Coronavirus might already have infected way more people than we know.
Thousands of cases of the illness have already been confirmed around the world. But the virus, which is in the same family as SARS, spreads to up to three people for every person infected, and researchers estimate that way more people are likely infected already than have been confirmed. Not everyone who’s showing symptoms of what could be coronavirus have been tested, and researchers say people could spread the virus before they’re even feeling sick.
“My best guess now is perhaps 100,000 cases right now,” Neil Ferguson, a public health expert at Imperial College in London who’s been estimating the disease’s spread for the World Health Organization, told the Guardian. He thinks the actual number could be anywhere between 30,000 and 200,000.
According to data compiled by researchers at Johns Hopkins University, 2,886 cases of the infection have been confirmed worldwide as of Monday — a number that’s risen dramatically over the last few days. Fewer than 1,000 cases were confirmed as of Friday. All 81 deaths so far were in China.
The number of confirmed cases could double every six days, according to researchers at Hong Kong University who are working with the World Health Organization. They expect that more than 43,000 people will contract the virus in Wuhan alone, a city of 11 million people in central China where the virus started. Authorities there are rushing to build a new hospital in just six days to treat new cases of coronavirus.
The virus is novel — this particular strain hadn’t been detected until December of last year — so scientists are rushing to figure out how exactly it spreads. And because it’s new, it’s harder to test for.
Right now, labs at the Centers for Disease Control are the only places that can test for the virus in the U.S., though public health officials are working to figure out how to roll out tests to local facilities.
About 100 samples from 26 states have been sent to the CDC for testing, according to NBC News. Five have come back positive, 25 tested negative, and they’re still working on the rest. So far, there are confirmed cases in California, Washington, Arizona, and Chicago.
As more samples are sent to the CDC for testing, experts expect to turn up more cases of the virus.