WESTPORT — With more than a dozen people showing flu-like symptoms following a party last week, the health director said the town can no longer effectively track who could potentially be exposed to the coronavirus.

“It would be like trying to determine who knows who, and who may have seen who when,” Mark Cooper, health director of the Westport-Weston Health District, said in a statement posted on the health district’s website Thursday. “That is no longer an efficient use of resources. Contact tracing usually involves two or three people with a limited number of cases. This has grown exponentially.”

The large private party held at a Westport home on March 5 was attended by dozens of people, including a man who does not live in the U.S. and is believed to have the coronavirus. The man, who has since left the country, told officials he has been diagnosed with COVID-19, the disease caused by the coronavirus.

Cooper said the town obtained test kits late Wednesday and has finished administering its first batch. Results are expected to return in three to five days.

“Everybody ought to think of it as if it’s potentially everywhere,” Cooper cautioned on Thursday.

While it’s too early to tell if the coronavirus has spread in Westport, just half an hour away, New Rochelle, N.Y., has created a “containment area” due to 121 cases coming back positive as of Wednesday.

“The population is certainly more concentrated in New York,” Cooper noted. “Whether those steps would be deemed to be necessary here in Connecticut is up to the governor.”

Cooper continues to advise residents to wash their hands, cover their mouths and stay home if they feel sick.

According to Cooper, the health district is still waiting medical records from the party guest to confirm a COVID-19 diagnosis.

“He indicated he went to medical professionals and we have no reason to doubt it at this point,” Cooper said.

The event was attended by a number of Westport parents and students, prompting Interim Superintendent of Schools David Abbey to close all schools indefinitely.

Similarly, Town Hall and the Westport Library were closed this week. The library will be open with limited services on Monday.

Westport has also been planning for the possibility of a prolonged school closure.

“This week, state officials provided districts with information regarding short-term school closures (up to two weeks),” a statement on the school district’s website read. “At that time, we were informed that if districts were to decide to close schools for up to two weeks, they would be required to make-up lost days by adding days to the school calendar and/or changing vacation days to school days.”

Adding lost days would enable the schools to meet their obligation concerning state and federal laws, including those associated with special education services. However, Gov. Ned Lamont on Thursday signed an executive order waiving the 180-day requirement for Connecticut schools amid the announcement of the state’s fifth confirmed coronavirus case, allowing more leeway for closed school districts.

If the decision is made to keep schools closed beyond a few days, the district plans to provide students activities for home learning and to keep them academically active.

“These activities are encouraged, but not required,” the notice on the school’s site reads. “Activities will not be graded and students will not be required to submit completed work.”

Westport’s Elementary Administrative Team notified K-5 parents on Thursday the district has prepared at-home learning modules, in case of a prolonged closure.

“It is our hope that during a school closing, these learning modules provide students with opportunities to learn and grow,” the statement reads. “The modules include educational activities designed to reinforce and practice previously learned concepts, preview content in preparation for a return to school, and extend understanding of previously learned concepts to new and deeper levels.”

All modules for reading, writing and social studies are available on the At Home Learning site, with art, music, physical education and Spanish as well.

Ann Leffert, interim director of pupil personnel services, notified parents of special needs students that plans were being made if the district is closed for two weeks.

“Classroom teachers, special education teachers and related services providers have or will be sending home learning opportunities appropriate for the grade level,” Leffert wrote in an email on Thursday. “The district will not be utilizing online or distance learning during the period of closure and teachers will not be providing instruction,” Leffert said. “The closure is being treated similar to a closure due to inclement weather; the days missed will be made up later in the school year.”

In the meantime, Cooper advised residents feeling flu-like symptoms should believe they have contracted COVID-19, even though there are active cases of seasonal flu. A test will still be required to be 100 percent sure, he said in the statement.

Residents who have symptoms and would like to be placed on a list to be screened for testing can call 203-227-9571, ext. 237 and leave their name and telephone number.

“We will get to everyone as efficiently as possible,” the statement continued.“If someone has been diagnosed with COVID-19 or is a confirmed case, the recommendation is to stay home, wear protective face covering if contact with other people is at all possible, and get plenty of rest to help the recovery process.”

Patients who are ill but not critically, should stay at home, the health district advises; and if they are at high risk for having contracted COVID-19, they should reach out to their physicians by phone or email. Patients’ physicians will contact the Department of Public Health and get advice as to whether they should be tested or just isolate themselves at home.

“This is a very fluid and fast-moving situation,” Cooper said in the statement. “The health district will continue to work with the town, state Health Department, and CDC (Center for Disease Control and Prevention) to reduce the impact to the community.”

In addition, First Selectman Jim Marpe on Thursday announced an Incident Command Structure has been set up to manage the town’s response to COVID-19.

“The Incident Command Structure is based on well-tested practices for similar community-wide incidents and includes key public safety and other town officials,” Marpe said in a news release. “What is important is that COVID-19 is in the community and collectively we have to take appropriate precautions to protect the health of our friends and family.”