The Risk Factors For Latent Tuberculosis Infection In Immigrant Factory Workers

Objective: To investigate the prevalence of Latent Tuberculosis infection in immigrant factory workers and its risk factors through using γ-interferon release test(IGRA) and Tuberculin skin test(TST). Analyze infection related factors of the group of latent infection,and acquire the risk factors for latent tuberculosis infection,in order to provide experience and reference for effective control of TB transmission in the floating population.Methods: A total of 2552 migrant workers from ten different factories with aquestionnaire and physical examination.Interferon gamma release(IGRA),chest X-ray,Tuberculin skin test(TST)were performed on all recruited subjects after the exclusion of active tuberculosis patients. Unconditional Logistic regression was use to identify the risk factors for LTBI among the immigrant factory workers.Results: 1. Among 2552 individuals examined,1465 were male and 1068 were fe male the sex ratio of 1.37:1.The standardized prevalence of active tuberculosis wa s 314/100000,smear positive tuberculosis was 118/100000.2. The positive rate was 17% to 29.6%.Age-standardised rates of skin-test positivit y(≥10mm) ranged from 21.7% to 41.7%,and QFT positivity rates ranged from 10.2% to 28.6%.Rates of positivity for the tuberculin skin test and the QFT test w ere increasing, gradually increased with age. Rates of latent tuberculosis infection were higher for men than women(p<0.05).3. With multivariate Logistic analysis,age and personal monthly income were signi ficantly associated with increased IGRA positivity. Ages of 26~35 years have 1.3times the risk of latent tuberculosis infection than the age group of 16~25 and1.83 times of 16~25 years old. As personal income increasing,there is a decrease in the risk for latent tuberculosis infection trends.4. With multivariate Logistic analysis, Married people are 1.34 times as likely to become LTBI than their single counterparts.Tuberculin skin test only positive res ults associated with the presence of BCG scar,BMI and age.Conclusions: Initially found out LTBI prevalence and characteristics of migrant workers with TB,in order to provide medical treatment of TB and facilitate the s urvey of LTBI in the furture.Age,personal monthly income and marriage were sig nificantly associated with LTBI. Our results hightlight that IGRA/TST based routi ne LTBI and TB surveillance among immigrant factory workers is important for TB control.