Background Transgenders (TG) are a marginalised population that has been greatly impacted by the HIV/AIDS epidemic. The objective of this study is to review the current literature citing risk factors and prevalence rates for HIV infection among male to female (MTF) and female to male (FTM) TG in the USA.

Methods A review of the original research articles published from 1981 to 2010 was performed through a Pubmed search using the terms “HIV risk” and “Transgender”.

Results Thirty-five articles were identified, with MTF described in thirty-three and FTM described in nine. Collectively all racial groups were represented. The majority of research was done in large urban cities in the Southwest, Midwest, and Northeast. Most studies relied on self-report of HIV infection; and only six studies tested participants for HIV. The prevalence rates of HIV infection ranged from 2.2% to 68.0%. Unprotected receptive anal intercourse (URAI), commercial sex work (CSW), and African American (AA) race were the most frequent HIV risk factors identified. Homelessness and financial instability were frequent among adolescents. When compared to men who have sex with men (MSM) and heterosexual females, MTF are more likely to have URAI with multiple sexual partners. Among MTF participants, AA and Hispanics were more likely to participate in CSW than Caucasians. Self reported prevalence of HIV was low in FTM population (0–2%), except in one study which tested for HIV and found similar HIV prevalence in both FTM (10%) and MTF (10%); risk factors associated with HIV infection in this study were unprotected sex with a partner of unknown HIV status and location in an urban metropolitan area.

Conclusions HIV rates among TG are high, especially among AA and Hispanics. Majority of MTF participate in high risk sexual activities. Geographically and ethnically diverse studies including MTF and FTM are needed to test HIV prevalence and associated risk factors in TG population.