Are animals susceptible to the Coronavirus?
The answer to that question is an ever-changing news story since I first wrote about it a month ago. The scientific community is not quite sure. As coronavirus continues to spread across the globe and has been currently spotted on the West coast of the U.S., it is natural to worry about our own safety —as well as that of our family and friends.
From Bats to Humans, via Pangolins
Scientists are scrambling to learn more about COVID-19. A recent study in the ACS Journal of Proteome Research suggests that the scaly anteater-like animal called pangolins is the missing link for SARS-CoV-2 transmission between bats and humans.
SARS-CoV2 is zoonotic, which means that the virus originated in animals and jumped to humans. In the case of COVID-19, the critical challenge is for scientists to determine what specific animals were responsible for this transmission.
Based on research conducted in the Zhang Lab, a team of researchers found that the pangolins receiving coronavirus from horseshoe bats served as the hosts to transmit it to humans.
The study also found that the genetic sequence of a coronavirus, discovered in lung samples of Malayan pangolins, was highly similar to SARS-CoV-2. The two viruses shared 91 percent of their genetic sequence.
Subsequently, several other research groups working with pangolins infected by coronaviruses found they were highly probably in becoming the stepping-stone for the virus transfer.
Pangolins are high on the list of most trafficked animals in the world, which contributed to their endangered status.
This species is nocturnal and shy. While they look like anteaters, they are not related to them. Their closest living relatives are actually carnivorans, which is the group that oddly enough includes wolves and cats.
Pangolins are illegally hunted and are traded for a couple of reasons. First, they are a delicacy in several south-east Asian countries, especially China and Vietnam. Secondly, their scales are used in Chinese traditional medicine.
Wu Chen of Guangzhou Zoo has researched these cases as well and found that Sunda pangolins carry coronaviruses.
Wuhan's Wet Markets
As far as the physical location, there is speculation that this virus could have derived from a seafood 'wet' market in Wuhan, where many species were packaged. Animals in such markets are often kept in closely packed and unsanitary conditions, with humans nearby. Those conditions are a perfect storm for a virus to jump species.
Bats are a known reservoir of coronaviruses. In fact, the intermediate horseshoe bats are known to carry a virus called RaTG13, whose genome is 96% identical to that of Sars-CoV-2.
The realization that wildlife markets allow diseases to spread to people may spur tactical preventative steps. When China announced a ban, the World Wide Fund for Nature (WWF) called it “a timely, necessary and critical step” – not just for safeguarding the wild animals, but for human health as well.
Their public statement noted: “This public health crisis must serve as a wake-up call to end the unsustainable use of endangered animals and their parts, whether as exotic pets, for food consumption or for their perceived medicinal value.”
In the best-case scenario, it will not just be pangolins that benefit. Reducing the demand for illegally traded wildlife will help many species – and protect us all from future pandemics into the bargain.
Primary Source: Zhang Lab