The National Park Service said Wednesday it had received a greater-than-normal number of reports of gastrointestinal illness in the parks in Wyoming and Montana parks.
Members of a tour group in Mammoth Hot Springs complained on June 7 of stomach flu and various GI symptoms, and within 48 hours, numerous park employees who were in direct contact with tourists reported similar symptoms. Results of tests on the visitors and employees were positive for norovirus, the most common cause nationwide of acute gastroenteritis, the National Park Service reported.
There have been, during the past week, more than 100 suspected cases of the virus among Yellowstone employees and around 50 suspected cases among Grand Teton employees. Fifty Yellowstone visitors with GI symptoms attended medical clinics, the park service said.
During the past week, additional cases of GI illness among visitors and employees have been reported at both national parks. To-date, those reports include more than 100 suspected cases of norovirus among employees in Yellowstone and about 50 suspected cases among employees in Grand Teton. Fifty visitors also went to medical clinics within Yellowstone with symptoms of gastrointestinal illness.
The norovirus can be contracted through direct contact with an infected person, by touching surfaces contaminated with the virus, or by ingesting contaminated food or drink.
The park service advised frequent hand washing with soap, particularly after eating or preparing food and when using the washroom and changing diapers. While soap-and-water cleaning is best, alcohol-based hand sanitizers will work as a temporary measure, the park service said.