CROI 2012: U.S. Black Women Have Higher Rates of HIV Infection and AIDS Death

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Urban black women in the U.S. are 5 times more likely to become infected with HIV than previously estimated, and are twice as likely to die of AIDS-related causes, according to 2 posters presented this month at the 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012) in Seattle.

HIV Incidence

Experts have estimated that women account for about 25% of new HIV infections in the U.S., about two-thirds of whom are black. But researchers need more precise incidence data when conducting prevention trials, in order to determine whether the intervention under study is beneficial.

Sally Hodder and fellow investigators with the HIV Prevention Trials Network 064 ISIS study team looked at the rate of new HIV infections among women in 6 U.S. cities: Atlanta, Baltimore, Newark, Raleigh-Durham, New York City, and Washington, DC. They recruited more than 2000 women using ethnographic mapping of venues frequented by at-risk women in communities with widespread poverty and high HIV prevalence rates. They enrolled women without a prior self-reported HIV diagnosis who had at least 1 individual or partner risk factor.

Most participants (88%) were blacks, 12% were Latina/Hispanic, and 8% were white. The median age was 29 years (range 18 to 44), 44% had an annual income below $10,000/year and 37% had less than a high school education. They had a median of 2 sex partners within the past 6 months and just 18% reported using a condom the last time they had vaginal sex.

Individual risk factors included binge drinking (40%), cocaine use (17%), and recent anal sex (38%). Partner risk factors included incarceration within the past 5 years (59%) and binge drinking (56%). Only 1% had recently had sex with a partner known to be HIV positive, but 41% had sex with partners of unknown status.

The women were followed for 6 to 12 months, receiving regular HIV testing and completing computer-assisted self interviews; testing for acute infection was performed retrospectively using specialized tests.

Results

The researchers concluded that recruitment at "hotspots" of HIV infection could identify women with few partners but a high level of risk behavior.

These findings show that HIV infection rates within this selected population are substantially higher than overall incidence rates for African-American adolescents or women, they elaborated in a press release issued by Johns Hopkins School of Medicine.

"HIV incidence in HPTN 064 (ISIS) was substantially (5 times) higher than CDC 2009 annual HIV incidence estimate for U.S. black women (0.05%) and comparable to estimated HIV adult incidence rates in parts of sub-Saharan Africa (Congo 0.28% and Kenya 0.53%), underscoring the urgency of conducting prevention trials among women at risk for HIV infection in the U.S.," the study team summarized.

"This study clearly shows that the HIV epidemic is not over, especially in urban areas of the United States, like Baltimore, where HIV and poverty are more common, and sexually active African-American men and women are especially susceptible to infection," said Baltimore principal investigator Charles Flexner from Johns Hopkins.

AIDS Mortality

In the second study, Kerry Murphy and colleagues with the long-term prospective Women's Interagency HIV Study (WIHS) looked at disease progression, AIDS-related illness, and death among women on combination antiretroviral therapy (ART).

Some prior observational studies have seen greater likelihood of disease progression and death among women compared with men, and among blacks compared with whites. This has largely been attributed to socioeconomic factors such as late diagnosis, less access to care, and poorer adherence, rather than biological factors. A prior WIHS study saw a higher rate of AIDS-related death among black compared with white women on ART, but the difference did not reach statistical significance.

In the present analysis, the researchers assessed the association between race and clinical outcomes among 1471 HIV positive women on continuous combination ART.

Results

Among continuous ART users, "black women were more than twice as likely to die from AIDS and more likely to experience an incident AIDS-defining illness compared to white women," the researchers concluded.

"Genetic polymorphisms in drug metabolism and transport that differ by ancestry may be playing a role in lower adherence and higher AIDS deaths in black women,"they suggested. For example, people of African descent are more likely to have genetic variations involved in drug transport and metabolism that may impact outcomes on ART.

"Future studies examining host genetic traits in these women are important and may inform selection of future HAART regimens for women of African ancestry," the researchers recommended.

 3/21/12

References

S Hodder, J Justman, J Hughes, et al. (HIV Prevention Trials Network 064 Study Team). The HPTN 064 (ISIS Study) -- HIV Incidence in Women at Risk for HIV: US.19th Conference on Retroviruses and Opportunistic Infections (CROI 2012). Seattle, WA. March 5-8, 2012. Abstract 1048.

K Murphy, D Hoover, Q Shi, et al. The association of race with death from AIDS in continuous HAART users: WIHS. 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012). Seattle, WA. March 5-8, 2012. Abstract 1045.

Other Source

Johns Hopkins School of Medicine. HIV Rates for U.S. Urban Black Women Five Times Higher than Previously Estimated. Press release. March 8, 2012.