10% of gay men in New York City is HIV positive.
In fact the prevalence of HIV infection within some U.S. populations now rivals that in some sub-Saharan African countries according to a stunning new report published in the New England Journal of Medicine.
For example, more than 1 in 30 adults in Washington, D.C., are HIV-infected — a prevalence higher than that reported in Ethiopia, Nigeria, or Rwanda.
Certain U.S. subpopulations are particularly hard hit.
In New York City, 1 in 40 blacks, 1 in 10 men who have sex with men, and 1 in 8 injection-drug users are HIV-infected. In Washington DC 1 in 16 black men are HIV positive.
In several U.S. urban areas, the HIV prevalence among men who have sex with men is as high as 30% as compared with a general-population prevalence of 7.8% in Kenya and 16.9% in South Africa.
During the first two decades of the epidemic, remarkable advances in preventing mother-to-child transmission, screening of blood and blood products, and behavior change among men who have sex with men resulted in significant decreases in new HIV infections in the United States — from approximately 130,000 in 1984 to about 60,000 in 1991.
For the past decade, however, progress has been stalled.
Unlike the generalized HIV epidemics in sub-Saharan Africa, the U.S. epidemic primarily affects certain discrete geographic areas — especially urban areas of the Northeast and West Coast and cities and small towns in the South.
Within these areas, specific neighborhoods are often disproportionately affected in part because of residents' engagement in unprotected sex within relatively insular social–sexual networks. Many of the populations most affected tend to have limited social mobility; thus, partner selection tends to concentrate transmission patterns and amplify spread within defined geographic areas.
For example, black men who have sex with men are at increased risk for HIV infection in part because of its high prevalence in their sexual networks and their likelihood of choosing racially similar partners; they have also been shown to be less likely than their white counterparts to be aware of their HIV status and thus are more likely to unknowingly transmit HIV.
Moreover, even those who are aware of their HIV infection may be less engaged in HIV care and less likely to avail themselves of antiretroviral therapy — behavior that limits the potential benefit of such therapy as a preventive strategy.
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