Detection and diagnosis of Salmonella typhi from stool and blood samples using Widal, Tubex<sup>-tf</sup> and polymerase chain reaction

Abstract

There are currently no effective, quick, and sensitive techniques for identification of Salmonella serovar Typhi. Typhoid fever is difficult to diagnose clinically in highly endemic areas, since the symptoms are vague and similar with other febrile disorders such as malaria, and dengue fever. Considering the challenges involved with typhoid diagnosis by blood culture and serology, the PCR approach has lately been used, however it is not the gold standard for typhoid diagnosis. The aim of this study is to determine the best diagnostic method used for detection of typhoid fever using Widal test, Tubex-tf and fecal culture for the detection of typhoid. Blood and stool samples were collected from febrile patient and were screened by Widal and Tubex-tf tests, while stool samples were screened for Salmonella Typhi by culture and PCR for confirmation. The results of stool samples obtained after screening by culture, biochemical tests and confirmation by PCR did not confirm Salmonella Typhi bacteria. The 28 blood samples have a corresponding rate of 0% Tubex-tf and Widal was 93.3%. Therefore, this study suggests that Tubex-tf should be offered in typhoid-endemic areas and also recommends its use in the diagnosis of typhoid fever because the results obtained correlate with stool culture leading to PCR Confirmation. Accurate diagnosis before establishing a case of febrile typhoid fever is very important, similarly, sensitivity should dictate the best of antibiotics to be used for treatment.