Early and rapid microscopy-based diagnosis of true treatment failure and MDR-TB.
METHODS
Damien Foundation tuberculosis (TB) control project in Bangladesh.


OBJECTIVE
Early diagnosis of true TB treatment failure and multidrug resistance (MDR) for more efficient DOTS-Plus.


METHODS
Prospective comparison of performance on smear-positive sputum of fluorescein diacetate (FDA) vital staining vs. culture, and of slide drug susceptibility testing (slide DST) vs. the Löwenstein-Jensen (LJ) proportion method.


RESULTS
FDA reached 92% positive and 97% negative predictive value directly on fresh sputum, but only 94% and 62%, respectively, on transported smears. Accuracy on washed cetylpyridinium chloride transported sputum was similar to that on fresh sputum. Slide DST on fresh smear-positive sputum failed less often than LJ DST, with 96% accurate results for rifampicin and MDR-TB diagnosis. Good results were obtained for isoniazid (90% accuracy), but not for ethambutol or streptomycin.


CONCLUSIONS
We can confirm that FDA staining allows rapid screening for viable acid-fast bacilli and true treatment failure in delayed smear converters or smear-defined failures, while slide DST assures fast and accurate confirmation of MDR-TB in selected populations. The tests can be applied safely in resource-poor settings. Their successive use could be an efficient strategy for screening and an early start on standardised regimens of DOTS-Plus candidates.
Hamid Salim
A
A
Damien Foundation Bangladesh, Dhaka, Bangladesh.
Aung
K J M
KJ
Hossain
M A
MA
Van Deun
A
A
D000995:Antitubercular Agents / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003937:Diagnosis, Differential; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011446:Prospective Studies; D015203:Reproducibility of Results; D013183:Sputum / Q000382:microbiology*; D013997:Time Factors; D017211:Treatment Failure; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy* / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy* / Q000382:microbiology
D000995:Antitubercular Agents