Detection of Salmonella typhi D, Vi, and d antigens, by slide coagglutination, in urine from patients with typhoid fever.

Salmonella typhi antigens D, Vi, and d were detected in the urine of 59 out of 61 (97%) bacteriologically confirmed typhoid fever patients by slide coagglutination with monovalent antisera coupled to protein A-rich staphylococci. These antigens were also detected in the urine of an additional 22 patients, 16 of whom subsequently demonstrated seroconversion by S. typhi O antibody agglutination, but from whom the bacterium was not isolated. The remaining 13 patients had negative urine coagglutination results, no isolation of S. typhi from blood or stool specimens, and no demonstration of seroconversion. These results suggest that the method of slide coagglutination of urine can be used to screen patients with suspected typhoid fever with a high degree of reliability. The method may also have potential importance in the diagnosis of typhoid when the bacterium is not isolated.