Article Text
Abstract
Background Roughly 1.3 million infants are exposed and 150,000 newly diagnosed with Human Immunodeficiency Virus (HIV) annually. Estimates of Vertical HIV transmission (VHT) rates vary by setting. In this study, we assessed the risk factors for VHT among infants born to women living with HIV in Tanzania and Mozambique.
Methods Between October 2019 and August 2021, data was collected from pregnant women living with HIV who participated in the LIFE study [RIA2016MC] at 28 obstetric health facilities in Tanzania and Mozambique. VHT was assessed up to month 3 of age in all infants. At baseline, demographics and clinical characteristics were collected to assess risk factors for VHT. Mixed effects models adjusted for health facility clustering were used to calculate risk ratios.
Results In total, 6,509 women living with HIV and their 6,605 exposed infants were included in the study. VHT up to month 3 of life was 2.69% (95% CI: 2.21, 3.24) in Mozambique, significantly higher than the 0.62% (95% CI: 0.35, 1.00) observed in Tanzania (RR: 4.45, 95% CI: 2.63, 7.99). On average, Tanzanian women were significantly older, attended antenatal care more frequently, and had been on antiretroviral treatment for a longer period. After adjusting for these factors, virologic non-suppression at delivery was the principal risk factor for transmission (RR: 35.7, 95% CI: 19.2, 73.1). In Mozambique, 31.0% of all mothers were not suppressed at delivery compared to 8.1% in Tanzania; only 8.9% (11/124) infants who acquired HIV by month 3 had mothers who were virally suppressed at delivery.
Conclusion We observed a striking difference in VHT between countries. Lack of viral suppression at delivery was the main risk factor for VHT, highlighting the need for better understanding the individual, community, and health system factors associated with lack of viral suppression in pregnant and lactating women living with HIV.