High Burden of STIs Among HIV-infected Adults Prior to Initiation of ART in South Africa: a Retrospective Cohort Study

Objectives: To assess the burden of sexually transmitted infections (STIs) among HIV-positive South Africans in the period prior to antiretroviral therapy (ART) initiation compared with the period once on ART.

Methods: We linked the clinic records of 1465 patients currently on ART to the electronic database which records all visits to city clinics. We used a mixed effects Poisson model to assess the relative rates of occurrence of treatment seeking for an STI in the periods prior to initiation of ART and while on ART.

Results: We accumulated 4214 person-years of follow-up, divided nearly equally between the pre-ART and on-ART periods. The rate of treatment seeking for new STIs was 5.50 (95% CI 5.43 to 5.78) per 100 person-years, and individuals had on average a sevenfold higher rate of seeking treatment for STIs in the period prior to initiating ART (9.57 per 100 person-years) compared with the period once on ART (5.5 per 100 person-years) (adjusted rate ratio (RR) 7.01, 95% CI 4.64 to 10.59). Being male (RR 1.73, 95% CI 1.18 to 2.55) or younger (age <25) (RR 2.67, 95% CI 1.53 to 4.65) was associated with higher incidence of clinic visits for STI treatment, while advanced stage of HIV disease (WHO stage 4) (RR 0.33, 95% CI 0.15 to 0.69) was associated with lower incidence.

Conclusions: The period prior to the initiation of ART is a critical period where increased attention should be focused on the detection and treatment of STIs. A successful effort to treat STIs in this period will likely reduce further HIV transmission and fits within a test-and-treat approach.