Infectious Causes of Stillbirths: A Descriptive Etiological Study in Uganda

Every year an estimated 2-3 million babies are stillborn, with a high burden in Africa. Infection is an important driver of stillbirth. There is a lack of data on the bacterial causes of stillbirth in Uganda, contributing to a lack of interventions such as effective prophylaxis and development of maternal vaccine options against the most implicated pathogens.

The PROGRESS study was an observational cohort study undertaken in Kampala, Uganda, between November 2018 and April 2021. If a woman delivered a stillborn baby, consent was sought for the collection of a heart-blood aspirate. One to three mL of blood was collected and sent for culture using the BD Bactec blood culture system. Organism identification was performed using biochemical testing and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Susceptibilities to appropriate panels of antimicrobials were determined by agar dilution.

Kawempe Hospital registered 34 517 births in the study period, of which 1717 (5.0%) were stillbirths. A total of 581 (33.8%) were recruited into the study, and heart blood aspirates were performed on 569 (97.9%). Blood samples were sufficient for analysis of 476, with a total of 108 positive cultures (22.7% of sampled stillbirths). Fifty-nine of 108 blood cultures contained organisms that were considered potential pathogens, giving a pathogen positivity rate of 12.4%. Common pathogens included Enterococcus spp. (n = 14), Escherichia coli (n = 13), viridans streptococci (n = 18), Klebsiella pneumoniae (n = 6), and group B Streptococcus (n = 5). Gram-negative organisms were frequently resistant to commonly used first-line antimicrobials.

The high proportion of stillbirths caused by likely pathogenic bacteria in Uganda highlights the potential for prevention with prophylaxis and stresses the need for further investment in this area.