|ASSESSMENT OF DIAGNOSIS OF PULMONARY TUBERCULOSIS
BY SPUTUM MICROSCOPY IN A DISTRICT TUBERCULOSIS PROGRAMME
|K Padmanabha Rao, SS Nair, N Naganathan & R Rajalakshmi:
Indian J TB 1971, 18, 10-25.
In the District Tuberculosis Programme (DTP) the
diagnosis is based on sputum microscopy. Majority of health institutions
in the district are provided with microscopes for this purpose.
In the Peripheral Health Institutions, the programme activities
have to be carried out by its staff after a short period of training
given by District TB Centre personnel on the spot. So the microscopy
work in the PHIs is likely to be carried out by any paramedical
personnel and not necessarily by a qualified laboratory technician.
It is therefore, necessary to know whether the standard of microscopy
carried out by these paramedical personnel after a short training
will be upto the mark. To assess the efficiency of smear examination
done by these individuals, a study was conducted in Bangalore district
covering nine microscopy centres in various types of health institutions,
a few months after the implementation of the programme. Under the
DTP a spot specimen is collected from every chest symptomatic attending
the health institutions and a smear is made and examined for the
presence of AFB and all positive cases are put under treatment.
The sputum specimens and the smears examined in these nine centres
were brought to National TB Institute laboratory. The smears were
examined by an experienced laboratory technician. Duplicate smears
were also prepared from these specimens and their results compared
with results of re examination and centre's examination. All specimens
were cultured by swab method and all positive cultures were subjected
to sensitivity and identification tests.
Analysis of the results based on culture showed
that barring a few centres where the performance was poor,
the standard of examination was fairly good. The under and
over diagnosis based on culture were 38.2% and 2.6% respectively,
and these were within the limits observed generally. Comparison
of results on re examination of centre smears and duplicate smears
indicated that both reading variation and defective smear preparations
and staining could have influenced under diagnosis in these centres.
The study has also thrown some light on methodology of assessment
of sputum examination that could be adopted wherever a tuberculosis
control programme is functioning.
|KEY WORDS: CONTROL PROGRAMME, ASSESSMENT, DIAGNOSIS,