Baseline Widal Titres among Healthy Volunteers

Objective Enteric fever is an endemic problem in India. The objective of this study was to determine average base -line widal titres among healthy volunteers in and around Tirunelveli. Materials and Methods Cross-sectional study was done on 200 voluntary blood donors. Widal titres were measured using Standard quantitative tube agglutination test. Results Among the 200 blood samples,70 were male 130 were female. A total of 122 individuals had titres greater than 20 for O agglutinins 136 individuals had titres greater than 20 for H agglutinins.Among the total population,53 individuals had only H agglutinins positive, while 39 individuals had only O agglutinins positive. Since positive sera with titres greater than 80 occurred in more than 5percentage of population, this could be taken as presumptive diagnosis of enteric fever in study area. Conclusion Thus the titres of greater than 180 for O agglutinins and greater than 1160 for H agglutinins are base line widal titres, when obtaining second serum sample is impractical.