The HIV incidence rate measured among pregnant women in this study is lower that measured among pregnant women in other sub-Saharan African settings,(7) but similar to other estimates of HIV incidence among members of the Botswana general population.(16) A systematic review of pregnant women in sub-Saharan African settings measured a pooled HIV incidence rate of 47 per 1,000 person-years.(7) While this estimate may be higher than that measured in our study (8 per 1,000 person-years), the review included sub-Saharan African countries that, relative to Botswana, are often in different HIV epidemic stages (17) and generally have achieved fewer HIV programmatic accomplishments (e.g., levels of HIV testing and treatment coverage).(18) Meanwhile, the control arm of a large community randomized trial testing the universal test and treat strategy in Botswana – i.e., the Ya Tsie trial or Botswana Combination Prevention Program (BCPP) – measured from 2013–2018 an HIV incidence (9 per 1,000 person-years) similar to that in our study.(16) Considering the existing levels of population HIV prevalence in Botswana (20%) (10) and the country’s many HIV programmatic accomplishments, the measures of HIV incidence in our study and the Ya Tsie trial are high and remain above levels of HIV epidemic control (≤ 1 per 1,000 person-years).(19)
The high levels of HIV incidence among pregnant women, measured using routine programmatic data in this study, suggest that routine HIV testing paired with primary HIV prevention interventions remain critical components of ANC programs in high HIV prevalence settings. Programs for condom distribution (20) and behavioral change interventions,(21) initiation of PrEP,(22,23) or secondary distribution of HIV self-tests (14) paired with HIV testing at ANC clinics may improve the lives of pregnant women and reduce perinatal HIV transmission. Additionally, the data from this study suggests that prioritizing older women and women who are not citizens of Botswana for HIV prevention programs might help further improve women’s health and prevent perinatal HIV transmission in Botswana.
This study has a number of strengths. This is the first evaluation to use programmatic data to measure HIV incidence within a HIV high-prevalence setting. Lately, there has been a call to utilize the rich health information systems in low-income, HIV prevalence settings to answer these types of research questions instead of building resource-intensive cohort studies for this purpose.(8) Using programmatic data to inform implementation of HIV prevention efforts is advantageous because the data are readily available (with limited additional costs for analysis) and can be analyzed as programs are ongoing to inform real-time implementation.(8)
This study also has weaknesses that are important to note. For example, limited information were available on the demographics of the women who HIV tested (e.g., education, income) and no details were available on the ANC visit women attended (e.g., their first, second, or third visit), which made difficult to determine how far along women were in their pregnancy. Additionally, data were not available for ANC visits at facilities excluded from this assessment. To best measure previously undiagnosed HIV infection and seroconversion despite these challenges, we limited our sample to women who had not previously tested HIV-positive at their first observed visit, and only measured follow-up until the first time a woman re-tested following a previous HIV-negative diagnosis. If our sample captured numerous women at their last ANC visit, we likely underestimated the prevalence of HIV re-testing in this population. Our sample also only included pregnant women who HIV tested at ANC clinics, and thus our estimates of previously undiagnosed HIV infection and HIV incidence may not be generalizable to pregnant women in this setting that do not engage in ANC. However, few women in Botswana do not engage in ANC.(24)