Utility of a rapid latex test for the detection of Clostridium difficile in fecal specimens

Currently, the method of choice for the laboratory diagnosis of Clostridium difficile disease is the detection of cytotoxin in stool filtrates by tissue culture. Since many hospital laboratories do not have tissue culture facilities, there is a need for a rapid test which is both sensitive and specific to diagnose C. difficile disease. A commercial latex agglutination was compared with the conventional cytotoxin tissue culture assay for the detection of C. difficile or its toxin(s) in fecal specimens. Of the 574 specimens evaluated, 111 were cytotoxin positive while 97 were positive by the latex agglutination test. There were 17 specimens positive by latex agglutination but negative by tissue culture assay. The overall sensitivity and specificity of the CDT latex test was 86.1 percent and 95.3 percent respectively. This rapid latex test can serve as an excellent screening procedure for the presence of C. difficile. Those specimens positive by the latex test should be further evaluated for the presence of cytotoxin by tissue culture.