Comparison of Diagnostic Accuracy in Enteric Fever: The Widal Test, Advantage Typhi, and Typhiwell IgM ELISA Against...

Introduction Enteric fever remains a significant public health issue in developing countries, where timely and accurate diagnosis is crucial for appropriate therapy and infection control. This study aimed to evaluate the diagnostic performance of the Widal test and two rapid IgM-based assays (Advantage Typhi and Typhiwell IgM enzyme-linked immunosorbent assays (ELISA)) compared with blood culture, the gold standard. Methods A prospective study involving 410 clinical samples from patients with suspected enteric fever based on clinical findings was conducted between December 2015 and June 2017. Blood culture, the Widal test, and two rapid Salmonella IgM assays (Advantage Typhi and Typhiwell IgM ELISA) were performed. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated. Results The Widal test demonstrated a sensitivity of 70.18%, a specificity of 74.22%, a PPV of 30.53%, an NPV of 93.91%, and an overall diagnostic accuracy of 73.66%. Advantage Typhi exhibited low sensitivity (12.28%) with moderate specificity (81.02%). The Typhiwell IgM ELISA showed the greatest sensitivity (88.46%) and the highest NPV (97.50%), but had reduced specificity (47.37%), leading to the highest overall diagnostic accuracy (95.89%). Conclusions The Typhiwell IgM ELISA provides improved diagnostic accuracy and may function as a rapid and effective diagnostic method in endemic regions. However, it should be used as a complementary test rather than a substitute for blood cultures. Additional studies, including molecular methods, are recommended to further enhance overall diagnostic accuracy.