Approximately 170 people who recently visited Yosemite are suffering stomach pain, nausea and diaherria.
CNN:
About 170 people who've gone to Yosemite National Park this month are suffering from gastrointestinal illness, including visitors and employees.
Two of the cases are confirmed as norovirus, and the majority of the others are consistent with the virus, the park said in a statement Thursday. Most of the incidents occurred around the first week of January, and there has been a decline of new cases in the past several days, it said.
The park is investigating the circumstances surrounding the illness and is interviewing affected people. It has also enhanced sanitation protocols to prevent further spread of the disease.