Researchers hint at another potential monkey virus spillover to humans
Arteriviruses are an obscure family of viruses endemic in a host of wild African primates – arteriviruses are considered a fatal threat to some species of monkeys. Researchers from the University of Colorado at Boulder (CU Boulder), evoking parallels to HIV (the viral precursor of which originated in African monkeys), are calling for vigilance from the global health community, to potentially avoid another devastating pandemic.
There are thousands of unique viruses circulating among animals worldwide, thankfully most of them cause no symptoms.
However, in recent decades, increasing numbers of these animal-borne viruses have jumped to humans, whose immune systems have no experience of fighting off. The list of spillover events includes the virus behind the Middle Eastern Respiratory Syndrome (MERS) in 2012, and SARS-CoV-2 (the virus that causes COVID-19) in 2020.
“This animal virus has figured out how to gain access to human cells, multiply itself, and escape some of the important immune mechanisms we would expect to protect us from an animal virus. That’s pretty rare,” said Sara Sawyer, a professor of molecular, cellular and developmental biology at CU Boulder.
For 15 years, Sawyer’s lab has used laboratory techniques and tissue samples from wildlife from around the globe to explore which arteriviruses may be prone to jump to humans – researchers homed in on the simian hemorrhagic fever virus (SHFV).
SHFV causes a lethal disease similar to the Ebola virus disease and has caused deadly outbreaks in captive macaque colonies dating back to the 1960s.
SHFV would invade and infect cells by first taking hold of the simian receptor called CD163. Through a series of laboratory experiments, the researchers discovered, to their surprise, that the virus was also remarkably adept at latching on to the human version of CD163, getting inside human cells and swiftly making copies of itself.
Like the human immunodeficiency virus (HIV) and its precursor simian immunodeficiency virus (SIV), simian arteriviruses also appear to attack immune cells, disabling key defense mechanisms and taking hold in the body long-term.
“The similarities are profound between this virus and the simian viruses that gave rise to the HIV pandemic,” said Cody Warren, an assistant professor in the College of Veterinary Medicine at The Ohio State University.
Although the public need not be alarmed just yet, the researchers suggest the global health community prioritise further study of simian arteriviruses, develop blood antibody tests for them, and consider surveillance of human populations with close contact to animal carriers.
There is no guarantee that these simian arteriviruses will jump to humans; but they will cause disease if they do.
“COVID is just the latest in a long string of spillover events from animals to humans, some of which have erupted into global catastrophes. Our hope is that by raising awareness of the viruses that we should be looking out for, we can get ahead of this so that if human infections begin to occur, we’re on it quickly,” Sawyer said.
