Comparative analysis of widal agglutination and typhoid humoral response assays in febrile patients at Kebbi State, Nigeria

Abstract

Typhoid fever is a life-threatening diseases caused by Salmonella enterica serovar Typhi that poses high-level of public health concern especially in Sub-Saharan Africa. Essentially, inadequate or inappropriate diagnosis of the human salmonellosis could be a factor that facilitated its dissemination in Nigeria. To determine the sensitivity and specificity of serological widal and Typhoid IgG/IgM tests in comparison with blood culture as a reference for typhoid diagnosis among febrile patients attending three public hospitals in Kebbi State, Nigeria. A hospital based cross-sectional study was carried out among 406 febrile patients with suspected typhoid fever (mean age = 34 years). Blood culture for bacterial isolation, subjects widal and Salmonella enterica serovar typhi IgM/IgG tests were performed on all participants by the use of selective bacteriological media, slide agglutination, rapid Typhoid IgG/IgM lateral flow immunochromatographic assay, respectively. Positive Salmonella typhi culture was obtained in 6.4% of the participants, of which a higher rate was recorded among males 7.5% than in females 5.0% participants. Anti-typhoid IgM and IgG were detected 25.1% and 21.9% of the participants while the widal agglutination was positive in 52% of the participants.. The sensitivity, specificity, positive, and negative predictive value of typhoid IgM was found as 88.46%, 79.21%, 22.55%, and 99.01%, respectively. Whereas, 65.38%, 48.95%, 8.06%, and 95.39% were obtained for Widal agglutination test, respectively. Based on these findings, the typhoid IgM and IgG demonstrated better diagnostic performance for serological identification of typhoid in the first week of illness than widal test. Hence, so it is suggested that healthcare facilities to considering replacing the widal test by typhoid IgM/IgG tests in cases when urgent test results are necessary in lieu of culture that has long turnaround time.