Incidence and sociocultural influences on postnatal HIV transmission among HIV-exposed infants in Manyara Region, Tanzania: a convergent mixed-methods study
摘要
Despite substantial progress in the Prevention of Mother-to-Child Transmission (PMTCT) of HIV in Tanzania, new pediatric HIV infections continue to occur during the postnatal period. Understanding both the incidence of postnatal HIV transmission and contextual factors influencing PMTCT engagement is essential for achieving elimination targets.
MethodsThe quantitative component used routinely collected PMTCT data for HIV-exposed infants and their mothers enrolled in PMTCT services in Manyara Region, Tanzania, between January 2019 and October 2023. Data were extracted from the national Care and Treatment Clinic (CTC-3/Macro-3) database. Infants entered the cohort at their first documented negative early infant diagnosis (EID) test performed at ≤ 6 weeks of age and were followed until HIV infection, death, loss to follow-up, transfer out, or administrative censoring at 19 months. Incidence rates were calculated per 1000 person-months of follow-up. The qualitative component involved in-depth interviews with 26 mothers of HIV-exposed infants and five PMTCT healthcare providers. Data were analyzed thematically using NVivo 12.
ResultsAmong 670 HIV-exposed infants, 12 acquired HIV Infection during follow-up, corresponding to an incidence rate of 1.35 per 1,000 person-months and a cumulative incidence of 1.79%. Most infections occurred between 3 and 15 months postpartum. Higher incidence rates were observed among infants exposed to mixed feeding and among infants born to mothers with viral load ≥ 1,000 copies/mL at delivery. Qualitative findings identified four major themes influencing PMTCT engagement: (1) HIV-related stigma and non-disclosure affecting ART adherence, (2) cultural beliefs and family influences shaping infant feeding practices, (3) Structural barriers to PMTCT services access, including transport challenges and health system constraints, and (4) Peer support as a facilitator of adherence and retention in care.
ConclusionAlthough postnatal HIV transmission in Manyara Region was relatively low, transmission persisted during the breastfeeding period. Elevated maternal viral load, mixed feeding practices, and sociocultural, behavioural, and structural barriers may contribute to ongoing transmission risk by undermining optimal PMTCT engagement. Strengthening maternal viral load monitoring, promoting exclusive breastfeeding, expanding peer-support interventions, and addressing stigma and access barriers are critical for achieving sustained elimination of mother-to-child transmission.