Evaluating an active case-finding strategy to identify smear-positive tuberculosis in rural Ethiopia

To assess an active case-finding strategy for the identification of smear-positive pulmonary tuberculosis (TB) in a rural district of Amhara Region, Ethiopia.

Study kebeles (smallest administrative units) were randomly selected in a cross-sectional study. House-to-house visits involving individuals aged >or=15 years in all households of the kebeles were conducted. The heads of households were asked to identify subjects with TB symptoms. Identified suspects were asked to provide three sputum samples for smear microscopy.

Among the 47,478 individuals living in households that were screened, 1006 TB suspects and 38 cases were detected. This resulted in 38 cases of smear-positive TB, i.e., 80 per 100,000 population, using cluster sampling. The ratio of active vs. passive case detection was 2.5:1, indicating 2.5 undetected TB cases in the community for every smear-positive TB case receiving treatment during the survey period. A higher proportion of female patients was detected by the survey.

The study revealed a very high proportion of undiagnosed TB. This indicates that the potential for a large infectious pool and significant transmission of TB in the community is high. The expansion of diagnostic facilities and the active involvement of health extension workers is necessary to expedite early detection, timely referral and treatment of TB.