The first results from the state’s antibody testing show that 13.9 percent of New Yorkers have COVID-19 antibodies, Governor Andrew Cuomo said at his press briefing on Thursday. The percentages were much higher downstate than upstate.

The survey developed a baseline infection rate by testing 3,000 people at grocery stores and other box stores over two days in 19 counties and 40 localities across the state. Those with antibodies are thought to be immune to the disease.

Cuomo noted that people with antibodies could donate blood so the plasma could be used to treat people currently suffering from COVID-19.

“The testing also can tell you the infection rate in the population, where it’s higher, where it’s lower,” Cuomo said, “to inform you on a reopening strategy and then, when you start reopening, you can watch that infection rate to see if it’s going up. If it’s going up, slow down on the reopening strategy.”

Twelve percent of the surveyed females tested positive, and 15.9 percent of the males, Cuomo reported.

Regionally, New York City tested at 21.2 percent, Long Island tested at 16.7 percent,  Westchester and Rockland counties tested at 11.7 percent, and the rest of the state tested at 3.6 percent.

“This basically quantifies what we’ve been seeing anecdotally and what we have known, but it puts numbers to it,” said Cuomo.

By race, he reported, African Americans tested at 22 percent; Hispanics at 22 percent; people describing their race as multi, none, or other at 22 percent; Asians tested at 11.7 percent; and whites at 9.1 percent.

“This reflects more the regional breakdown, African-American and Latinos are in this survey, disproportionately from New York City, and New York City is at 21 percent. So, the African-American number, Latino number is 22 percent,” said Cuomo. “Upstate, whites, they’re talking about more upstate, which is 9, but it’s 3.6 in the survey.”

Only people 18 or older were tested. Those ages 18 to 24 tested positive at 8 percent; those 45 to 54 at 16 percent, and those 75 or older at 13 percent.

Nursing homes

Also on Thursday, Cuomo announced that the state’s health department is partnering with the attorney general to investigate nursing-home violations. Facilities that are violating executive orders requiring them to communicate COVID-19 test results and deaths to residents’ families will be investigated.

The department will inspect facilities that have not complied with its directives, including separation and isolation policies, staffing policies, and inadequate personal protective equipment. Those not in compliance will have to submit action plans. Facilities could be fined $10,000 per violation or potentially lose their operating license.

The state will increase staffing through its professional staffing portal and expand training and technical assistance for nursing homes to use the portal. The state will continue to provide personal protective equipment, like masks and gloves, on an emergency basis. Families of nursing home residents who are concerned about the care residents are getting can file complaints by calling 833-249-8499 or by visiting www.ag.ny.gov/nursinghomes.

Albany County’s nursing home, as of Thursday morning, has had 27 residents who have tested positive for COVID-19 and 13 employees, including one who has recovered and returned to work. Two residents have died of the disease.

Albany County’s executive, Daniel McCoy, has said testing for staff and residents has been aggressive at the facilityand families have been informed of the results.

The county’s health commissioner, Elizabeth Whalen, has said residents at Shaker Place with COVID-19 are housed separately from others.

— Melissa Hale-Spencer