Comparison of a rapid commercial test, Enterocheck WB®, with automated blood culture for diagnosis of typhoid fever

Background: Rapid diagnosis of typhoid fever is very important in the timely initiation of therapy. Objectives: To evaluate the sensitivity and specificity of the Enterocheck WB (R) test. Methods: In a prospective study, the sensitivity and specificity of Enterocheck WB (R) that detects IgM antibodies to Salmonella typhi were compared with blood culture using BacT/Alert. Results: Four hundred and fifty patients with suspected typhoid fever were assessed both by blood culture and Enterocheck WB (R); 100 of them were either Enterocheck WB (R)-positive or blood culture-positive or both for S. typhi. Both tests were positive in 47 of the 100 patients. In 45 patients, Enterocheck WB (R) was positive but blood culture was negative. In eight cases, Enterocheck was negative but blood culture was positive. Using blood culture as the gold standard, the sensitivity of Enterocheck WB (R) was 85.5%, specificity 88.6%, negative predictive value 97.7% and positive predictive value 51.1%. Conclusion: The Enterocheck WB (R) test can be performed at the bedside in 15 minutes and is a useful rapid method for diagnosis of typhoid fever.