Evaluation of false negativity of the Widal test among culture proven typhoid fever cases.

Abstract

BACKGROUND: The Widal test is the most common, specific and quick diagnostic method available in the world for diagnosis of typhoid fever; however, false negativity is one of the obstructive features of the test. The aim of this study was to evaluate the associated factors with Widal test negativity in an endemic area. METHODS: Widal test negativity was retrospectively analyzed among culture-proven typhoid fever cases. The potential features including age, gender, previous antibiotic usage, duration of symptoms, leucopoenia, hematocrit value, and erythrocyte sedimentation rate (ESR) were evaluated for association with Widal test negativity. RESULTS: A total of 166 culture-proven typhoid fever cases (93 or 56.0% males) were included in the study. The mean age +/- SD was 23.3 +/- 10.6 years. Mean time of interval between first symptom and test performance time was 10.6 +/- 7.8 days. The Widal test (STO and/or STH) was found positive in 75 cases (45.2%). The statistical analyses revealed that none of these variables were significant for false negativity of the Widal test. Age was found to be a possible factor for a false negative Widal test (p=0.06). CONCLUSION: Of existing compatible clinical findings, age should be considered in cases of Widal test negativity.