“The explosive outbreak of gastroenteritis that erupted in the Grand Canyon earlier this year was likely sparked by multiple people hauling in norovirus infections, according to a recent study published by the Centers for Disease Control and Prevention in its Morbidity and Mortality Weekly Report. The infectious blast ended up violently hollowing out at least 222 visitors to the geologic marvel over a brisk but brutal three-month period.” https://arstechnica.com/science/2022/09/grand-canyons-explosive-gastroenteritis-was-a-3-month-multisource-outbreak/?comments=1
Eideard 
“The explosive outbreak of gastroenteritis that erupted in the Grand Canyon earlier this year was likely sparked by multiple people hauling in norovirus infections, according to a recent study published by the Centers for Disease Control and Prevention in its Morbidity and Mortality Weekly Report. The infectious blast ended up violently hollowing out at least 222 visitors to the geologic marvel over a brisk but brutal three-month period.” https://arstechnica.com/science/2022/09/grand-canyons-explosive-gastroenteritis-was-a-3-month-multisource-outbreak/?comments=1