Patients are seen every 3–6 months or as clinically indicated. YRG CARE has developed a voluntary counselling and testing

(VCT) programme for partners of HIV-infected individuals receiving care [27]. At the time of HIV VCT, each patient gave informed consent. All patients tested for HIV underwent pre- and post-test counselling. Data were collected under the approval of YRG CARE’s free-standing Institutional Review Board (IRB). This case–control study nested within a larger cohort of 2135 discordant couples included patients presenting consecutively with the HIV-infected partner RG 7204 (index patient) seeking care at YRGCARE between June 2006 and March 2008. Analyses were restricted to couples in whom one partner was infected with HIV and one partner was HIV negative (discordant) at enrolment and for whom there was at least 12 months of follow-up. The outcome variable was the couple’s HIV status (concordant

or discordant). Patients were encouraged to attend all clinic visits with their spouses. HIV-infected patients were interviewed separately Enzalutamide mouse without their spouses at the time of enrolment to care. A total of 2135 discordant couples enrolled in care during this time period amongst whom, 84.7% of the men and 58.6% of the women later initiated highly active antiretroviral therapy (HAART). Among these discordant couples at enrolment, 70 couples (3.3%) later seroconverted (concordant). Orotidine 5′-phosphate decarboxylase The current analyses were undertaken using a nested case–control model in which 167 discordant couples (controls) were matched to the 70 concordant couples

(cases) based on the median years of follow-up in care (1.7 years) of the 70 concordant couples. Both cases and controls had the same period of follow-up in clinical care based on matching; controls were sampled at the end of the follow-up period based on cumulative incidence sampling. Additional confounding variables between cases and controls were controlled in the multivariate logistic regression model. The following analyses were undertaken only among these 167 discordant controls and 70 concordant cases. After conducting baseline analyses at the time of enrolment to care, 12-month follow-up data are presented separately for cases in which HIV transmission was documented between enrolment and 6 months (N=52) and cases in which HIV transmission was documented between 6 and 12 months after enrolment (N=13). Two cases were in relationships in which the seronegative partner seroconverted after 730 days and thus these two cases are not included in this 12-month follow-up analysis. Both groups of cases (i.e. patients in which HIV transmission was documented between enrolment and 6 months and patients in which HIV transmission was documented between 6 and 12 months after enrolment) are compared with control patients who remained in discordant relationships (N=167).