E. coli-contaminated lake’s beaches closed through at least Aug. 23

Here's what you need to know about E. coli

Here are the basics on how E. coli outbreaks happen and what symptoms to look for.
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Here are the basics on how E. coli outbreaks happen and what symptoms to look for.

An E. coli-contaminated lake in Nevada County linked to the illnesses of 14 people will remain closed until at least Aug. 23, county officials announced Wednesday.

Authorities closed all of Lake Wildwood’s public beaches last week after water testing confirmed reports linking E. coli infections to the lake’s Main Beach, also called Commodore Park. The county also advised against any swimming in the lake.

As of Wednesday, 14 people – 11 children and three adults – are believed to have contracted E. coli after visiting the Main Beach and, in many cases, ingesting lake water, according to the Nevada County Public Health Department. Lab results so far confirm 11 of those 14 cases are connected to the lake’s bacteria.

By Tuesday, nine people had been hospitalized in connection with the outbreak, six of whom have been discharged, county Public Health Coordinator Patti Carter said.

Four sickened children developed a serious condition called hemolytic uremic syndrome, which can lead to potentially fatal kidney failure and anemia. Most people with the syndrome recover, according the public health department.

Based on recommendations from the California Department of Public Health and the U.S. Centers for Disease Control and Prevention, the county said, the lake’s beaches will reopen when contamination levels in the water become safe and after three “incubation periods” pass since the latest date someone was exposed to the bacteria. An incubation period is the time it takes for someone to begin showing symptoms after ingesting E. coli.

That means the lake could open Aug. 23 at the earliest, given that July 23 was the last known day someone was exposed to the E. coli, the public health department said.

“Unfortunately, this is a natural bathing area, and unlike a swimming pool, chemicals cannot be added to remedy the E. coli bacteria,” Amy Irani, the county’s environmental health director, told The Bee last week. “Time is what is needed, and thus the closures will remain in effect until further notice.”

The county’s Environmental Health Department is testing Lake Wildwood’s water twice each week at eight locations to monitor contamination. Results from samples taken Monday showed unusually high levels of sickness-causing bacteria at seven spots, with the highest concentrations around Meadow Park, the county reported. Bacteria levels in that area were more than 12 times the minimum needed for beach closure.

All five of Lake Wildwood’s public beaches remain closed as a precaution even though only three of the beaches are being repeatedly tested, the county’s public health department said.

Authorities are investigating the source of the E. coli, testing feces found in the area and sand, as well as water sources that feed into the lake. The county also tested nearby wastewater and canals.

E. coli symptoms include bloody diarrhea, nausea and vomiting.

Hannah Knowles: 916-321-1141, @KnowlesHannah

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