A longitudinal analysis of the completeness of maternal HIV testing, including repeat testing, during pregnancy, and the predictors thereof, in Mitchell’s Plain, Cape Town

HIV testing during pregnancy is the gateway to the HIV-related services that are part of the prevention of mother-to-child transmission (PMTCT) cascade. The virtual elimination of vertical HIV transmission cannot be achieved without universal antenatal care (ANC) HIV testing. Furthermore, women are at an increased risk of HIV infection and subsequent mother-to-child transmission (MTCT) during pregnancy. Emphasis has thus been placed on repeat testing during pregnancy among women who have a HIV-negative result at their first ANC test. Very little has been published on the current uptake and adherence to antenatal and repeat HIV testing in sub-Saharan Africa (SSA) countries. In line with the World Health Organization Guidelines, the Western Cape Prevention of Mother-to-Child Transmission of HIV (PMTCT) Clinical Guidelines in 2014 recommended a repeat HIV test between 32 - 34 weeks gestation and again at delivery in addition to testing at “booking” (5 days before delivery with 98% testing completeness at “booking”. Only 49% of women eligible for testing “booked” ≤22 weeks gestation. Among women that “booked” ≤22 weeks gestation who weren’t diagnosed HIV-positive before delivery and delivered >5 days after the start of the third trimester, 10% received tests in all three recommended windows. Thirty-one percent of women that had not been diagnosed HIV-positive before delivery had an uncertain (i.e. last tested ≥3 months before delivery) or unknown (i.e. never tested) HIV status after delivery. Out of the women that had a known HIV status at delivery, 21% were HIV-positive of whom 95% were known HIV-positive before current pregnancy and 4% were diagnosed at “booking”. Overall, HIV incidence in those with ≥2 HIV tests during pregnancy/at delivery was estimated to be 0.2% between “booking” and delivery. Women who enrolled after 2014 were less likely to miss ≥1 of the three recommended tests (aOR: 0.70; CI: 0.55 - 0.90) and not test at delivery (aOR: 0.63; CI: 0.55 - 0.71) compared to those who enrolled in 2014. Conclusion: In our study, HIV testing completion at “booking” was high, but women tended to “book” late during pregnancy resulting in late initial testing and missed opportunities for early HIV diagnosis. Implementation of repeat HIV testing is poor, particularly at delivery. HIV incidence between first negative ANC test and delivery is very low and therefore future studies to assess the most cost-effective number and timing of HIV tests, and feasibility of implementation, should be considered. Overall, maternal HIV testing within the PMTCT programme in Cape Town has matured post 2014 with improved implementation over time