REKAP

Duration

01/10/2025 - 30/09/2027

Coordinator

Anna Roca

Funded by

The Gates Foundation

Africa bears the highest global burden of perinatal mortality, accounting for nearly half of all stillbirths and early neonatal deaths (defined as deaths occurring within the first 72 hours after birth). Evidence from cohort studies conducted in The Gambia and Burkina Faso, including over 12,000 pregnant women and their offspring, indicates that more than 80% of neonatal deaths occur during this early neonatal period. Perinatal mortality rates ranged from 17 to 30 per 1,000 deliveries across different sub-Saharan African settings.

ISGlobal and partners have recently been awarded a project (GBS-A; Gates Foundation, INV-091973) to evaluate the role of Group B Streptococcus (GBS) in stillbirths within the PRECISE cohort. This initiative leverages existing biological samples (cord blood and placental tissue) and clinical data collected through the PRECISE maternal–child cohort study (www.precisenetwork.org). Building on this platform, the REKAP project expands the scope to investigate additional pathogens of major relevance.

Emerging evidence suggests that a substantial proportion of stillbirths may be associated with Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae. At the same time, investment in vaccine development targeting these pathogens is increasing. Understanding their contribution to perinatal mortality, as well as identifying immune correlates of protection, is critical to accelerate vaccine development, inform maternal immunisation strategies and identify women at higher risk.

Aim and Objectives

The overall aim of the REKAP project is to determine the role of E. coli and K. pneumoniae in perinatal mortality, including stillbirths and deaths within the first 72 hours after birth.

Primary objectives

• Estimate the burden and population attributable risk (PAR) of E. coli and K. pneumoniae in perinatal mortality.
• Identify immune correlates of protection (e.g. specific antibodies) against these pathogens using cord blood and vaginal samples.
• Transfer Luminex-based immunological analysis technology to a laboratory in South Africa.

Secondary objectives

• Identify demographic, epidemiological and serological risk factors associated with perinatal mortality.
• Assess risk factors for rectovaginal carriage of E. coli and K. pneumoniae.

Study Design

The project will use a retrospective case–control design based on data and samples collected within the PRECISE cohort in The Gambia, Kenya and Mozambique.

Cases: Intrapartum stillbirths (≥22 weeks gestation, ICD-11 definition) and early neonatal deaths (within 72 hours).

Controls: Newborns with normal Apgar scores (≥7 at 1 and 5 minutes) who remain healthy during the neonatal period.

Approximately 205 cases and 410 controls (1:2 ratio) will be included. Statistical power calculations will account for pathogen prevalence and population attributable risk.

A nested case–control design will be used to study immune correlates of protection, including pathogen-positive cases and two control groups: (i) perinatal deaths negative for the pathogens and (ii) healthy newborns.

Samples and Laboratory Methods

The study will include 615 mother–newborn pairs. Analyses will be conducted using cord blood, maternal blood and vaginal swabs stored in the PRECISE biobank.

Pathogen detection

• qPCR: Highly sensitive detection and quantification of bacterial DNA in culture-enriched samples.
• Microbiology: Culture-based identification and antibiotic susceptibility testing following international standards.

Quality control will be ensured through cross-site validation, with 5% of samples re-analysed to confirm consistency.

Genomic analysis

Whole-genome sequencing will be conducted at the MRC Unit The Gambia to characterise antimicrobial resistance, virulence profiles and genetic diversity of isolates.

Immune profiling

ISGlobal will lead immunological analyses using multiplex bead-based assays (xMAP Luminex) to quantify antibodies against selected antigens of E. coli and K. pneumoniae. Complementary platforms (e.g. Olink) may be used to identify biomarker signatures related to immune response and inflammation.

Statistical Analysis

Logistic regression models will be used to estimate odds ratios (OR) and 95% confidence intervals for associations between infection and perinatal mortality. Population attributable risk (PAR) will be calculated accordingly. Additional analyses will explore risk factors and immune correlates of protection.

Technology Transfer

ISGlobal will support capacity building through the transfer of Luminex technology to a South African laboratory. This includes:

• A two-month on-site training programme at ISGlobal laboratories.
• Training in quality assurance, data processing and analysis.
• Remote support over 6–8 months.
• A follow-up technical visit to the partner institution.

This approach aims to strengthen local research capacity and ensure sustainability of advanced immunological analyses in low- and middle-income settings.

Total Funding

$556,556

Funded by the Gates Foundation.