South Africa is facing a devastating HIV pandemic, with nearly 5 million individuals or 16.2% of the population between the ages of 15 and 49 years currently HIV infected . Reducing unprotected sex, partly by linking HIV prevention with HIV clinical care, is recommended as a priority HIV/AIDS prevention strategy by the Joint UN Programme on HIV/AIDS , the World Health Organization  and the Global HIV Prevention Working Group .
Little is known about the incidence and behavioural predictors of HIV transmission among HIV-positive individuals in South Africa. Moreover, the few studies that have examined unprotected sex among HIV-positive individuals in South Africa have assessed it solely in relation to condom use or non-use at the last sexual encounter [1,5,6], which does not provide information about unprotected sex in terms of the numbers of unprotected sex events or the number of partners potentially exposed to HIV over meaningful intervals of time . With a national antiretroviral rollout underway in South Africa [8,9], comprehensive information about unprotected sexual behaviour among HIV-positive individuals on antiretroviral therapy is especially critical in order to know how to direct secondary prevention efforts .
The goals of the present study were to: (i) assess the incidence of unprotected vaginal and anal sex among South African HIV-positive individuals receiving clinical care; and (ii) examine whether levels of unprotected sex vary as a function of taking antiretroviral drugs, partner type, partner HIV serostatus, alcohol use during sex, and other demographic and behavioural variables.
Participants were 152 HIV-infected patients (69 men, 83 women) recruited in February 2005 while attending an urban hospital-based HIV clinic in KwaZulu-Natal, South Africa. Patients were new attendees referred by other hospitals and by word-of-mouth. Patients pay approximately US$25 a month for comprehensive care including antiretroviral drugs, which may limit generalizability to patients who attend free clinics. The average age was 34 years (SD 5.93) and 68% of patients were unemployed. Two patients declined to participate. Participant demographics appear in Table 1.
Structured individual interviews were conducted in isi-Zulu or English. Unprotected sex was assessed for each sexual partner in the preceding 3 months, with participants reporting the number of sexual events (vaginal, anal, and oral sex) with each partner, whether a condom was used for each sexual event, each partner's perceived HIV serostatus (HIV positive, HIV negative, or unknown), the partner type (steady or casual), and whether they had disclosed their HIV status to the partner . Yes–no questions assessed whether participants had disclosed their HIV status to someone outside of the clinic, and if they had been physically forced to have sex in the previous 3 months. Alcohol use during sex in the previous 3 months was assessed on a five-point scale with 1 = ‘never’ and 5 = ‘always’ .
A regression model was estimated using generalized estimating equations to account for repeated observations for those reporting more than one partner and specifying a Poisson distribution that is appropriate for count data [13–15]. The outcome was the number of unprotected vaginal or anal sex events. Data were analysed using SPSS version 11.5 (SPSS Inc., Chicago, Illinois, USA) and HLM version 6.02 (Scientific Software International Inc., Lincolnwood, Illinois, USA) for Windows.
Forty-seven per cent of the HIV-positive sample reported having vaginal or anal sex in the past 3 months for a total of 676 vaginal and 12 anal sex events, whereas only 3% reported having oral sex for a total of 17 oral sex events. Of the sexually active patients (N = 71), 23 (30%) reported one or more unprotected vaginal or anal sex events for a total of 171 unprotected sex events in the previous 3 months with 27 different partners. Sixty-seven of the unprotected sex events (39.2%) were with partners perceived to be HIV negative or HIV status unknown, with a total of nine such partners potentially exposed to HIV. Only four sexually active participants (5.6%) reported having more than one sexual partner.
According to the generalized estimating equations model the following variables were associated with more unprotected sexual events: alcohol use during sex, forced sex, having an HIV-positive partner, and having a casual partner. Having disclosed one's HIV status to someone outside of the clinic was associated with fewer unprotected sexual events. Adjusted event rate ratios with confidence intervals and mean numbers of unprotected sexual events by sex based on these factors are presented in Table 1. There were no effects of sex, age, length of time since HIV diagnosis, ethnicity, socioeconomic status, employment, education level, taking antiretroviral drugs, reported sexually transmitted infection diagnosis in previous 3 months, or for disclosure of HIV status to the partner on levels of risk behaviour.
This study represents one of the first investigations of the incidence and correlates of unprotected sex in an HIV-positive clinical care population in South Africa and among those taking antiretroviral drugs. Not only is this study the first of its kind in South Africa, but it is one of only a small number of such studies in Africa.
The finding that those who reported recent forced sex had higher rates of unprotected sex is an important acknowledgement of the power dynamics and circumstances that might affect one's ability to practise safer behaviour [16,17], although perplexingly this finding did not differ by sex, which is consistent with our qualitative research findings. Contrary to speculation about the impact of antiretroviral drugs on unprotected sexual behaviour in sub-Saharan Africa , patients who reported taking antiretroviral drugs engaged in no more unprotected sex than those who were not taking antiretroviral drugs. Many of our patients had initiated antiretroviral therapy within the past 2 months, however, and it is unknown what the effect of antiretroviral drugs will be on patients' unprotected sexual behaviours longitudinally.
With a national antiretroviral rollout currently underway in South Africa, increasing numbers of HIV-positive individuals are entering clinical care [8,9], affording the opportunity to deliver HIV prevention interventions in this setting. This approach is advocated by international agencies [2–4,19] as an essential HIV prevention strategy because it takes advantage of the efficiencies and potential synergy of linking treatment and prevention.
The authors thank the participants in the study and the following individuals for their roles in the project: Linda Lodge, Aleeta Sabasaba, Monty Thomas, Musa Cele, and the clinic counsellors as well as Drs Helga Holst and Janet Giddy for their support of the project.
Sponsorship: This study was supported by the National Institutes of Mental Health (grant no. RO1 MH59473) and by a development grant from the Center for Health/HIV Intervention and Prevention at the University of Connecticut.
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