Browsing by Author "Gouws, Eleanor."

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Early sexual debut among young men in rural South Africa: heightened vulnerability to sexual risk?
(BMJ publishing group., 2005) Harrison, Abigail.; Cleland, J.; Gouws, Eleanor.; Fröhlich, Janet Ann.
Objective: This report examines early sexual debut (3 partners in the past 3 years (OR = 10.26, p<0.01). Conclusions: Men who initiate sex before age 15 form a distinct risk group in this setting. Specific interventions are needed for young men in the preteen years, before sexual debut.
Epidemiological impact of Tenofovir gel on the HIV epidemic in South Africa.
(Lippincott Williams & Wilkins., 2011) Williams, Brian G.; Abdool Karim, Salim Safurdeen.; Abdool Karim, Quarraisha.; Gouws, Eleanor.
Background: Tenofovir gel, an antiretroviral-based vaginal microbicide, reduced HIV acquisition by 39% in women in a recent randomized controlled clinical trial in South Africa. Methods: To inform policy, we used a dynamical model of HIV transmission, calibrated to the epidemic in South Africa, to determine the population-level impact of this microbicide on HIV incidence, prevalence, and deaths and to evaluate its cost-effectiveness. Results: If women use tenofovir gel in 80% or more of sexual encounters (high coverage), it could avert 2.33 (0.12 to 4.63) million new infections and save 1.30 (0.07 to 2.42) million lives and if used in 25% of sexual encounters (low coverage), it could avert 0.50 (0.04 to 0.77) million new infections and save 0.29 (0.02 to 0.44) million deaths, over the next 20 years. At US $0.50 per application, the cost per infection averted at low coverage is US $2392 (US $562 to US $4222) and the cost per disability-adjusted life year saved is US $104 (US $27 to US $181); at high coverage the costs are about 30% less. Conclusions: Over 20 years, the use of tenofovir gel in South Africa could avert up to 2 million new infections and 1 million AIDS deaths. Even with low rates of gel use, it is highly cost-effective and compares favorably with other control methods. This female-controlled prevention method could have a significant impact on the epidemic of HIV in South Africa. Programs should aim to achieve gel use in more than 25% of sexual encounters to significantly alter the course of the epidemic.
Global epidemiology of HIV-AIDS.
(WB Saunders., 2007) Abdool Karim, Salim Safurdeen.; Abdool Karim, Quarraisha.; Gouws, Eleanor.; Baxter, Cheryl.
HIV, the cause of AIDS, has in the 25 years since its discovery spread rapidly to every region in the world [1]. To date, more than 65 million people have been infected with HIV and about 25 million people have died from AIDS [1]. In the current decade of the epidemic, there has been a substantial increase in HIV infection in women, and about 40% of all new infections among adults occurred in young people 15 to 24 years of age. At the end of 2006 [2], the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimated that there were a total of 39.5 million (34.1–47.1 million) adults and children living with HIV. In 2006, a total of 4.3 million (3.6–6.6 million) new infections occurred and 2.9 million (2.5–3.5 million) people died from AIDS.
The impact of incident and prevalent herpes simplex virus-2 infection on the incidence of HIV-1 infection among commercial sex workers in South Africa.
(Lippincott Williams & Wilkins., 2004) Ramjee, Gita.; Williams, Brian G.; Gouws, Eleanor.; Van Dyck, Eddy.; De Deken, Benedicte.; Abdool Karim, Salim Safurdeen.
This study investigated the impact of prevalent and incident HSV-2 infection on the incidence of HIV-1 infection in a cohort of female commercial sex workers in KwaZulu-Natal, South Africa. Prior to a vaginal microbicide trial, 416 women were screened for antibodies to HIV-1 and herpes simplex virus-2 (HSV-2) infections and a questionnaire was used to establish behavioral, social, and demographic characteristics. A total of 187 HIV-1-seronegative women were followed up at monthly intervals when blood was drawn and used to detect HIV-1 and HSV-2 antibodies. The median duration of follow-up was 2.2 years. At screening 50% of the women were HIV-1 seropositive and 84% were HSV-2 seropositive. The hazards of HIV-1 among women who were HSV-2 seropositive or seronegative throughout, or among those who seroconverted during the study, were not significantly different. When HSV-2 seroconversion was analyzed as a time-dependent covariate, the hazard ratio for HIV-1 seroconversion was 6.0 (95% CI: 2.6–14.0) times greater among women with incident than among women with prevalent HSV-2 infections. Drawing on other recent studies these data suggest that incident HSV-2 infection increases the risk of HIV-1 infection; the effect wanes with time since infection; and the effect is significantly greater for men than it is for women.
Incidence of HIV infection in rural KwaZulu-Natal in the context of the epidemiology and impact of HIV/AIDS in South Africa.
(2007) Gouws, Eleanor.; Abdool Karim, Salim Safurdeen.; Jinabhai, Champaklal Chhaganlal.
South Africa has had one of the fastest growing HIV epidemics in the world and almost 30% of women attending public antenatal clinics (ANC) are currently infected with the virus. But as the epidemic is starting to level off and antiretroviral therapy (ART) is becoming increasingly available, few methods exist to determine the impact of ART or other interventions on the epidemic in South Africa. This thesis explores the epidemiology and dynamics of HIV infection and investigates the potential impact of ART. Methods Total and age-specific prevalence data are analysed in time and space and are used to investigate patterns of infection in men and women, urban and rural, and low and high risk populations. Dynamical models are developed to estimate incidence from age-specific prevalence and trends over time and are compared to laboratory-based estimates of recent HIV sero-conversion. Incidence is estimated in different populations in South Africa. A dynamical model is developed to estimate the impact of ART on the future course of the HIV epidemic. Results HIV prevalence varies geographically and by age, sex and race. The average female-tomale HIV prevalence ratio is 1.7 and prevalence peaks at an older age among men than women. The age at which prevalence peaks among women has increased from 23.0 to 26.5 years between 1995 and 2002. Four patterns of infection are identified: among pregnant women attending ANCs, among men and women in the general population, and among migrant workers. HIV incidence among ANC attendees peaked in the mid to late 1990s (at 6.6% per year nationally) with variation between provinces. Current estimates of HIV prevalence and incidence among the general population in South Africa (aged 15-49 year) are 18.8% and 2.4% per year, respectively. Age-specific incidence estimates from dynamical models and laboratory methods are in good agreement provided the window period for the laboratory method is increased. Over the next ten years the provision of ART could avert 1 to 1.5 million deaths depending on whether it is provided when the CD4 cell count falls to 200 or 350 cells/ul. By 2015 about 1.1 million people will be receiving ART but this will have little impact on the incidence of HIV and scaling up of prevention efforts remains urgent. Conclusions The thesis explores some of the determinants and patterns of HIV prevalence and incidence in South Africa in order to find better ways to manage the epidemic of HIV, monitor changes and evaluate progress in control efforts. In order to fight the epidemic we need to mobilize the best possible science in support of those people and communities affected by the epidemic.