Tuberculosis prevalence survey in Tumkur district

Abstract

A Tuberculosis Prevalence Survey was carried out in Tumkur District, Mysore State, India, to provide basic information regarding age-sex specific prevalence rates for infection, radiologically active disease and bacillary cases. The survey was confined to 66 groups—62 rural and 4 semi-urban selected at random. Coverages were about 92 to 95 per cent. The results of the survey showed (and confirmed) the limitations of these examinations in providing clear indices for prevalence. Attempt has been made to find the best possibe indices for prevalence of infection, radiologically active disease and bacillary cases by correlating the findings of one with the other two and making use of all types of data available. A clear cut choice of the best possible indices was still not available, but a basis for further work has been defined. Some interesting variations in prevalence, which have been observed in this survey, indicated the desirability of stratified samples for such surveys. The main findings of the survey, in the defacto population examined are: 1. 38.3 per cent were infected; 42.8 per cent among males and 33.9 per cent among females. 2. The percentage of infected persons rises with age, reaching a maximum at about 40 years. 3. For age group 10-19 years and above, infection rates are consistently higher among males than among females. 4. Complications to tuberculin test were observed in about 5 per cent of the tests read and consisted mostly of oedema; incidence of complications was significantly more among females. 5. Large reactions of 20 mm. or more were observed among a larger proportion of females than males. 6. Incidence of infection rises with age at first, but drops in later years. 7. 1.9 per cent had radiologically active disease; 2.5 per cent among males and 1.2 per cent among females. 8. 66.3 per cent of the radiologically active cases were persons aged 40 years or more. 9. Prevalence rate for radiologically active disease increases steadily with age; the increase being particularly marked among males. 10. 0.41 per cent were bacillary cases among persons of age 10 or more; 0.56 per cent among males and 0.25 per cent among females. 11. Prevalence of bacillary cases steadily increases with age among males. 12. 50 per cent of the bacillary cases were persons aged 40 years or more.