First description of a herpesvirus infection in genus Lepus

ABSTRACT - During the necropsies of Iberian hares obtained in 2018/2019, along with signs of the nodu- lar form of myxomatosis, other unexpected external lesions were also observed. Histopa- thology revealed nuclear inclusion bodies in stromal cells suggesting the additional presence of a nuclear replicating virus. Transmission electron microscopy further demon- strated the presence of herpesvirus particles in the tissues of affected hares. We confirmed the presence of herpesvirus in 13 MYXV-positive hares by PCR and sequencing analysis. Herpesvirus-DNA was also detected in seven healthy hares, suggesting its asymptomatic circulation. Phylogenetic analysis based on concatenated partial sequences of DNA poly- merase gene and glycoprotein B gene enabled greater resolution than analysing the sequences individually. The hare’ virus was classified close to herpesviruses from rodents within the Rhadinovirus genus of the gammaherpesvirus subfamily. We propose to name this new virus Leporid gammaherpesvirus 5 (LeHV-5), according to the International Com- mittee on Taxonomy of Viruses standards. The impact of herpesvirus infection on the repro- duction and mortality of the Iberian hare is yet unknown but may aggravate the decline of wild populations caused by the recently emerged natural recombinant myxoma virus.Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon