Field evaluation of Kyasanur forest disease real-time PCR point-of-care assay.

Background and objectives Kyasanur Forest Disease (KFD) is a tick-borne viral haemorrhagic fever endemic to Western Ghats in India, necessitates rapid and accurate field-based diagnostics for effective outbreak response and timely patient management. Traditional diagnostic methods require laboratory infrastructure, sometimes limiting timely case detection in resource limited settings. We evaluated the diagnostic performance, usability, and operational feasibility of a point of care (POC) assay for detection of KFD virus under field conditions. Methods We assessed a real-time PCR-based portable point-of-care (PoC) test for KFD virus on retrospective clinical samples (n=247) that were obtained from the Goa and Karnataka States in the year 2024. The assay's sensitivity, specificity, and turnaround time (TAT) were assessed in comparison with gold standard real time RT-PCR assay. Operational feasibility and validation was carried out in field laboratory setting in Shivamogga, Karnataka, and North Goa. Results Out of 247 samples analysed, the PoC assay was 97-100% sensitive and 95-98% specific in two sites with less turnaround time than gold standard test. High diagnostic accuracy was demonstrated by the assay which require minimal training for its field application. Interpretation and conclusions The real-time PCR-based PoC assay performed well under field conditions for a reliable and early detection of KFD virus infection. This PoC assay represents a practical and time-efficient diagnostic approach for field use and has the potential to be incorporated into existing KFD surveillance.