Some US companies with operations in China fear the growing coronavirus outbreak will kill more than half their revenues there if the crisis doesn’t abate soon.

Nearly one-fifth of the more than 160 firms surveyed by the American Chamber of Commerce in China say their Chinese revenues for 2020 will drop by more than 50 percent if the epidemic persists through the end of August.

And close to half of the companies surveyed foresee some decline in revenue if business doesn’t get back to normal before the end of April, according to the business group’s flash survey released Thursday. About 40 percent say it’s too soon to tell, the findings show.

“There is, in the short term, a clear and significant negative impact to member company operations” from the coronavirus, chamber chairman Greg Gilligan said in a statement.

The chamber said US companies have been grappling with travel disruptions, higher costs and reductions in staff productivity as well as falling revenues because of the outbreak. The virus has killed nearly 2,800 people and infected more than 80,000 worldwide, the vast majority of them in mainland China, according to Reuters.

But the epidemic’s long-term impact remains uncertain in many respects, the survey found. More than half of the surveyed companies said it’s still too early to estimate the cost of delays in returning to normal operations, and 43 percent say it’s too soon to determine how the disease will affect market growth this year, chamber officials said.

Even so, only 12 percent of the firms expect virus-related delays to continue through the summer, while close to a third say normal business operations should resume by the end of March, according to the group.

The chamber’s “member companies, like much of society here, face a large number of uncertainties in combating COVID-19,” Gilligan said, using the medical name for the disease caused by the virus.

Fears about the outbreak and uncertainty about how it will affect global growth have roiled businesses around the world and sent the US stock market plummeting into correction territory on Thursday. The outbreak has forced major airlines to suspend flights into mainland China and led to the cancellation of major business conferences such as the Mobile World Congress, the world’s largest smartphone trade show.

The American Chamber surveyed its member companies between Feb. 17 and 20. The 169 firms that responded range in size and include some with operations in China’s Hubei province, the epicenter of the coronavirus outbreak, the chamber said.