AEGiS-14IAC: Assessing the Importance of HIV Prevalence in Risk Prevention: An application of the Bernoulli Process Model of HIV infection.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Assessing the Importance of HIV Prevalence in Risk Prevention: An application of the Bernoulli Process Model of HIV infection.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10071)

Sarr M
Westat, Inc, Rockville, MD, United States

BACKGROUND: To assess the importance of HIV prevalence as a determinant of HIV risk for individuals engaged in long-term monogamous relationship with a partner with an unknown HIV status.

METHODS: The Bernoulli model of HIV transmission has been utilized to compute the risk of HIV infection. According to this model, the probability of HIV infection is determined by the total number of sexual acts, the prevalence of HIV infection in the population, the presumed infectivity of HIV per sexual act, and the number of partners. We assumed in our models that all individuals are involved in a long-term monogamous relationship. The country specific prevalence rates, the HIV infectivity rate, the average frequency of sexual acts, and the effectiveness of condoms in preventing HIV transmission were obtained from a previously published studies and reports.

RESULTS: The individual risk estimates of HIV infection in a monogamous relationship of 10 year duration, with 100% unprotected vs. 100% protected sex were respectively 0.33% and 0.06% in Equatorial Guinea, 1.22% and 0.20% in Senegal, 4.45% and 0.71% in Burkina Faso, 7.06% and 1.19% in Cote d'Ivoire, 13.78% and 2.21% in South Africa and 24.74% and 3.97% in Botswana. The risk of 100% protected minus the risk of 100% unprotected sex (monogamous) during the same period were 0.3% in Equatorial Guinea, 1.03% in Senegal, 3.74% in Burkina Faso, 5.87% in Cote d'Ivoire, 11.57% in South Africa and 20.78% in Botswana.

CONCLUSION: If unprotected sex in a long term monogamous relationship with a partner with an unknown HIV status can be considered as "safe sex" in countries/areas with a low prevalence of HIV infection, in countries/areas with a high prevalence it is a high risk behavior. In areas of high prevalence knowing the HIV serostatus of a long-term monogamous partner prior to engaging in unprotected sexual relationships may be promoted as a risk reduction message.

Keywords: AEGIS, Prevalence, HIV Infections, HIV Seropositivity, Condoms, Safe Sex, Coitus, Probability, Burkina Faso, Cote d'Ivoire, Equatorial Guinea, Senegal, Botswana, South Africa, epidemiology, prevention & control

020707
A10071