High Latent TB Infection Rate and Associated Risk Factors in the Eastern China of Low TB Incidence

Objectives: To disclose the associated risk factors for latent tuberculosis infection (LTBI) and the current situation of LTBI in the eastern China. Methods: A cross-sectional study was undertaken to evaluate the LTBI rate and risk factors. Results: A total of 5305 subjects were finally included, with the IGRA positive rate of 19.98% (1060/5305). The LTBI rates were increasing with age (ORs were in significance from 6.60 to 20.92). Male gender significantly increased the risk of LTBI by 0.52 fold (OR = 1.52). Both smoking and drinking significantly increased the risk of LTBI (OR = 1.83 and OR = 1.67, respectively). Meanwhile, overweight and close contact with tuberculosis were risk factors for LTBI (OR = 1.36 and OR = 2.38, respectively). However, higher level of education and BCG vaccination lowered the risk of LTBI (OR = 0.16 and OR = 0.39, respectively). The multivariate logistic regression showed that age, male gender, smoking, overweight and close contacting with tuberculosis were risk factors for LTBI, but BCG vaccination was a protective factor for LTBI. Conclusions: BCG vaccination exerted protective effect on tuberculosis. However, LTBI rate in the Chinese rural area was critical and subjects above 30 years, male, smoking, overweight and close contact with tuberculosis wound be the targets for LTBI screening and source of tuberculosis.