Comparison of four laboratory tests for diagnosis of Clostridium difficile-associated diarrhea.
Four different laboratory tests for diagnosis of Clostridium difficile-associated diarrhea were compared to determine the optimal one for management of patients with hospital-acquired diarrhea. Stool samples from 231 patients with diarrhea were tested by the following methods: culture for Clostridium difficile with subsequent determination of exotoxin production, with a toxigenic Clostridium difficile positive (TCP) result considered truly positive; enzyme immunoassay (EIA); latex agglutination test; and an immunobinding blot assay. The rates of positive results were as follows: EIA 5.5%, TCP 7.3%, latex agglutination 16.7%, and immunobinding blot assay 26.1%. Compared to the TCP results, the sensitivity and specificity were, respectively, 61 and 98% for EIA, 47 and 85% for latex agglutination, and 60 and 76% for the immunobinding blot assay. Samples from patients with > or = 6 stools/day were TCP and EIA positive in 27 and 17% of cases, respectively, whereas in patients with < 6 stools/day, these percentages decreased to 2 and 3%, respectively (p < 0.001). In hospitalized patients with > or = 6 stools/day, EIA appears to be the optimal test for diagnosis of Clostridium difficile-associated diarrhea, with a 73% positive predictive value and a 97% negative predictive value. However, in patients with < 6 stools/day, the prevalence of Clostridium difficile is low, and laboratory detection of this organism remains problematic.
Jacobs
J
J
Department of Geriatrics, Shaare Zedek Medical Center, Jerusalem, Israel.
Rudensky
B
B
Dresner
J
J
Berman
A
A
Sonnenblick
M
M
van Dijk
Y
Y
Yinnon
A M
AM
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001431:Bacteriological Techniques; D019411:Clinical Laboratory Techniques / Q000379:methods*; D016360:Clostridioides difficile; D003428:Cross Infection; D003967:Diarrhea / Q000175:diagnosis* / Q000188:drug therapy; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000188:drug therapy; D005098:Exotoxins / Q000096:biosynthesis; D005243:Feces / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007841:Latex Fixation Tests; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D000900:Anti-Bacterial Agents; D005098:Exotoxins