H. Dele Davies

Updated Guidance for Palivizumab Prophylaxis Among Infants and Young Children at Increased Risk of Hospitalization for Respiratory Syncytial Virus Infection

Palivizumab was licensed in June 1998 by the Food and Drug Administration for the reduction of serious lower respiratory tract infection caused by respiratory syncytial virus (RSV) in children at increased risk of severe disease. Since that time, the American Academy of Pediatrics has updated its guidance for the use of palivizumab 4 times as additional data became available to provide a better understanding of infants and young children at greatest risk of hospitalization attributable to RSV infection. The updated recommendations in this policy statement reflect new information regarding the seasonality of RSV circulation, palivizumab pharmacokinetics, the changing incidence of bronchiolitis hospitalizations, the effect of gestational age and other risk factors on RSV hospitalization rates, the mortality of children hospitalized with RSV infection, the effect of prophylaxis on wheezing, and palivizumab-resistant RSV isolates. This policy statement updates and replaces the recommendations found in the 2012 Red Book.

Clostridium difficile Infection in Infants and Children

Infections caused by Clostridium difficile in hospitalized children are increasing. The recent publication of clinical practice guidelines for C difficile infection in adults did not address issues that are specific to children. The purpose of this policy statement is to provide the pediatrician with updated information and recommendations about C difficile infections affecting pediatric patients.

Population-based active surveillance for neonatal group B streptococcal infections in Alberta, Canada: implications for vaccine formulation.

Background. Knowledge of circulating serotypes of group B Streptococcus (GBS) is important for formulation of vaccines. There are no Canadian data on the serotype distribution of neonatal GBS isolates. Methods. Using a retrospective laboratory and health record survey between 1993 and 1994 (before introduction of Canadian prevention guidelines) and prospective active laboratory-based surveillance from 1995 to 1999 of all laboratories in Alberta, we identified 168 cases of invasive neonatal GBS infections including stillbirths among 262 398 total births; 118 of 123 (96%) isolates from 1995 to 1999 were serotyped, and the corresponding neonatal health records were reviewed. Results. The average annual incidence was 0.64 of 1000 total births/year. Of these 95 (57%) had early onset disease (EOD), 15 (9%) were still births and 58 (34%) had late onset disease (LOD). Eighty-one percent of EOD cases were caused by serotypes Ia, Ia/c, Ia/c/R, III, III/R and V, V/R, whereas 81% of LOD cases were caused by serotypes III and III/R. GBS serotypes containing the C protein along with serotypes III and V as a group constituted 91% (107 of 118) of all GBS cases in our population. The most common clinical presentation was bacteremia without focus (74%) followed by meningitis (14%) and pneumonia (12%). During 1995 to 1999, in addition to 13 stillbirths, there were 6 of 64 (9%) neonatal deaths among EOD cases and 1 of 46 (2%) neonatal death among LOD cases. Conclusions. In this population-based study stillbirths account for a proportion of cases that are not routinely counted and represent a group for which intrapartum antibiotics would likely not be effective, but potentially preventable by vaccination. Inclusion of serotypes Ia, III and V in a conjugate vaccine or serotypes III and V conjugated with the C protein in a GBS vaccine could theoretically provide protection against the majority of GBS invasive disease in Alberta neonates.

Multilocus Sequence Types Associated with Neonatal Group B Streptococcal Sepsis and Meningitis in Canada

ABSTRACT Group B streptococci (GBS), a leading cause of neonatal sepsis and meningitis, are transferred to neonates from colonized mothers during childbirth. Prior studies using multilocus sequence typing (MLST) have found specific GBS clones (e.g., sequence type 17 [ST-17]) to be associated with neonatal disease in several geographic locations. Few population-based studies, however, have been conducted to determine the frequency of disease caused by specific GBS clones. MLST was used to assess the genetic diversity of 192 GBS strains from neonates and young children identified by population-based surveillance in Alberta, Canada, from 1993 to 2002. Comparisons were made to 232 GBS strains collected from colonized pregnant women, and all strains were characterized for one of nine capsule (cps) genotypes. A total of 47 STs were identified, and more than 80% of GBS strains were represented by 7 STs that have been shown to predominate in other populations. ST-17 and ST-19 were more prevalent in strains causing early onset disease (EOD) and late onset disease (LOD) than from pregnant women, whereas STs 1, 12, and 23 were more common in pregnant women. In addition, ST-17 strains and close relatives more frequently caused meningitis than sepsis and LOD versus EOD in this population of neonates. Further research is required to better understand why strains belonging to the ST-17 phylogenetic lineage are more likely to cause both LOD and meningitis and may provide clues into the pathogenesis of these conditions.

Recommendations for Prevention and Control of Influenza in Children, 2012–2013

The purpose of this statement is to update recommendations for routine use of trivalent seasonal influenza vaccine and antiviral medications for the prevention and treatment of influenza in children. The key points for the upcoming 2012–2013 season are: (1) this year’s trivalent influenza vaccine contains A/California/7/2009 (H1N1)–like antigen (derived from influenza A [H1N1] pdm09 [pH1N1] virus); A/Victoria/361/2011 (H3N2)–like antigen; and B/Wisconsin/1/2010–like antigen (the influenza A [H3N2] and B antigens differ from those contained in the 2010–2011 and 2011–2012 seasonal vaccines); (2) annual universal influenza immunization is indicated; and (3) an updated dosing algorithm for administration of influenza vaccine to children 6 months through 8 years of age has been created. Pediatricians, nurses, and all health care personnel should promote influenza vaccine use and infection control measures. In addition, pediatricians should promptly identify influenza infections to enable rapid treatment, when indicated, to reduce morbidity and mortality.

Antibodies to Capsular Polysaccharides of Group B Streptococcus in Pregnant Canadian Women: Relationship to Colonization Status and Infection in the Neonate

In a cohort study of 1207 pregnant women in Alberta, Canada, the serotype distributions of vaginal-rectal group B Streptococcus (GBS) isolates were compared with all isolates from neonates with invasive GBS disease identified by population-based surveillance. Serum concentrations of Ia, Ib, II, III, and V capsular polysaccharide (CPS)-specific IgG also were determined, according to serotype of the vaginal-rectal colonizing GBS strain. GBS colonization was detected in 19.5% (235 of 1207) of women. Serotype III accounted for 20.6% (48 of 233) of colonizing strains available for typing but for 37% (27 of 73) of invasive isolates from neonates (P<.01). Maternal colonization with type III was least likely to be associated with moderate concentrations of III CPS-specific IgG. Serotype III GBS is more invasive than other serotypes in this population; this may be due, at least in part, to poor maternal type III CPS-specific antibody response.

Strategies for Prevention of Health Care-Associated Infections in the NICU

Health care–associated infections in the NICU result in increased morbidity and mortality, prolonged lengths of stay, and increased medical costs. Neonates are at high risk of acquiring health care–associated infections because of impaired host-defense mechanisms, limited amounts of protective endogenous flora on skin and mucosal surfaces at time of birth, reduced barrier function of their skin, use of invasive procedures and devices, and frequent exposure to broad-spectrum antibiotic agents. This clinical report reviews management and prevention of health care–associated infections in newborn infants.

Biofilm Formation by Group A Streptococci: Is There a Relationship with Treatment Failure?

ABSTRACT Group A streptococcus (GAS) is the primary cause of bacterial pharyngitis in children and adults. Up to one-third of patients treated for GAS pharyngitis fail to respond to antibiotic therapy. The objective of this cohort study was to evaluate GAS biofilm formation as a mechanism for antibiotic treatment failure using previously collected GAS isolates and penicillin treatment outcome data. The minimum biofilm eradication concentration (MBEC) assay device was used to determine the biofilm-forming capabilities, efficiencies, and antibiotic susceptibilities of GAS isolates. The MBECs and MICs of several antibiotics for GAS were determined. All 99 GAS isolates available for this study formed biofilms, with various efficiencies. Antibiotic MBECs were consistently higher than MICs for all of the GAS isolates. MBECs indicated penicillin insensitivity in 60% of GAS isolates, producing the first report of in vitro GAS insensitivity to penicillin. Using MBECs to predict penicillin treatment failure had better sensitivity (56%) but lower specificity (36%) than the sensitivity (0%) and specificity (100%) when MICs were used. However, the positive predictive value of the MBEC was superior to that of the MIC (56 versus 0%), while the negative predictive values (42 and 47%) were similar. More studies are needed to understand the roles of biofilms and the MBEC assay in predicting GAS treatment failure. In addition, further investigations are necessary to determine if non-biofilm-forming strains of GAS exist and the roles of in vivo monospecies and multispecies biofilms in streptococcal pharyngitis treatment failure.

Determination of immune memory to hepatitis B vaccination through early booster response in college students

The long‐term protection of hepatitis B (HB) vaccination has been debated for years. The purpose here was to evaluate the kinetic changes of antibody to HB surface antigen (anti‐HBs) and define immune memory of the HB vaccine among college students who had previously received full neonatal immunization against HB. In all, 127 college students aged 18‐23 years born after July 1984 who had completed HB vaccination and were seronegative for all three HB viral markers, including HB surface antigen (HBsAg), antibody to HB core protein (anti‐HBc), and anti‐HBs, were recruited. They received three doses of HB vaccine at enrollment, 1 month and 6 months after enrollment. Their anti‐HBs titers were assayed at enrollment, 7‐10 days, 1 month, 6 months, and 7 months following the first dose of HB vaccine. The anti‐HBs seroprotective rates for subjects 7‐10 days, 1 month, 6 months, and 7 months postvaccination were 20.5%, 75.6%, 94.5%, and 99.2%, respectively. Those who were seroprotective at 7 to 10 days after one dose of HB vaccine booster developed significantly higher levels of anti‐HBs at 1 and 6 months than those not developing seroprotective anti‐HBs response at an earlier timepoint. Conclusion: At least one‐quarter of HB vaccinees have lost their immune memory to the HB vaccine when entering college. Immune memory to HB vaccine was identified by early seroconversion, which was present in only 20% of vaccinees in the present study. To ensure higher than 90% anti‐HBs seroconversion rates, at least 2 doses of HB booster vaccines are recommended for at‐risk youths who received complete HB vaccinations in neonatal or infant periods but are seronegative for HBsAg, anti‐HBs, and anti‐HBc in adolescence. (Hepatology 2010;)

HPV Vaccine Recommendations

On October 25, 2011, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommended that the quadrivalent human papillomavirus vaccine (Gardasil; Merck & Co, Inc, Whitehouse Station, NJ) be used routinely in males. The American Academy of Pediatrics has reviewed updated data provided by the Advisory Committee on Immunization Practices on vaccine efficacy, safety, and cost-effectiveness as well as programmatic considerations and supports this recommendation. This revised statement updates recommendations for human papillomavirus immunization of both males and females.