WESTPORT — More than a dozen people who attended a private party in town last week are now suffering flu-like symptoms and one of the guests who does not live in the U.S. is believed to have the coronavirus, officials said Wednesday.

Mark Cooper, director of health for Westport, said about 40 people attended a going away party on March 5. One man, who has since left the country, told officials he has been diagnosed with COVID-19, the disease caused by the coronavirus. The man did not suffer symptoms until he returned to his home country, according to officials, who did not disclose where he lives.

“We are seeking his medical records to confirm it’s a correct diagnosis,” Cooper said, adding the man verbally told his department of the diagnosis.

The event was attended by a number of Westport residents, prompting town schools to be closed until further notice.

“We have just learned that a number of Westport parents and Westport Public School students, in schools throughout our district, were in contact with an individual presumed to be positive with coronavirus,” Interim Superintendent David Abbey said in an email to families Wednesday.

SIGN UP: Get the latest Connecticut coronavirus news delivered directly to your inbox

Cooper said the health district is contacting everyone at the party to assess their condition to reduce any potential spread.

“There is no positive confirmation of anyone having COVID-19 in Westport right now,” he said, adding those who have flu-like symptoms should presume it is COVID-19.

Human Resources Director John Bayers said schools were informed early Wednesday of the gathering that took place last week.

“Understanding that this could impact many of our schools, we made the decision we need to close our schools to make sure things were being taken care of,” Bayers said.

More communications are planned to go out throughout the week to update parents on the district’s plans, he said.

Westport Fire Chief Robert Yost said emergency responders haven’t seen any immediate calls for service, but are prepared and equipped.

First Selectman Jim Marpe encouraged residents who feel sick to seek medical attention. He added Town Hall will be closed Thursday and Friday to assess the situation.

“We want to make sure that Town Hall doesn’t become a center of transmission for COVID-19,” Marpe said. Tthe Senior Center will also be closed on Thursday and Friday.

A deep cleaning of schools and town hall is planned, and all municipal public meetings have been closed for the forseeable future. The Teen Center will also be closed for the rest of the week.

Elaine Daignault, director for the Human Services Department, said her department will maintain its essential services. Remote access will be provided to residents, and home-delivered meals will continue to be delivered to home-bound and at-risk residents.

“There are a growing number of ‘hot zones’ where the exposure risk and developing illness is increasing and more stringent community-based controls are being implemented such as in New York, just across the border from Connecticut,” the health district stated on its website on Wednesday, noting residents should continue to take precautions by washing hands.

Bill Harmer, executive director of the Westport Library, said the library will be closed starting Thursday to do a deep cleaning and to start planning for the future.

“We’ll open on Monday, but only for essential services,” he said. “Those services will include allowing patrons to enter the building to take out books and materials, or ask reference questions, but that will be the extent of the service we provide.”

So far, three Connecticut residents have been confirmed to have coronavirus in the past week — a man from Wilton, a woman from Bethlehem and an elderly man from New Canaan.

The Wilton man was the first Connecticut resident to test positive for coronavirus on Sunday. The man, who has only been identified by state officials as being in his 40s, had begun showing symptoms shortly after returning from a work conference in California, according to his wife.

The resident has since developed pneumonia and is now at Danbury Hospital in a medically induced coma, his wife said. A GoFundMe site for the family has raised more than $50,000 as of March 11.

The second patient is a woman in her 60s who is a health care worker at Bridgeport Hospital. She recently returned from a trip to Nevada, where it is believed she may have contracted COVID-19. She is being treated at Bridgeport Hospital.

The third individual is an elderly man who lives in a private residence in New Canaan. He is hospitalized at Norwalk Hospital. This case is not connected to any known cases in Connecticut, according to a Wednesday news release from the governor’s office.

Elsewhere in the state, Region 14 schools, which includes Bethlehem, is closed for the rest of the week after a student came into contact with someone who tested positive for coronavirus. A student at Wilcoxson Elementary School in Stratford is being tested for coronavirus after possible contact with someone who tested positive, prompting the closure of the school for the remainder of the week.

After the parents of a student had direct contact with a potentially presumptive positive COVID-19 patient, Wilton announced Wednesday that its schools and several town buildings have also shut down. It’s unclear how they came in contact with the virus.

Parents are being asked to keep their children home, check their temperatures two times a day and call their docter if they show any sign of fever, cough and difficulty breathing.

In an email to the Weston community on Wednesday, Superintendent of Schools William McKersie said the district was notified that members of the school community may have been exposed to COVID-19.

“We immediately consulted with the Westport-Weston Health District as well as the Emergency Mangement officials within,” McKersie said. “Based on this consultation, in an abundance of caution, and at the recommendation of the Westport-Weston Health District, the Weston Public Schools will be closed effective immediately and until further notice.”

Gov. Ned Lamont declared a state of emergency on Tuesday in response to the spread of virus, and residents have been implored to avoid public events or gatherings of more than 100 people.

Health experts have said that COVID-19 can be dangerous to the elderly and those with certain medical conditions. The Westport-Weston Health District stated on its site that all chronic and convalescent nursing homes and rest homes with nursing supervision should impose restrictions on all visitors, except when a current health state is in question.

dj.simmons@hearstmediact.com; Includes reporting by Jeannette Ross