Even Donald Trump asks people to go back to work and reopen the economy, the analysis shows that thousands of people are getting sick from Covid-19 at work.
Recent figures show an increase in infections in meat and poultry processing facilities, according to the Associated Press.
There has been a wave of new cases among construction workers in Austin, Texas, where this sector has recently returned to work.
The White House was vulnerable, with officials testing positive.
The developments highlight the high risks for communities across the country, as business restrictions gradually ease.
"People who are getting sick now are usually people who work," said Mark Escott, a regional health official, to the Austin city council. "This risk is going to increase the more people are working."
There are many new infections outside the workplace in nursing homes and among retirees and the unemployed, especially in densely populated locations such as New York, Chicago, Philadelphia and urban areas in New Jersey and Massachusetts.
However, of the 15 US counties with the highest infection rates per capita between April 28 and May 5, all house meat and poultry processing factories or state prisons, according to data compiled by the AP.
The county with the highest per capita rate was Trousdale County, Tennessee, where about 1,300 inmates and 50 employees recently tested positive at the privately run Trousdale Turner Correctional Center.
County No. 2 on the AP list is Minnesota's Nobles County, which now has about 1,100 cases, compared to two in mid-April. There, Dakota County, Nebraska, and Cass County, Indiana, are home to large meat-processing industries.
They have also been hit hard by recent infections in Virginia, Delaware and Georgia counties, where poultry processing plants are located.
In New York, the state most affected during most of the pandemic, people who stay at home are still sick.
Meanwhile, in Pennsylvania, of 2,578 new cases between May 4 and 6, more than 40% were people living in long-term care facilities.
And across the country, many health professionals were among the first Americans to be positive. They continue to be infected in large numbers.