ATLANTA — Georgia’s fourth-largest school district is closing all its schools for at least one day on Tuesday after a teacher at two middle schools was found to have COVID-19.

Fulton County Superintendent Mike Looney said the teacher was taken away by ambulance Friday from Bear Creek Middle School in Fairburn, south of Atlanta. The teacher also worked at Woodland Middle School in East Point. Employees and students from those two schools, as well as Creekside High School in Fairburn were sent home early Monday.

“This particular employee had a lot of contact with students,” Superintendent Mike Looney told reporters Monday.

He said the typical teacher in the district instructs more than 100 students a day. Looney said he didn’t know how the teacher had become infected, and couldn’t comment on the teacher’s current medical condition.

Looney said he decided to close the district’s 100-plus schools to allow for disinfecting schools, to let health officials follow up with potentially infected students and teachers and to “pause to assess the potential additional risk that our school community might face.” Looney said the district would decide Tuesday afternoon whether it would reopen on Wednesday. The district has more than 93,000 students.

“Until we can understand the breadth of this particular issue, I think caution is better than negligence,” Looney said.

Looney said the district has a virtual learning plan, but said it wouldn’t begin until schools have been closed for three days.

Eleven Georgia residents have now tested positive for the COVID-19, with five tests federally confirmed.

U.S. Rep. Doug Collins, R-Ga, said in a statement on Monday he was notified that he was in a photo with a person who attended a recent political conference and who subsequently tested positive for coronavirus.

“Several” members of Congress had contact with the person, but remain in good health, the Capitol’s attending physician said. Collins said he feels “completely healthy,” but has decided to isolate himself for the remainder of a 14-day quarantine period.

Health officials say they don’t know how the most recent COVID-19 infections happened in Georgia, though all of the cases are in the metro Atlanta area.

Georgia Gov. Brian Kemp said late Sunday the people in the four recent cases are from Fulton, Cobb and Cherokee counties, but have no connection to each other. They were hospitalized as of Sunday.

Test results by the state health lab are awaiting confirmation by the federal Centers for Disease Control and Prevention.

Georgia officials, meanwhile, are turning part of a state park into a site where they can isolate and monitor coronavirus patients, the governor’s office said.

The office stressed in a news release Monday that state officials are making the preparations at Hard Labor Creek State Park in Morgan County “out of an abundance of caution,” and no patients are currently scheduled to be transferred there.

Officials have already installed seven emergency trailers at the park about 50 miles (80 kilometers) east of Atlanta. The Department of Public Safety will provide security, the governor’s office said.

Cases of the new coronavirus have been confirmed in a total of five people in Fulton, Cobb and Polk counties. The Polk County resident had previously been reported as from Floyd County.

Those from Fulton County include a 56-year-old man who had returned to Atlanta from Milan, Italy, on Feb. 22, and his son.

The 46-year-old Polk County woman had gone twice to a Georgia emergency center with flu-like symptoms in February but was originally turned down for testing because she had not traveled abroad or had known of any contact with travelers from abroad.

Dozens of Americans on a cruise ship off the California coast are expected to arrive Monday night or Tuesday for quarantine and testing at Dobbins Air Reserve Base in Marietta, officials said Sunday. They include 34 Georgia residents.

The vast majority of people recover from the new virus. According to the World Health Organization, people with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover. In mainland China, where the virus first exploded, more than 80,000 people have been diagnosed and more than 58,000 have so far recovered.