Identification, Characterization, and In Vitro Culture of Highly Divergent Arenaviruses from Boa Constrictors and Annulated Tree Boas: Candidate Etiological Agents for Snake Inclusion Body Disease

Stenglein, Mark D.; Sanders, Chris; Kistler, Amy L.; Ruby, J. Graham; Franco, Jessica Y.; Reavill, Drury R.; Dunker, Freeland; DeRisi, Joseph L.

Here we described the discovery and characterization of two complete viruses and partial sequence from a related, yet potentially distinct third virus, isolated from cases of snake inclusion body disease. These viruses share a typical arenavirus-like genome organization, but the protein sequences of Z and GPC imply a more complicated evolutionary relationship to previously characterized arenaviruses. These viruses were detected in 6/8 snakes with confirmed IBD diagnoses and 0/18 IBD-negative animals. In infected animals, viral RNA and protein were detected in tissues with cytoplasmic inclusions, and indeed, viral nucleoprotein was found to localize to the same eosinophilic inclusions that give the disease its name. Although formal confirmation that these novel arenavirus-like agents cause disease in snakes will require experimental challenge studies, their detection in reptiles raises an array of intriguing questions about the host range, evolution, basic biology, and mechanisms of pathogenesis associated with this unusual branch of the virus phylogeny.