Use of Data from Various Sources to Evaluate and Improve the Prevention of Mother-to-child Transmission of HIV Programme in Zimbabwe: a Data Integration Exercise

Introduction: Despite improvements in prevention of mother-to-child transmission (PMTCT) of HIV outcomes, there remain unacceptably high numbers of mother-to-child transmissions (MTCT) of HIV. Programmes and research collect multiple sources of PMTCT data, yet this data is rarely integrated in a systematic way. We conducted a data integration exercise to evaluate the Zimbabwe national PMTCT programme and derive lessons for strengthening implementation and documentation.

Methods: We used data from four sources: research, Ministry of Health and Child Care (MOHCC) programme, Implementer - Organization for Public Health Interventions and Development, and modelling. Research data came from serial population representative cross-sectional surveys that evaluated the national PMTCT programme in 2012, 2014 and 2017/2018. MOHCC and Organization for Public Health Interventions and Development collected data with similar indicators for the period 2018 to 2019. Modelling data from 2017/18 UNAIDS Spectrum was used. We systematically integrated data from the different sources to explore PMTCT programme performance at each step of the cascade. We also conducted spatial analysis to identify hotspots of MTCT.

Results: We developed cascades for HIV-positive and negative-mothers, and HIV exposed and infected infants to 24 months post-partum. Most data were available on HIV positive mothers. Few data were available 6-8 weeks post-delivery for HIV exposed/infected infants and none were available post-delivery for HIV-negative mothers. The different data sources largely concurred. Antenatal care (ANC) registration was high, although women often presented late. There was variable implementation of PMTCT services, MTCT hotspots were identified. Factors positively associated with MTCT included delayed ANC registration and mobility (use of more than one health facility) during pregnancy/breastfeeding. There was reduced MTCT among women whose partners accompanied them to ANC, and infants receiving antiretroviral prophylaxis. Notably, the largest contribution to MTCT was from postnatal women who had previously tested negative (12/25 in survey data, 17.6% estimated by Spectrum modelling). Data integration enabled formulation of interventions to improve programmes.

Conclusions: Data integration was feasible and identified gaps in programme implementation/documentation leading to corrective interventions. Incident infections among mothers are the largest contributors to MTCT: there is need to strengthen the prevention cascade among HIV-negative women.