A previously unidentified coronavirus has been detected in pneumonia patients at a hospital in Sarawak, Malaysia – and it appears to have come from dogs. It is not yet clear if the virus caused their illness, but its discovery raises fresh concerns about how frequently coronaviruses jump from animals to people and the public health threat they could pose.

Anastasia Vlasova and Annika Diaz at Ohio State University and their colleagues made the discovery while validating a new pan-species coronavirus PCR test. Unlike the existing PCR test for COVID-19, it is designed to detect members of a coronavirus subfamily that infects various animals – including unknown viruses. Further genetic sequencing can then be used to understand more about such viruses, and where they came from.

Although there is currently no evidence of human-to-human transmission of the virus, it is possible the team has caught a new animal coronavirus on its journey to becoming one that readily transmits between people.

During these initial validation tests, the team identified genetic material from a canine coronavirus in nose swabs from eight patients hospitalised with pneumonia in Sarawak during 2017-18, accounting for 2.5% of all such cases in the region at that time. Seven of the patients were young children from rural areas where exposure to domestic animals and jungle wildlife is common.

One of these samples contained enough virus for its genome to be fully sequenced. The results, published in Clinical Infectious Diseases, suggest it could be a new coronavirus that has jumped from dogs to humans, and may also have infected cats and pigs at some point in its evolutionary history. The researchers have named it CCoV-HuPn-2018.

Worryingly, they also identified a mutation in a part of its genome that codes for a protein called nucleocapsid, which helps the virus package its genetic material. This mutation isn’t found in other dog coronaviruses, but is similar to one found in some human coronaviruses, including the viruses that cause COVID-19 and SARS.

Although there is currently no evidence of human-to-human transmission of the virus, it is possible the team has caught a new animal coronavirus on its journey to becoming one that readily transmits between people.

“To our knowledge, this is the first report suggesting that a canine coronavirus without major genomic re-arrangements or adaptive modifications in the [spike] protein might replicate in association with pneumonia in a human host,” the team writes. “If confirmed as a pathogen, it may represent the eighth unique coronavirus known to cause disease in humans. Our findings underscore the public health threat of animal coronaviruses and a need to conduct better surveillance for them.”

TOPICS: COVID-19

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