Comparison of four methods in the diagnosis of Clostridium difficile disease.
Nine hundred forty-five stool specimens from patients suspected of having Clostridium difficile disease were examined using a cell culture cytotoxicity assay (CTA), two enzyme immunoassay (EIA) kits (Cytoclone for toxins A and B; VIDAS for toxin A) and a latex agglutination assay (CDT). One hundred nineteen specimens had positive titers (> or = 90) in the CTA; clinical review of 16 discordant samples and 49 controls supported the significance of 90 as the positive cut-off titer. The performance of the two EIAs and the latex assay was assessed relative to CTA titers of the samples. Sensitivity was < or = 50% for all three assays for the 24 specimens with CTA titers of 90, but it reached 97-100% for the two EIAs and 84% for the latex assay at titers of > or = 2,250. The Cytoclone EIA exhibited higher sensitivity at the lower positive titers. Overall, specificity of the methods ranged from 96.7% (CDT latex assay) to 99.1% (Cytoclone EIA).
Mattia
A R
AR
Clinical Microbiology Laboratories, Massachusetts General Hospital, Boston 02114.
Doern
G V
GV
Clark
J
J
Holden
J
J
Wu
L
L
Ferraro
M J
MJ
D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000032:analysis; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003601:Cytotoxicity Tests, Immunologic; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis*; D004768:Enterotoxins / Q000032:analysis; D005243:Feces / Q000382:microbiology; D006801:Humans; D007124:Immunoenzyme Techniques; D007841:Latex Fixation Tests; D012680:Sensitivity and Specificity
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile