Real-Time Polymerase Chain Reaction Systems for Detection and Differentiation of Unclassified Viruses of the Phenuiviridae Family.

The family Phenuiviridae, part of the order Hareavirales, includes arboviruses and arthropod-associated viruses, with sandflies, mosquitoes, and ticks as primary vectors. Historically, only sandfly/mosquito-borne phenuiviruses were associated with human diseases, but the emergence of severe fever with thrombocytopenia syndrome (SFTS) has highlighted the potential of tick-borne phenuiviruses as human pathogens. Recent discoveries of new arthropod-associated viruses, some of which remain unclassified, underscore the need for sensitive detection and differentiation methods, particularly in regions where these viruses may co-circulate. This study aimed to develop real-time PCR test systems for identifying and differentiating unclassified viruses within the Phenuiviridae family. In this study, tick suspensions containing phenuiviruses, previously obtained during the screening of ticks from various regions of Russia using pan-phenuivirus primers, were used. Specific primers and probes were designed to differentiate five Phenuiviridae viruses of genera Uukuvirus, Ixovirus, Phlebovirus and one unclassified phenuivirus, and their analytical sensitivity and specificity were evaluated. These PCR-based tools provide a robust method for detecting and classifying uncharacterized phenuiviruses, contributing to improved surveillance and understanding their potential epidemiological and epizootological impacts.