Tuberculosis in Thai prisons: magnitude, transmission and drug susceptibility

Abstract

Background: Because of the human immunodeficiency virus (HIV) epidemic, tuberculosis has reemerged as a major public health problem in Thailand. Prison inmates are at high risk for developing tuberculosis because of the high prevalence of HIV infection.

Objectives: To determine the magnitude, transmission, and drug susceptibility of tuberculosis in Thai prisons.

Settings: Four provincial prisons in Southern Thailand.

Design: Cross-sectional, descriptive, clinical and molecular study.

Results: Miniature chest roentgenograms were performed on 304 (6.4%) of 4751 inmates screened for a > or = 2 week history of chronic cough and fever. At least 17 (35%) of 49 inmates who had a miniature chest roentgenogram compatible with tuberculosis were HIV-positive. The prevalence of smear-positive pulmonary tuberculosis was 568 per 100,000 inmates, which was eight times higher than that in the general population. Eight (38%) of 21 culture-positive Mycobacterium tuberculosis isolates had DNA fingerprints matching those of another inmate who was housed in the same room or in the same dormitory unit; 39% of the M. tuberculosis isolates were resistant to isoniazid; three of these isolates were also borderline resistant to rifampicin.

Conclusion: The prevalence of pulmonary tuberculosis in these prisons was high. A substantial proportion were acquired in the prisons. Isoniazid (INH) resistance was common, and theoretically precludes the use of INH-preventive therapy for contacts of these cases. Active case finding should be done and directly observed therapy implemented to prevent the spread of tuberculosis into the community.