Increase in tuberculosis incidence among the staff working at the Tuberculosis Demonstration and Training Centre in Addis Ababa, Ethiopia: a retrospective cohort study (1989-1998)

The incidence rate of tuberculosis was studied among the staff of the Tuberculosis Demonstration and Training Centre (TDTC) of Addis Ababa between 1989 and 1998, by reviewing all clinical charts of the 175 staff members for evidence of tuberculosis. During the study period, 24 cases of tuberculosis were diagnosed, including 12 who were bacteriologically confirmed. The incidence rate of tuberculosis increased from 1695 per 100 000 person-years (py) in 1989 to 55561100 000 py in 1998 (test for trend, P < 0.001). Urgent measures are required for better protection of the staff from human immunodeficiency virus infection and tuberculosis.