SARS-CoV-2 seropositivity in African women living with HIV and their infants

TL;DR

This study found that about 60% of HIV-positive mothers and 40% of their children in Africa had been infected with SARS-CoV-2 by late 2021, with breastfeeding and undetectable HIV viral load linked to infection risks.

Contribution

The study provides novel seropositivity data for SARS-CoV-2 in HIV-positive women and their infants in sub-Saharan Africa, highlighting risk factors like breastfeeding and maternal HIV control.

Findings

Maternal SARS-CoV-2 seropositivity was 60.1%, and children's was 41.5% in HIV-affected families in East/Southern Africa.

Non-breastfeeding mothers had a 31% higher risk of SARS-CoV-2 seropositivity compared to breastfeeding mothers.

Discordant serostatuses were observed in 43.1% of mother-infant pairs, suggesting varied household transmission dynamics.

Abstract

SARS-CoV-2 seropositivity data in women living with HIV (WLHIV), their infants and associated factors in this subpopulation remain limited. We retrospectively measured SARS-CoV-2 seropositivity from 07/2020-11/2021 among WLHIV and their children in the PROMOTE observational cohort in Uganda, Malawi, and Zimbabwe prior to widespread SARS-CoV-2 vaccination in those countries.

Plasma stored during 3 waves of the COVID-19 pandemic in East/Southern Africa were tested for SARS-CoV-2 specific IgG antibodies (Ab) using serological assays that detect adaptive immune responses to SARS-CoV-2 spike protein. (EUROIMMUN, Mountain Lakes, New Jersey and Roche Diagnostics, Indianapolis, IN). Modified-Poisson regression models were used to calculate prevalence rate ratios (PRR) and 95% confidence intervals (CI) to identify sociodemographic and clinical risk factors.

PROMOTE samples from 918 mothers and 1237 children were analysed. Overall, maternal SARS-CoV-2 seropositivity was 60.1% (95% CI: 56.9 -63.3) and 41.5% (95%CI: 38.8 – 44.2) for children. Non-breastfeeding mothers had a 31% higher risk of SARS-CoV-2 seropositivity compared to breastfeeding mothers (aPRR=1.31, 95%CI: 1.08-1.59). WLHIV with undetectable viral load had a 10% increased risk of SARS-CoV-2 seropositivity (aPRR=1.10, 95%CI: 0.89-1.37). Moreover, those who were normotensive had 12% increased risk SARS-CoV-2 seropositivity (aPRR= 1.12, 95% CI: 0.68-1.85) compared to women with hypertension. Children between 2 and 5 years had a 19% reduced risk of SARS-CoV-2 seropositivity (aPRR=0.81, 95%CI: 0.64-1.02) when compared to younger children. Mother/infant SARS-CoV-2 serostatuses were discordant in 346/802 (43.1%) families tested: mothers+/children- in 72.3%; mothers-/children+ in 26.3%; child+/sibling+ concordance was 34.6%.

These SARS-CoV-2 seropositivity data indicate that by late 2021, about 60% of mothers and about 40% of children in a cohort of HIV-affected families in eastern/southern Africa had been infected with SARS-CoV-2. More mothers than their infants tested SARS-CoV-2+, likely due to a greater external exposure for mothers linked to daily routines/employment, and school closures. Breastfeeding was protective for mothers, likely because of higher likelihood of staying home with young children, and thus less exposure. Discordant results between children within the same families underscores the need to further understand transmission dynamics within households.

The online version contains supplementary material available at 10.1186/s12879-024-09591-8.

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