RESUMO
Detection of salmonella typhi specific antigens in urine by a slide Co-agglutination test using monoclonal salmonella typhi specific antibodies [09, Hd, Vi] was evaluated as a rapid screening test for typhoid fever in comparison to the Widal agglutination test. Out of 460 clinically diagnosed early typhoid fever cases, blood culture was positive for Salmonella typhi in 276 cases [60%]. The urine slide Co-agglutination test was positive in 253 cases [91. 66%] of blood culture proven cases. It was uniformly negative with urine samples from the control group which included 200 healthy individuals, 50 patients with febrile non typhoid infectious diseases and 50 febrile patients with non infectious diseases. The test was highly specific [100%], sensitive [91. 61%] and with a positive predictive value of 100%. As regards Widal test it was found that among the 276 blood culture positive cases 61 [22%], 72 [26%] and 82 [30%] had an [O], [H] or combined [O], [H] agglutinin respectively of titre level equal or more than 200, as compared to only 33 [33%] of the both febrile control group and 5 [2.5%] of the normal control group. The high specificity [87.33%] sensitivity [77.9%] and positive predictive value [84.98%] confirmed the value of the Widal test as an acceptable and diagnostic tool in typhoid fever. However Co-agglutination test with urine offers a simple, rapid, sensitive, specific and economical method for the diagnosis of typhoid fever within the first two weeks, in endemic areas like Egypt