First report of Karimabad virus in Rhombomys opimus in China

Karimabad virus (KARV) is an arthropod-borne viral agent originally found in the Mediterranean region that can cause human infection via sandfly as the main vector. The KARV virion has been only detected from sandfly in western Asian countries and specific antibody has been detected from Rhombomys opimus and human in countries in Africa, Western and Central Asia. In this study, by next-generation sequencing (NGS) on a high variety of wild small animals in Xinjiang Autonomous Region in China, we obtained a complete sequence of KARV from Rhombomys opimus. An expanded epidemiological investigation was subsequently performed on 1713 small wild mammals that were widely collected from seven bioclimatic distinct sites in China by applying KARV specific RT-PCR and sequencing. Positive results were only obtained from 8 (2.29%) of the Rhombomys opimus captured in Xinjiang Autonomous Region, while not in 57 rodent species that were captured in other six provinces. Sequence analysis revealed the currently identified KARV was clustered with Gabek Forest virus, and they shared 79.1–93.9% identity with Iranian KARV that differed for L, M and S segments. Phylogenetic analysis based on eight partial L gene sequences demonstrated the separation of two lineages of the current KARV sequences. The first report of KARV in Rhombomys opimus in China expanded the currently known geographic scope, reservoirs types and the genetic heterogeneity of KARV. Our results show a new host, Rhombomys opimus, for KARV and highlight potential zoonotic transmission of KARV in humans.