended did not appear to provide protection in this study.

Children in the study, who were aged 6 months to 17 years during the 2010-2011 and 2011-2012 influenza seasons, were recruited within 7 days of symptom onset from 21 U.S. PICUs in the Pediatric Acute Lung Injury and Sepsis Investigators Network. Cases included those with acute severe respiratory illness who tested positive for influenza by reverse-transcription polymerase chain reaction; controls were PICU patients who tested negative for influenza, and children from the community who were matched for comorbidities and geographic region and who had no recent history of an influenza-related hospitalization.

Vaccine status was verified by medical record review, except in the community controls, whose vaccine status was based on parent report.

The low vaccine coverage in this study population, even among those at increased risk for influenza-related complications, is troubling, he said.

Although numerous studies have looked at flu vaccine efficacy in children, this study is among the first to look at the effects on severe influenza-related illness in children, he said, noting that about 1-7/10,000 children are hospitalized with influenza every year, which translates to 8,000-54,000 children per year.

"So that’s substantial morbidity – and of those, about 4%-24% require ICU admission," he said.

The results highlight the value of increasing the use of influenza vaccine among children, he concluded.

Dr. Ferdinand and her coauthors reported having no relevant financial disclosures. Dr. Belangia was not involved in the study.

SAN FRANCISCO – Physicians continue to inappropriately prescribe antibiotics for sore throat and bronchitis, according to analyses of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey.

Doctors prescribed antibiotics in 60% of office visits for sore throats and 73% of visits for acute bronchitis. However, the antibiotic prescribing rate should be about 10% for sore throats – based on the prevalence of group A Streptococcus (GAS), the only common cause of sore throat for which antibiotics are indicated – and the rate should be almost zero for acute bronchitis, which is almost always caused by a virus, Dr. Jeffrey A. Linder reported during a press conference at an annual scientific meeting on infectious diseases.

The findings are based on cross-sectional analyses of the nationally representative surveys on visits by adults for either a sore throat or for acute bronchitis. The sore throat findings were based on 8,191 visits between 1997 and 2010.

The overall national antibiotic prescribing rate for sore throats did not change from 1997-1998 to 2009-2010, nor did the prescribing rate among office-based physicians or emergency departments during that time period.

Physicians reported increased prescribing of broad-spectrum, expensive, or nonrecommended antibiotics. However, prescriptions for penicillin – the antibiotic of choice for GAS – remained stable at 9% across the study period.

The bronchitis findings are based on surveys for 3,667 visits by adults with a diagnosis of acute bronchitis to primary care physicians and emergency departments between 1996 and 2010. The overall national antibiotic prescribing rate did not change during the study period, but the prescribing rate in emergency departments increased from 69% in 1996 to 73% in 2010, said Dr. Linder* of Harvard Medical School and Brigham and Women’s Hospital, Boston.

Also, physicians increasingly prescribed extended-spectrum macrolides across the study period, with such prescriptions provided at 25% of visits in 1996 and at 41% of visits in 2010, he noted.

Fluoroquinolones were prescribed at 11% of visits, aminopenicillins were prescribed at 7% of visits, and cephalosporins were prescribed at 7% of visits.

The findings were reported in posters at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. The sore throat findings were also reported concurrently online in the Oct. 4 issue of JAMA Internal Medicine (2013 [doi:10.1001/jamainternmed.2013.11673]).

"The really bad news here is that (the antibiotic prescribing) hasn’t changed at all across the course of the study ... looking back into how we’ve done over past 20 years or so, there’s a little improvement, but it’s painfully slow, and we’re still very far away from the appropriate rate of antibiotic prescribing," he said, noting that this is despite years of effort to promote antibiotic stewardship.

Based on a prior analysis, the antibiotic prescribing rate for sore throat dropped from about 80% to 70% around 1993, and dropped again to 60% by 2000. The current findings show that the prescribing rate remains stable at the 60% level.

Although there was some indication in the survey data that patients are being a little more selective in seeking care for these conditions – perhaps because they are beginning to understand that antibiotics aren’t effective for viral illness – the findings regarding prescribing are troubling, the investigators noted.

Recently, the Centers for Disease Control and Prevention reported that 2 million people are infected with antibiotic-resistant bacteria each year, and 25,000 of those patients die as a result. Antibiotic resistance also causes a great deal of "collateral damage," such as increasing rates of Clostridium difficile infection, said Dr. Ed Septimus, who moderated the press conference.

That results in huge societal costs, estimated at about $35 billion, said Dr. Septimus of Texas A&M Health Science Center, Houston.

Education and improved communication between doctors and patients are needed to address the problem, Dr. Linder and Dr. Septimus agreed.

"Patients and doctors need to have a conversation about the illness ... some of our research suggests that patients don’t want antibiotics as much as doctors think they do," Dr. Septimus said. Doctors often prescribe out of fear that patients will walk away unsatisfied if they don’t get a prescription, he added, but frequently patients just want reassurance that they don’t need an antibiotic.

Accountability is another factor lacking in the outpatient setting, he said.

"We as physicians need to take accountability for our actions ... we need to be reminded that antibiotics, for many of these conditions, are not indicated," he said.

Dr. Linder and Dr. Septimus reported having no disclosures.

*Correction, 10/9/2013: An earlier version of this story misspelled Dr. Linder's name.

SAN FRANCISCO – Physicians continue to inappropriately prescribe antibiotics for sore throat and bronchitis, according to analyses of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey.

Doctors prescribed antibiotics in 60% of office visits for sore throats and 73% of visits for acute bronchitis. However, the antibiotic prescribing rate should be about 10% for sore throats – based on the prevalence of group A Streptococcus (GAS), the only common cause of sore throat for which antibiotics are indicated – and the rate should be almost zero for acute bronchitis, which is almost always caused by a virus, Dr. Jeffrey A. Linder reported during a press conference at an annual scientific meeting on infectious diseases.

The findings are based on cross-sectional analyses of the nationally representative surveys on visits by adults for either a sore throat or for acute bronchitis. The sore throat findings were based on 8,191 visits between 1997 and 2010.

The overall national antibiotic prescribing rate for sore throats did not change from 1997-1998 to 2009-2010, nor did the prescribing rate among office-based physicians or emergency departments during that time period.

Physicians reported increased prescribing of broad-spectrum, expensive, or nonrecommended antibiotics. However, prescriptions for penicillin – the antibiotic of choice for GAS – remained stable at 9% across the study period.

The bronchitis findings are based on surveys for 3,667 visits by adults with a diagnosis of acute bronchitis to primary care physicians and emergency departments between 1996 and 2010. The overall national antibiotic prescribing rate did not change during the study period, but the prescribing rate in emergency departments increased from 69% in 1996 to 73% in 2010, said Dr. Linder* of Harvard Medical School and Brigham and Women’s Hospital, Boston.

Also, physicians increasingly prescribed extended-spectrum macrolides across the study period, with such prescriptions provided at 25% of visits in 1996 and at 41% of visits in 2010, he noted.

Fluoroquinolones were prescribed at 11% of visits, aminopenicillins were prescribed at 7% of visits, and cephalosporins were prescribed at 7% of visits.

The findings were reported in posters at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. The sore throat findings were also reported concurrently online in the Oct. 4 issue of JAMA Internal Medicine (2013 [doi:10.1001/jamainternmed.2013.11673]).

"The really bad news here is that (the antibiotic prescribing) hasn’t changed at all across the course of the study ... looking back into how we’ve done over past 20 years or so, there’s a little improvement, but it’s painfully slow, and we’re still very far away from the appropriate rate of antibiotic prescribing," he said, noting that this is despite years of effort to promote antibiotic stewardship.

Based on a prior analysis, the antibiotic prescribing rate for sore throat dropped from about 80% to 70% around 1993, and dropped again to 60% by 2000. The current findings show that the prescribing rate remains stable at the 60% level.

Although there was some indication in the survey data that patients are being a little more selective in seeking care for these conditions – perhaps because they are beginning to understand that antibiotics aren’t effective for viral illness – the findings regarding prescribing are troubling, the investigators noted.

Recently, the Centers for Disease Control and Prevention reported that 2 million people are infected with antibiotic-resistant bacteria each year, and 25,000 of those patients die as a result. Antibiotic resistance also causes a great deal of "collateral damage," such as increasing rates of Clostridium difficile infection, said Dr. Ed Septimus, who moderated the press conference.

That results in huge societal costs, estimated at about $35 billion, said Dr. Septimus of Texas A&M Health Science Center, Houston.

Education and improved communication between doctors and patients are needed to address the problem, Dr. Linder and Dr. Septimus agreed.

"Patients and doctors need to have a conversation about the illness ... some of our research suggests that patients don’t want antibiotics as much as doctors think they do," Dr. Septimus said. Doctors often prescribe out of fear that patients will walk away unsatisfied if they don’t get a prescription, he added, but frequently patients just want reassurance that they don’t need an antibiotic.

Accountability is another factor lacking in the outpatient setting, he said.

"We as physicians need to take accountability for our actions ... we need to be reminded that antibiotics, for many of these conditions, are not indicated," he said.

Dr. Linder and Dr. Septimus reported having no disclosures.

*Correction, 10/9/2013: An earlier version of this story misspelled Dr. Linder's name.

SAN FRANCISCO – Physicians continue to inappropriately prescribe antibiotics for sore throat and bronchitis, according to analyses of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey.

Doctors prescribed antibiotics in 60% of office visits for sore throats and 73% of visits for acute bronchitis. However, the antibiotic prescribing rate should be about 10% for sore throats – based on the prevalence of group A Streptococcus (GAS), the only common cause of sore throat for which antibiotics are indicated – and the rate should be almost zero for acute bronchitis, which is almost always caused by a virus, Dr. Jeffrey A. Linder reported during a press conference at an annual scientific meeting on infectious diseases.

The findings are based on cross-sectional analyses of the nationally representative surveys on visits by adults for either a sore throat or for acute bronchitis. The sore throat findings were based on 8,191 visits between 1997 and 2010.

The overall national antibiotic prescribing rate for sore throats did not change from 1997-1998 to 2009-2010, nor did the prescribing rate among office-based physicians or emergency departments during that time period.

Physicians reported increased prescribing of broad-spectrum, expensive, or nonrecommended antibiotics. However, prescriptions for penicillin – the antibiotic of choice for GAS – remained stable at 9% across the study period.

The bronchitis findings are based on surveys for 3,667 visits by adults with a diagnosis of acute bronchitis to primary care physicians and emergency departments between 1996 and 2010. The overall national antibiotic prescribing rate did not change during the study period, but the prescribing rate in emergency departments increased from 69% in 1996 to 73% in 2010, said Dr. Linder* of Harvard Medical School and Brigham and Women’s Hospital, Boston.

Also, physicians increasingly prescribed extended-spectrum macrolides across the study period, with such prescriptions provided at 25% of visits in 1996 and at 41% of visits in 2010, he noted.

Fluoroquinolones were prescribed at 11% of visits, aminopenicillins were prescribed at 7% of visits, and cephalosporins were prescribed at 7% of visits.

The findings were reported in posters at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. The sore throat findings were also reported concurrently online in the Oct. 4 issue of JAMA Internal Medicine (2013 [doi:10.1001/jamainternmed.2013.11673]).

"The really bad news here is that (the antibiotic prescribing) hasn’t changed at all across the course of the study ... looking back into how we’ve done over past 20 years or so, there’s a little improvement, but it’s painfully slow, and we’re still very far away from the appropriate rate of antibiotic prescribing," he said, noting that this is despite years of effort to promote antibiotic stewardship.

Based on a prior analysis, the antibiotic prescribing rate for sore throat dropped from about 80% to 70% around 1993, and dropped again to 60% by 2000. The current findings show that the prescribing rate remains stable at the 60% level.

Although there was some indication in the survey data that patients are being a little more selective in seeking care for these conditions – perhaps because they are beginning to understand that antibiotics aren’t effective for viral illness – the findings regarding prescribing are troubling, the investigators noted.

Recently, the Centers for Disease Control and Prevention reported that 2 million people are infected with antibiotic-resistant bacteria each year, and 25,000 of those patients die as a result. Antibiotic resistance also causes a great deal of "collateral damage," such as increasing rates of Clostridium difficile infection, said Dr. Ed Septimus, who moderated the press conference.

That results in huge societal costs, estimated at about $35 billion, said Dr. Septimus of Texas A&M Health Science Center, Houston.

Education and improved communication between doctors and patients are needed to address the problem, Dr. Linder and Dr. Septimus agreed.

"Patients and doctors need to have a conversation about the illness ... some of our research suggests that patients don’t want antibiotics as much as doctors think they do," Dr. Septimus said. Doctors often prescribe out of fear that patients will walk away unsatisfied if they don’t get a prescription, he added, but frequently patients just want reassurance that they don’t need an antibiotic.

Accountability is another factor lacking in the outpatient setting, he said.

"We as physicians need to take accountability for our actions ... we need to be reminded that antibiotics, for many of these conditions, are not indicated," he said.

Dr. Linder and Dr. Septimus reported having no disclosures.

*Correction, 10/9/2013: An earlier version of this story misspelled Dr. Linder's name.