Objective

Pregnant and postpartum women (PPW) in Southern Africa are at increased risk of acquiring HIV and curable sexually transmitted infections (STIs). Oral pre-exposure prophylaxis (PrEP) is safe and effective to use during pregnancy to reduce HIV acquisition and vertical transmission. Point-of-care (POC) STI testing can identify PPW at risk of HIV and facilitate risk-differentiated and person-centred counselling to improve PrEP initiation, persistence and adherence. We evaluated the impact of POC STI testing compared with STI syndromic management on PrEP outcomes among PPW in Cape Town, South Africa.

Methods

The STI and PrEP in Pregnancy Study enrolled PPW without HIV and ≤34 weeks pregnant at their regular antenatal care visit with follow-up after 1 month. PPW were randomised to receive POC STI testing or STI syndromic management. PPW randomised to POC STI testing self-collected vaginal swabs for Chlamydia trachomatis, Neisseria gonorhoeae and Trichomonas vaginalis (Cepheid GeneXpert) testing and were offered same-day treatment if diagnosed. We compared PrEP initiation at baseline, PrEP prescription refill at 1 month (persistence) and adherence through tenofovir-diphosphate detection in dried blood spots by randomisation arm. In a secondary analysis, we evaluated the association between an STI diagnosis (positive STI test or reporting STI symptoms) with PrEP outcomes.

Results

We enrolled and randomised 268 pregnant women. Twenty-eight per cent of women were diagnosed with ≥1 STI. Overall, 65% of women initiated and 79% persisted on PrEP with no significant differences by randomisation arm. Secondary analysis demonstrated that an STI diagnosis (positive STI test or reporting STI symptoms) was associated with higher PrEP initiation (adjusted relative risk=1.28; 95% CI 1.08 to 1.52), controlling for arm, maternal and gestational age.

Conclusions

POC STI testing was not associated with PrEP initiation or persistence relative to syndromic management. However, improving STI diagnosis by supplementing syndromic management with POC STI testing could improve PrEP initiation among PPW.

Trial registration number

NCT03902418; Clinical Trials.gov; 1 April 2019.

Background Preexposure prophylaxis (PrEP) programs present a platform for diagnostic sexually transmitted infection (STI) testing in low- and middle-income countries, and availability of targeted STI testing has been hypothesized to influence PrEP use. We evaluated the association of STI testing modality and PrEP uptake among pregnant women in antenatal care. Methods We enrolled pregnant, HIV-uninfected women (16 years or older) at their first antenatal visit with follow-up through 12 months postpartum. Women were offered oral PrEP and tested for Chlamydia trachomatis and Neisseria gonorrhoeae using a point-of-care (POC; Cepheid, August 2019-November 2020) or laboratory-based (Thermofisher, December 2020-October 2021) test. We compared the proportion of women initiating and continuing PrEP by STI test adjusting for confounders. Results We evaluated 1194 women (median age, 26 years [interquartile range, 22-31 years]) with an STI result (46% POC and 54% laboratory-based). The prevalence of any STI was the same in POC-tested (28%) and laboratory-tested (28%) women - 25% versus 23% for C. trachomatis (P = 0.35) and 7% versus 9% for N. gonorrhoeae (P = 0.11). Mean time from testing to result was 0 day for POC and 26 days for laboratory testing, and mean time from testing to treatment was 3 days for POC and 38 days for laboratory testing. Receiving a POC STI test was associated with higher PrEP initiation compared with women receiving a laboratory-based test (90% vs. 78%; adjusted odds ratio, 2.1; 95% confidence interval, 1.5-2.9), controlling for age, gravidity, STI diagnosis, intimate partner violence, gestational age, employment, HIV risk perception, and cohabiting status. Conclusions Point-of-care STI testing, offering same-day results and treatment initiation, may increase PrEP initiation among pregnant women in antenatal care.