Secondary Attack Rate (SAR) of Tuberculosis in Hamedan Province, 2005 - 2013

This cross-sectional study was conducted on all registered smear-positive Tuberclosis (TB) patients during a time period of eight years (2005 - 2013); patients with records in the Hamadan provincial surveillance database were studied, in order to find secondary attack rate of TB. The contact investigation in 510 clusters resulted in secondary attack rate (SAR) of 18.75 per 1000 (95% confidence interval: 1.3 - 38.7) children below the age of 15; SAR of 6.7 per 1000 (95% confidence interval: 2.1 - 11.3) adults; and overall SAR of 8.14 per 1000 contacts (95% confidence interval: 3.4 - 12.8). we concluded that age and household size had a significant impact on the transmission of TB to household contacts.