Coronavirus Could Infect 650,000 People in the U.S. by May, Even If Transmission Is Cut in Half: Study

There are 11 times more undetected COVID-19 cases in the U.S. than reported ones and well over half a million people across the country could contract the disease in the next two months, new analysis has suggested.

The stark conclusions come from a research team at Columbia University which examined a New York Times database of known cases and linked it with Census Bureau data on commuting patterns and other data that were available through March 13.

The study found the virus was spread mostly by those who were unaware they are infected, or only displaying mild symptoms and that each infected person spreads it to an average of 2.2. other people. Even if the rate of transmission could be cut in half, which would require considerable effort and further societal lockdowns, as many as 650,000 people could become infected by May, it concluded.

"We're looking at something that's catastrophic on a level that we have not seen for an infectious disease since 1918," Jeffrey Shaman, research team leader, told The New York Times. "It's requiring sacrifices we haven't seen since World War II. There are going to be enormous disruptions. There's no easy way out."

A woman cleans the Hollywod and Highland mall stairs in Hollywood on March 20, 2020, a day after Los Angeles County announced a near-lockdown, urging all residents to stay home except for essential needs. A study has suggested that more than half a million Americans might contract the disease in the next two months. AGUSTIN PAULLIER/Getty Images

The research team's model, which is only an estimate and does not include the states of Hawaii and Alaska, suggests that outbreaks in New York City, Seattle, Boston, and parts of California will spike, despite the tough restrictions already put in place to the movement of those populations.

Where there are fewer coronavirus cases, restrictions like school closures, banning mass gatherings, and ordering sick people and those close to them to stay at home, could stymie the spread of the disease inland, but those controls needed to be implemented straight away, the study suggested.

If tougher controls are not put in place, the outbreak would go across the country and peak in California, Florida and north east by May, sickening millions of people or more on the coasts before slowing and then spreading to the rest of the country over the summer.

Connecticut, Illinois, New York, and California have said that all non-essential workers must stay at home, as orders from local and state leaders have followed the warnings from U.S. health officials.

However president of the American Academy of Emergency Medicine Resident and Student Association, Haig Aintablian, told NPR that the virus may have already spread too widely.

"I think the stay at home order is necessary and I think it should be done across the nation but I wonder if that might be too little, too late," he said, "because this virus is showing symptoms so much later."

The graph below from Statista compares the number of coronavirus cases with recoveries.

Coronavirus Recoveries and Cases March 19
Number of COVID-19 cases compared to recoveries.