Inefficiency of 0.3% carbol fuchsin in ziehl-neelsen staining for detecting acid-fast bacilli.
We compared the sensitivity and specificity of a modified Ziehl-Neelsen (modified-ZN) staining method for acid-fast bacilli (AFB) with that of the standard Ziehl-Neelsen (standard-ZN) staining method, using culture results with Mycobacterium tuberculosis as the "gold standard." The sensitivity (72%; 101 of 140) of the modified-ZN staining method, which uses 0.3% carbol fuchsin, was significantly lower than that of the standard-ZN staining method (84%; 117 of 140); the modified-ZN method missed 21% of cases detected by the standard-ZN method and 11% more of culture-positive samples than the standard-ZN method. The World Health Organization recommendation of 0.3% carbol fuchsin in the ZN method for staining AFB needs to be reconsidered.
Selvakumar
N
N
Tuberculosis Research Centre, Indian Council of Medical Research, Chennai, 600 031 Tamil Nadu, India. selvakumarn@hotmail.com
Rahman
Fathima
F
Rajasekaran
S
S
Narayanan
P R
PR
Frieden
Thomas R
TR
D004396:Coloring Agents; D003470:Culture Media; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012394:Rosaniline Dyes; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D013194:Staining and Labeling / Q000379:methods / Q000592:standards*; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*; D014944:World Health Organization
D004396:Coloring Agents; D003470:Culture Media; D012394:Rosaniline Dyes; C006898:carbol-fuchsin solution