Missed PrEP opportunities and vulnerability to HIV during rifampicin-resistant tuberculosis treatment in South Africa

Background: Adults receiving rifampicin-resistant TB (RR-TB) treatment have prolonged engagement with the health system, yet healthcare professionals frequently miss opportunities to promote HIV prevention-particularly pre-exposure prophylaxis (PrEP)-in high-burden settings. We examined HIV vulnerability, PrEP awareness and uptake, and HIV and sexually transmitted infection (STI) incidence among HIV-negative adults receiving RR-TB treatment. Methods: We conducted an exploratory analysis within the BringBPaL2Me (BB2) Trial across two South African provinces. HIV-negative adults who had a BB2 study outcome within the first 24 months of the trial were included. Sexual risk indicators, HIV testing, and PrEP outcomes were assessed longitudinally. HIV and STI incidence rates were calculated per 100 person-years with exact Poisson 95% confidence intervals. Results: Among 288 participants (mean age 38.0 years; 72.9% male), HIV vulnerability was prevalent, with 45.8% reporting condomless sex and 5.9% empirically treated for an STI at enrollment. Forty-two percent were aware of PrEP; 60.8% were offered PrEP, yet only 10.1% initiated PrEP. Over 110.7 person-years of follow-up, six incident HIV infections occurred (5.42 per 100 person-years; 95% CI: 1.99-11.80) and empiric treatment for an STI resulted in an STI incidence of 9.66 per 100 person-years (95% CI: 4.99-16.88). Conclusion: HIV-negative adults receiving RR-TB care experience substantial and ongoing HIV risk, yet uptake of biomedical prevention remains limited. Strengthening integration of HIV prevention within TB services represents a critical opportunity to advance sexual health and reduce HIV incidence in high-risk, underserved populations.