English

Abstract

AIM AND OBJECTIVE: The interpretation of the Widal test depends upon the baseline titre among healthy individuals in a particular geographical area. This study was undertaken to determine the baseline Widal titre in apparently healthy individuals in, Hadoti region, Rajasthan. MATERIALS AND METHODS: Blood samples were collected from healthy blood donors (n= 200) who attended blood bank of this institution from May 2012 to August 2012. The Widal tube agglutination test was carried out. 0.5 ml of two fold serially diluted patients' sera (dilutions from 1:20 to 1:160) in 0.9% normal saline was tested by adding an equal amount of antigen. RESULTS: Of the 200 serum samples which were tested, 108 serum samples were positive for agglutinins against Salmonella serotypes (≥ 1:20) and 92 serum samples were negative for agglutinins. Among 54 samples with an anti-O titer (≥ 1:20) , 39 samples had titres of 1:40. Among the 63 samples demonstrating anti-H titres of ≥ 1:20 to salmonella serotype, 48 had a titer of 1:40. For salmonella Paratyphi A and B, anti-H titres of 1:20 were found in 3% and 1.5%, respectively, of all samples tested. CONCLUSION: We recommended that the significant titre of the 'H' agglutinin and the 'O' agglutinin of Salmonella Typhi is ≥ 1: 80. While the significant titre of the 'H' agglutinins of Salmonella Paratyphi A and Salmonella Paratyphi B is ≥ 1: 40.