Diagnostic Value of Widal Test in the Diagnosis of Typhoid Fever: A Systematic Review

Introduction: Typhoid fever the common cause of morbidity and mortality especially in the developing countries where Widal test is routinely used as diagnostic tool to rule out the disease. The diagnostic ability of Widal test is debatable as the test method has a low sensitivity, specificity and positive predictive value (PPV). Therefore, reviewing articles across the world regarding the diagnostic value of Widal test is necessary. Methods: Systematic review of published articles regarding the diagnostic value of Widal test to rule out typhoid fever was carried out. Published articles were identified from PubMed, Google scholar, HINARI and other sources. The mean, median, percentile and standard deviation of sensitivity, specificity, NPV and PPV of the reviewed articles were computed by SPSS software version 24. Results: A total of 16 articles were included in the systematic review with the oldest publication in the year 1994 and the recent in 2015. The mean sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Widal test was 73.5%, 75.7%, 60% and 75.2%, respectively. Conclusion: The systematic review results show that the reliability of Widal test is comparatively poor. Therefore, Widal test should not be used as a diagnostic tool to rule out typhoid fever unless supported by invasive clinical pictures and other confirmatory tests.