When it broke out among humans in 2002, severe acute respiratory syndrome (SARS) killed 750 people, sickened around 8,000, and drained at least $40 billion from the global economy. Since 2004, no SARS cases have been reported.
New research suggests that’s probably more due to luck than to vigilance. A colony of bats in southern China carry at least seven SARS-like viruses—and at least one of these viruses can infect people directly, according to the study. This is the most compelling evidence yet that SARS may have come directly from bats.
This is scary because it means people can pick up these SARS-like viruses—they’re technically coronaviruses, which mainly infect the upper respiratory and gastrointestinal tracts—from any sort of contact with bats. That discovery knocks a step out of the “spillover” process, referring to how a virus leaps from animal to human cells.
While we’ve known for a while that bats were probably the SARS host, we didn’t know they gave the virus to humans directly. Past research suggested that people picked up SARS from mongoose-like creatures called civets, a southern Chinese delicacy, when they caught, slaughtered or served them.
The lack of an intermediary host makes it much harder to control an outbreak. When the SARS virus was isolated in civets in “wet markets” (where live animals are sold), the Chinese government shuttered the markets. But the new research shows that when another outbreak of a SARS-like virus hits, that might not help much. “It changes the equation” for public health, Peter Daszak, the lead author, told The Wall Street Journal. “We can close all the markets in China and still have a pandemic.”