Background
Women who acquire HIV during pregnancy are at increased risk for vertical HIV transmission. Major intervention efforts have sought to rapidly reduce HIV incidence in Botswana over the past decade. The Tsepamo Study captures data on ~70% of all deliveries in Botswana including HIV test dates and results during antenatal care. We assessed whether HIV incidence among pregnant women in Botswana is declining by comparing data collected 2017-2021 and 2022-2024.
Methods
We used data collected from women who gave birth at 16 public maternity wards. HIV seroconversion was measured as having an initial negative/indeterminate HIV test in pregnancy followed by a positive test during the same pregnancy or at delivery. To calculate the HIV incidence rate, seroconversion date was approximated as the mid-point between last negative/indeterminate test and first positive HIV test. Logistic regression was used to identify factors associated with incident HIV during pregnancy.
Results
Among 51,013 women who delivered September 2022-September 2024 and had an initial negative/indeterminate test in pregnancy, 45,110 (88%) had ≥2 known HIV test dates in the same pregnancy and were included in this analysis. There were 75 seroconversions (1.67/1000 pregnancies, 0.17%) among 45,110 women with ≥ 2 known HIV test dates during pregnancy, yielding an incidence rate of 0.43/100 person-years (38% lower than 0.69/100 person-years among women who delivered May 2017-August 2021). Infections were highest among the 20–24-year age group with an incidence rate of 0.61/100 person-years. Factors associated with greater risk for seroconversion during pregnancy included being aged 20-24 (unadjusted odds ratio [uOR] vs. age >35 = 3.09, 95% CI 1.09-8.79), being unmarried (uOR = 4.32: 95% CI 1.06-17.62), not having salaried/self-employment (uOR = 1.91, 95% CI 1.11-3.29) and having less than a tertiary level of education (uOR = 2.16, 95% CI 1.11-4.21). There were no significant differences in risk for seroconversion by geographic region or by urban vs. rural delivery site.
Conclusions
Compared with 2017-2021, the rate of seroconversions during pregnancy among pregnant women in Botswana between 2022-2024 has declined. However, HIV incidence remains high among younger women with less education and without salaried employment, presenting opportunities for targeted PrEP. Long-acting injectable options, which can prevent both maternal and subsequent infant infection, could strengthen HIV prevention efforts in this critical population.
Table or Figure
