Suspected pulmonary tuberculosis in rural South Africa--sputum induction as a simple diagnostic tool?
OBJECTIVE
To assess the value of sputum induction (SI) as a diagnostic tool for patients with suspected pulmonary tuberculosis (PTB) who are unable to expectorate or who have a negative sputum smear.


METHODS
Study of an inpatient cohort undergoing SI.


METHODS
Mseleni Hospital, a rural district hospital in northern KwaZulu-Natal.


METHODS
All adult patients with suspected TB seen at the hospital over a 4-month period.


METHODS
(i) Successful SI; (ii) sputum acid-fast smear result; (iii) change of admission diagnosis as a result of the induction procedure; and (iv) number of patients discharged with a diagnosis other than TB who represented within 4 months with TB.


RESULTS
A total of 51 patients (31 female) underwent SI; of these 36 (71%) were able to produce a sputum sample. Fifteen (42%) of those were acid-fast smear-positive (29% of all patients included). The admission diagnosis was changed in 16 (44%) of the patients who were able to give an induced sputum sample as opposed to 4 (27%) who had been unable to expectorate despite an induction attempt (P = 0.38). Three (12.5%) of the 24 patients with a discharge diagnosis other than TB (17 pneumonia, 3 old TB, 2 carcinoma of the lung, 1 bronchiectasis) turned out to have TB within the follow-up period; 2 of those had extrapulmonary TB.


CONCLUSIONS
SI produced a positive smear result in 29% of patients with suspected TB who had previously been smear-negative or unable to expectorate. The method proved an aid to clinical decision making.
Hartung
T K
TK
Department of Respiratory Medicine, Ninewells Hospital, Dundee, UK.
Maulu
A
A
Nash
J
J
Fredlund
V G
VG
D000293:Adolescent; D000328:Adult; D003948:Diagnostic Techniques, Respiratory System; D005260:Female; D006801:Humans; D008297:Male; D026741:Physical Therapy Modalities / Q000379:methods*; D013183:Sputum / Q000382:microbiology*; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*