|EVALUATION OF SPUTUM SMEARS PREPARED BY DIFFERENT
|N Naganathan, KT Ganapathy & R Rajalakshmi: Indian
J Med Res 1979, 69, 893-900.
Sputum microscopy is the main casefinding tool
in tuberculosis control programmes. The technique of smear preparation
is an important step which needs to be simple for wide applicability.
It is often stressed that smear should be prepared from the purulent
portions of the sputum as they are likely to have more number of
bacilli. It may not be possible for the microscopist/paramedical
worker at the periphery to strictly follow this procedure. Hence,
a study was conducted to compare the sensitivity of 4 methods of
sputum smear preparation viz., direct smear prepared (i) blindly
without making any selection of portions of sputum specimen, (ii)
from portions of sputum material likely to contain the bacilli,
(iii) after mixing up the sputum specimens thoroughly, and (iv)
from centrifuged deposit after homogenization of sputum with sodium
hydroxide and concentration by centrifugation. Culture was also
done for Mycobacterium tuberculosis.
A total of 549 specimens were employed. Positivity
rates by four methods were: 79.6% by method (i), 80.3% by method
(ii), 80.7% by method (iii) and 77.2% by method (iv). There was
no statistically significant difference in the number of positives
obtained from different methods. Centrifuged deposit smears proved
to be in no way better than the direct smears. The differences
in the methods lay only in the classification of positive smear
as of a low or high grade.
|KEY WORDS: SMEAR EXAMINATION, SENSITIVITY METHODS,
|VALUE OF SPUTUM EXAMINATION IN PREDICTING PROGNOSIS
DURING SHORT COURSE CHEMOTHERAPY
|Sujatha Chandrasekaran, R Rajalakshmi & P Jagota:
NTI Bulletin 1993, 29, 41-44.
Culture examination of sputum is known to be the
best tool for assessing the prognosis of pulmonary tuberculosis
patients. Controlled clinical trials with Short Course Chemotherapy
(SCC) have shown that culture examination of sputum at the end of
two months elicited a high degree of conversion, while smear results
were inferior due to presence of dead organisms in the sputum. But,
it is not possible to provide sputum culture facilities in the District
TB Programme (DTP). Since smear examination facilities is widely
available under the DTP, this paper examines the comparability of
smear results with culture in patients treated with SCC. It also
examines the value if any, of an early evaluation of the treatment
outcome with SCC under operational conditions by doing smear examination
at two months. Data from two operational studies on SCC are utilised
for this purpose.
Of 256 total patients examined, 62 were smear positive
at the end of two months, but 41 of them were excreting non- viable
bacilli and were culture negative. Nevertheless, in predicting the
final outcome of chemotherapy, no significant difference was observed
between smear and culture examination at the end of two months.
Smear positivity at the end of 2 months, by itself, cannot be considered
to bode an unfavourable response, whereas negativity had a good
probability of a favourable response. Microscopy in SCC gave
as reliable a result as culture both during and at the end of chemotherapy.
Hence, a properly conducted smear examination is as good as culture
for diagnostic and prognostic purposes under operational conditions.
|KEY WORDS: SMEAR EXAMINATION, SCC, PREDICTIVE
VALUE, CONTROL PROGRAMME, FIELD CONDITIONS.