There's a virus in Chinese horseshoe bats that is similar to SARS, and a recent study shows that it could be right on the cusp of infecting people - but isn't doing so yet.
But it's worth watching for sure, say the new findings.
Considering that Ebola, Zika and SARS all originated in animals or insects, we need to keep a close eye on other potentially zoonotic diseases - those spread from other creatures to humans. After all, Ebola and Zika have claimed lives in the thousands and have run up billions of costs in slowed economic growth.
"The capacity of this group of viruses to jump into humans is greater than we originally thought," said Vineet Menachery, a postdoc at the University of North Carolina at Chapel Hill.
The viruses might still need to make a few other adaptations in order to leap to humans, but "several viral strains circulating in bat populations have already overcome the barrier of replication in human cells and suggest reemergence as a distinct possibility," noted Menachery.
With Ralph Baric, an epidemiology professor at UNC Chapel Hill, Menachery looked at SARS-like sequences of coronaviruses from Chinese horseshoe bats. Taking those sequences as a basis, they looked at the likelihood of the viruses of infecting human cells and those in mice and learned that the newly known virus, WIV1-CoV, is able to bind to the same receptors used by SARS-CoV.
The study findings also demonstrate that the virus can replicate - quickly and efficiently - in cultures of human airway tissues. This suggests they have the ability to leap in a direct path to humans.
"To be clear, this virus may never jump to humans, but if it does, WIV1-CoV has the potential to seed a new outbreak with significant consequences for both public health and the global economy," Menachery said.
The team also learned that antibodies developed previously by scientists to fight SARS worked effectively in human and animal tissue samples to counter WIV1-CoV. This is useful information if the new virus ever breaks out among humans.
"This type of work generates information about novel viruses circulating in animal populations and develops resources to help define the threat these pathogens may pose to human populations," Baric said.
The findings were published in the Proceedings of the National Academy of Sciences.
Follow Catherine Arnold on Twitter at @TreesWhales.
