Many of those exposed were seniors who had just finished their final year at two elite private schools.
On a warm summer weekday in the middle of July in Greenwich, Conn., one of the wealthiest communities in the country, a group of teenagers gathered at a house party. Many were seniors who had just finished their final year at two elite private college-preparatory schools, Greenwich Academy and the Brunswick School, as well as the local public high school, Greenwich High School, according to accounts from students and school officials.
They had endured weeks of lockdown, had time on their hands and now Connecticut was among the few states in the country where the coronavirus appeared to be under control. As the weekend approached, some of the teenagers would attend more get-togethers, according to the accounts.
Two weeks after the parties, Greenwich is experiencing what health officials called a “mini surge” of infections, an outbreak that has cascaded through the community and underscored how social gatherings among young people are posing fresh challenges to containing the virus.
More than 20 people between the ages of 16 and 21 have tested positive for the virus, with more cases expected as testing continues, according to Greenwich health officials.
“I think it has been a wake up call for a lot of people,” said Tom Philip, the head of the Brunswick School.
Some members of the Greenwich High School football team were placed in quarantine after a player tested positive, school officials said. About a dozen students did not attend a socially distanced Brunswick School commencement ceremony on Saturday after acknowledging that they had been exposed to someone who had tested positive.
A pool at a country club in Greenwich said on Wednesday that it would shut down for at least two days after a swim coach came into contact with someone who had tested positive.
While the parties that are believed to have seeded the outbreak have been widely discussed among students, parents and others in Greenwich, the conversation on social media has taken place largely on private accounts and pages.
Greenwich health officials have said that contact tracers have had a difficult time tracking down teenagers willing to admit having been at the gatherings.
Several students contacted for this article said they did not feel comfortable discussing the events. In some cases, students said that they had been told by their parents not to share information about the parties.
Still, the outbreak is sowing frustration among some students and parents who fear that allowing parties to be held showed that some residents may not be taking the risks seriously and that any rise in cases could influence plans to reopen schools for in-person learning.
Fred Camillo, the first selectman of Greenwich’s board of selectmen, said the board had scheduled a special meeting on Wednesday to talk how the town would better enforce rules on social distancing and mask wearing.
Across the country, officials have sounded similar concerns, targeting parties involving teenagers and young adults where little or no social distancing takes place and where drinks and food make consistently wearing face masks difficult.
In New Jersey, a recent increase in cases has been attributed in part to outbreaks among young people gathering along the Jersey Shore.
In New York City, as images of young people crowding outside bars and other venues circulated this month, Mayor Bill de Blasio said there had been an uptick in infections among people in their 20s.
The governor of Mississippi, Tate Reeves, said last week that his state had seen “a tremendous amount of spread in young people.”
“I’ve been talking for about a week about wanting to do something to curb the spread among young, drunk, careless folks,” he said.
And in Connecticut, officials in Darien, another affluent community not far from Greenwich, raised the alarm last week after five people between the ages of 10 and 19 tested positive for the virus on one day. Some of the infections are believed to be linked to parties.
“It’s summertime,” said Jayme Stevenson, the first selectman of Darien. “It’s beach weather. People are out on boats. They are having parties. And I think they are beginning to let their guard down. It’s critically important that young people understand that they can get the virus and they can spread the virus.”
The state’s governor, Ned Lamont, put out a statement this week warning about “outbreak clusters among teens and young adults” accompanied by a photo of a densely packed party on a string of boats on a state waterway.
“A small cluster of cases can turn into hundreds of new infections within days,” Mr. Lamont said. “If you multiply that, we are looking at major impact to our ability to continue to reopen our economy or even send children back to school in September for in-person instruction.”
The warnings came as researchers are still trying to understand how the virus affects children and other young people and how efficiently it spreads. Public health experts say children under 10 appear far less likely to transmit the virus than older children.
The caseload in the state has been steady for weeks and, over the last week, the average has been 188 cases per day. Only seven states had a lower per capita case count over the last seven days, according to a database maintained by The New York Times.
Caroline Baisley, the health director for Greenwich, said officials first realized something was amiss when they began hearing rumors of large parties around the weekend of July 18. In the following weeks, they started looking at testing data and noted a trend — several young people were testing positive.
“When you start to see multiple 18-year-olds and 17-year-olds, then you have to start to wonder what’s going on here,” she said.
Mr. Philip at the Brunswick School said at least one student at the school had been infected at a birthday party for that student’s father.
The parties have cast a shadow over the school’s preparation for reopening in the fall, he said, advising that young people avoid large indoor gatherings, and that parents should forbid them from going.
Mr. Camilo said the kind of socializing that is typical among young people can make it hard to keep everyone safe.
“One kid goes to a party in Greenwich, next thing you know there’s a little bit of an outbreak,” he said.
News – In Ultra-Wealthy Greenwich, Teen Parties Lead to Jump in Virus Cases