Diagnostic Accuracy of Rapid Diagnostic Tests for Typhoid Fever among Patients in Ga West Municipality, Ghana

Abstract

Background: Typhoid fever remains a major public health challenge in many low- and middle-income countries, particularly in sub-Saharan Africa, where diagnostic limitations complicate the management of febrile illness. Rapid diagnostic tests (RDTs) are widely used as point-of-care tools in resource-limited settings, but concerns remain about their diagnostic accuracy in endemic settings. Aim: This study assessed the diagnostic accuracy of RDTs for typhoid fever among febrile patients in Ga West Municipality, Ghana. Methods: A quantitative cross-sectional design was used to recruit 284 febrile patients from health facilities in Ga West Municipality. Each participant underwent both RDT and blood culture testing, with blood culture serving as the reference standard. We calculated diagnostic accuracy parameters, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and conducted hypothesis tests to assess diagnostic misclassification. Results: The RDT showed an observed sensitivity (100%) and a negative predictive value of 100% in the study sample. However, specificity was poor (52.5%), and the positive predictive value was extremely low (5.8%), reflecting a substantial number of false-positive results. The diagnostic misclassification rate was 46.1%, and the reported hypothesis tests rejected all three null hypotheses (P<0.05). Conclusion: Although the RDT showed high observed sensitivity in this sample, its poor specificity and low PPV make it unreliable for definitive typhoid diagnosis in this setting. The study recommends confirmatory testing for all positive RDT results and supports improvements in diagnostic algorithms to guide clinical decision-making and reduce inappropriate antibiotic use in febrile illness management.