Zimbabwe Approaching Virtual Elimination of Mother-to-Child Transmission of HIV Following Implementation of Option A Raluca Buzdugan, Sandra I McCoy, Constancia Watadzaushe, Mi-Suk Kang Dufour, Maya Petersen, Jeffrey Dirawo, Angela Mushavi, Hilda Angela Mujuru, Agnes Mahomva, Barbara Engelsmann, Hakobyan Anna, Mugurungi Owen, Frances M Cowan, Nancy S Padian
PMTCT Effectiveness WHO guidelines for PMTCT in developing countries: – 2010: Option A, B – 2013: Option B+, B Important to assess the population-level effectiveness of the WHO guidelines
PMTCT in Zimbabwe 16% HIV prevalence in pregnant women (2012 sentinel data) 9,000 HIV infant infections in 2013 Option A rolled out in Aug-Dec 2011 – 1344 of the existing 1,560 health facilities – point-of-care CD4 testing machines – community mobilization Option B+ started in Nov 2013
Impact Evaluation of Option A in Zimbabwe Serial cross- sectional community-based serosurveys Pre-post design with the facility catchment area as unit of analysis: – Baseline – 2012, Endline Mashonaland West, 2. Mashonaland Central 3. Harare, 4. Matabeleland South, 5. Manicaland
Methods SAMPLING STRATEGY DATA COLLECTION METHODS OUTCOMES MEASURED 157 health facilities randomly selected from 5 of Zimbabwe’s 10 provinces Identified all eligible infants living in the catchment areas of these facilities (using a combination of methods) Selected a pre- determined fraction of all eligible mother- infant pairs and invited them to participate in the survey 9,087 mother- infant pairs at baseline (2012) 10,646 mother- infant pairs at endline (2014) - Facility questionnaire, head nurse - Questionnaire with mothers/ caregivers - Blood samples of living infants & mothers - Verbal autopsies of deceased mothers & infants STAGE I STAGE II Time of Option A rollout at facility-level - HIV free infant survival at 9-18 months -MTCT rate at 9-18 months
Methods Eligible women were ≥16 years old and biological mothers of infants (alive or deceased) born 9-18 months prior. The impact analysis was limited to 113 catchment areas unexposed to Option A activities at baseline according to facility records.
Methods HIV-free infant survival = proportion of infants born to HIV-infected mothers who were alive and HIV-uninfected at 9-18 months of age MTCT = proportion of infants born to HIV-infected mothers who were HIV-infected at 9-18 months We estimated the HIV-free infant survival and MTCT rate in each catchment area and compared the 2012 and 2014 estimates using a paired t-test.
Study Enrolment 2012 survey2014 survey Mother-infant pairs recruited9,08710,646 Overall response rate98.9%99% Mother-infant pairs with alive infants 9,01910,625 Mother-infant pairs with viable maternal blood specimens 8,5689,826 Questionnaires completed9,01810,637
Individual-level analyses 2012 survey (n=1065) 2014 survey (n=1316)
Individual-level analyses 2012 survey (n=1062) 2014 survey (n=1316)
Option A Impact In the 132 catchment areas where Option A was implemented after infants surveyed in 2012 were born (“catchment areas unexposed to Option A”): 5.5 percentage point (95% CI: 2.6, 8.5) mean increase in HIV-free infant survival (from 89.6% in 2012, p<0.001) 5.2 percentage point (95% CI: 2.2, 8.2) mean decrease in MTCT (from 10.0% in 2012, p<0.001) since the rollout of Option A
# of HIV+ infants and MTCT rate in 156 CAs
Definition and distribution of health facility catchment area priority levels Catchment Area Priority Level Definition*N (%) High ≥3 HIV+ infants 9-18 months of age and MTCT ≥10% 18 (11%) Medium 1-2 HIV+ infants 9-18 months of age or 0 ≤ MTCT <10% 33 (21%) Low No (0) HIV+ infants 9-18 months of age and MTCT = 0% 106 (68%)
Self-reported uptake of maternal ARV by CA priority level, Zimbabwe, 2014.
Comparing 2012 and 2014
Limitations Data were cross-sectional Data are not representative of all regions in Zimbabwe Many mothers were still breastfeeding at the time of survey (71% in 2012, 78% in 2014) Infant deaths may have been underreported Quasi experimental design
Conclusions Zimbabwe approaching virtual elimination of MTCT Substantial and statistically significant increase in HIV-free infant survival and decrease in MTCT at 9-18 months after Option A implementation Our community-based surveys included women who did not access health services
Acknowledgements Ministry of Health and Child Care EGPAF Zimbabwe Reuben Musarandega Funders: Children’s Investment Fund Foundation (CIFF) & the National Institutes of Heath. UC Berkeley Tyler Martz CeSHHAR Zimbabwe Survey team Study participants