Comparison of the Vi indirect fluorescent antibody test with the Widal agglutination method in the serodiagnosis of typhoid fever

The indirect fluorescent antibody test using a whole Salmonella typhi Vi suspension as the antigen has been evaluated for the diagnosis of typhoid fever. Results using sera from 140 patients with S typhi infections proved on culture show the test to have good sensitivity. The test appears to be highly specific, although it has not yet been investigated with respect to typhoid vaccination or in the context of infections due to salmonellas other than S typhi.