Willingness to Receive Latent Tuberculosis Infection Treatment Among Migrants in Tijuana, Baja California, Mexico

Over 80% of tuberculosis cases in the United States are due to reactivation of untreated latent tuberculosis infection (LTBI), most of whom were foreign born. LTBI treatment can greatly lower the risk of progression to active TB disease, and shorter treatment regimens increase the potential of migrants and other persons in vulnerable conditions, to complete treatment. We conducted across-sectional study to assess willingness to complete a one-month course of LTBI treatment among internal and international migrants living in Tijuana, BC, Mexico, and to identify factors associated with treatment unwillingness between November 2020 and April 2021. Prior to administering TB skin tests (TST), participants were asked if they would accept LTBI treatment if indicated by test results and clinical examination. Recruitment occurred in migrant shelters throughout Tijuana and at a storefront office conducting research and harm reduction services for people who use drugs. Among 595 participants, 80.4% were living in shelters, 3.5% were recruited at shelters but living independently, and 16.1% were recruited through the storefront office. Overall, 71 (11.9%) indicated that they were unwilling to take LTBI treatment and 109 (18.3%) had positive TST results. Unwillingness to take LTBI treatment was more common among participants from the storefront office compared to the shelter (64.6% vs. 1.8%, p<0.001). Since only 1.8% of shelter participants were unwilling to receive treatment, multivariable Poisson regression with robust variance estimation via GEE for identifying factors independently associated with LTBI treatment unwillingness was restricted to storefront participants. Treatment unwillingness among storefront participants was positively associated with perceiving health status as "good" or "very good" (prevalence ratio [PR]=2.37, 95% confidence interval [CI]: 1.52, 3.99) and heroin use in the past six months (PR=1.70; 95% CI: 1.33, 2.19). Unstable housing was reported as a barrier to treatment. These findings suggest that most migrants in Tijuana were willing to receive short-course LTBI treatment if indicated, yet willingness was lower among those at greatest risk of TB. Efforts to increase testing and treatment, as well as further research on overcoming barriers to treatment willingness are needed.