The expanding epidemics of HIV type 1 among men who have sex with men in low- and middle-income countries: diversity and consistency.

Men who have sex with men (MSM) have borne a disproportionate burden of human immunodeficiency virus (HIV) infection and remain a markedly underresourced population globally. To better describe HIV epidemics among MSM in low- and middle-income countries, the authors conducted a systematic review of published and unpublished literature available after January 1, 2000 (2000-2009). A total of 133 HIV prevalence studies from 50 countries met the search criteria. Data were used to develop an algorithmic approach to categorize these epidemics. The authors found that the HIV epidemic in low- and middle-income countries may be described using the following 4 scenarios: 1) settings where MSM are the predominant contributor to HIV cases; 2) settings where HIV transmission among MSM occurs in the context of epidemics driven by injection drug users; 3) settings where HIV transmission among MSM occurs in the context of well-established HIV transmission among heterosexuals; and 4) settings where both sexual and parenteral modes contribute significantly to HIV transmission. The authors focused on Peru, Ukraine, Kenya, and Thailand to describe the diversity across and similarities between proposed epidemic scenarios. This scenario-based categorization of HIV epidemics among MSM may assist public health agencies and civil societies to develop and implement better-targeted HIV prevention programs and interventions.