Prevalence of smear-positive pulmonary tuberculosis among prisoners in Malawi: a national survey.

A cross-sectional cell-to-cell survey was conducted in 18 of 22 prisons in Malawi to determine the period prevalence of smear-positive pulmonary tuberculosis (PTB). In each prison, prisoners were interviewed using a structured questionnaire. Prisoners with cough of >1 week's duration were investigated by sputum smear examination. Of 7661 prisoners, 3887 had cough of > or =1 week, of whom 3794 submitted three sputum specimens: 54 (0.7%) had smear-positive PTB. The prevalence of PTB was higher in large urban prisons (1.1%) than in district prisons (0.3%, P < 0.001). More needs to be done to improve TB control in urban prisons.