Scientists have found a new canine coronavirus in some people hospitalized with pneumonia. This can be alarming, but if we open it, you’ll see that there’s no reason to lose any sleep.
The discovery of canine coronavirus in eight people at a hospital in Sarawak, Malaysia, was reported by Clinically Infectious Diseases to a group of respected international scientists. Does this mean that dogs can spread coronaviruses to humans?
The first clarified what is canine coronavirus. Importantly, it is different from SARS-CoV-2, the virus that causes COVID-19. The coronavirus family can be divided into four groups of viruses: alpha, beta, gamma and delta coronaviruses. SARS-CoV-2 falls within the group of betacoronaviruses, while canine coronaviruses are in the entire separate group of alphacoronaviruses.
Scientists know about canine coronavirus for almost 50 years. These viruses exist relatively unnoticed for most of this time, of interest only to veterinary virologists and occasional dog owners. There have been no previous reports of viruses coming to humans. But the sudden international spotlight of all coronaviruses is to find coronaviruses in areas we have never seen before.
Canine coronavirus infections recently identified in humans have actually been found to be serendipitous. Scientists are not specifically looking for canine coronavirus, and patients involved have long since recovered. Researchers are trying to make a new test that finds all the different types of coronavirus at once-one called pan-CoV test.
After it was confirmed that the test was performed on samples of viruses grown in laboratories, they it was tested on 192 human swabs from hospitalized pneumonia patients in Malaysia. Nine of these samples tested positive for coronaviruses.
Further analysis showed that five of the nine samples had simple human coronaviruses that could cause the common cold. But, surprisingly, four of the samples had canine coronavirus. A further study of patients from the same hospital revealed four more positive patients.
The researchers studied nose and throat swabs from all eight Malaysian patients to try to determine the presence of canine coronaviruses. The samples were placed in the dog’s cells in the lab to determine if any live virus was present. Properly copy the virus from a sample, and detect virus particles using electron microscopy. Scientists have also been able to trace the genome of the virus.
Analysis has found that this canon coronavirus is related to several different alphacoronaviruses – including those from pigs and cats – and has shown that it has never been found anywhere else.
There is no evidence of continued spread
Is canine coronavirus responsible for pneumonia in patients? Right now, we just can’t say. Seven of the eight patients were equally infected with another virus, either adenovirus, influenza or parainfluenza virus. We know that all of these viruses can cause pneumonia on their own, so there is a possibility that they are responsible for the disease. We can say that there is a link between pneumonia and canine coronavirus in these patients, but we cannot say that this is the cause.
There are concerns that the canine coronavirus identified in these Malaysian patients may have spread from person to person, resulting in a more widespread outbreak. How much news headlines do not clarify so that these human infections actually occurred in 2017 and 2018. This makes the probability of a canine coronavirus outbreak from this source much lower because there is no evidence of continued spread in the intervening three to four years.
Since coronaviruses have become the center of attention and we are looking for related viruses, it is inevitable that we will find many positive samples in unexpected places. Most of them are of academic interest only, and should not raise the alarm. However, it is critical that surveillance of new coronaviruses continues and expands to have the best chance of detecting significant cross-species leaps in the future.