RAPID DIAGNOSIS OF TYPHOID-FEVER BY DETECTION OF BARBER PROTEIN AND VI-ANTIGEN OF SALMONELLA SEROTYPE TYPHI

Co-agglutination (coagg) and latex agglutination (LA) tests were used for the detection of Salmonella serotype Typhi Vi and Barber protein ( BP) antigens in sera from five groups of individuals (A-E). Group A co nsisted of 30 blood culture-positive cases of typhoid fever and group B consisted of 30 suspected cases of typhoid fever who had sterile blo od cultures but positive Widal tests. Thirty cases of pyrexia of unkno wn origin (PUO) were placed in group C, while group D consisted of 15 cases of septicaemia caused by organisms other than Salmonella serotyp e Typhi. Group E comprised 50 normal healthy individuals with no histo ry of typhoid fever or TAB vaccination in the previous 5 years. The Vi -LA test performed best with 96.7 % of group A sera and 90 % of group B sera giving positive results. No false positive results and only 2.5 8 % false negative results were obtained with this test. Considering p atients with positive blood culture results or positive Widal tests as true positives, the sensitivities of the Vi-LA, BP-LA, Vi-coagg and B P-coagg tests were 93.3, 91.7, 83.3 and 86.7 %, respectively. The spec ificities of these tests were 100, 98.5, 98.5 and 98.5 %, respectively . It is suggested that the Vi-LA test can be used for the rapid and ea rly diagnosis of typhoid fever.