According to The Associated Press, Yosemite officials revealed Thursday two visitors contracted the extremely contagious virus after spending time in Yosemite Valley during the first week of January.
In total, the NPS has received more than 170 complaints of visitors suffering from gastrointestinal issues since visiting the park this month, with authorities saying the symptoms being reported are “consistent with norovirus.”
The Centers for Disease Control and Prevention’s (CDC) official website said norovirus can be transmitted through “contaminated food, surfaces or objects,” and causes symptoms such as diarrhea, nausea and vomiting.
“Yosemite National Park officials and medical professionals with the National Park Service Office of Public Health (OPH) are continuing to investigate the circumstances surrounding the illness and are continuing to conduct interviews with affected people,” an NPS spokesperson said in a statement.
A report from the San Francisco Chronicle claims the NPS has launched a massive “clean-up and disinfection” effort that is targeting “the park’s many food establishments, which include restaurants, snack stands and hotels.”
The NPS said both park visitors and employees have fallen ill.
In November, a Princess Cruises sailing was marred when a norovirus outbreak forced some 2,000 passengers to evacuate in Singapore. The unpleasant gastrointestinal illness struck at least 229 passengers and crew aboard the Sun Princess.