Improved sensitivity of sputum smear microscopy after processing specimens with C18-carboxypropylbetaine to detect acid-fast bacilli: a study of United States-bound immigrants from Vietnam.
The goal of this study was to evaluate the effect of the specimen-processing method that uses the detergent C18-carboxypropylbetaine (CB-18) on the sensitivity of acid-fast bacillus (AFB) staining. Vietnamese immigrants with abnormal chest radiographs provided up to three sputum specimens, which were examined for acid-fast bacilli by use of direct auramine and Ziehl-Neelsen staining. The remaining sputum was split; half was cultured, and the other half was incubated with CB-18 for 24 h, centrifuged, and examined for AFB by both staining methods. CB-18 processing improved the sensitivity of AFB staining by 20 to 30% (only differences in auramine sensitivity were statistically significant) but reduced specificity by approximately 20% (P < 0.05). These findings have direct utility for overseas migrant tuberculosis screening programs, for which maximizing test sensitivity is a major objective.
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E-10 Atlanta, GA 30333, USA. klaserson@cdc.gov
K F
KF
Laserson
N T N
NT
Yen
C G
CG
Thornton
V T C
VT
Mai
W
W
Jones
D Q
DQ
An
N H
NH
Phuoc
N A
NA
Trinh
D T C
DT
Nhung
T X
TX
Lien
N T N
NT
Lan
C
C
Wells
N
N
Binkin
M
M
Cetron
S A
SA
Maloney
D000328:Adult; D001576:Benzophenoneidum; D001622:Betaine / Q000031:analogs & derivatives*; D004641:Emigration and Immigration; D006801:Humans; D008853:Microscopy / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000382:microbiology*; D013194:Staining and Labeling; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology; D014481:United States; D014744:Vietnam
C114390:C(18)-carboxypropylbetaine; D001576:Benzophenoneidum; D001622:Betaine