Scientists have discovered that a new coronavirus appears to be able to pass back and forth from animals to humans, which would make eliminating the virus difficult or impossible. Since June, the new coronavirus, called hCoV-EMC, has been linked to 5 deaths and several other cases of severe disease that originated in Middle Eastern countries. The new virus is closely related to the coronavirus that in 2003 caused 8098 cases of severe acute respiratory syndrome (SARS), resulting in 774 deaths.
Like the SARS virus, hCoV-EMC is most closely related to coronaviruses carried by bats. In a study appearing online today in mBio, a team of researchers from Germany, the Netherlands, and Saudi Arabia were able to grow hCoV-EMC, the strain isolated from human patients, in cells from a variety of bat species—a most unusual finding, said coauthor Christian Drosten, of the University of Bonn Medical Centre in Germany.
“This was a big surprise,” Drosten said in a release. “It’s completely unusual for any coronavirus to be able to do that—to go back to its original reservoir.” The researchers were also able to infect cells from pigs with the coronavirus, suggesting that the virus uses the same receptor on the cells of humans, bats, and pigs to infect these species, thus allowing the virus to pass back and forth between animals and humans.
The research team also investigated whether both the hCoV-EMC and SARS coronaviruses use the same receptor to infect humans. Previous research had found that the SARS virus uses a receptor called ACE2, which is found mostly on certain cells deep within the human lung. The location of this receptor helped limit the 2003 SARS epidemic because for infection to occur, an individual needs to inhale many SARS viruses to reach the susceptible lung tissue. The researchers found that hCoV-EMC does not use ACE2, which leaves open the question of whether the new virus uses a receptor found in a more accessible area of the human lung, which might thus render it more infectious to humans than the SARS coronavirus.