Comparison of widal and typhoid immunoglobulin M and immunoglobulin G in rapid and early diagnosis of enteric fever

Abstract

Objective: Typhoid fever is one of the major public health problems in developing countries including India. A simple, reliable, rapid, and early diagnostic test has been one of the important needs of the clinicians. The present study was carried out to compare the Widal test and typhoid immunoglobulin M (IgM) and immunoglobulin G (IgG) rapid test in diagnosing of Salmonella typhi infection. Methods: A total of 100 cases having clinical suspicion of typhoid fever and 40 controls (20 healthy persons and 20 non-typhoidal febrile patients) were studied. Participants were investigated by blood culture, clot culture, Widal test, and typhoid IgM and IgG rapid test, and the results were compared. Results: Typhoid IgM and IgG test was positive for IgM in 70 cases and IgG for 6 cases of typhoid fever compared to Widal test which showed only 58 positive cases. The sensitivity, specificity, positive, and negative predictive value of typhoid IgM was found as 70%, 90%, 94.59%, and 54.55%, respectively. On the other hand, corresponding values for Widal test were 58%, 85%, 90.63%, and 44.74%, respectively. Conclusion: In the present study, the typhoid IgM and IgG yielded remarkable high sensitivity and specificity to diagnose typhoid fever in the first week of illness, so it is recommended to use the test in small and less equipped laboratories as a complementary test to Widal.