HIV/AIDS and Other Sexually Transmitted Infections (STIs)

INTRODUCTION
RESEARCH

I. INTRODUCTION

The number of people in the world living with HIV has reached an estimated 42 million and is still growing with some 5 million new infections each year. An annual toll of 3 million deaths is rapidly increasing the ranks of the 20 million people who have already died of AIDS. In Africa, the most severely affected region, the estimated number of children orphaned by AIDS has exceeded 11 million and in the hardest hit countries more than one-third of young women are infected with the HIV virus.

Other sexually transmitted infections (STIs) also contribute to a widespread but largely unacknowledged epidemic with some 340 million new infections each year caused by microorganisms other than the HIV virus.

Because of the high prevalence of HIV and other STIs, and the seriousness of the diseases they cause, research to improve the efficiency and effectiveness of control measures is urgent. The difficulty and cost of treating STIs, and the fact that some STIs, especially HIV infections, are not curable, places a great premium on prevention.

II. RESEARCH

II.A. Background

Because the risk of sexually transmitted diseases is so intimately conditioned by behavior, studies go beyond the search for disease prevention technology. They address relevant economic, social and cultural issues such as community level education and women’s equality and autonomy in making decisions about their sexual behavior.

The majority of new infections in developing countries are transmitted through heterosexual contact. A common pattern of transmission of HIV and other STIs in developing countries is from commercial sex workers to their male clients and in turn to their girlfriends and wives. Although the male latex condom is an effective way to prevent STI transmission, its use requires male cooperation. Many women in all settings, but especially in developing countries, are not in a position to successfully negotiate condom use. This has led to two of the major goals: to develop simple “woman-controlled” technologies that would allow women to protect themselves against STI transmission and research to better understand the cultural, educational, economic and gender related power correlates of high-risk behavior and to test intervention strategies that decrease the risk of contracting sexually transmitted diseases.

II.B. Projects in Africa

II.B.i. Preventing HIV Infection by Protecting the Cervix

A study is being carried out in Zimbabwe and South Africa to determine if protecting the cervix with an inexpensive reusable contraceptive diaphragm is safe and effective as a women-controlled HIV preventive. With funding from the Gates Foundation, the randomized, controlled trial will be carried out among 4,500 women in Zimbabwe and South Africa. This study was preceded by a study that demonstrated that the diaphragm was highly acceptable to Zimbabwean women.

A Safety Trial of the Diaphragm and Microbicide in Zimbabwe

With funding from Contraceptive Research and Development (CONRAD), a safety trial of the diaphragm and a microbicide is also being carried out in Zimbabwe. The purpose of the study is to see if prolonged use of a chemical, sodium cellulose sulfate (CS), (an antifertility agent with a broad spectrum of antimicrobial activity) can be used safely when combined with a mechanical barrier to the cervix. This study is a necessary step prior to testing the efficacy of protecting the cervix, the likely entry point for many HIV infections, with a diaphragm combined with CS as a preventive measure to HIV transmission.

II.B.ii. The HIV Prevention Trials Network

Zimbabwe is the site of an HIV Prevention Trials Network funded by the National Institutes of Allergies and Infectious Disease. The network is a worldwide collaborative research program with more than two-dozen international sites partnered with WGHI and two other US based institutions that develop and test the safety and efficacy of interventions designed to prevent the transmission of HIV.

WGHI is currently conducting the following projects through the HIV Prevention Trials Network:

Condom Promotion: Because women often have difficulty negotiating condom use, the study seeks to identify and test condom promotion and counseling techniques. The study will evaluate the effect of promoting condoms to men by measuring the acceptability and consistency of condom use and pregnancy rates. Another study was conducted to estimate the prevalence and incidence of genital herpes, an infection that increases susceptibility to HIV infections, evaluate the interaction between herpes and HIV, and measure the effect of condom use on the prevention of genital herpes.

Effectiveness of vaginal microbicides: This study will determine the effectiveness of two novel vaginal microbicides, BufferGel and Pro2000, on the prevention of HIV.

Treating herpes to prevent HIV: Herpes Simplex virus 2 (HSV-2) infection, is the most common cause of genital ulcer disease, is one of the most prevalent sexually transmitted infections in Zimbabwe. Considerable data suggests that having genital herpes increases the risk for HIV acquisition and transmission, and having HIV increases susceptibility to HSV-2. The study will determine the effectiveness of providing suppressive herpes treatment on the prevention of HIV acquisition.

Treating HIV to prevent further transmission: Antiretroviral therapy is widely available in developed countries, and is now being introduced into many developing countries. The purpose of this study is to determine whether antiretroviral therapy can reduce or prevent sexual transmission of HIV among couples where one person is not infected with HIV.

Nevirapine to prevent mother-to-child transmission: This study will evaluate the effectiveness of an extended regimen of Nevirapine on prevention of HIV when given to infants who are born to HIV infected women.

II.B.iii. Economic Opportunity for Zimbabwean Female Adolescent Orphans

With funds provided by the National Institute of Child Health and Development, this study is testing weather an economic and life-skills intervention designed to increase control over sexual interactions prevents the adverse consequences of unprotected sex among out-of-school female orphans aged 16-19 in Zimbabwe. The intervention consists of an integrated micro-credit program, including entrepreneurial training, loan provision, practical business education, mentorship, and peer support groups. This will be combined with a previously-tested life-skills education curriculum that delivers HIV/reproductive health education through the use of role playing, drawing exercises, and other techniques, to help participants negotiate the terms of their sexual relationships. Although there is great potential for such combined economic and life-skills programs to improve the reproductive health of female adolescent orphans, no research to date has assessed the effect of such interventions on sexual risk behaviors,acquisition of HIV and other sexually transmitted infections and on unintended pregnancy.

II.B.iv. Adolescent Livelihoods

Funded by the National Institute of Child Health and Development and the National Institute of Mental Health, this research program in Zimbabwe will develop and evaluate economic and educational interventions to bolster women’s economic power and reduce their dependence on male partners for survival, thereby reducing risk of HIV infection, other STIs, and unintended pregnancy. Because of poverty and gender inequities, many adolescent girls and young women trade sex for survival needs, such as food, rent, living expenses, material goods, school fees etc. This “sugar daddy” phenomenon is widely thought to be a major risk factor contributing to the high incidence of HIV among African girls and women. Dependence on older male partners limits women’s power to control when, with whom, and under what circumstances they have sex, or whether protection is used.

II.B.v. Hormonal contraception and risk for HIV acquisition

With support from the National Institute for Child Health and Development, this study will measure the effect of various hormonal contraceptives on HIV susceptibility in Zimbabwe. This study is part of a multi-site prospective cohort study in Uganda, Thailand, and Zimbabwe and will follow 6360 women over a 15-month period.

Five ancillary studies are being conducted in conjunction with this trial, including a randomized, crossover reliability study of ACASI data, a study looking at the relationship between contraceptive practices and bacterial vaginosis, a study examining the relationship between contraceptive practices, HIV and HSV-2, a longitudinal observational study of the effect of hormonal contraception on HIV genital shedding among women with primary HIV infection, and an observational study to determine the prevalence of HIV-related oral disease and the virus that causes kaposi sarcoma (HHV8).

II.C. Projects in Asia

II.C.i. Adolescent Livelihoods

As in Africa, Indian women typically have little access to economic resources, and are forced into a dependence on male partners for economic survival. This limits their ability to negotiate within sexual relationships, and to control when, how, and under what circumstances they have sex, and whether protection is used. However the various forms of “transactional sex” in India are not well understood. This study, in Bangalore, seeks to develop interventions to bolster adolescent girls’ socio-economic status as a means to reduce dependence on male partners and susceptibility to HIV and STIs

II.C.ii. Gender, Power, Susceptibility to HIV/STIs

Funded by the National Institute of Mental Health/ National Institute of Child Health and Development, this study seeks to characterize the nature of gender-based power and its association with HIV and other STIs among married women and their husbands in Bangalore, India. Women’s disempowered status relative to men is considered to be a risk factor for HIV and other STIs and an important cause of women’s poor reproductive health in India. Gender-based power (measured in terms of women’s access to resources and agency to make decisions) affects women’s susceptibility in a number of ways, including by limiting women’s access to information and reproductive health technologies and by limiting women’s power to negotiate when and how they have sex.

II.E. Projects in the United States

II.E.i. STI Risk and Latino Adolescents’ Sexual Networks

Latino adolescents in San Francisco’s Mission District are disproportionately at risk for sexually transmitted infections and unintended pregnancies. This study, supported by the National Institute of Allergy and Infectious Disease, seeks to examine Latino adolescents’ sexual networks and to determine the relationship between network membership and adverse reproductive health outcomes.