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Updated: May 19, 2026

Ex vivo Culture of Human Placental Explants for the Study of Viral Transmission Across the Maternal-Fetal Interface
Published on: December 30, 2025
Maternal HIV infection and vertical transmission of pathogenic bacteria
Clare L Cutland1, Stephanie J Schrag, Elizabeth R Zell
1Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases & Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Soweto, South Africa.
Background:
HIV-exposed newborns may be at higher risk of sepsis because of immune system aberrations, impaired maternal antibody transfer and altered exposure to pathogenic bacteria.
Methods:
We performed a secondary analysis of a study (clinicaltrials.gov, number NCT00136370) conducted between April 2004 and October 2007 in South Africa. We used propensity score matching to evaluate the association between maternal HIV infection and (1) vaginal colonization with bacterial pathogens; (2) vertical transmission of pathogens to the newborn; and (3) sepsis within 3 days of birth (EOS) or between 4-28 days of life (LOS).
Results:
Colonization with group B Streptococcus (17% vs 23%, P = .0002), Escherichia coli (47% vs 45%, P = .374), and Klebsiella pneumoniae (7% vs 10%, P = .008) differed modestly between HIV-infected and uninfected women, as did vertical transmission rates. Maternal HIV infection was not associated with increased risk of neonatal EOS or LOS, although culture-confirmed EOS was >3 times higher among HIV-exposed infants (P = .05). When compared with HIV-unexposed, neonates, HIV-exposed, uninfected neonates (HEU) had a lower risk of EOS (20.6 vs 33.7 per 1000 births; P = .046) and similar rate of LOS (5.8 vs 4.1; P = .563). HIV-infected newborns had a higher risk than HEU of EOS (134 vs 21.5; P < .0001) and LOS (26.8 vs 5.6; P = .042).
Conclusions:
Maternal HIV infection was not associated with increased risk of maternal bacterial colonization, vertical transmission, EOS, or LOS. HIV-infected neonates, however, were at increased risk of EOS and LOS.
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