Following SARS-CoV, MERS, and SARS-CoV-2 (the cause of COVID-19), researchers have detected yet another novel coronavirus jumping from animals to people. In this case, the source are dogs. Spurred by the current pandemic, the scientists from Duke University's Global Health Institute developed a genetic test to detect all kinds of coronaviruses including those that haven't yet been identified. The good news is that the new coronavirus they found hasn't yet mutated into a form that can easily spread between people. Not yet anyway. From National Public Radio:
In the first batch of samples tested last year, [virologists Gregory] Gray and [Leshan] Xiu found evidence of an entirely new coronavirus associated with pneumonia in hospitalized patients — mostly in kids. This virus may be the eighth coronavirus known to cause disease in people, the team reports Thursday in the journal Clinical Infectious Diseases[…]
"There's no evidence yet of transmission from human to human," says virologist Xumin Zhang at University of Arkansas for Medical Sciences. But it's not known how these patients became infected with the virus, or if they had direct contact with infected animals.
Zhang has studied coronaviruses for more than 30 years. He thinks it's too early to call this new virus a human pathogen. "As the authors are careful to say in their paper, they have not proven what's called Koch's postulates," he says. That is, [Ohio State University Anastasia] Vlasova, Gray and colleagues haven't shown that the new coronavirus causes pneumonia; so far, it's only been associated with the disease. "To do that, strictly, they need to inject the virus into humans and see if it reproduces the disease," he says. "Of course [for ethical reasons], we cannot do that." Instead, Zhang says, they can look to see how common the virus is in pneumonia patients around the world — and they can test to see if it makes mice or another animal sick.
Yet Zhang says he wouldn't be surprised if this dog virus is, in fact, a new human pathogen. He thinks the more scientists look for unknown coronaviruses inside pneumonia patients, the more they are going to find. "I believe there are many animal [coronaviruses] out there that can transmit to humans."
image: Electron micrograph of SARS-CoV-2 virions with visible coronae, NAID (CC BY 2.0)