As a contact tracer for Ledge Light Health District, public health nurse Mary Day recalls learning of about 40 people attending a birthday party at a restaurant this fall that resulted in as many as 10 COVID-19 cases and five hospitalizations.

"Multiple people from this birthday party ended up sick, and then as a result, their household members ended up sick," she said.

Kris Magnussen, who also does contact tracing for Ledge Light, recalls that 10 of the 14 people who attended another birthday party, inside and without masks, ended up infected.

"Because they were family, they thought, 'We were OK,'" Magnussen said, "and this is what we hear: 'They're my friends, they're my family, we thought that we were careful, we thought we were OK.'"

There also was a group that got together to watch a game on TV, with three households ending up with the virus; a local case connected to the Sturgis Motorcycle Rally in August in South Dakota; and another linked to an out-of-state horse show.

Public health experts have been saying for weeks that private gatherings of family members and friends are driving increased disease transmission in the region.

Day said she's seeing a lot of transmission with birthday parties, dinner parties, sleepovers and sporting events, and said transmission is often happening from events with about 10 to 40 attendees. Magnussen said the gatherings that lead to increased spread are generally a few hours or more.

She said Halloween parties impacted schools, because some of the people who had to quarantine as a result were teachers, and then students had to quarantine.

In another situation, she said three people were going for a walk outside, one with a mask and two without. One person tested positive for the coronavirus and Ledge Light quarantined the other two, who ended up also testing positive.

This is an example in which being outside doesn't negate the need for social distancing and masks, though she said, "if you're outside, distanced, then you can certainly take your mask off." For example, Magnussen will sit on her sister's porch and eat dessert.

Magnussen said when she does contact tracing, she hears a lot of regret. But some people who test positive aren't willing to cooperate and share contacts, and Day said the investigation "sometimes reaches a dead halt."

Magnussen said some people who were exposed to an infected person get upset when they're told they have to quarantine for 14 days despite having gotten a negative test.

"People just don't understand that the incubation is two to 14 days," she said, adding, "It's great they're negative at that point in time, but it's no guarantee. I actually talked to somebody who ended up with symptoms on the 13th day, and that's unusual."

Day said she's seen people test negative during quarantine and then test positive 24 hours later.

While it can take up to 14 days for an exposed person to develop COVID-19, those who have tested positive are presumed to not be infectious after nine days and are asked to quarantine for only 10. Magnussen said some close contacts are angry that their quarantine period is longer than that of the person who actually tested positive.

Magnussen also has had to intervene at a few workplaces to say that an employer can't require an employee with COVID-19 to test negative before returning to work. That's because even though the person isn't infectious after nine days, they may still have RNA fragments in their system up to 90 days out — and therefore continue testing positive.

Transmission happening in restaurants

Magnussen said people who have symptoms and get tested need to stay home before they get the results. She said she "can't tell you how many people we talk to" continued going to work while awaiting results.

Day recalled one instance in which a restaurant employee had multiple symptoms but went to work for four days and ended up infecting a co-worker. She has "seen many restaurants with clusters of positive employees," including one eatery with five infected employees and another with seven or eight.

Magnussen said some restaurants are small and it's hard to maintain a 6-foot distance, and there are times when servers get together after work and take off their masks. But she said many businesses are trying their best to do the right thing, and she commended restaurants for quarantining their staff even though it was difficult.

She also said there are times when contact tracers have no way of knowing whether the coronavirus was spread to an employee because of another employee or because of a customer.

"They need to keep their masks on when they're not eating," Magnussen said of customers. When she and her husband go out to eat, they dine outside, put their masks on while they're chewing, and put their masks on when a server approaches.

'It's going to get even harder to identify the potential source'

Uncas Health District contact tracer Jennifer Ceccarelli referenced a family gathering of about 13 people within the last week or two, with at least four testing positive so far, three of whom are symptomatic.

"When we're with our families and friends and we're with people we're comfortable with, we sort of let our guard down," she said. Ceccarelli, a nurse, began working for Uncas Health District a month ago.

Patrick McCormack, director of Uncas Health District, said he keeps hearing about problems around laundry rooms in apartment buildings.

"A laundry room is a perfect example (that) if people continue to operate the way they have always in the past, they are going to get sick," he said. He encouraged people to do their laundry at different times, allow for someone in the room to leave before entering, and wear masks.

He acknowledged that "sometimes the locations where people live are not set up that well for social distancing" and "we don't all have the benefit of having an acre of property around us."

Ceccarelli said there "are some people where we will never figure out where they got it, and as community spread increases, it's going to get even harder to identify the potential source."

McCormack said in the early spring, people said the only place they could have gotten COVID-19 is from someone they live with, but now that people are out more, most will say they have no idea where they got it.

Ceccarelli encouraged people not to dismiss symptoms as just allergies or a cold they always get this time of year, saying she's heard the sentiment on multiple phone calls, "'I was blown away when it came back positive for COVID; I just thought it was my allergies.'"

e.moser@theday.com