Anti-group B Streptococcus antibody in infants born to mothers with human immunodeficiency virus (HIV) infection.

BACKGROUND: HIV-exposed uninfected infants have increased infection risk and mortality compared to HIV-unexposed infants. HIV-exposed infants may be at increased risk of invasive GBS disease due to reduced maternal antibody against GBS. METHODS: We quantified antibodies that bind to the surface of whole Group B Streptococcus (GBS) of serotypes Ia, Ib, II, III and V using novel flow cytometry assays in South African HIV-infected and non-infected mothers and their uninfected infants. Antibody-mediated complement C3b/iC3b deposition onto GBS of these serotypes was also quantified by a novel flow cytometry assay. RESULTS: Geometric mean concentration (GMC) of both surface-binding anti-GBS antibody and antibody-mediated complement deposition onto GBS were reduced in HIV-infected women (n=46) compared to HIV-uninfected women (n=58) for ST1a (surface-binding: 19.3 vs 29.3; p=0.003; complement deposition: 2.9 vs 5.3 SU/mL; p=0.003), STIb (24.9 vs 47.6; p=0.003; 2.6 vs 4.9 SU/mL; p=0.003), STII (19.8 vs 50.0; p=0.001; 3.1 vs 6.2 SU/mL; p=0.001), STIII (27.8 vs 60.1; p=0.001; 2.8 vs 5.3 SU/mL; p=0.001) and STV (121.9 vs 185.6 SU/mL; p<0.001) and in their infants for STIa (complement deposition 9.4 vs 27.0 SU/mL; p=0.02), STIb (13.4 vs 24.5 SU/mL; p=0.02), STII (14.6 vs 42.7 SU/mL; p=0.03), STIII (26.6 vs 62.7 SU/mL; p=0.03) and STV (90.4 vs 165.8 SU/mL; p=0.04). Median transplacental transfer of antibody from HIV-infected women to their infants was reduced compared to HIV-uninfected women for GBS serotypes II (0.42 [IQR 0.22-0.59] vs 1.0 SU/mL [0.42-1.66]; p<0.001), III (0.54 [0.31-1.03] vs 0.95 SU/mL [0.42-3.05], p=0.05) and V (0.51 [0.28-0.79] vs 0.75 SU/mL [0.26-2.9], p=0.04). The differences between infants remained significant at 16 weeks of age. CONCLUSIONS: Maternal HIV infection was associated with lower anti-GBS surface binding antibody concentration and antibody-mediated C3b/iC3b deposition onto GBS bacteria of serotypes Ia, Ib, II, III and V. This may render these infants more susceptible to early and late onset GBS disease.

Neonatal infections: group B streptococcus.

INTRODUCTION: One in four women carry group B streptococci vaginally, which can infect the amniotic fluid even if the membranes are intact, or can infect the baby during delivery, causing sepsis, pneumonia, or meningitis. Very-low-birthweight infants are at much higher risk of infection or mortality, with up to 3% infected, and mortality rates of up to 30% even with immediate antibiotic treatment. Late-onset group B streptococcal infection begins after 7 to 9 days, and usually causes fever or meningitis, but is less often fatal compared with early infection. METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical question: What are the effects of prophylactic treatment of asymptomatic neonates less than 7 days old with known risk factors for group B streptococcal infection? We searched: Medline, Embase, The Cochrane Library and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). RESULTS: We found 12 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: different antibiotics, monitoring and selective treatment, and routine antibiotic prophylaxis.

Antimicrobial policies in the neonatal units of the United Kingdom and Republic of Ireland.

OBJECTIVES: To review antibiotic and antifungal policies in British and Irish neonatal units (NNUs). METHODS: A telephone survey was performed regarding empirical antimicrobial guidelines of NNUs in the UK and Republic of Ireland. RESULTS: The response rate was 91% (202 of 222 NNUs). The guidelines from all responding units covered group B Streptococcus and Escherichia coli, the most common causes of neonatal septicaemia and meningitis. However, 19% did not cover Listeria, the cause of meningitis in 5% to 7% of cases in England and Wales. Second-line recommendations varied greatly between units, with widespread use of broad-spectrum agents. Fungal prophylaxis and treatment guidelines were generally rudimentary. CONCLUSIONS: Empirical antimicrobial recommendations on many NNUs include broad-spectrum antibiotics without ensuring universal coverage of important pathogens. We raise concerns about the selection pressures exerted for resistant pathogens and invasive fungal disease, especially as few units specify fungal prophylaxis or treatment guidance. Development of rational guidelines for the UK and Irish neonatal units might help to optimize treatment while minimizing overuse of broad-spectrum agents.