Identification and characterization of novel serpentoviruses in viperid and elapid snakes

Tillis, Steven B.1, Sarah B. Chaney2, Esther E. V. Crouch2, Donal Boyer3, Kevin Torregrosa3, Avishai D. Shuter3, Anibal Armendaris2, April L. Childress1, Denise McAloose2, Jean A. Paré2, Robert J. Ossiboff1 and Kenneth J. Conley2

1Department of Comparative, Diagnostic and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, Florida USA

2Wildlife Conservation Society, Zoological Health Program, Bronx, New York USA

3Wildlife Conservation Society, Bronx Zoo, Bronx, New York USA

Present address:

Sarah B. Chaney: Independent Researcher                                                                                                   

Kenneth J. Conley: Disney’s Animals, Science and Environment, Lake Buena Vista, Florida USA                   

Esther E.V. Crouch: Charles River Laboratories International, Inc., Wilmington, Massachusetts USA            

Anibal Armendaris: Independent Researcher

Viruses in the subfamily Serpentovirinae (order Nidovirales, family Tobaniviridae) can cause significant morbidity and mortality in captive snakes, but documented infections have been limited to snakes of the Boidae, Colubridae, Homalopsidae, and Pythonidae families. However, in this study we document vipers (Viperidae) and an elapid (Elapidae) as recognized hosts of serpentoviruses, expanding the known host range into venomous snakes for the first time. In a disease investigation that began in June 2019, over 150 confiscated snakes in quarantine were screened for serpentovirus infection using PCR analysis of oropharyngeal swabs or postmortem lung tissue. Of 165 snakes tested, 92 (56.0%) were positive. Fourteen species of vipers native to Asia, Africa, and South America were affected, alongside one elapid species from Australia. Clinical signs observed in vipers included thin body condition, abnormal breathing or behavior, stomatitis, and in some cases, death. Postmortem examinations commonly revealed inflammation, necrosis, and epithelial proliferation in the respiratory and upper gastrointestinal tracts. Genetic analysis of viral sequences identified four unique serpentovirus clades in vipers, phylogenetically distinct from known serpentovirus genera. These results suggest the presence of a novel genus within the subfamily Serpentovirinae. Host species-dependent relationships between viral prevalence and diversity are supported by positive snake data. The detection of serpentoviruses in Viperidae and Elapidae snakes highlights the need for increased surveillance and health monitoring in venomous snake species.