Evaluation of a commercial latex agglutination assay for screening for Clostridium difficile-associated disease.
OBJECTIVE
To determine if the Clostridium difficile latex agglutination assay is an effective screening procedure for the diagnosis of C. difficile-associated disease (CDAD).


METHODS
Convenience sample.


METHODS
The Washington Hospital, a 364-bed, secondary, acute-care center in Washington, Pennsylvania.


METHODS
A total of 321 women and 195 men aged 21 days to 100 years.


METHODS
Diarrheal stool specimens from patients on antibiotic therapy were randomly tested for the presence of C. difficile-associated antigen by CULTURETTE brand latex agglutination assay (Beckton Dickinson Microbiology Systems, Cockeyesville, MD 21030). Latex-positive samples were confirmed or negated by cytotoxin assay using the Toxi-titer microtiter plate system (Baxter Healthcare Corp., Bartels Diagnostic Division, Issaquah, WA 98027).


METHODS
Comparative statistical analysis of the raw data to develop the sensitivity and specificity of the latex screening assay.


RESULTS
Stool specimens of 403 patients (78.1%) were negative for C. difficile-associated antigen. Of the latex-positive specimens, 70 (69.3%) were also cytotoxin-positive. Of the indeterminate latex specimens, four (33.3%) were cytotoxin-positive. A total of 70 specimens (13.6%) were positive by both methods and 74 patients (14.3%) were diagnosed with CDAD. Based on this data, the latex agglutination screening assay had a sensitivity of 77.1% and a specificity of 93.4%.


CONCLUSIONS
Latex agglutination for C. difficile-associated antigen is a moderately sensitive screening test for a presumptive diagnosis of CDAD. However, it is not the best screening test for CDAD compared with the new enzyme-linked immunosorbent assay (ELISA) techniques for toxins A and B.
Washington Hospital, Pennsylvania, USA.
P A
PA
Stella
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000276:immunology; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007841:Latex Fixation Tests; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity