Study of respiratory symptoms among sputum positive

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smaller volumes. Quality and quantity of sputum specimens were assessed
independently. The likelihood of a positive smear is increased three-folds,
and that of a culture two folds when sputum quality is good, irrespective of
sputum quantity. In specimens of sufficient quantity, both smear and
culture positivity are doubled when compared to specimens with a volume
of less than 3m!. More than 80 % of positive smears and cultures are
originated from specimens of good quality and of sufficient quantity.
Macroscopical evaluation of sputum specimens contributes to optimizing
laboratory diagnosis, and may have a financial impact on the cost involved
in the diagnosis ofpulmonary TB (Weyer, 1990 and kramer et aI., 1990).
2) Sputum induction:
There are several methods for obtaining sputum from the cooperative
patients with non productive cough. One ofthese methods is the inhalation
of warm, aerosolized hypertonic (5 % -10 % ) saline which irritates the
lungs enough to induce both coughing and the production ofa thin, watery
specimen. After induction, patient may cough and produce additional good­
quality specimens, which should also be submitted to the laboratory (ATS,
1990). It has been concluded that in addition to obtaining sputum from
patients who are unable to expectorate, sputum induction may have a useful
role in improving the care detection rate ofsmear positive pulmonary TB,
particularly in areas where facilities for more invasive and expensive
techniques such as fibreoptic bronchoscopy are not available (Parry et aI.,
1995).
3) Bronchoscopic specimens:
When neubulization is ineffective or an immediate diagnosis is
needed bronchoscopy is the next best choice because this procedure
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