Yosemite Park has recently been linked to an illness that has affected about 170 people who have visited the park around the first week of January. The U.S. Centers for Disease Control and Prevention say the virus is called norovirus, a very contagious stomach illness spread by contact with an infected person or contaminated surfaces, that causes vomiting and diarrhea. Ranger Scott Gediman said Yosemite was undertaking “extensive cleaning and enhanced sanitation protocols” following the outbreak. The Park officials say that 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 even the flu.

A Middle school recently went on a field trip there when their supervisor found out that 10 of his students had stomach pain, nausea, diarrhea and fever which are characteristic signs of norovirus infection.

Some of his students wondered if norovirus was in the packaged yogurt parfait, it was sold a week past the sell-by date on its label. Others said it was the scrambled eggs that just didn’t taste right, or the sliced fruit and red Jell-O scooped out of large plastic bowls with the same ladle and utensils that customers pulled out of containers full of forks and spoons.

Their kitchen was also under construction as a 12-year-old said as to what the kitchen looked like “filthy, disgusting.”