Use of onsite typhoid IgG/IgM combo test as rapid diagnostic test for typhoid fever

Abstract

Abstract Background The incidence of typhoid fever is increasing in Egypt. The Widal test is the evaluation most widely used in Egypt for diagnosis, but it has many drawbacks; therefore, new diagnostic tools are needed. Our aim was to evaluate the diagnostic accuracy of the onsite typhoid IgG/IgM combo rapid test in diagnosing typhoid fever. Method Blood specimens were collected from 90 patients (of all ages) who presented with fever of more than 4 days’ duration. The OnSite Combo test and the Widal test were performed for all patients. Results The OnSite Combo test results were positive in approximately 24% of all patients; the Widal test results were positive in 18.9%; and typhoid was diagnosed through blood culture in 32.2%. The OnSite Combo test had 72.4% sensitivity, 98.4% specificity, a positive predictive value of 95.5%, and a negative predictive value of 88.2%. In contrast, the Widal test had 51.7% sensitivity, 69.7% specificity, a positive predictive value of 88.2%, and a negative predictive value of 80.8%. Conclusions The onsite combo test was more efficacious than the Widal test in diagnosing typhoid fever.