(HealthDay News) — An outbreak of gastrointestinal illness that was traced back to an Oregon lake has led U.S. health officials to issue guidelines on swimming hygiene.
Seventy people who swam at a lake near Portland last July became ill via norovirus, according to a report from the U.S. Centers for Disease Control and Prevention. More than half were children aged 4–10 years. Health officials believe a swimmer infected with norovirus vomited or had diarrhea in the water, and other swimmers swallowed the contaminated water.
“Children are prime targets for norovirus and other germs that can live in lakes and swimming pools because they’re so much more likely to get the water in their mouths,” Michael Beach, PhD, associate director for healthy water at the CDC, said in an agency news release.
Between 1978–2010, norovirus was the second-leading cause of illness outbreaks associated with untreated recreational water, such as lakes, the agency said. People who swim in areas with no chlorine treatment are at particular risk since there are no chemicals in the water to kill the virus. Moreover, norovirus can survive in water for several months or even years.