Health officials have confirmed 69 people became ill after swimming in Lake Nokomis in Minneapolis, a week after the lake's beaches were closed following an E. coli outbreak.
The update Tuesday from the Minnesota Department of Health means an additional 20 people have shown symptoms of bacterial infection since Friday. To contain the outbreak, the lake's two beaches will remain closed for the rest of the season.
Of the 69 cases, 20% were children 10 years old or younger, according to Doug Schultz, a spokesman with the Department of Health. None of the sickened people have been hospitalized, he said.
Meanwhile, four other public beaches in Minneapolis remain closed for another week after showing levels of E. coli that exceeded state standards, according to the Minneapolis Park and Recreation Board. The season has brought the most beach closures at any one time since the city began testing for the bacteria in 2003.
The Park Board tested for bacteria in every lake but Nokomis on Monday. Theodore Wirth Lake Beach, Lake Hiawatha Beach and the beaches at Bde Maka Ska Thomas and Bde Maka Ska 32nd Street will stay closed for another week, said Park Board spokeswoman Robin Smothers.
For the Park Board to close a beach, the E. coli levels must exceed either the single-day or 30-day guidelines set by the Minnesota Pollution Control Agency.
That means a beach has either a single result of more than 1,260 E. coli bacteria organisms per 100 milliliters of water, or five samples over 30 days that exceed 126 organisms per 100 milliliters of water. All four beaches except for Nokomis were closed because they exceeded the 30-day guideline, according to the Park Board.
The beach at Theodore Wirth Lake, in west Minneapolis, has had an early closure in four of the last seven years, Smothers said. The Park Board, she said, believes the high E. coli levels are related to geese and other waterfowl that flock there during migration and befoul the beach.