Dental researcher starts study of narwhals’ vulnerability to COVID-19
Narwhals lack “key gene” to fight off viruses
Research is now underway to determine whether narwhals, which are known to have a high potential for viral infection, are susceptible to catching COVID-19.
The narwhal study is part of a larger project to see how SARS-CoV-2, the virus that causes COVID-19, could spread to certain non-domesticated animals, including gorillas.
The focus is looking at their susceptibility to COVID-19, Martin Nweeia, a dental researcher with Case Western Reserve University in Cleveland, Ohio, told Nunatsiaq News: “This is not about transmission from animal to human.”
Hunters recently sent down samples of narwhal tissue from Nunavut in liquid nitrogen for analysis as part of Nweeia’s project, which received all necessary research approvals.
The international team of researchers will now carry out a series of experiments with the tissues, said Nweeia, who is also a lecturer at the Harvard School of Dental Medicine.
The main test is to see whether SARS-CoV-2 can bind with living narwhal cells, he said.
“That only tells us about susceptibility, not about transmission,” he said.
Although the United States Centers for Disease Control and Prevention says COVID-19 originally came from an animal, likely a bat, since then it’s been detected only in domesticated animals or those in captivity.
So Nunavut hunters can continue to safely hunt and consume narwhals, Nweeia said.
But, depending on the project’s results, expanded monitoring could be put in place.
Meanwhile, Nweeia noted there’s increasing concern about COVID-19 contamination flowing into the Arctic Ocean from wastewater in Arctic waters or escaping from ballast water in ships.
“Everything we put into the water has an impact,” Nweeia said.
In the Arctic Ocean, the cold and lack of salinity actually makes it easier for viruses to survive, he said.
The virus that causes COVID-19 has also been found to spread from people to animals in some situations.
But, based on the limited information available to date, the risk of animals spreading COVID-19 to people is considered to be low, the CDC said.
More studies are needed to understand if and how different animals could be affected by COVID-19, the CDC said.
Previous research has suggested that baleen and toothed whales could be susceptible to COVID-19.
A 2015 study from Stanford University also found toothed whales, like narwhals and belugas, have also lost a “key gene” that helps fight viruses.
“We want to check if narwhal fits the model, and the only way you know that is by doing the work with individual species,” Nweeia said.
Narwhals were selected over belugas for the research project because Nweeia, as a dental researcher, has studied the narwhal’s tooth or tusk for 20 years.
Nweeia found that the narwhal’s tusk is like a giant sensor, with 10 million nerve connections from the central nerve of the tusk to its outer surface.
These allow the tooth to detect changes in water temperature.
And Nweeia found a ligament that’s normally found inside teeth—called cementum—was found on the outside of the narwhal tusk.
That cementum had what he called sensitive “porous channels” in it.
Nweeia said these sensory receptors may help male narwhals seek and attract females.
He also said the receptors may allow narwhal to sense or capture certain foods at different depths.
Or, as Nweeia told Nunatsiaq News in 2014, it could be all of the above.