[Comparison between direct smear by Ziehl-Neelsen and concentrated smear by fluorochrome stain].
OBJECTIVE
For the purpose of supporting more completely our assertion that two times concentrated sputum smear tests by fluorochrome stain are more sensitive than or at least equal to 3 times direct smear tests by Ziehl-Neelsen stain, we compare the sensitivity of concentrated smear by stain (conc-smear) and direct smear by Ziehl-Neelsen stain (di-smear).


OBJECTIVE
Retrospective study of sputum acid-fast smear tests in our hospital with tuberculosis ward from Jan. 1, 2003 to Sep. 30, 2005.


RESULTS
170 of 899 sputums on which both conc-smear and di-smear were done, were smear positive by at least one of the two smear method. Of those 170, 167 (98.2%) were positive by conc-smear and 113 (66.5%) were positive by di-smear, and the difference was statistically significant (p<0.001). Of those 110 that were positive by both conc-smear and di-smear, in 65 (59.1%) smear grade by conc-smear were higher than that of di-smear, and in 3 (2.7%) smear grade by di-smear were higher than that of conc-smear. Smear grades in conc-smear were significantly higher than that of di-smear (p< 0.001).


CONCLUSIONS
In sensitivity and smear grades, conc-smear was superior to di-smear. Together with previous report, 2 times conc-smear tests are supposed to be superior to 3 times di-smear.
Ito
Kunihiko
K
Department of Research, Research Institute of Tuberculosis, JATA, 3-1-24, Matsuyama, Kiyose-shi, Tokyo 204-8533 Japan. ito@jata.or.jp
D001431:Bacteriological Techniques / Q000379:methods*; D004396:Coloring Agents; D005456:Fluorescent Dyes; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000382:microbiology
D004396:Coloring Agents; D005456:Fluorescent Dyes