Incidence rate of sexually transmitted infections among HIV infected patients on long-term ART in an urban and a rural clinic in Uganda.

backgroundHIV immunosuppression increases susceptibility to other STIs and STIs can enhance HIV transmission, reduce CD4 cell count and increase viral load. Co-infections of HIV and STIs may thus reduce the preventive benefits of ART. Little is known about the incidence rate of STIs among long-term patients on ART.

methodWe conducted a secondary data analysis of all patients enrolled in a rural and an urban longitudinal cohort studies who initiated ART between April 2003 and July 2007 followed up to 2016. Patients were screened for STI every three months using "a syndromic and case management approaches". STI incidence rate, was defined as the number of new cases per population at risk over the follow-up review period. We performed a time-to-event and Kaplan Meier analysis. We used a multivariable Cox proportional hazards regression model to assess for factors associated with STI incidence.

resultOf 1012 participants, 402 (39.8%) were urban and 610 (60.2%) rural residents. Mean age was 42.8 years (SD 8.5). The total number of follow up time was 44,304 person years. We observed STI incidence rate of 2.1 per 1000 person-years after follow-up. Rural residence (adjusted hazard ratio [aHR] 3.53, 95% CI: 1.95-6.39), younger age (aHR 2.05, 95% CI: 1.02-4.12 for 18-34 years and aHR 1.65, 95% CI: 1.00-2.72 for 35-44 years) were factors associated with higher incidence of STIs. Being male (aHR 0.51, 95% CI: 0.27-0.93) was associated with a lower incidence of STIs.

conclusionWe found STIs incidence rate of approximately 3 per 1000 person-years among patients on long-term (≥ 4 years) ART followed up-to 3.5 years. Rural and younger persons on ART should be routinely screened for STIs because high incidence of STIs may undo the preventative effects of ART for all.