Background : Transgender people represent a marginalized and under-researched population worldwide. Despite reportedly high rates of HIV and sexually transmitted infections (STIs) among transgender people, prevalence of these infections in this group has not been systematically reviewed. Our primary objective was to perform a systematic review of the medical literature on rates of HIV and other STIs among transgender men (TM) and transgender women (TW). Given the sexual risk factors traditionally associated with TW (commercial sex work, for example), we hypothesized that HIV/STI prevalence would be higher among TW compared to TM.
Methods : A systematic review of the literature on original English-language research involving HIV and/or STI testing in transgender populations within the last 50 years (1968-2018) was performed using PubMed, Google Scholar, Embase, and Scopus. Various search terms and phrases pertinent to this topic were employed. Reference lists of relevant articles were also reviewed to expand the search.
Results : Literature search yielded 118 studies, with 32 meeting inclusion criteria. The studies came from 14 countries, with 11 of the 32 studies from the United States. Included studies were published between 2001 and 2018. The majority of studies focused on TW, with only 10 (31%) including data on TM. TW were the only transgender population investigated in 22 (69%) of studies. Of the studies investigating STIs in TW people, the majority were focused on sex workers and persons living in urban areas. Of the studies evaluating TW people, 7 (22%) exclusively evaluated sex workers. The most studied STI was HIV, with 31 (97%) of the eligible studies citing HIV related prevalence data; 8 (25%) studies only evaluated HIV. Syphilis was the next most studied infection, with 18 (56%) studies reporting data. Regarding gonorrhea and chlamydia, 15 (47%) studies presented testing data, but only 7 of those reported both urogenital and extragenital results. No studies tested for trichomoniasis transgender people. In TW, prevalence of HIV, syphilis, gonorrhea, and chlamydia ranged from 0%-70.3%, 1.4%-50.4%, 0%-29.4%, and 2.7%-24.7%, respectively. In the TM, prevalence of HIV, syphilis, gonorrhea, and chlamydia ranged from 0%-8.3%, 0%-4.2%, 0%-10.5%, and 0-11.1%, respectively.
Conclusions : Currently, the literature involving STIs in transgender people is primarily focused on TW and testing for HIV. While there is some data for bacterial STIs, testing patterns were variable, especially for gonorrhea and chlamydia. From the available data, STIs appear to be more prevalent in TW people than their TM counterparts. This finding, however, may not be representative of the TW community as a large proportion of studies only included commercial sex workers. There is a marked paucity in studies involving the TM community. Therefore, it is difficult to know how truly representative these data are. These gaps in the literature present numerous opportunities for future studies, particularly involving the epidemiology of STIs in the TM population and the relevance of extragenital bacterial, parasitic, and non-HIV viral STIs in all transgender people.