This study contributes significant and critical information to the literature addressing HIV-related risk in trans communities. First, the study uses respondent-driven sampling, which through design and analysis strategies minimizes biases associated with convenience sampling that are present in the published literature. The estimates of HIV-related risk behaviours are considerably lower than in studies where convenience samples were used. Trans people were also more heterogeneous with regard to sex partner numbers and types, as well as for the types of sex they engaged in, with the majority not at high risk for sexually acquired HIV within the past year. A high proportion (one quarter of FTMs and half of MTFs) did not have any past-year sex partners, contributing to low prevalences of high-risk sex. FTMs reported unprotected receptive genital sex and MTFs insertive genital sex as the most common high-risk behaviours. Unlike other studies, high-risk sex did not differ across ethno-racial groups, though HIV testing history did. Low rates of HIV testing among trans people in Ontario were reported, compared to other jurisdictions, with the lowest lifetime testing among non-Aboriginal racialized people and the highest among Aboriginal people. In addition, while the focus of previous studies suggests that sex work is largely the purview of MTFs, in this study, MTFs and FTMs did not differ in both their historic and current engagement in sex work. Finally, prevalences of HIV infection were lower compared with other studies that used convenience sampling. Given low prevalences of testing and low statistical precision, however, estimates for self-reported HIV prevalence of 0.6% for FTMs and 3% for MTFs should be interpreted with caution.
That our estimates for trans people were similar to the broad Ontario population with regard to education, region of residence, and birth within versus outside of Canada, support the success of our sampling method in reaching trans people broadly. However, trans people constitute a hidden population, and it is not known to what extent trans demographics actually mirror population demographics. To assume similarity would be to assume trans people are born at, transition at, immigrate at, and survive at rates proportionate to the population, and there are reasons to expect that this may not be true. Violence against trans people and suicide, in particular, have been recently raised as serious health and equity concerns [
30-
32]. These may seriously impact the survival of trans people, though little published research exists. Immigration, transition and survival may also explain, to some extent, the reduced ethno-racial diversity among MTFs in particular. However, it is also possible that these differences were created in the process of network-based data collection, through network structural factors, or differences in recruitment or participation across groups. Trans population estimates describe a population that is younger and has lower personal income than Ontarians broadly. A younger age distribution has been observed consistently across trans studies. This may in part explain low incomes, as income generally increases with age, however high levels of employment discrimination have been documented [
33], and it is unlikely that low incomes are simply an age-related effect.
Existing trans-specific or trans-friendly services, while limited, are concentrated in Toronto. That two-thirds of trans people did not live in metropolitan Toronto illustrates the need for development of trans-friendly services in smaller Ontario cities and towns. A recent population-based study, using a broad definition of transgender, estimated that 0.5% of the adult Massachusetts population was trans [
34]. While it is not clear how this estimate would apply to the Ontario population, as a population-based estimate it represents the best information to date. Applying this estimate to the 2008 population of 10,710,200 Ontario residents over age 15 [
35] (to most closely match the 16-year age limit of our study), we would estimate that there are approximately 53,500 trans residents of Ontario, 36,000 of whom do not live in Toronto.
Self-reported HIV prevalence was estimated at 0.6% for FTMs and 3% for MTFs, higher than expected based on overall population estimates for Ontario. In 2008, there were an estimated 26,627 prevalent HIV infections in Ontario [
36], for a 2008 population of 10,710,200 residents age 15 and over [
35], representing an overall HIV prevalence of 0.25% or 1 in 400. Of these, it has been estimated that two-thirds, or about 0.17%, were aware of their HIV status [
36]. Estimates from the current analysis are that 2% of trans people (1.7% without rounding) self-report HIV positivity, 10 times the expected baseline value. However, given the width of the confidence intervals and the high proportion of trans people that had never been tested, it is not possible to accurately estimate HIV prevalence from these survey data. As in any study, there are limitations to this analysis. While estimates from RDS have been shown to be statistically unbiased [
27], confidence intervals are wide. For this reason, point estimates should not be over-interpreted, but rather interpreted with regard to the range of plausible values.
Self-reported HIV prevalence was lower than in other studies with more urban, street-active samples (e.g. 11.8% from a U.S. meta-analysis for MTFs) [
3]. While existing studies point to extremely high vulnerability to HIV within segments of trans communities in some cities, our evidence did not support the existence of such high levels on a broader population basis in Ontario. Our estimates were similar to, though slightly lower than, the self-report estimates obtained in the U.S. National Transgender Discrimination Survey [
31]; prevalences of HIV and other sexually transmitted infections in Canada are lower than those in the U.S, in general. Whether between-study differences reflect effects of sampling high-risk versus broad population groups of trans participants, differences related to testing, or differences between actual HIV risk and prevalence in the U.S. and other countries versus Canada is unclear. While it is not a perfect remedy, Canada has human rights protections in place for trans people (under the grounds of sex) that do not exist in many other jurisdictions. Further, within Canada, most health care services are freely available to all Canadians, with administration and delivery responsibilities falling on each province or territory. Additionally, costs of specific surgeries associated with transitioning are covered in some provinces and territories, including Ontario. Costs for prescription drugs, including hormones, are largely not covered by the public health care system, but are lower than in the U.S. It is possible that existing protections may serve to mitigate some of the serious effects of discrimination, and the health inequities they produce.
It is important to note that self-reported estimates are likely underestimates of actual HIV prevalence. About a quarter of trans people reported that they were unsure of their HIV status, and about half have never been tested. History of testing varied significantly by ethno-racial group, but not by gender spectrum. Only 15% of Aboriginal trans people had never been tested, versus 44% of non-Aboriginal white people and 67% of non-Aboriginal racialized people. While we were not able to determine why these differences may exist, it is possible that the higher testing rates in Aboriginal trans people result from inclusive campaigns targeting Two-Spirit people. Outside of Aboriginal communities, campaigns targeting MSM, for example, may not even seem relevant to trans MSM. It is also possible that the greater awareness of HIV-related issues in Canadian Aboriginal communities may also contribute to increased perception of risk by Aboriginal trans people or their health care providers.
It is surprising that HIV testing was so low, given that it is free across the province of Ontario, and anonymous testing is available in most jurisdictions. As a comparison, despite similarities in estimates of partner types, MTF vs. FTM frequencies of sex, and transition status, a survey of trans people in Virginia found that only 18% had never been tested for HIV [
37], versus 46% in our study. It has been argued that Canada’s punitive HIV non-disclosure laws, in place since 1998, may deter people from testing [
38]. In the context of HIV testing services, barriers to inclusion can also occur due to erasure of trans people at the informational and institutional levels [
21]. Erasure is the process through which trans people, and by extension trans communities, are systematically rendered invisible through passive or active exclusion, including the assumption that information on trans people, or policies to accommodate them are not relevant [
21]. As an example, for many years the largest anonymous HIV testing site in Ontario’s largest city had “men’s days” and “women’s days” and when to attend – and indeed the safety of attending – was unclear to potential users who were trans. It is not readily apparent which factors affect HIV testing, and to what extent non-testing is due to low risk of HIV versus barriers that prevent testing in moderate- to high-risk individuals.
The profile of HIV risk with regard to sexual behaviours is highly heterogeneous. In the past year, MTF individuals were both more likely to have high-risk sex and to not have partner sex at all. Population statistics indicate that about 16% of a young- to middle-age adult population will not have had sex in a given year [
39]. That half of MTFs and a quarter of FTMs have not had past-year sex is likely indicative of the difficulties trans people face in finding romantic or sexual partners. Gender spectrum differences may be due to a greater difficulty for MTFs in finding good romantic or sexual partners who will see them as their core gender sexually; effects of hormonal treatments on sex drive may possibly play a contributing role. Based on the comparisons of ethno-racial groups, only non-Aboriginal racialized trans people were similar to expected population levels with regard to having past-year partner sex; an estimated 81% had sex and 19% did not. While non-Aboriginal racialized trans people were more likely to be sexually active than other trans ethno-racial groups, this did not correspond with an increase in high-risk sex or in sex while drunk or high, where proportions were similar to other groups.
While sexual behaviours—which could involve penetration with fingers, penile prostheses, or toys as well as flesh genitals—were highly varied, most did not correspond to high-risk (i.e. flesh contact and fluid exposed) activities. Indeed, the greatest contributors to HIV-related sexual risk were the two sexual activities some might assume trans people are unlikely to engage in: receptive genital sex for FTMs, and insertive genital sex for MTFs. For MTFs at least, this differs from some previous studies. For example, in one San Francisco study, of over 300 MTFs, only 2 had insertive genital sex in the prior 6 months [
1].
While most research on trans sex workers focuses on MTFs, FTMs in our study were similar with regard to sex work histories, as well as current sex work. Other studies have documented high frequencies for sex work among trans men in U.S. cities [
1]. It is unknown whether FTMs engaged in sex work while presenting as male or female, and whether the frequency and duration of sex work involvement is similar to MTFs.
Overall, the sexual risk profile observed for Ontario trans people is quite different from the bulk of existing studies. The breadth of the population, both geographically and demographically, may provide a broader picture of trans sexuality and health outside of urban centres. Moreover, it may be that effects of transphobic discrimination in Canada are mitigated by the existence of legal human rights protections and processes for redress, and by the social safety net to the extent that it exists. While some segments of trans communities in Ontario are at higher risk than others, we do not see evidence of uniformly high risk. Indeed, the majority of trans people were not at high risk for sexually acquired HIV in the past year.