GBS-A

Duration

01/07/2025 - 31/07/2027

Coordinator

Anna Roca

Funded by

The Gates Foundation

Maternal infection with Group B Streptococcus (GBS) during pregnancy is a global health priority due to its association with serious neonatal complications, including preterm labor, chorioamnionitis and intrauterine infections such as sepsis. These conditions can result in stillbirth and neonatal deaths, which are alarmingly high in Sub-Saharan Africa (SSA). According to data from the CHAMPS surveillance study, GBS is responsible for a notable proportion of these outcomes, contributing to 2% to 6% of neonatal deaths but being present in up to 20% of the deceased. While the burden of GBS varies across SSA sub-regions, it remains a critical public health issue across all regions.

The CHAMPS study, a large-scale surveillance involving six African countries, provides valuable aetiological data on neonatal deaths that inform policy development and priority-setting. However, the study design has inherent limitations that hinder a comprehensive evaluation of the public health impact of specific pathogens. For instance, the absence of a control group, makes it difficult to directly attribute deaths to specific pathogens. As a result, in 80% of neonatal deaths with GBS, the bacterium has not been identified as the causative agent. Another limitation is the incomplete sample collection from deceased participants, with samples taken in fewer than 50% of deaths in the study areas. These factors may affect the accuracy and representativeness of the findings. In addition, focusing solely on deaths may overlook the public health relevance of pathogens contributing to severe infections with potential long-term complications among survivors.

In a recent study conducted in The Gambia and Burkina Faso which included a cohort of 12,000 pregnant women and their offspring, we observed that intrapartum-related asphyxia (IRA) is the leading cause of both neonatal mortality and long-term neurological disabilities.

In SSA, more than 5% of newborns are affected by IRA, which is often linked to complications during labor. IRA, however, can be exacerbated by infection, further increasing the risk of perinatal mortality and the severity of long-term sequelae in survivors. Emerging evidence suggests that GBS may play a leading role in the development of IRA, but data on is SSA remains extremely scarce. Given the ongoing efforts to develop a GBS vaccine, it is critical to better understand GBS broader impact on neonatal health across regions. Quantifying the role of GBS in both IRA and stillbirths is crucial for assessing the potential benefits of a GBS vaccine and setting regional and sub-regional priorities for its deployment.

This study will utilize a case-control design leveraging data and samples previously collected by the PRECISE maternal-child cohort study conducted across three SSA sub-regions. The case-control design and the inclusion of IRA beyond stillbirth as an outcome will complement data generated from CHAMPS on the role of GBS in early mortality.

Total funding

$ 770,737