SAN FRANCISCO — The most important recently published articles on pediatric infectious diseases include four articles on herpes viruses and two on meningococcal vaccines, two speakers said at the annual meeting of the Infectious Diseases Society of America.
Dr. Joseph W. St. Geme III, professor of pediatrics at Duke University, Durham, N.C., and Dr. Parvin H. Azimi, director of infectious diseases at Children's Hospital, Oakland, Calif., described their picks for the most significant articles.
Getting Clinical With MRSA
Houston investigators provided clinical descriptions of the increasing number of adolescents admitted to intensive care for severe community-acquired Staphylococcus aureus infection (Pediatrics 2005;115:642–8).
“In considering pressing issues in pediatric infectious diseases, I think most of us would agree that at the top of the list, these days, is community-acquired methicillin-resistant Staph aureus” (MRSA), Dr. St. Geme said.
A review of records for a 16-month period at Texas Children's Hospital, Houston, found that 14 adolescents were admitted for sepsis and coagulopathy from community-acquired S. aureus, 12 with MRSA and 2 with methicillin-susceptible S. aureus. Thirteen patients had pulmonary involvement, and 13 had bone and/or joint infection. Of the latter group, 10 patients had infection in two or more bones or joints. Their mean age was 13 years. Three patients died.
Getting a better understanding of the factors responsible for these infections should be a priority, he said.
HSV Suppression No More
A report of a premature infant with cutaneous herpes simplex virus (HSV) disease who developed herpes encephalitis despite suppressive therapy called into question assumptions about the efficacy of oral acyclovir regimens for HSV suppression (Pediatrics 2005;115:804–9).
The authors concluded that suppressive therapy with oral acyclovir cannot be recommended at this time.
“Many of us use suppressive therapy,” Dr. Azimi said. “We really need a randomized, placebo-controlled study so we can see if it is efficacious.”
Don't Forget Early-Onset GBS
Despite a big drop in the incidence of early-onset group B streptococcal (GBS) disease since adoption of universal screening for GBS colonization, cases of early-onset GBS disease still occur, and most of these are in infants whose mothers screened negative for GBS colonization, a review of 25 cases at one hospital found (Pediatrics 2005;115:1240–6). Many of the mothers had intrapartum risk factors for neonatal infection but received no prophylactic antibiotics before delivery. Assessment of intrapartum risk factors remains important, the investigators concluded.
“In addition, this study highlights that pending the introduction of a GBS vaccine, more effective prevention of GBS disease will require more rapid, more sensitive techniques to screen for GBS colonization and GBS antibiotic resistance,” Dr. St. Geme said.
Type of Herpesvirus Matters
Congenital infections occur with human herpesvirus 6 (HHV-6) but not with the closely related human herpesvirus 7 (HHV-7), investigators reported (J. Pediatr. 2004;145:472–7). DNA tests found no HHV-7 in 2,129 cord blood samples but showed HHV-6 in 1% of 5,638 cord blood samples, similar to the rate for cytomegalovirus infection. Congenital HHV-6 infections were asymptomatic, without the acute febrile illnesses seen with postnatal infections. It's not yet known whether congenital HHV-6 infection might cause subsequent hearing loss or developmental delay, as can happen with cytomegalovirus infection.
Uncovering Details of HHV-6 Infection
Little is known about HHV-6 infection in infants, so investigators prospectively studied 277 children from birth through the first 2 years of life, testing their saliva weekly for HHV-6 DNA and reviewing parents' logs of symptoms or signs of illness. Primary HHV-6 infection occurred in 40% by 1 year of age and in 77% by age 2 (N. Engl. J. Med. 2005;352:768–76).
Infections usually were symptomatic (associated with fever, fussiness, diarrhea, and roseola) and often resulted in a visit to a physician. Having older siblings was a risk factor for HHV-6 infection, but exposure to group child care was not. Girls were more likely than boys to get HHV-6 infection.
Varicella Vaccination Saves Lives
Universal childhood vaccination against varicella reduced deaths from varicella disease by 66%, a review of national death records found (N. Engl. J. Med. 2005; 352:450–8). Deaths for which varicella was listed as the underlying cause averaged 0.41 per 1 million people in the United States in 1990–1994 but only 0.14 per million in 1999–2001, after introduction of the varicella vaccine. The greatest reduction in mortality (92%) was seen in children aged 1–4 years, but deaths from varicella fell in all age groups.
AAP Recommends MCV4
The American Academy of Pediatrics published recommendations for administering the quadrivalent meningococcal conjugate vaccine (MCV4, marketed as Menactra), which was licensed in 2005 for use in people aged 11–55 years. The guidelines call for immunizing young adolescents (aged 11–12 years), adolescents when they reach age 15 years or enter high school (whichever comes first), and college freshmen who will be living in dormitories (Pediatrics 2005;116:496–505). Approximately 1,400–3,000 cases of invasive meningococcal disease occur each year, and 10%–14% are fatal. Survivors are left with significant sequelae in 11%–19% of cases.