|SIGNIFICANCE OF PATIENTS WITH X-RAY EVIDENCE OF
ACTIVE TUBERCULOSIS NOT BACTERIOLOGICALLY CONFIRMED
|SS Nair: Indian J TB, 1974, 21, 3-5.
Available data from longitudinal study (1961-68)
from several different situations have been reviewed to understand
the significance of patients showing radiological evidence of pulmonary
tuberculosis without bacteriological confirmation. SITUATION IN
GENERAL POPULATION: Few of the smear negative but X-ray active tuberculous
patients (suspect cases) found in a survey of rural population done
by National TB Institute, were culture positive (7-10%). On follow
up for 18 months, only 3% of them became culture positive under
conditions where intervention with specific treatment was absent
or minimum. It is thus concluded that most of the cases diagnosed
as active tuberculosis on the basis of single X-ray are not likely
to be cases of tuberculosis. SITUATION AMONG SYMPTOMATICS ATTENDING
HEALTH INSTITUTIONS: Data from the State TB Demonstration and Training
Centres (STDTC) and the District Tuberculosis Programmes (DTP) have
been presented. The New Delhi Tuberculosis Centre records (1970)
show that only 27% of microscopy negative radiologically positive
patients were confirmed on culture. For Bangalore and Agra STDTC,
the proportions so confirmed were 20% and 25% respectively. It has
been calculated that in the DTPs, not more than 30% of the microscopy
negative radiologically positive patients could be the real cases
of tuberculosis. In the DTP situation not more than 10% of the suspect
cases may develop bacteriologically confirmed disease. Thus, not
many of the suspect cases could be real cases of tuberculosis either
on the basis of confirmation by culture or on the basis of development
of bacteriologically positive disease in future.
Are the cases diagnosed early by
radiology? The hypothesis that X-ray discovers cases in the
early stages has not yet been put to a scientific test. Further,
the large differences even between experienced readers in interpreting
X-ray shadows, render the method of X-ray diagnosis questionable.
Is anti tuberculosis treatment of suspect cases warranted?
The possible advantage of considering treatment of suspect cases
as chemoprophylaxis has to be weighed against conservation of resources
for treatment of infectious cases and the possible harmful effects
of anti TB drugs to persons who are not suffering from tuberculosis.
|KEY WORDS: CHEST SYMPTOMATICS, RURAL COIMMUNITY,