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(®) test.

Methods: In a prospective study, the sensitivity and specificity of Enterocheck WB(®) 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(®); 100 of them were either Enterocheck WB(®)-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(®) 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(®) was 85.5%, specificity 88.6%, negative predictive value 97.7% and positive predictive value 51.1%.

Conclusion: The Enterocheck WB(®) test can be performed at the bedside in 15 minutes and is a useful rapid method for diagnosis of typhoid fever.