Pigs and poultry are among the subjects of susceptibility studies
By Jackie Clark
Researchers and risk-assessment experts in Canada are studying the potential for COVID-19 to infect different animal species, and any associated threats. Canadian results are pending, but the international research community has found that swine and poultry are not susceptible to this strain of coronavirus.
These experts including federal and provincial public health officials as well as academic researchers, are collaborating with the global community to build a knowledge base on COVID-19.
“They come together and they look at the existing research” to understand and characterize the risk associated with livestock and companion animals, Dr. Jaspinder Komal told Farms.com. He’s the chief veterinary officer for Canada.
The Canadian Food Inspection Agency (CFIA) is involved in research “focused on animal susceptibility studies, animal models for vaccine development, point-of-care diagnostics work, research capacity development, immunization strategies, and field-deployable diagnostic tests,” he explained.
CFIA scientists are conducting “studies to ascertain the susceptibility of animals to this coronavirus specifically in chicken, turkeys and pigs,” Komal said.
The animals are housed in a secure facility and challenged with the virus. Researchers also maintain a healthy control group, and another pen where they mix healthy and inoculated animals to test for transmission between animals. The scientists monitor animals for symptoms and take blood and stool samples.
“The experiments run over three weeks because the incubation period (for COVID-19) is 14 days,” Komal said. “We sacrifice a few animals every so often to look at where the virus is present, because we also want to know, given that these are food animals, whether any virus goes into muscles.”
Researchers are working at the National Centre for Foreign Animal Disease, part of the Canadian Science Centre for Human and Animal Health in Winnipeg, where they have a biosafety level 3 and level 4 laboratory. Level 4 labs are designed to study diseases that pose a serious threat to human health and spread easily.
“We’re in the process of completing those experiments and that research should be published soon,” Komal said. So far, food safety scientists have found “the risk from food is negligible to low.”
Similar investigations in China and Germany “didn’t find that pigs are susceptible,” Komal said.
Researchers in the United States are conducting susceptibility experiments on ruminants.
A lot of unknowns still surround COVID-19 and, because of its long incubation period and the potential for asymptomatic transmission, “our feeling is that this is going to go on for some time until we find a vaccine. As (new) information becomes available, we’ll have to continue to do studies on the animal side,” Komal said.
Canada is a member of an advisory group studying animal susceptibility to COVID-19 with the World Organisation for Animal Health (OIE).
That group has established that “so far, pigs, chicken, ducks and turkeys are not susceptible. They don’t show any medical signs and they don’t transmit (the virus) between them,” Komal said. Dogs, however, can contract the virus, and feline species, like house cats and tigers are even more susceptible. Ferrets, minks, Egyption fruit bats and golden Syrian hamsters can also contract this strain.
However, in most animal species that have been tested, infections are minor.
“The main thing to retain is that, so far, it’s a human-to-human disease,” Komal said. “Companion animals like cats and dogs have got the infection but there’s very low mortality.”
Transmission from animals back to humans is rare, he added. Mink farm workers have reported a few cases of transmission between humans and minks, however, this is a low risk for the population in general because so few people work closely with these animals.
Canada has been an international leader in studying the animal-human interface with regards to COVID-19.
CFIA and Public Health coordinates research between the 17 biosafety level 3 and 4 laboratories located throughout Canada, the United Kingdom, Germany, the U.S. and Australia.
“That’s pretty good from a leadership point of view for Canada,” Komal said.
Also, “we were working through Global Affairs Canada to help build capacity in Ghana. We built a level 3 facility and we trained scientists there. … When the pandemic hit, they were very quickly able to use those facilities to test for COVID in humans,” he added.
Canadian scientists will continue to be on the forefront of assessing and protecting from risks of COVID-19 to humans and animals.
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