Island Health has confirmed the cause of illness in more than 80 people who swam in Thetis Lake last weekend is norovirus.
After dozens of reports of vomiting, abdominal cramps and diarrhea followed visits to the popular swimming lake June 6 and 8, Island Health's medical microbiology lab tests this week confirmed the highly contagious virus was the cause.
Island Health spokesperson Valerie Wilson said it's unfortunate when incidents like this happen, but there are steps the public can take to promote safety in public places.
"If someone has norovirus and doesn't clean their hands and touches another surface or touches food and someone picks it up or eats it, it is spread very easily," she said. "Natural water sources like lakes and beaches are not treated or disinfected like swimming pools… Visitors should take precautions when swimming in untreated water sources."
Wilson cautioned the public not to swim when they are ill or consume the water when ever possible. She also said washing hands thoroughly before eating and drinking, and taking a shower after swimming at a public beach, are good habits as well.
Lab-tested specimens from some of the complainants who became ill after visiting the beach, also showed no elevated bacterial counts. The likeliest source of contamination was from someone who was ill with the virus contaminating the water. The pollutant would dissipate over a period of time, Wilson said, but how quickly would depend on such factors as weather and water conditions. Most people recover from the symptoms in 24 to 48 hours.
"Most people who get a gastroenteritis-type illness will recover quickly and can manage symptoms at home," she continued. "It is important to rehydrate yourself after the illness, because you get dehydrated from excessive vomiting and or diarrhea."
Following the incidents, public washrooms at Thetis Lake Regional Park underwent additional sanitary procedures above and beyond regular cleaning. If symptoms persist, Wilson said, seek medical attention or call the HealthLine at 8-1-1 for advice.
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