Study of TUBEX as a Rapid Diagnostic Test of Typhoid Fever

Abstract

Background and study aim : Several serologic tests for typhoid fever have been introduced which detect IgM or IgG antibodies to various purified antigens of S. Typhi as TUBEX test. This study aims to evaluate the performance of TUBEX test as a rapid diagnostic test of typhoid fever. Patients and Methods: The present study involved 44 patients admitted to Shebin El Kom Fever Hospital fulfilling the criteria of typhoid fever by WHO as (suffering from continuous fever at least 2 days, greater than 38.5°C in addition to headache, constipation or diarrhea) without identified cause of fever as pneumonia. Compared with 20 subjects; 10 with non specific fevers and 10 without fever using TUBEX test in correlation to the usual Widal test and blood culture as a gold standard. Results: We revealed sensitivity, specificity, positive predictive value and negative predictive value respectively for Widal; 75%, 60%, 80.5%, 52.2% and for culture; 65.9%, 100%, 100%, 57.1%. In correlation with TUBEX test the results are at cutoff point 5 showing sensitivity, specificity, positive predictive value and negative predictive value respectively; 84.1%, 95%, 97.4% and 73.1%. Conclusion: TUBEX results are superior to Widal test results in specificity and slightly in sensitivity as compared to the blood culture as a reference test.