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