Story at a glance

  • Park officials have confirmed at least two cases of norovirus.
  • The National Park Service is investigating, but it is still unclear what prompted people to become sick.
  • Norovirus is a contagious virus that can cause vomiting, diarrhea and stomach pain.

Around 170 people who visited Yosemite National Park this month have reported becoming ill with gastrointestinal illnesses, with at least two confirmed cases of norovirus, park officials said Thursday.

The National Park Service began investigating after visitors and employees reported being sick and are continuing to investigate the circumstances surrounding the illness and conduct interviews with affected people. 

“The overwhelming majority of the reported cases are consistent with norovirus,” park officials said in a statement.

The majority of those who became ill spent time in Yosemite Valley around the first week of January. Park officials say there has been a decline in new cases in the past several days. While those who reported becoming ill had symptoms of norovirus, park officials say some might have had food poisoning or the flu. 

The origin of the outbreak is unclear at this time, and park officials have yet to confirm whether those who became ill contracted something inside or outside of the park. 

Norovirus is a very common and contagious virus that can cause vomiting, diarrhea and stomach pain. It can spread by having direct contact with an infected person, consuming contaminated food or water, or by touching contaminated surfaces then putting unwashed hands in your mouth. It causes about 21 million illnesses every year in the United States. 

Park officials say they are undertaking extensive cleaning and enhanced sanitation protocols in response to the outbreak.

Published on Jan 17, 2020