Tuberculin survey in Ethiopia

For planning and implementation of effective national tuberculosis control programme (NTP) in Ethiopia, it is essential to know the real magnitude of tuberculosis problem. Previous tuberculin survey carried out during the period from 1953 to 1955 revealed the annual risk of infection 3.0%, and since then, there has been no survey. A new tuberculin survey was thus conducted during the period from December 1987 to April 1990. In order to get a sample of 47 previously BCG unvaccinated children, aged 6 to 10 years, selected from each 480 representative clusters of randomly selected 16 Woredas (districts), a total of 26,529 children, approximately 55 in each cluster, were given tuberculin intradermal injection, and the reaction was read in 26,269 children (99.0%). A scar survey was done, and 23,695 had no BCG scar, while 2,574 (10.1%) had BCG scar. Out of the former, 2,503 children (10.6%) were positive, and the annual risk of infection thus calculated was 1.4%. Out of the latter, 591 (23.0%) were positive. The results of these two surveys indicate that tuberculosis showed decline in the past 37 years with the annual reduction rate of 2.2%, however, the trend might change in the future due to present pandemic of HIV infection.