SALISBURY — During the last weekend before schools resumed, the beach at Branbury State Park was closed after more than 50 swimmers reported that they were sick to their stomachs.
Vermont State Parks officials closed the beach on Friday, Aug. 21, due to a suspected norovirus outbreak.
By Monday, the Vermont Department of Health was still waiting for lab results to confirm the source of the illness but recommended that the beach be reopened once it determined that the outbreak and the conditions causing it had passed. The beach was reopened Monday, Aug. 24, at 9:48 a.m.
On Tuesday, the Department of Health received lab confirmation that the illnesses had indeed been caused by norovirus.
According to the Vermont Department of Health, 54 people who swam at the beach reported stomach illness, including nausea, stomach cramping and diarrhea.
Most of those who reported the stomach illness were at the lake on Tuesday or Wednesday, Aug. 18 or 19. All who reported illness had somehow swallowed water or gone underwater. Visitors to the lake who merely waded in the water during the outbreak were not affected.
Norovirus, which is caused by bacteria in human waste, is extremely infectious, said health department infectious-disease epidemiologist Bradley Tompkins. And even one dirty diaper could cause this kind of outbreak.
Once even a small amount of infected fecal matter gets into the swimming area, weather conditions and other environmental factors play a part, including sunlight, temperature, depth of the water, and water circulation, Tompkins said. Last week was extremely hot, and there was no rain. The Branbury swimming area is especially wide and shallow — one of the reasons it’s such a popular spot for families with young children — and water warms up in shallow areas, making conditions likelier for a viral or bacterial outbreak.
The beach is tested weekly for E. coli bacteria, and Branbury tested low for the week of the norovirus outbreak. But screening for E. coli would not reveal the presence of a virus such as norovirus.
“As we move forward,” said Rick Hedding, the Forest, Parks and Recreation regional ranger supervisor for Branbury State Park, “the state parks are going to help promote safe swimming techniques and strategies.”
Common-sense ideas from both the state parks and the health department include frequent bathroom breaks for young children, checking swim diapers regularly and changing them in the park restrooms immediately if soiled, and being careful not to swallow water when you swim. Adults who’ve had a recent bout with diarrhea or similar intestinal illness are advised to stay out of the water until they’ve been well for a couple of days.
“What we’d encourage people to do is — the park is open, go out and enjoy it, but take the proper precautions,” said Tompkins. “Do what you can to not get water in your mouth. That would be our message for any beachgoer in any part of Vermont when they’re swimming. It’s never really a good idea to ingest water wherever you happen to be swimming.”