Unprotected sex following HIV testing among women in Uganda and Zimbabwe: short- and long-term comparisons with pre-test behaviour.
Despite widespread condom promotion for HIV prevention, prospective measurement of condom use before and after HIV testing is infrequent. We analysed data from a prospective study of hormonal contraception and HIV acquisition among Zimbabwean and Ugandan women (1999-2004), in which HIV testing and counselling were performed approximately every 3 months. We used zero-inflated negative binomial (ZINB) models to examine the number and proportion of unprotected sex acts, comparing behaviour reported 2-6 months before HIV testing with behaviour reported both 2-6 months (short-term analysis) and 12-16 months (long-term analysis) after HIV testing. Short- and long-term analyses were similar, so we present only long-term findings from 151 HIV-infected and 650 uninfected participants. The proportion of HIV-infected women reporting any unprotected acts in a typical month declined from 74% (pre-infection behaviour) to 56% (12-16 months after HIV diagnosis). In multivariable models, HIV-infected women were twice as likely to report that all sex acts were protected by condoms after diagnosis compared with beforehand [adjusted odds ratio (aOR): 1.99, 95% confidence interval (CI): 1.12-3.53]; uninfected women were somewhat less likely to report that all acts were protected (aOR: 0.82, 95% CI: 0.64-1.04). HIV-infected women also reduced their number of unprotected acts by 38% (95% CI: -16 to -55%). However, their proportion of unprotected acts changed little (7% reduction, 95% CI: -18 to + 6%). Uninfected women reported little change in number or proportion of unprotected acts over the same time period. HIV-infected women reduced the number, but not the proportion, of unprotected acts. HIV-negative women did not increase condom use after testing and counselling, but neither did they decrease condom use, suggesting that testing negative was not interpreted as endorsement of risky behaviour.