In the 1970’s, a disease had arisen and was a deadly threat to dogs. This disease is called canine parvovirus, or CPV. It is believed to have been a direct transfer from a disease or similar virus that was found in domesticated cats called feline panleukopenia. Recently researchers have found that CPV has been transferred to wild forest-dwelling animals, including raccoons. Nobody knows for sure how this disease has spread from one animal to others. Colin Parrish, professor of virology and director of the Baker Institute for Animal Health at Cornell University, has been looking into this mystery. He co-authored a research paper with Susan Daniel, who is an associate professor at Cornell’s School of Chemical and Biomolecular Engineering, and they found that there is a mutation in the protein shell of CPV, which allows the virus to have the ability to infect hosts of different species. It is a single amino acid substitution. Another factor that gives the virus this ability is that during the TfR binding, CPV’s infectivity is adhesion strengthening. He said that at first there is an attachment that is not very strong. There then is a second attachment that is much stronger and does not let go. The second attachment is where they believe to be the most important step. They believe that it causes a shift in the virus that makes it possible to infect successfully. Daniels had developed a method in which studies the effects of single virus particles on many different membrane host receptors. They used this method to research dogs and raccoons. With this method they can test various kinds of chemistries. They are still looking to find the exact reason behind the ability of viruses to switch host species, specifically CPV.
Viruses having the ability to switch host species can be frightening. If viruses evolve enough, one specific virus found only in one species could possibly infect another species very easily. For example if you have a dog and it comes across a squirrel with a virus, your dog could potentially contract the virus. There could even be a chance for humans to contract these viruses. I think that understanding how a virus can do this is very important. Studying where or why this takes place could help scientists create vaccinations that will help all species. I think they should continue to research this topic.