Rapid detection of typhoid carriers by means of fluorescent antibody techniques.

Fluorescent antibody techniques have proved advantageous for rapid detection of enteropathogenic Escherichia coli. Previous attempts to adapt these procedures to the rapid identification of Salmonella typhi have been limited by the number of cross-reactions obtained when a polyvalent Salmonella or a S. typhi O conjugate was used to stain faecal smears. The results obtained using a purified Vi conjugate and a S. typhi O, Vi conjugate to screen faecal smears from a number of typhoid carriers are described in this report. The data show that essentially the same number of carriers were found positive by fluorescent antibody as were found by conventional bacteriological methods, although each technique missed a number of positive specimens that were detected by the other. The immunofluorescent technique has the advantage of being more rapid and economical to perform than cultural procedures.