This study examines barriers to HIV testing in the two largest Mexican – US border cities. The findings revealed that nearly two-thirds of IDUs had never received an HIV test, which is higher than a 2003 study of Tijuana IDUs [7
]. Although HIV prevalence was low in both cities, most HIV-positive IDUs were unaware of their serostatus. Moreover, of the 281 IDUs who had had no prior HIV testing, 65% had had at least one missed testing opportunity. This study’s finding of an HCV-antibody prevalence over 95% is probably reflective of common risky injection behaviours and suggests the potential speed with which HIV and other blood-borne infections (BBIs) could spread. Increased prevention efforts, including wider availability of VCT, are crucial, considering the potential for transmission of BBIs among this high-risk population [20
Correlates of having never been tested for HIV differed between the cities. In Tijuana, non-testers were less likely to have been diagnosed with an STI and more likely to spend more time on the streets and be male. In Ciudad Juarez, non-testers were more often single, and less likely to have been in drug rehabilitation or lived or worked outside Mexico in the past decade.
Migration has been linked to lower socioeconomic status, limited access to health services, power inequalities, social and cultural alienation, a breakdown of family units and fear of deportation and violence [21
]. However, migration may also have benefits, such as increasing exposure to HIV/AIDS education. For instance, we found that participants in Ciudad Juarez who had not lived or worked outside Mexico in the past decade were less likely to have had an HIV test than migrants. It is possible that more mobile Ciudad Juarez residents, who migrated from or worked abroad (primarily the United States), were more aware of the risk of HIV through exposure to programmes attempting to connect migrant populations to health care. For instance, since 1996 Programa Compañeros, a nongovernmental organisation in Ciudad Juarez, has had education projects targeting transborder IDUs (Ramos et al
In Ciudad Juarez, unmarried IDUs were less likely to have been tested for HIV (), possibly a result of social instability. Similarly, Tijuana IDUs who spent 12 hours or more per day on the street were less likely to have been tested. Such people may be highly marginalised and distrustful of traditional health-care services, suggesting that alternatives, such as mobile health clinics, may help to reach these populations. In Tijuana, a mobile clinic called the prevemovihl
was implemented in 2005 to promote outreach to the city’s most vulnerable populations. The National Center for the Prevention and Control of HIV/AIDS (CENSIDA) and the state of Baja California recently added two more prevemovihls
to the Baja California harm reduction efforts. Although there are no such vehicles in Ciudad Juarez, the harm reduction programme and needle exchange are very mobile, in that outreach workers bring materials and supplies directly to shooting galleries and other locations where IDUs congregate. However, mistrust and isolation need to be addressed on several levels. Health promotion campaigns highlighting the benefits of HIV testing have proved effective in settings where stigma and other barriers are at play [25
]. Further, in addition to testing and treatment, drug users need access to temporary and long-term housing, as well as family support for single parents.
Our study found that opportunities for voluntary testing in public and private settings were utilised inadequately. This was similar to a 10-year retrospective chart review of US patients seen at an HIV intake clinic, which showed that HIV testing was recommended to only one in five STI clinic patients [26
]. In our study, those without prior HIV testing in Ciudad Juarez were less likely to have been in drug treatment, and those in Tijuana were less likely to have been diagnosed with an STI. This suggests that some providers are sensitised to the importance of HIV testing and are probably offering VCT, but there were many missed opportunities for testing. Drug treatment facilities, doctor visits and time in jail are opportunities to offer HIV testing. In the US state of Rhode Island, routine HIV testing at entry into correctional facilities identifies approximately one-third of all people who test positive in the state [27
]. A key strategy of the CDC’s HIV prevention campaign is to make VCT a routine part of medical care [28
]. A 2002 study offering routine HIV testing to patients entering one of four hospital-associated urgent care centres found that, among the 3068 patients tested voluntarily, HIV seroprevalence was 2.0%, underscoring the effectiveness of routine testing [29
]. In the current study, at least 255 HIV testing opportunities were missed, and 182 participants (65%) without prior testing experienced at least one missed opportunity. Missed testing opportunities may reflect insufficient HIV services, lack of testing standards or lack of awareness of the availability or importance of HIV testing. Further studies and information on why this gap in opportunities for testing and actual utilisation exists along the Mexico – US border are needed.
In studies in the United States and Canada, homosexual men have traditionally had higher rates of HIV testing [30
]. Although 44% of male IDUs in Tijuana reported having had sex with men (MSMs), these participants were not more likely to have been tested for HIV. Different social norms regarding homosexuality in Mexico and the tendency of MSMs in our sample not to self-identify as ‘homosexual’ may have led to lowered risk perception. Male gender, regardless of sexual orientation, was associated with lower prevalence of testing, similar to a US study of IDUs which found that women tested for HIV more often than men [33
Lack of knowledge of how HIV is transmitted was associated with a lack of HIV testing for both cities, as reported elsewhere [34
], reinforcing the need for continued intensive education to address gaps in such knowledge. However, as this was a cross-sectional study and causal relationships cannot be determined, it is possible that knowledge of HIV transmission increased as a result of HIV testing, as opposed to predicting testing.
Study limitations included limited sample size and cross-sectional design. Also, the ‘knowledge of HIV transmission’ variable used in the analysis was based on self-reported knowledge. However, we were fairly confident of this variable, in that 99% of participants reporting knowledge of HIV transmission also identified correctly one or more ways HIV is transmitted. Although we used sampling methods to achieve a random and representative sample, we do not know if the seeds encountered refusals. However, of recruits who returned with a coupon, almost all were eligible and willing to participate.
This study provided valuable insights into testing barriers and suggests direction for prevention programmes in Tijuana and Ciudad Juarez. Existing prevention programmes in Tijuana and Ciudad Juarez have incorporated important components to reach the IDU population, including mobile health clinics, needle exchange and targeting places frequented by IDUs. However, HIV testing is also a fundamental component of prevention programmes, and thus it is of great concern that only about one-third of IDUs in our study had ever been tested for HIV, and few HIV-positive participants were aware of their serostatus. In both cities, efforts to make HIV VCT available at drug treatment centres, medical visits and jails should be encouraged. Although IDUs who had been diagnosed with an STI in Tijuana were more likely to have had an HIV test, nearly two-thirds of IDUs who had never been tested reported at least one missed testing opportunity, suggesting that improvements are needed.
Our findings underscore the immediate need to increase and fund HIV testing on the Mexico – US border, specifically targeting the IDU population. Existing prevention programmes and available HIV testing sites need to be evaluated and adjusted to address barriers and improve the uptake of regular HIV testing among IDUs.