Extrapulmonary and pulmonary tuberculosis in antananarivo (madagascar): high clustering rate in female patients

Antananarivo, the capital city of Madagascar, has an endemic focus of tuberculosis (TB). We specifically studied patients with extrapulmonary TB (EPTB) and grouped patients according to infected body site. The strains were characterized by IS6110 fingerprinting and compared with those isolated from patients with pulmonary TB (PTB) during the same period in order to determine the possible association between the genotype and the clinical expression of TB. A total of 316 TB patients were included in this study: 151 individuals with EPTB, 10 with both PTB and EPTB, and 155 with PTB alone. Pleural TB was the major EPTB localization (77%) and was found more often in older patients, while PTB or EPTB in which the localization was other than pleural (other EPTB) was found in younger patients. The male-to-female ratio was slightly higher in pleural TB patients (3.06:1) than in patients with other EPTB (1.35:1). There was no significant difference in the BCG status among patients with PTB, pleural TB, and other EPTB. Analysis of IS6110 patterns showed that 167 patients (52.8%) were assigned to 37 clusters of 2 to 34 patients. Analysis of the IS6110 clusters and the IS6110 families did not show any association with a particular clinical expression of the disease. Patients with PTB or other EPTB were more likely to have strains with one IS6110 copy than patients with pleural TB. The clustering rate was found to be significantly higher in female patients (62%) than in male patients (48%) (P = 0.029), suggesting that Malagasy women were more likely to progress to disease after infection than men.