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.

Whether infection by these viruses causes disease in snakes is perhaps the principal open question following from this study. It is possible that-as is often the case in rodents-arenavirus infection of snakes is chronic and subclinical. Indeed, the CAS snakes diagnosed as IBD and virus positive (Table 1) were not showing any of the typical signs of regurgitation, anorexia, or central ner-vous system abnormalities at the time of sample collection, though it could have been relatively early in the course of infection. In contrast, the snake from Tennessee that was diagnosed as IBD and arenavirus positive (Table 1) was diagnosed in a postmortem exam. This snake had produced a clutch of infertile eggs (slugs), developed dysecdysis (incomplete shedding), continued to decline, and ultimately died. It is clear that arenavirus infection does result in large viral protein-containing inclusions, a diagnostic finding believed to be prognostic of a fatal outcome, although disease progression has proven variable, with animals surviving for weeks to months after first clinical manifestation, and with the caveat that "IBD" in different snake species may ultimately prove attributable to different causes.