Prevalence and risk factors associated with tuberculosis disease in Suratthani Central Prison, Thailand

Abstract

Setting: A prison in Suratthani Province, South Thailand.

Objectives: To measure the prevalence of and identify the risk factors associated with tuberculosis (TB) disease among prison inmates.

Method: This was a cross-sectional surveillance study. All prison inmates were screened for TB using a national TB screening questionnaire and chest X-ray (CXR) in July-December 2015. We collected sputum smear and Xpert® MTB/RIF results from prison inmates with a questionnaire score of 3 points or CXR suggestive of TB. Case definitions were: 1) definite TB: TB confirmed using sputum smear microscopy or Xpert; 2) probable TB: CXR consistent with active TB, together with clinical and CXR improvement after treatment; 3) TB case: definite and probable cases.

Results: Of 4007 prison inmates, 84 were diagnosed with TB. TB prevalence was 2.1%: 61 (1.6%) were definite TB cases. TB was associated with human immunodeficiency virus (HIV) positivity (adjusted OR [aOR] 7.22, 95%CI 1.85-28.22, P = 0.004), pre-incarceration income <Thai baht 15 000 (aOR 4.63, 95%CI 1.37-15.69, P = 0.014), overcrowding (aOR 3.73, 95%CI 1.08-12.93, P = 0.038) and prolonged incarceration 3 years (aOR 3.29, 95%CI 1.39-7.82, P = 0.007).

Conclusions: Prevalence of TB disease in Suratthani Central Prison was high. HIV infection, prolonged incarceration, overcrowding and low pre-incarceration income were significant risk factors associated with TB.