Standardisation of the Widal test.

In the past, a number of studies had been carried out to evaluate the significance and interpretation of a single Widal result in the diagnosis of typhoid fever in this country. Hand/or o agglutinin titres of ~1:40 to ~1 :500 had been recommended as significant levels in the absence of paired sera results. 1 , 2 , 3 Though at least two of the authors had acknowledged that these ~ criteria were only applicable to their laboratories, many clinicians and epidemiologists were not aware of it and may have considered it as applicable universally. In this communication, I would like to reemphasize that there is a lot of interlaboratory variation in the performance of the Widal test." Therefore it is inappropriate to use any of the criteria in another laboratory which may be using a different technique.