Objective: To determine the prevalence of latent and active TB among detainees in a prison hospital in Bahia, Brazil. Methods: A cross-sectional study with prospective data collection was carried out comprising 237 inmates in the Bahia State Prison Hospital between July 2003 and April 2004. A standardized questionnaire was applied and completed by medical students. The detainees were systematically submitted to the following tests: tuberculin skin test, chest X-ray (anteroposterior), sputum smear microscopy and culture for mycobacteria. The events of interest were active TB and latent TB. Results: The mean age of the participants was 36.6 years, and 89.9% were male. Smoking and alcohol consumption were reported by 70.0% and 43.9% of the inmates, respectively. A history of treatment for TB was reported by 11.3% of the inmates. Of the inmates evaluated, 36.3% reported cough and 31.4% reported expectoration. Other less common symptoms were asthenia (in 26.2%), weight loss (in 23.1%), loss of appetite (in 17.7%), fever (in 11.3%) and hemoptysis (in 6.7%). Of the 86 inmates tested, none presented positive HIV serology. The prevalence of latent TB was 61.5% (96 of the 156 inmates submitted to tuberculin skin tests), whereas that of active TB was 2.5% (6 of the 237 inmates evaluated). The presence of cough was a determinant of active TB (prevalence ratio = 8.8; 95% CI: 1.04-73.9; p = 0.025). Conclusions: Active and latent TB are highly prevalent among inmates hospitalized in the Bahia State Prison Hospital. Our findings justify the need to implement public policies specifically directed towards the control of TB in this population.

Keywords: Tuberculosis; Prisons; Hospitals; Prevalence.

Tuberculosis chemoprophylaxis is a therapeutic measure for the prevention of infection by Mycobacterium tuberculosis or to avoid development of the disease in individuals already infected with it. Isoniazid is the most commonly used therapy; however, the use of rifampicin and pyrazinamide has recently been introduced. The objectives of this study were to review the results of the principal studies evaluating the indications for chemoprophylaxis with isoniazid alone and in association with other drugs, its efficacy in the prevention of tuberculosis with respect to the different risk groups and the alternative regimens available. A systematic revision of the medical literature was carried out with particular emphasis on clinical trials and meta-analyses. Official records were also consulted. Those studies involving randomized clinical trials on the use of isoniazid, rifampicin or pyrazinamide in HIV-positive or negative patients were selected. Isoniazid continues to be effective for the prevention of tuberculosis in populations of both HIV-negative and HIV-positive individuals. The standard dose of 5-15 mg/kg/day has shown similar protection over treatment periods ranging from six to twelve months. The risk of developing hepatitis was less than 1%; however monitoring during treatment is recommended in patients over 35 years of age and in users of alcohol. Studies involving treatment regimens with other forms of medication were inconclusive and new studies would have to be performed to evaluate the efficacy of these regimens in populations at high risk of developing tuberculosis.

Keywords: Tuberculosis. Chemoprophylaxis. Isoniazid.