Background: Ensuring HIV testing for pregnant and ^{breastfeeding} women at points along the prevention of mother-to-child (PMTCT) cascade is of critical importance. In Swaziland, which has a national HIV prevalence and incidence among women aged 15+ of 32.5% and 1.7% respectively, national guidelines require retesting for HIV-negative pregnant women every 2 months. Understanding the frequency of seroconversion in this population is also important, as incident infections in pregnant women pose substantial risk for transmission to the child. We describe the proportions of pregnant women in Manzini Region, Swaziland, who tested positive after initial negative HIV test.
Methods: All HIV negative pregnant/lactating women are to be retested every 8 weeks during their antenatal/postnatal visits. We analyzed aggregate PMTCT data routinely reported to the Swaziland Ministry of Health between January 2016-September 2017. We examined the numbers of women newly attending ANC, with a known HIV status at first visit, completing HIV retesting in ANC or at delivery in the maternity, and the numbers testing HIV-positive at first visit or during retesting.
Results: Of the 17,739 pregnant women newly attending ANC during the period, 98% (17,384) were tested and/or had a known HIV + status including 4,132 (24%) who were already known to be HIV-positive and 1,945 (11%) who newly tested HIV positive. Of the 10,588 women that tested HIV-negative at first ANC visit, 9439 (89 %) women were retested during their ANC visits and 1149 (11 %) at delivery. Among women retested in ANC, 178 (1.9%) tested HIV-positive; in maternity, 27 (2.3%) tested HIV-positive.
Conclusions: In Swaziland, high numbers of pregnant women who test HIV negative on initial visits test HIV positive on repeat testing possibly representing acute infection and/or false negatives during initial testing. The maternal seroconversion can contribute significantly to the pediatric HIV burden, and needs attention as the country seeks to avert new HIV infections. In view of this and considering the limitations of aggregate data, further study is required to validate the findings. It is critical to continue supporting HIV prevention services including PrEP in pregnant women.