We will apply technology developed in Phase I to create a rapid, simple diagnostic for C. difficile diarrhea which can be used in the field thereby widening the user base and facilitating improved patient care. This program will develop a monoclonal antibody based latex immunoassay for the detection of Toxin A and Toxin B in human fecal samples. The assay will be adapted to capillary slide technology that combines the ease of use and speed of latex tests with the control of an instrumented system for on site testing. This patented technology, the slide immunoassay (SIA) has been devised at Cambridge Biotech. For agglutination to occur two monoclonals are required. The results of the new system will be compared with the cellular cytotoxicity test and the FDA approved Enzyme Immunoassay developed in Phase I (Cytoclone A+B). Sensitivities and the elimination of non-specific reactions will be a major challenge of this effort. The need for a universal set of reference standards will be addressed. Reliable reference standards that will ensure the routine quality of testing and enable meaningful comparison of multicenter data will be developed. These standards will be used to determine the performance of the new SIA will respect to the currently available toxin based assays. Extensive testing of the SIA will be conducted in the field. A study of the prevalence of symptomatic and asymptomatic C. difficile infections in pre-school children attending day care centers will be undertaken. A testing algorithm will be developed to aid the diagnosis of C. difficile disease.
