In the summer of 2017, Lake Wildwood experienced an outbreak when 18 people fell ill with Shiga toxin- producing E. coli O157 (STEC O157), most after unintentionally ingesting lake water. At the time of the outbreak, the STEC O157 collected from human specimens matched STEC O157 identified in lake water, submerged sediment, and one goose scat sample.

The original source of that 2017 outbreak strain was never determined. Because STEC can be widely distributed in the environment mainly from animal waste, published studies on recreational water related STEC outbreaks often are unable to pinpoint the specific original source.

Given the history of the outbreak in 2017 and Lake Wildwood’s intermittent detections of STEC O157 since that time, the Nevada County Public Health Department wants to remind the community of its existing lake advisory: Do not ingest lake water. Swallowing lake water, especially near the shoreline or sandy beaches, has resulted in serious illness. Swimming or splashing is not advised in any location experiencing high E. coli levels or in areas with evidence of goose fecal droppings.

This advisory to not ingest lake water should be taken to heart and is most critical for more vulnerable populations including young children, the elderly, pregnant women, and those with weakened immune systems. And while no one may intentionally ingest lake water, consuming even small amounts of contaminated water while swimming and/or splashing can cause infection.

For more information about E.coli, visit the CDC’s website located at