Comparative Assessment of the Rapid Immune Chromatographic Test (RICT) and Direct Fluorescent Antibody Test (DFAT) for Rapid and Accurate Laboratory Diagnosis of Rabies

Rabies is a fatal zoonotic disease that continues to present a public health challenge globally, in particular the endemic regions such as sub-Saharan Africa. In Nigeria, rabies is mainly acquired through dog-mediated exposures, and indeed the true burden is often underestimated due to poor surveillance and diagnostic tools. Rapid and accurate laboratory diagnosis is vital to effective post exposure prophylaxis (PEP) and outbreak control. The Direct Fluorescent Antibody Test (DFAT), is considered to be the gold standard and is reliable for detecting rabies, but it requires proper trained personnel and specialized equipment which is needed in many resource-limited areas. This investigation examined how good a Rapid Rabies Test (RRT), a type of Rapid Immune Chromatographic Test (RICT), is by comparing it to the DFAT on a cohort of 234 canine brain tissues from Nigeria’s North Central states (Benue, Nasarawa, and Plateau). The DFAT found a prevalence of Rabies virus (RABV) antigens of 8.12% in the cohort examined. The RRT diagnostic test was found to have a sensitivity of 78.9% (95% CI: 56.7–92.2%), and specificity of 98.1% (95% CI: 95.7–99.4%). The high specificity of the RRT diagnostic test supports its use as a quick and on-site screening mechanism for rabies and as an early detection test, while the moderate sensitivity indicates that some cases may be missed, resulting in a false negative test result. This report concludes that RRT is a great preliminary screening tool for rabies in the field, and is certainly an acceptable test for rabies screening, it should not be used as a stand-alone diagnostic test and not replace the DFAT that would be used to ultimately assess canine rabies, especially if it is to be used as part of public health interventions, as the public health consequences of missing rabies cases could be quite acute.