Serosurveillance Study of Maternally Derived Anti-GBS Antibody

Globally, neonatal mortality remains unacceptably high, with little change in the death rate in the first 28 days of life since 1990, despite reductions in under-5 mortality of up to 50% over the same period. In 2014, neonatal deaths accounted for 44% of all deaths in children under 5 with neonatal infection accounting for over a third of all deaths. Group B Streptococcus (GBS) is a major cause of septicemia and meningitis in infants globally and a cause of severe adverse neurodevelopmental outcomes in up to 50% of meningitis survivors. It can also lead to sepsis in pregnant women. GBS acquisition occurs through vertical transmission in 15%-50% of infants born to a vaginally/rectally colonized mother. Maternal colonization is a prerequisite for early onset (EO) and a risk factor for late onset (LO) disease.

Our proposal will provide these critical data in Uganda (a country with high neonatal disease burden) in a 12 month pilot study to determine: the burden of GBS disease in a cohort of mother/infant pairs and establish an active surveillance platform for monitoring of early and late onset neonatal infection in term and preterm infants in Uganda and compare this to the burden known for other African countries. This provides essential data on GBS disease outcomes from a high-HIV burden African cohort reflecting the usual standard of care in a low income, highly deprived urban environment. This pilot study will establish minimum disease estimates in the Ugandan cohort to determine the feasibility of a cohort study over three years to determine the level of antibody against GBS in cord blood from pregnancies where women are GBS colonized and non-colonized but whose infants do not develop GBS disease in the first three months of life and compare this to the level in the blood of infants who develop GBS disease. We will compare these results with those from other African countries such as South Africa to enable a robust estimate of potential sero-correlates of protection from natural infection against the most common GBS-disease-causing serotypes.