Emily Susan Edwards, MD, MS

In this question-and-answer article (the second in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

9. For uncomplicated chlamydia infection in a pregnant woman, what is the most appropriate treatment?

Uncomplicated chlamydia infection in a pregnant woman should be treated with a single 1,000-mg oral dose of azithromycin. An acceptable alternative is amoxicillin 
500 mg orally 3 times daily for 7 days.

In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days is also an appropriate alternative. However, doxycycline is relatively expensive and may not be well tolerated because of gastrointestinal adverse effects. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

10. What are the characteristic mucocutaneous lesions of primary, secondary, and tertiary syphilis?

The characteristic mucosal lesion of primary syphilis is the painless chancre. The usual mucocutaneous manifestations of secondary syphilis are maculopapular lesions (red or violet in color) on the palms and soles, mucous patches on the oral membranes, and condyloma lata on the genitalia. The classic mucocutaneous lesion of tertiary syphilis is the gumma.

Other serious manifestations of advanced syphilis include central nervous system abnormalities, such as tabes dorsalis, the Argyll Robertson pupil, and dementia, and cardiac abnormalities, such as aortitis, which can lead to a dissecting aneurysm of the aortic root. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

11. In a pregnant woman with a history of recurrent herpes simplex virus infection, what is the best way to prevent an outbreak of lesions  near term?

Obstetric patients with a history of recurrent herpes simplex infection should be treated with acyclovir 400 mg orally 3 times daily from 36 weeks until delivery. This 
 regimen significantly reduces the likelihood of a recurrent outbreak near the time of delivery, which if it occurred, would necessitate a cesarean delivery. In patients at increased risk for preterm delivery, the prophylactic regimen should be started earlier.

Valacyclovir, 500 mg orally twice daily, is an acceptable alternative but is significantly more expensive.

Continue to: 12. What are the best office-based tests for the diagnosis of bacterial vaginosis?...

12. What are the best office-based tests for the diagnosis of bacterial vaginosis? 

In patients with bacterial vaginosis, the vaginal pH typically is elevated in the range of 4.5. When a drop of potassium hydroxide solution is added to the vaginal secretions, a characteristic fishlike (amine) odor is liberated (positive “whiff test”). With saline microscopy, the key findings are a relative absence of lactobacilli in the background, an abundance of small cocci and bacilli, and the presence of clue cells, which are epithelial cells studded with bacteria along their 
 outer margin.

13. For a moderately ill pregnant woman, what is the most appropriate antibiotic combination for inpatient treatment of community-acquired pneumonia?

This patient should be treated with intravenous ceftriaxone (2 g every 24 hours) plus oral or intravenous azithromycin. The appropriate oral dose of azithromycin is 500 mg on day 1, then 250 mg daily for 4 doses. The appropriate intravenous dose of azithromycin is 500 mg every 24 hours. The goal is to provide appropriate coverage for the most likely pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and mycoplasmas. (Antibacterial drugs for community-acquired pneumonia. Med Lett Drugs Ther. 2021:63:10-14. Postma DF, van Werkoven CH, van Eldin LJ, et al; CAP-START Study Group. Antibiotic treatment strategies for community acquired pneumonia in adults. N Engl J Med. 2015;372: 1312-1323.)

14. What tests are best for the diagnosis of COVID-19 infection?

The 2 key diagnostic tests for COVID-19 infection are detecting antigen in nasopharyngeal washings or saliva by nucleic acid amplification tests and identifying groundglass opacities on computed tomography imaging of the chest. (Berlin DA, Gulick RM, Martinez FJ. Severe Covid-19. N Engl J Med. 2020;383:2451-2460.)

15. What is the most appropriate treatment for a pregnant woman  who is moderately to severely ill  with COVID-19 infection?

Moderately to severely ill pregnant women with COVID-19 infection should be hospitalized and treated with supplementary oxygen, remdesivir, and dexamethasone. Other possible therapies include inhaled nitric oxide, baricitinib (a Janus kinase inhibitor), and tocilizumab (an anti-interleukin 6 receptor antibody). (RECOVERY Collaborative Group; Horby P, Lim WS, Emberson JR, et al. Dexamethasone in hospitalized patients with COVID-19. N Engl J Med. 2021;384:693704. Kalil AC, Patterson TF, Mehta AK, et al; ACTT-2 Study Group. Baricitinib plus remdesivir for hospitalized adults with COVID-19. N Engl J Med. 2021;384:795-807. Berlin DA, Gulick RM, Martinez FJ, et al. Severe COVID19. N Engl J Med. 2020;383;2451-2460.)

16. What is the best test  for the diagnosis of acute  hepatitis A infection?

The single best test for the diagnosis of acute hepatitis A infection is detection of immunoglobulin M (IgM)–specific antibody to the virus.

17. What are the best tests for identification of a patient  with chronic hepatitis B infection?

Patients with chronic hepatitis B infection typically test positive for the hepatitis B surface antigen (HBsAg) and for IgG antibody to the hepatitis B core antigen (HBcAg). In addition, they also may test positive for the hepatitis B e antigen (HBeAg), and their viral load can be quantified by polymerase chain reaction (PCR) when significant antigenemia is present. The presence of the e antigen indicates a high rate of viral replication and a corresponding high rate of infectivity.

18. What antenatal treatment is indicated in a pregnant woman at 28 weeks’ gestation who has a hepatitis B viral load of 2 million copies/mL?

This patient has a markedly elevated viral load and is at significantly increased risk of transmitting hepatitis B infection to her neonate even if the infant receives hepatitis B immune globulin immediately after birth and quickly begins the hepatitis B vaccine series. Daily antenatal treatment with tenofovir (300 mg daily) from 28 weeks until delivery will significantly reduce the risk of perinatal transmission.

19. Should a postpartum patient with chronic hepatitis C infection be discouraged from breastfeeding her infant?

Hepatitis C is not a contraindication to breastfeeding. Although the virus has been identified in breast milk, the risk of transmission to the infant is exceedingly low.

20. What are the principal microorganisms that cause puerperal mastitis?

Staphylococci and Streptococcus viridans are the 2 dominant microorganisms that cause puerperal mastitis. For the initial treatment of mastitis, the drug of choice is dicloxacillin sodium (500 mg orally every 6 to 8 hours for 7 to 10 days). If the patient has a mild allergy to penicillin, cephalexin (500 mg orally every 6 to 8 hours for 7 to 10 days) is an appropriate alternative. If the allergy to penicillin is severe or if methicillin-resistant Staphylococcus aureus (MRSA) infection is suspected, either clindamycin (300 mg orally twice daily for 7 to 10 days) or trimethoprim-sulfamethoxazole double strength orally twice daily for 7 to 10 days should be used. ●
 

In this question-and-answer article (the second in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

9. For uncomplicated chlamydia infection in a pregnant woman, what is the most appropriate treatment?

Uncomplicated chlamydia infection in a pregnant woman should be treated with a single 1,000-mg oral dose of azithromycin. An acceptable alternative is amoxicillin 
500 mg orally 3 times daily for 7 days.

In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days is also an appropriate alternative. However, doxycycline is relatively expensive and may not be well tolerated because of gastrointestinal adverse effects. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

10. What are the characteristic mucocutaneous lesions of primary, secondary, and tertiary syphilis?

The characteristic mucosal lesion of primary syphilis is the painless chancre. The usual mucocutaneous manifestations of secondary syphilis are maculopapular lesions (red or violet in color) on the palms and soles, mucous patches on the oral membranes, and condyloma lata on the genitalia. The classic mucocutaneous lesion of tertiary syphilis is the gumma.

Other serious manifestations of advanced syphilis include central nervous system abnormalities, such as tabes dorsalis, the Argyll Robertson pupil, and dementia, and cardiac abnormalities, such as aortitis, which can lead to a dissecting aneurysm of the aortic root. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

11. In a pregnant woman with a history of recurrent herpes simplex virus infection, what is the best way to prevent an outbreak of lesions  near term?

Obstetric patients with a history of recurrent herpes simplex infection should be treated with acyclovir 400 mg orally 3 times daily from 36 weeks until delivery. This 
 regimen significantly reduces the likelihood of a recurrent outbreak near the time of delivery, which if it occurred, would necessitate a cesarean delivery. In patients at increased risk for preterm delivery, the prophylactic regimen should be started earlier.

Valacyclovir, 500 mg orally twice daily, is an acceptable alternative but is significantly more expensive.

Continue to: 12. What are the best office-based tests for the diagnosis of bacterial vaginosis?...

12. What are the best office-based tests for the diagnosis of bacterial vaginosis? 

In patients with bacterial vaginosis, the vaginal pH typically is elevated in the range of 4.5. When a drop of potassium hydroxide solution is added to the vaginal secretions, a characteristic fishlike (amine) odor is liberated (positive “whiff test”). With saline microscopy, the key findings are a relative absence of lactobacilli in the background, an abundance of small cocci and bacilli, and the presence of clue cells, which are epithelial cells studded with bacteria along their 
 outer margin.

13. For a moderately ill pregnant woman, what is the most appropriate antibiotic combination for inpatient treatment of community-acquired pneumonia?

This patient should be treated with intravenous ceftriaxone (2 g every 24 hours) plus oral or intravenous azithromycin. The appropriate oral dose of azithromycin is 500 mg on day 1, then 250 mg daily for 4 doses. The appropriate intravenous dose of azithromycin is 500 mg every 24 hours. The goal is to provide appropriate coverage for the most likely pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and mycoplasmas. (Antibacterial drugs for community-acquired pneumonia. Med Lett Drugs Ther. 2021:63:10-14. Postma DF, van Werkoven CH, van Eldin LJ, et al; CAP-START Study Group. Antibiotic treatment strategies for community acquired pneumonia in adults. N Engl J Med. 2015;372: 1312-1323.)

14. What tests are best for the diagnosis of COVID-19 infection?

The 2 key diagnostic tests for COVID-19 infection are detecting antigen in nasopharyngeal washings or saliva by nucleic acid amplification tests and identifying groundglass opacities on computed tomography imaging of the chest. (Berlin DA, Gulick RM, Martinez FJ. Severe Covid-19. N Engl J Med. 2020;383:2451-2460.)

15. What is the most appropriate treatment for a pregnant woman  who is moderately to severely ill  with COVID-19 infection?

Moderately to severely ill pregnant women with COVID-19 infection should be hospitalized and treated with supplementary oxygen, remdesivir, and dexamethasone. Other possible therapies include inhaled nitric oxide, baricitinib (a Janus kinase inhibitor), and tocilizumab (an anti-interleukin 6 receptor antibody). (RECOVERY Collaborative Group; Horby P, Lim WS, Emberson JR, et al. Dexamethasone in hospitalized patients with COVID-19. N Engl J Med. 2021;384:693704. Kalil AC, Patterson TF, Mehta AK, et al; ACTT-2 Study Group. Baricitinib plus remdesivir for hospitalized adults with COVID-19. N Engl J Med. 2021;384:795-807. Berlin DA, Gulick RM, Martinez FJ, et al. Severe COVID19. N Engl J Med. 2020;383;2451-2460.)

16. What is the best test  for the diagnosis of acute  hepatitis A infection?

The single best test for the diagnosis of acute hepatitis A infection is detection of immunoglobulin M (IgM)–specific antibody to the virus.

17. What are the best tests for identification of a patient  with chronic hepatitis B infection?

Patients with chronic hepatitis B infection typically test positive for the hepatitis B surface antigen (HBsAg) and for IgG antibody to the hepatitis B core antigen (HBcAg). In addition, they also may test positive for the hepatitis B e antigen (HBeAg), and their viral load can be quantified by polymerase chain reaction (PCR) when significant antigenemia is present. The presence of the e antigen indicates a high rate of viral replication and a corresponding high rate of infectivity.

18. What antenatal treatment is indicated in a pregnant woman at 28 weeks’ gestation who has a hepatitis B viral load of 2 million copies/mL?

This patient has a markedly elevated viral load and is at significantly increased risk of transmitting hepatitis B infection to her neonate even if the infant receives hepatitis B immune globulin immediately after birth and quickly begins the hepatitis B vaccine series. Daily antenatal treatment with tenofovir (300 mg daily) from 28 weeks until delivery will significantly reduce the risk of perinatal transmission.

19. Should a postpartum patient with chronic hepatitis C infection be discouraged from breastfeeding her infant?

Hepatitis C is not a contraindication to breastfeeding. Although the virus has been identified in breast milk, the risk of transmission to the infant is exceedingly low.

20. What are the principal microorganisms that cause puerperal mastitis?

Staphylococci and Streptococcus viridans are the 2 dominant microorganisms that cause puerperal mastitis. For the initial treatment of mastitis, the drug of choice is dicloxacillin sodium (500 mg orally every 6 to 8 hours for 7 to 10 days). If the patient has a mild allergy to penicillin, cephalexin (500 mg orally every 6 to 8 hours for 7 to 10 days) is an appropriate alternative. If the allergy to penicillin is severe or if methicillin-resistant Staphylococcus aureus (MRSA) infection is suspected, either clindamycin (300 mg orally twice daily for 7 to 10 days) or trimethoprim-sulfamethoxazole double strength orally twice daily for 7 to 10 days should be used. ●
 

In this question-and-answer article (the second in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

9. For uncomplicated chlamydia infection in a pregnant woman, what is the most appropriate treatment?

Uncomplicated chlamydia infection in a pregnant woman should be treated with a single 1,000-mg oral dose of azithromycin. An acceptable alternative is amoxicillin 
500 mg orally 3 times daily for 7 days.

In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days is also an appropriate alternative. However, doxycycline is relatively expensive and may not be well tolerated because of gastrointestinal adverse effects. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

10. What are the characteristic mucocutaneous lesions of primary, secondary, and tertiary syphilis?

The characteristic mucosal lesion of primary syphilis is the painless chancre. The usual mucocutaneous manifestations of secondary syphilis are maculopapular lesions (red or violet in color) on the palms and soles, mucous patches on the oral membranes, and condyloma lata on the genitalia. The classic mucocutaneous lesion of tertiary syphilis is the gumma.

Other serious manifestations of advanced syphilis include central nervous system abnormalities, such as tabes dorsalis, the Argyll Robertson pupil, and dementia, and cardiac abnormalities, such as aortitis, which can lead to a dissecting aneurysm of the aortic root. (Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morbid Mortal Wkly Rep. 2015;64[RR3]:1-137.)

11. In a pregnant woman with a history of recurrent herpes simplex virus infection, what is the best way to prevent an outbreak of lesions  near term?

Obstetric patients with a history of recurrent herpes simplex infection should be treated with acyclovir 400 mg orally 3 times daily from 36 weeks until delivery. This 
 regimen significantly reduces the likelihood of a recurrent outbreak near the time of delivery, which if it occurred, would necessitate a cesarean delivery. In patients at increased risk for preterm delivery, the prophylactic regimen should be started earlier.

Valacyclovir, 500 mg orally twice daily, is an acceptable alternative but is significantly more expensive.

Continue to: 12. What are the best office-based tests for the diagnosis of bacterial vaginosis?...

12. What are the best office-based tests for the diagnosis of bacterial vaginosis? 

In patients with bacterial vaginosis, the vaginal pH typically is elevated in the range of 4.5. When a drop of potassium hydroxide solution is added to the vaginal secretions, a characteristic fishlike (amine) odor is liberated (positive “whiff test”). With saline microscopy, the key findings are a relative absence of lactobacilli in the background, an abundance of small cocci and bacilli, and the presence of clue cells, which are epithelial cells studded with bacteria along their 
 outer margin.

13. For a moderately ill pregnant woman, what is the most appropriate antibiotic combination for inpatient treatment of community-acquired pneumonia?

This patient should be treated with intravenous ceftriaxone (2 g every 24 hours) plus oral or intravenous azithromycin. The appropriate oral dose of azithromycin is 500 mg on day 1, then 250 mg daily for 4 doses. The appropriate intravenous dose of azithromycin is 500 mg every 24 hours. The goal is to provide appropriate coverage for the most likely pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and mycoplasmas. (Antibacterial drugs for community-acquired pneumonia. Med Lett Drugs Ther. 2021:63:10-14. Postma DF, van Werkoven CH, van Eldin LJ, et al; CAP-START Study Group. Antibiotic treatment strategies for community acquired pneumonia in adults. N Engl J Med. 2015;372: 1312-1323.)

14. What tests are best for the diagnosis of COVID-19 infection?

The 2 key diagnostic tests for COVID-19 infection are detecting antigen in nasopharyngeal washings or saliva by nucleic acid amplification tests and identifying groundglass opacities on computed tomography imaging of the chest. (Berlin DA, Gulick RM, Martinez FJ. Severe Covid-19. N Engl J Med. 2020;383:2451-2460.)

15. What is the most appropriate treatment for a pregnant woman  who is moderately to severely ill  with COVID-19 infection?

Moderately to severely ill pregnant women with COVID-19 infection should be hospitalized and treated with supplementary oxygen, remdesivir, and dexamethasone. Other possible therapies include inhaled nitric oxide, baricitinib (a Janus kinase inhibitor), and tocilizumab (an anti-interleukin 6 receptor antibody). (RECOVERY Collaborative Group; Horby P, Lim WS, Emberson JR, et al. Dexamethasone in hospitalized patients with COVID-19. N Engl J Med. 2021;384:693704. Kalil AC, Patterson TF, Mehta AK, et al; ACTT-2 Study Group. Baricitinib plus remdesivir for hospitalized adults with COVID-19. N Engl J Med. 2021;384:795-807. Berlin DA, Gulick RM, Martinez FJ, et al. Severe COVID19. N Engl J Med. 2020;383;2451-2460.)

16. What is the best test  for the diagnosis of acute  hepatitis A infection?

The single best test for the diagnosis of acute hepatitis A infection is detection of immunoglobulin M (IgM)–specific antibody to the virus.

17. What are the best tests for identification of a patient  with chronic hepatitis B infection?

Patients with chronic hepatitis B infection typically test positive for the hepatitis B surface antigen (HBsAg) and for IgG antibody to the hepatitis B core antigen (HBcAg). In addition, they also may test positive for the hepatitis B e antigen (HBeAg), and their viral load can be quantified by polymerase chain reaction (PCR) when significant antigenemia is present. The presence of the e antigen indicates a high rate of viral replication and a corresponding high rate of infectivity.

18. What antenatal treatment is indicated in a pregnant woman at 28 weeks’ gestation who has a hepatitis B viral load of 2 million copies/mL?

This patient has a markedly elevated viral load and is at significantly increased risk of transmitting hepatitis B infection to her neonate even if the infant receives hepatitis B immune globulin immediately after birth and quickly begins the hepatitis B vaccine series. Daily antenatal treatment with tenofovir (300 mg daily) from 28 weeks until delivery will significantly reduce the risk of perinatal transmission.

19. Should a postpartum patient with chronic hepatitis C infection be discouraged from breastfeeding her infant?

Hepatitis C is not a contraindication to breastfeeding. Although the virus has been identified in breast milk, the risk of transmission to the infant is exceedingly low.

20. What are the principal microorganisms that cause puerperal mastitis?

Staphylococci and Streptococcus viridans are the 2 dominant microorganisms that cause puerperal mastitis. For the initial treatment of mastitis, the drug of choice is dicloxacillin sodium (500 mg orally every 6 to 8 hours for 7 to 10 days). If the patient has a mild allergy to penicillin, cephalexin (500 mg orally every 6 to 8 hours for 7 to 10 days) is an appropriate alternative. If the allergy to penicillin is severe or if methicillin-resistant Staphylococcus aureus (MRSA) infection is suspected, either clindamycin (300 mg orally twice daily for 7 to 10 days) or trimethoprim-sulfamethoxazole double strength orally twice daily for 7 to 10 days should be used. ●
 

What are the major manifestations of congenital rubella syndrome?

Continue to the answer...

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

What are the major manifestations of congenital rubella syndrome?

Continue to the answer...

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

What are the major manifestations of congenital rubella syndrome?

Continue to the answer...

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Continue to the answer...

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Continue to the answer...

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Continue to the answer...

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

What are the major complications of pyelonephritis in pregnancy?

Continue to the answer...

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

What are the major complications of pyelonephritis in pregnancy?

Continue to the answer...

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

What are the major complications of pyelonephritis in pregnancy?

Continue to the answer...

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

In this question-and-answer article (the first in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

1. What are the best tests for the diagnosis of congenital cytomegalovirus (CMV) infection?

When congenital CMV is suspected, if the patient is at least 15 weeks’ gestation, an amniocentesis should be performed to test for CMV DNA in the amniotic fluid using polymerase chain reaction (PCR) methodology. If the initial test is negative, amniocentesis should be repeated in approximately 4 weeks. Coincident with amniocentesis, a detailed ultrasound examination should be performed to search for findings suggestive of fetal injury, such as growth restriction, microcephaly, periventricular calcifications, hepatosplenomegaly, echogenic bowel, and serous effusions in the pleural space or abdomen.

2. Which major organisms cause urinary tract infections (UTIs) in women?

The most common causative organism is Escherichia coli, which is responsible for approximately 70% of all UTIs. Klebsiella pneumoniae and Proteus species are the 2 other aerobic gram-negative bacilli that are common uropathogens. In addition, 3 gram-positive cocci are important: enterococci, Staphylococcus saprophyticus, and group B streptococcus.

3. What are the major complications of pyelonephritis in pregnancy?

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

4. What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

5. What are the major manifestations of congenital rubella syndrome?

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

6. Which vaccines are contraindicated in pregnancy?

Live virus vaccines should not be used in pregnancy because of the possibility of teratogenic effects. Live agents include the measles, mumps, and rubella (MMR) vaccine; live influenza vaccine (FluMist); oral polio vaccine; BCG (bacille Calmette-Guerin) vaccine; yellow fever vaccine; and smallpox vaccine.

7. What is the most appropriate treatment for trichomonas infection in pregnancy?

Trichomonas infection should be treated with oral metronidazole 500 mg twice daily for 7 days. Metronidazole also can be given as a single oral 2-g dose. This treatment is not quite as effective as the multidose regimen, but it may be appropriate for patients who are not likely to be adherent with the longer course of treatment.

Resistance to metronidazole is rare; in such instances, oral tinidazole 2 g in a single dose may be effective.

8. For uncomplicated gonorrhea in a pregnant woman, what is the most appropriate treatment?

The current recommendation from the Centers for Disease Control and Prevention for treatment of uncomplicated gonorrhea is a single 500-mg intramuscular dose of ceftriaxone. For the patient who is opposed to an intramuscular injection, an alternative treatment is cefixime 800 mg orally. With either of these regimens, if chlamydia infection cannot be excluded, the pregnant patient also should receive azithromycin 1,000 mg orally in a single dose. In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days should be used to cover for concurrent chlamydia infection.

In a patient with an allergy to β-lactam antibiotics, an alternative regimen for treatment of uncomplicated gonorrhea is intramuscular gentamicin 240 mg plus a single 2,000-mg dose of oral azithromycin. (St Cyr S, Barbee L, Workowski KA, et al. Update to CDC’s treatment guidelines for gonococcal infection, 2020. MMWR Morbid Mortal Wkly Rep. 2020;69:1911-1916.) ●

In this question-and-answer article (the first in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

1. What are the best tests for the diagnosis of congenital cytomegalovirus (CMV) infection?

When congenital CMV is suspected, if the patient is at least 15 weeks’ gestation, an amniocentesis should be performed to test for CMV DNA in the amniotic fluid using polymerase chain reaction (PCR) methodology. If the initial test is negative, amniocentesis should be repeated in approximately 4 weeks. Coincident with amniocentesis, a detailed ultrasound examination should be performed to search for findings suggestive of fetal injury, such as growth restriction, microcephaly, periventricular calcifications, hepatosplenomegaly, echogenic bowel, and serous effusions in the pleural space or abdomen.

2. Which major organisms cause urinary tract infections (UTIs) in women?

The most common causative organism is Escherichia coli, which is responsible for approximately 70% of all UTIs. Klebsiella pneumoniae and Proteus species are the 2 other aerobic gram-negative bacilli that are common uropathogens. In addition, 3 gram-positive cocci are important: enterococci, Staphylococcus saprophyticus, and group B streptococcus.

3. What are the major complications of pyelonephritis in pregnancy?

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

4. What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

5. What are the major manifestations of congenital rubella syndrome?

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

6. Which vaccines are contraindicated in pregnancy?

Live virus vaccines should not be used in pregnancy because of the possibility of teratogenic effects. Live agents include the measles, mumps, and rubella (MMR) vaccine; live influenza vaccine (FluMist); oral polio vaccine; BCG (bacille Calmette-Guerin) vaccine; yellow fever vaccine; and smallpox vaccine.

7. What is the most appropriate treatment for trichomonas infection in pregnancy?

Trichomonas infection should be treated with oral metronidazole 500 mg twice daily for 7 days. Metronidazole also can be given as a single oral 2-g dose. This treatment is not quite as effective as the multidose regimen, but it may be appropriate for patients who are not likely to be adherent with the longer course of treatment.

Resistance to metronidazole is rare; in such instances, oral tinidazole 2 g in a single dose may be effective.

8. For uncomplicated gonorrhea in a pregnant woman, what is the most appropriate treatment?

The current recommendation from the Centers for Disease Control and Prevention for treatment of uncomplicated gonorrhea is a single 500-mg intramuscular dose of ceftriaxone. For the patient who is opposed to an intramuscular injection, an alternative treatment is cefixime 800 mg orally. With either of these regimens, if chlamydia infection cannot be excluded, the pregnant patient also should receive azithromycin 1,000 mg orally in a single dose. In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days should be used to cover for concurrent chlamydia infection.

In a patient with an allergy to β-lactam antibiotics, an alternative regimen for treatment of uncomplicated gonorrhea is intramuscular gentamicin 240 mg plus a single 2,000-mg dose of oral azithromycin. (St Cyr S, Barbee L, Workowski KA, et al. Update to CDC’s treatment guidelines for gonococcal infection, 2020. MMWR Morbid Mortal Wkly Rep. 2020;69:1911-1916.) ●

In this question-and-answer article (the first in a series), our objective is to reinforce for the clinician several practical points of management for common infectious diseases. The principal references for the answers to the questions are 2 textbook chapters written by Dr. Duff.^1,2 Other pertinent references are included in the text.

1. What are the best tests for the diagnosis of congenital cytomegalovirus (CMV) infection?

When congenital CMV is suspected, if the patient is at least 15 weeks’ gestation, an amniocentesis should be performed to test for CMV DNA in the amniotic fluid using polymerase chain reaction (PCR) methodology. If the initial test is negative, amniocentesis should be repeated in approximately 4 weeks. Coincident with amniocentesis, a detailed ultrasound examination should be performed to search for findings suggestive of fetal injury, such as growth restriction, microcephaly, periventricular calcifications, hepatosplenomegaly, echogenic bowel, and serous effusions in the pleural space or abdomen.

2. Which major organisms cause urinary tract infections (UTIs) in women?

The most common causative organism is Escherichia coli, which is responsible for approximately 70% of all UTIs. Klebsiella pneumoniae and Proteus species are the 2 other aerobic gram-negative bacilli that are common uropathogens. In addition, 3 gram-positive cocci are important: enterococci, Staphylococcus saprophyticus, and group B streptococcus.

3. What are the major complications of pyelonephritis in pregnancy?

Pyelonephritis is an important cause of preterm labor, sepsis, and adult respiratory distress syndrome. Most cases of pyelonephritis develop as a result of an untreated or inadequately treated lower urinary tract infection.

4. What is the most ominous manifestation of congenital parvovirus infection, and what is the cause of this abnormality?

Hydrops fetalis is the most ominous complication of congenital parvovirus infection. The virus crosses the placenta and attacks red cell progenitor cells, resulting in an aplastic anemia. In addition, the virus may cause myocarditis that, in turn, may result in cardiac failure in the fetus.

5. What are the major manifestations of congenital rubella syndrome?

Rubella is one of the most highly teratogenic of all the viral infections, particularly when maternal infection occurs in the first trimester. Manifestations of congenital rubella include hearing deficits, cataracts, glaucoma, microcephaly, mental retardation, cardiac malformations such as patent ductus arteriosus and pulmonic stenosis, and growth restriction.

6. Which vaccines are contraindicated in pregnancy?

Live virus vaccines should not be used in pregnancy because of the possibility of teratogenic effects. Live agents include the measles, mumps, and rubella (MMR) vaccine; live influenza vaccine (FluMist); oral polio vaccine; BCG (bacille Calmette-Guerin) vaccine; yellow fever vaccine; and smallpox vaccine.

7. What is the most appropriate treatment for trichomonas infection in pregnancy?

Trichomonas infection should be treated with oral metronidazole 500 mg twice daily for 7 days. Metronidazole also can be given as a single oral 2-g dose. This treatment is not quite as effective as the multidose regimen, but it may be appropriate for patients who are not likely to be adherent with the longer course of treatment.

Resistance to metronidazole is rare; in such instances, oral tinidazole 2 g in a single dose may be effective.

8. For uncomplicated gonorrhea in a pregnant woman, what is the most appropriate treatment?

The current recommendation from the Centers for Disease Control and Prevention for treatment of uncomplicated gonorrhea is a single 500-mg intramuscular dose of ceftriaxone. For the patient who is opposed to an intramuscular injection, an alternative treatment is cefixime 800 mg orally. With either of these regimens, if chlamydia infection cannot be excluded, the pregnant patient also should receive azithromycin 1,000 mg orally in a single dose. In a nonpregnant patient, doxycycline 100 mg orally twice daily for 7 days should be used to cover for concurrent chlamydia infection.

In a patient with an allergy to β-lactam antibiotics, an alternative regimen for treatment of uncomplicated gonorrhea is intramuscular gentamicin 240 mg plus a single 2,000-mg dose of oral azithromycin. (St Cyr S, Barbee L, Workowski KA, et al. Update to CDC’s treatment guidelines for gonococcal infection, 2020. MMWR Morbid Mortal Wkly Rep. 2020;69:1911-1916.) ●