|TUBERCULOSIS IN A RURAL POPULATION OF SOUTH INDIA:
REPORT ON FIVE SURVEYS
|AK Chakraborty, Hardan Singh, K Srikantan, KR Rangaswamy,
MS Krishnamurthy & JA Steaphen: Indian J TB 1982, 29, 153-67.
The trend of tuberculosis in a sample of 22 villages
of Bangalore district observed over a period of about 16 years (1961-77)
is reported. Distribution of tuberculin indurations did not show
a clear cut demarcation between infected and non-infected. The method
adopted to demarcate the cut off point has been described herewith:
Distribution of tuberculin induration size of 0-14 years was attempted
and extrapolated to higher age groups. Even in these younger age
groups the antimodes were not clearly defined, so the antimode was
arrived by fitting two normal curves as two likely modes.
The choice of demarcation level, therefore, is
somewhat arbitrarily made on the basis of the distributions and
these varied from survey to survey; between 10 mm at survey I and
16 mm at survey V. The actual and standardized infection rates showed
more or less declining trend in 0-4 years, 5-9 years and 10-14 years
age groups. The prevalence of cases was not significantly different
from survey to survey (varying from 3.96 to 4.92 per thousand from
first to fifth survey). However, there was a shift in the mean age
of cases, and better survival rate of cases diagnosed at later surveys.
|KEY WORDS: TREND, CASE, INFECTION, PREVALENCE,
TUBERCULIN READING METHOD, LONGITUDINAL SURVEY.