Evaluating alternatives to the Widal test for typhoid fever diagnosis in developing countries: A targeted literature review.

Abstract

Background: Typhoid disease, caused by Salmonella typhi, is prevalent in developing countries with poor sanitation. The Widal test, despite its century-old history, has drawbacks in diagnostic capacity because of inherent characteristics, cross-reactivity and repeated exposure to the pathogen in endemic regions.

Aim: The study evaluates the utility of the Widal test for the diagnosis of typhoid infections and emphasises the need for a better diagnostic modality in endemic regions.

Setting: The study included research conducted in developing countries where typhoid fever is endemic.

Method: A targeted literature review was conducted utilising the MEDLINE and Embase databases on 19 October 2022, encompassing publications from the preceding 10 years. Manual searches were executed using Google Scholar and the Google Search Engine on 02 November 2022. The initial search yielded 657 articles, of which 20 met the inclusion criteria and were subsequently incorporated into the final review.

Results: The mean sensitivity, specificity, positive predictive value and negative predictive value of the Widal test in this study were 62.94 ± 17.83 (95% confidence interval [CI]: 49.23-76.64); 73.31 ± 18.75 (95% CI: 58.89-87.73); 58.85 ± 40.07 (95% CI: 16.80-100.90) and 75.96 ± 25.93 (95% CI: 46.08-100.45), respectively.

Conclusion: The different studies in this review have shown that the Widal test performs poorly in identifying typhoid infections compared to other rapid diagnostic tests (RDTs). In addition, the current alternative RDTs are not accurate enough to reliably identify or rule out typhoid infection.

Contributions: A shift in diagnostic approach for typhoid fever in developing countries is required and an accurate and feasible point-of-care test is urgently needed.