EPIDEMIOLOGY <<Back
 
 
048
PREVALENCE, INCIDENCE AND FATE OF SUSPECT CASES OF TUBERCULOSIS IN A RURAL POPULATION OF SOUTH INDIA
VV Krishna Murthy: NTI Newsletter 1982, 19, 75-80.

The data from a longitudinal survey conducted in Bangalore district from 1961-1968 by National Tuberculosis Institute was analysed to find out the prevalence, incidence and fate of suspect cases. In brief, the survey was conducted in 119 randomly selected villages in three taluks of Bangalore district and repeated within the next five years. At each survey, eligible population was subjected to tuberculin, X-ray & sputum smear and culture examinations.

The overall prevalence rate of suspect cases among persons aged five years and more was 1.06% at I survey, 0.68%, 0.49% and 0.43% at II, III and IV survey respectively. In males, the prevalence rate was 1.19% at I survey & 0.62% at IV survey corresponding figures for females were 0.94% and 0.24% respectively. A decline of prevalence of suspect cases from 1.06% at I survey to 0.43% at IV survey was observed. The overall incidence of suspect cases was 0.16% between I & II surveys, 0.10% between II & III, and 0.06% between III & IV surveys. The overall as well as age specific annual incidence rates between III & IV surveys were significantly less than that between I & II surveys. At all the three intervals the incidence increased with the age. Incidence of suspect cases in males was more than that in females. Change in disease status over a period of time is termed as "fate". The disease status was classified as (i) cure (ii) continued to be suspect case (iii) converted into bacillary cases and (iv) dead. The percentage of cure (51.9%, 53.2% and 50.3%) and conversion into bacillary cases(7.2%,5.8% and 5.4%) were almost the same at all the three intervals. But the percentage of those who remained suspect cases reduced from 33.5% at the end of 18 months to 17.5% at the end of 60 months. On the other hand, the death rate increased from 7.4% at the end of 18 months to 26.8% at the end of 60 months. The decreasing trend of continuing to be suspect cases at the rate of 10% between two observations, appears to be corresponding to the increasing trend in the death rate as seen from the observations made at the three intervals.

KEY WORDS: PREVALENCE, INCIDENCE, FATE, SUSPECT CASE, RURAL COMMUNITY, LONGITUDINAL SURVEY.
 
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