Diagnostic Accuracy of Point-of-Care and Pathological Methods for Canine Parvovirus in Namibia: A Comparison with PCR and Implications for Clinical Practice

Abstract

Canine parvoviral enteritis (CPVE), caused by canine parvovirus (CPV), is a highly contagious and often fatal disease primarily affecting puppies under six months of age. Characterised by acute vomiting, hemorrhagic and foul-smelling diarrhoea, dehydration, and rapid progression to death, CPVE poses a significant challenge to canine health in resource-limited settings. Accurate and timely diagnosis is essential for effective case management and outbreak control. The present study evaluated the diagnostic performance of three commonly used methods: rapid antigen (Snap®) test, postmortem examination, and histopathology, against polymerase chain reaction (PCR) as the reference standard in dogs presenting with clinical signs of CPVE in Windhoek, Namibia. Of 211 suspected cases, 195 (92.4%) tested positive by PCR, with 82.5% of affected dogs aged less than three months, and most having unknown vaccination status. The rapid test demonstrated excellent diagnostic accuracy (AUC: 0.997; sensitivity: 99.5%; specificity: 100%), while postmortem examination showed good accuracy (AUC: 0.877; sensitivity: 75.4%), and histopathology exhibited fair performance (AUC: 0.753; sensitivity: 88.2%; specificity: 62.5%). Agreement with PCR was excellent for the rapid test (Cohen’s κ = 0.967) but only fair for postmortem (κ = 0.317) and histopathology (κ = 0.340). These findings support the use of rapid antigen testing as a reliable point-of-care tool in Namibian clinical settings, though confirmatory PCR remains critical in ambiguous or vaccinated cases. Further studies are warranted to determine CPV prevalence, circulating strains, and risk factors driving outbreaks in Namibia.