Duration of appearance of Vi antigen and Salmonella typhi in blood and urine of infected models.

Salmonella typhi (S typhi) infected models were established to evaluate the latex agglutination test (LAT) and staphylococcal coagglutination test (SCT) for the detection of S typhi Vi antigen in blood and urine. Antigens in serum or urine were detected within 7 days after infection with positive cultures, and decreased in 2 weeks. LAT and SCT were positive in 7 mice with no bacteria isolation from blood and urine but their spleen aspirates yielded S typhi. Both tests are rapid and sensitive and may be used for the diagnosis of typhoid infection, especially in partially treated patients when their blood cultures are negative.