UC Davis

Canine distemper virus (CDV) is a highly contagious respiratory pathogen that infects a broad range of terrestrial carnivores with documented spillover into marine mammals. The virus is particularly prevalent in urban wildlife, but the transmission dynamics that maintain the virus in wildlife are unclear. We conducted a survey of the literature to summarize what is known about CDV in wildlife and to identify gaps and biases in our understanding of this virus. Though CDV is well characterized in dogs, gaps and biases limit our understanding about CDV in wildlife including how the virus evolves within and between hosts. We present two original contributions that aim to address these gaps in knowledge – a proposed study to evaluate a commercially available lateral flow diagnostic for use in raccoons and the results of an initial study to look at signatures of positive selection in each of the proteins CDV encodes. A sensitive and specific point of care diagnostic could be used at wildlife rehabilitation centers, not only to potentially prevent unnecessary euthanasia of an uninfected animal, but also to identify infected animals for further testing of wildtype viral genomes. The results of our positive selection study indicate that additional proteins encoded by CDV, beyond the hemagglutinin and fusion proteins, which are commonly cited in the literature, may also be under positive selection pressure. These results indicate more detailed studies may be warranted for a deeper understanding of selection pressures on the virus.