The risk to develop tuberculosis and efficacy of its preventive treatment in labor migrants residing in the Republic of Tajikistan

Abstract

Objective: to study the prevalence of latent tuberculosis infection (LTBI), risk factors for LTBI to develop into active tuberculosis, the efficacy of preventive treatment in those with LTBI among labor migrants, residing in the Republic of Tajikistan.Subjects and methods. In the Republic of Tajikistan, 500 residents were followed up as Main Group, they all were labor migrants for more than 3 months and returned to their homeland within one year before inclusion in this study. All of them participated in a questionnaire survey to identify risk factors for developing tuberculosis and had the examination that included Mantoux test with 2 TE and chest X-ray. Comparison Group (CG) consisted of 500 citizens of compatible gender and age who did not travel as labor migrants; they all participated in the same survey and had the same examination.Results. The positive results of Mantoux test with no abnormalities on X-ray were observed in 40% of people in Main Group and 33.4% of people in Comparison Group.The following factors were found to be more frequent in Main Group versus Comparison Group, respectively: frequent and continuous exposure to a TB case – 78.2 and 23.1% (p < 0.01); no tuberculosis prevention – 83.1% and 48.4% (p < 0.01); poor accommodation and work conditions 87.9 and 13.6% (p < 0.01); inadequate diet and lack of proper clothes – 79.4 and 24.3% (p < 0.01); limited access to medical care – 85.4 and 22.6% (p < 0.01). MG was found to have a higher summarized risk coefficient (r = 4.75) versus CG (r = 2.0), p < 0.01. During 2–3-year follow-up of those with LTBI who had no preventive treatment with isoniazod, tuberculosis was diagnosed in 44.4% of people from MG and 18.5% of people from CG. The introduction of the integrated approach to tuberculosis control among people preparing for labor migration allowed reducing the proportion (from 19.7 to 13.7%) of labor migrants in the structure of TB incidence.