Tuberculosis in Thai prisons: magnitude, transmission and drug susceptibility

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.

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

Four provincial prisons in Southern Thailand.

Cross-sectional, descriptive, clinical and molecular study.

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.

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.