HIV transmission risk behaviours among HIV-positive persons in serodiscordant relationships.

As many as one in three persons living with HIV-AIDS continue to practise unprotected sexual intercourse and these practices often occur with HIV-negative or unknown HIV serostatus (serodiscordant) partners. The current study examined the rates of HIV transmission risk behaviours in non-regular (e.g. casual) and regular (e.g. steady) serodiscordant relationships. HIV positive men (n = 269) and women (n = 114) responded to measures of demographic characteristics, health and mental health status, and sexual behaviours assessed in partner-by-partner interviews. 257 (67%) participants were sexually active in the preceding three months and 182 (71%) of the sexually active persons had engaged in vaginal or anal intercourse with serodiscordant partners. Comparisons of persons with non-regular (n = 97) and regular (n = 85) serodiscordant partners showed that overall rates of unprotected and protected intercourse were greater with regular partners than non-regular partners. Disclosure of HIV status to regular and non-regular serodiscordant partners did not appear to influence the pattern of results. Mathematical modelling showed that HIV transmission estimates over a one-year horizon were significantly greater for male regular partners of HIV-positive men than non-regular partners and there was a trend toward greater HIV transmission rates from HIV-positive men to their regular serodiscordant female partners compared to non-regular partners. Results suggest an urgent need for HIV transmission risk reduction interventions for HIV serodiscordant couples, particularly for couples in established, regular relationships.