Characterization and Identification of a Novel Coronavirus in Alpacas

Principal investigator:

Beate M. Crossley, DVM
California Animal Health and Food Safety Laboratory System
University of California-Davis, Davis

In 2007 a respiratory disease of alpacas starting at the east coast moving west was described and rumors linked outbreaks of ARS to attendance at certain camelid shows and events. As part of an intensive follow up on several alpacas with clinical sings of ARS, a corona virus was isolated from lung tissue of an alpaca submitted for necropsy. Until then, only one other camelid/alpaca corona virus — genetically closely related to the bovine corona viruses — had been reported in the literature and the presence of the virus was linked to enteric symptoms. Comparison of the genome sequence of the virus isolation from the alpaca with ARS symptoms with the genomic sequence information of the corona virus that causes enteric disease in alpacas was of special interest due to proposed interest of using bovine enteric corona virus vaccines in alpacas. Complete genome analysis data of the newly discovered respiratory corona virus was found to be different from the enteric corona virus suggesting that the two viruses have different binding mechanism used to attach to the host cells. Therefore, enteric bovine corona virus vaccines will most probably not induce a protective antibody response against the respiratory corona virus. Additionally, the newly generated data were used to find out more about the origin of the suddenly appearing and devastating virus. Where the true ancestor of this virus is unknown, a common ancestor between a human Coronavirus (associated with the common cold in people) and the respiratory alpaca virus appears to have existed prior to the 1960’s. This suggests a virus transmission either from humans to alpacas or the other way around has occurred. The generated sequencing data provided also the foundation for the development of a real-time PCR assay used to diagnose respiratory disease in alpacas in the future.