Prevalence of Latent Tuberculosis Infection in Multiple Sclerosis Patients from an Endemic Country: A Cross-Sectional Study.

BACKGROUND: MS patients are at increased risk for tuberculosis reactivation due to immunosuppressive therapies. Prevalence of latent tuberculosis in MS from our country is unknown. OBJECTIVE: To assess the prevalence and determinants of latent tuberculosis infection (LTBI) in MS patients from Colombia. METHODS: Multicentric, cross-sectional, retrospective study involving confirmed MS patients. LTBI was defined as a positive tuberculin skin test in asymptomatic patients with normal chest imaging. The prevalence (95 %CI) of LTBI was estimated and compared to the general prevalence with a one-sample proportion test. Determinants of LTBI were analysed using adjusted logistic regression. RESULTS: 481 patients were included, with a mean age of 42 years and a mean MS duration of 10 years. The prevalence of LTBI was 6.24 % (95 %CI: 4.25-8.78), significantly lower than that of the general population (21.11 %; p < 0.001). Male sex (OR: 2.52; 95 %CI: 1.00-6.28, p = 0.046) was independently associated with LTBI. CONCLUSION: LTBI is significantly less prevalent among our sample compared to the general population, and is associated with male sex.