The results of the tuberculosis prevalence surveys carried out in 59 villages of Tumkur district, Karnataka in 196l before launching the District Tuberculosis Control Programme (1964) and the second one, nine years after the introduction of the programme (1973), were compared.

The prevalence rates in both the surveys were similar viz. 0.41 per cent in 1961 and 0.44 per cent in 1973 indicating the poor impact of the programme. The present analysis provides information on long term cumulative performance of the District Tuberculosis Programme (DTP) in diagnosing the cases detected in a prevalence survey at a point of time. Of the 70 cases diagnosed during I survey 12 (17.1%), and of 121 during II survey 20 (16.5%) were diagnosed by the District TB Programme independently over a total period of 19 years. Of the 12 DTP cases of I survey, 1/3rd were diagnosed by DTP within 3 years and the remaining were distributed over a period of 12 years. Similarly, of the 20 cases of II survey, 45% were found within 3 years after the survey and 25% within 3 year periods immediately prior to it. In subsequent years, Case-finding activity about these prevalence cases was erratic and at much lower rate. There was no difference between smear positive and culture positive survey cases with respect to their diagnosis by DTP. The changes brought about in the prevalence of cases from year to year by death, cure, incidence and performance of DTP, in diagnosing such prevalence cases, could not be studied from the available material. Under reporting of the diagnosed cases and missed diagnosis are attributed to be the main factors for poor performance of the DTP.