High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico

University of California San Diego, School of Medicine, San Diego, California, USA.
The International Journal of Tuberculosis and Lung Disease (Impact Factor: 2.32). 06/2009; 13(5):626-32.
Source: PubMed


We studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic.
IDUs aged > or =18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using Quanti-FERON((R))-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression.
Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09-2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07-1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03-1.18). Speaking some English (aOR 0.38, 95%CI 0.25-0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45-0.99) were inversely associated with IGRA positivity.
Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana's IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide.

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    • "As noted above, nearly all PWID in Tijuana (95%) are HCV-positive [38,39], while PWID in San Diego were found to have comparatively low HCV prevalence (27%) [64]. Similarly, in contrast to the high prevalence of LTBI among PWID in Tijuana [65], less than 15% of HIV-positive PWID tested in a San Diego HIV clinic were found to have LTBI [40,41]. The disparities in disease prevalence between Tijuana and San Diego raised concerns that PWID travelling from the United States to Mexico to buy or use drugs could face increased risk of acquiring these diseases through social, sexual, or drug use interactions [64]. "
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