Research Offers Best Promise for Female-Controlled HIV Prevention

Women account for an increasing proportion of newly reported AIDS cases in the United States. The proportion of female adult and adolescent AIDS cases increased from 7% of the annual total in 1985 to 19% in 1995. Overall, estimated AIDS incidence is increasing most rapidly among people infected heterosexually. Between 1993 and 1994, heterosexually-acquired AIDS incidence increased 17%. During that time, the annual rate of increase among men actually slowed, to 5%. But the annual rate of increase among women was 10%.

Trends like this point to the ongoing importance of female-controlled HIV protection. CDC researchers are working with scientists worldwide to evaluate the effectiveness of female condoms and to develop effective topical microbicides that can kill HIV and the pathogens that cause other STDs. As with any new tool for prevention, scientists must also determine what influences people's willingness and ability to use these methods. CDC behavioral scientists are simultaneously working to evaluate the factors that will contribute to women's use of these products and how these new prevention methods can and should be balanced with existing prevention options.

Biomedical and Behavioral Research: Prevention Building Blocks

CDC has a broad array of behavioral and biomedical research on determinants of transmission of HIV and STD in women and prevention methods. Among the biomedical research being conducted are studies that examine:

• HIV in cell-free and cell-associated cervicovaginal secretions
• HIV infectivity by contraceptive method
• Clinical trials of microbicide-containing gel
• Risk factors for cervicovaginal HIV shedding and the effect of STD treatment on shedding
• The efficacy of the female condom
• Natural history of HIV disease in women

Behavioral researchers are seeking to better understand the social and individual factors that influence women's sexual risk behaviors, and thus how to best design and deliver community-wide interventions that advance women along the continuum of behavior change. Research topics include:

• Determinants of female condom use
• The effectiveness of hierarchical prevention messages for women of color (African-Americans and Latinas) within a framework of prevention choices, from safest (abstinence) to safer (using a condom with sexual partners) to less safe (using spermicide only)
• How socially disadvantaged women communicate about sex and sexual risk reduction, and how that affects their acceptance, short-term use, and personal and partner reactions to the female condom
• Acceptability of nonoxynol-9 to women
• Women's preferences among spermicide formulations (film, foam, suppositories, tablets, jelly)

A Closer Look at Topical Microbicide Research

Microbicides are chemical compounds that can kill HIV and other sexually transmitted pathogens, such as herpes, chlamydia, syphilis, gonorrhea, and human papilloma virus. Microbicides are most often talked about in the context of female-controlled prevention methods, but they may also be able to be used by men who have sex with men.

Several steps are involved in putting any new product into people's hands. The U.S. Food and Drug Administration (FDA) is the licensing and regulatory agency, and works with CDC to share information and develop policies related to new technologies. Product development and testing can take many years, as each of the following steps is completed:

• Pre-clinical Testing -- New products are typically tested on animals for safety and biologic activity. To gauge effectiveness, a consistent set of laboratory standards is needed; in the case of microbicides, HIV infectivity assays may be more useful than other measures. If the product is shown to be safe for animals and effective, human studies are conducted.
• Phase I -- In addition to examining human safety, dosage and toxicity are often determined by having a few healthy people use the product. These trials are limited, and may not include participants who share characteristics of the product's target population -- for example, sexually active women who have a history of STDs.
• Phase II -- The product is used by a larger number of subjects to study dosage, toxicity, possible side effects, and other factors.
• Phase III -- Tests on large numbers of volunteers, usually thousands, to verify Phase II results and monitor long-term side effects. To measure the disease reduction effect, volunteers are usually people at higher risk for disease than those who took part in Phase I or II testing.

Even with expedited review, in which the second and third phases are combined, microbicide development and testing could take as long as 5-10 years.

In the interim, continued research into existing microbicide products other biomedical options and behavioral research on women's knowledge, attitudes, beliefs, and actions related to HIV/AIDS, sexual activity, substance use, and related factors will be vital to developing a constellation of effective prevention choices. As research sheds light on prevention, CDC will continue to provide communities with the information they need to create, deliver, and evaluate programming for women and others.

For more information on women and HIV, see these companion documents: HIV and AIDS Trends; CDC's Role in HIV Prevention: Research and Support for Community Action; Mother-to-Child HIV Transmission Decreases in the U.S. But Challenges Remain To Perinatal Prevention; The Control of Sexually Transmitted Diseases as an HIV Prevention Strategy; and Developing Health Skills for a Lifetime: CDC's Role in Preventing HIV Infection Among Young Americans.

Women/Microbicide Presentations in Vancouver

Oral

Heterosexual Risk for HIV among Puerto Rican Women: Does Power Influence Self-protective Behavior? Harrison, Janet S.

HIV Prevalence among U.S. Childbearing Women, 1989-1994, Susan Fischer Davis.

Declining Prevalence of Gonorrhea (GC) and Chlamydia (CT) in Female Sex Workers (FSW), Chiang Rai, Thailand, 1991-94, Peter H. Kilmarx.

Risk of HIV Transmission During The Seroconversion Period, Ann Duerr.

Poster

Methodologic Issues in Microbicidal Development, Margaret Scarlett, Ann Duerr.

Predicting Contraceptive Use among Women at Risk for or Infected with HIV, Christine Galavotti.

Breastfeeding Among HIV-Infected Women, Los Angeles and Massachusetts, 1988-1993, Jeanne Bertolli.

Who Uses HIV Prevention Counseling for Women? Bobby Milstein

Involving the Community: A Model for Community-level HIV Prevention Activities, Bobbie Person.

Prevalence of High-Risk Sexual Behavior among HIV-Infected Women, Tedd V. Ellerbrock.

Risk Factors for HIV Seroconversion among Young Women in a Rural Community in the Southeastern United States, Kenneth L. Dominguez.

High Prevalence of Abnormal Vaginal Flora And Bacterial Vaginosis in Women With or at Risk For HIV Infection, Dora Warren.

Direct Assessment of Physical Barrier Method Failure Using A Self-Sampling Technique, Amy S. Bloom.

Estimating Factors Influencing Acceptance and Adherence to Zidovudine Treatment to Prevent

Vertical Transmission of HIV, Brenda F. Seals.

Geographical Variation of AIDS Associated Kaposi's Sarcoma (KS) in Europe, Shahul H. Ebrahim.

Lack Of Timely Prenatal Care Among Women Infected With HIV: Implications For Prevention Of Perinatal HIV Transmission In The United States, Anna Shakarishvili.

Perinatal Zidovudine Use after Perinatal ZDV Recommendations in the United States, Sherry L. Orloff.

Trends in HIV Seropositivity Among Clients Attending Publicly Funded HIV Counseling and Testing Sites Across the U.S.A., 1990--1994, Ronald Valdiserri.

HIV Seroincidence Among Persons Attending Sexually Transmitted Disease Clinics In The United States, 1988-1995, Hillard Weinstock.

Association of Penicillin Mass Treatment Program with Sexually Transmitted Diseases among Female Sex Workers in Indonesia, M. Riduan Joesoef.

Preventing Perinatal HIV Infection: Costs And Effects Of A Recommended Intervention In The U.S., Paul G. Farnham.

Sexual Involvement with Older Men: HIV-Related Risk Factors for Adolescent Women, Bonita Westover.

Risk Factors for Pneumocystis Carinii Pneumonia: Delayed Diagnosis of HIV-infection and Failure to Receive Prophylactic Therapy, Jeffrey S. Duchin.

The HIV Outpatient Study (HOPS) Description and Initial Findings, Scott D. Holmberg.

Detection of Phylogenetically Linked HIV Strains Among a Population of Epidemiologically Unrelated Women, Marcia L. Kalish.

Analysis of Genetic Diversity of HIV-1 in Cote D'Ivoire Using Restriction Fragment Length Polymorphism (Rflp) Analyses, John Nkengasong.