Prevalence of tuberculosis in prisons: risk factors and molecular epidemiology.

SETTING: Tuberculosis (TB) in prisons is a challenge for the public health system. Active and passive case screening are important tools for TB case detection.

OBJECTIVE: To characterise TB in a southern Brazil prison in terms of epidemiological variables, diagnostic approaches and clinical isolate genotypes.

DESIGN: Inmates of a southern Brazilian prison were assessed using active and passive TB case screening. Sputum microscopy, culture, drug susceptibility testing and genotyping were performed. Data were analysed using descriptive statistics and multivariable logistic regression.

RESULTS: TB prevalence was 4712 per 100 000 inmates, and was associated with low educational level, time incarcerated, productive cough, previous TB history, smoking and human immunodeficiency virus (HIV) infection. Overall, 27.8% of TB cases were detected by culture only; the prevalence of drug-resistant strains was 7.8%; 58.3% of clinical isolates had an identical genotypic profile.

CONCLUSION: The study showed extensive circulation of Mycobacterium tuberculosis strains in a highly endemic prison. It is recommended that priority be given to the evaluation of prison inmates with longer jail times, those who are HIV-positive, those with symptoms and those with a previous history of tuberculosis. We observed that active case finding induced passive case detection.