CDC: Possible norovirus outbreak affected numerous Grand Canyon National Park visitors

GRAND CANYON NATIONAL PARK, Ariz. (Arizona’s Family/Gray News) - The Centers for Disease Control and Prevention released details about a possible norovirus outbreak affecting Grand Canyon National Park visitors earlier this year.

Previously, Arizona’s Family reported that the virus hit dozens of river rafters and backcountry campers who said they had “explosive” gastrointestinal illnesses after a rafting group reported the first case on April 6.

According to the CDC, 11 of 28 rafters got sick on that trip while initially reporting having norovirus-like symptoms, with some samples testing positive for the virus.

As weeks passed, more reports of illnesses came in as hiking groups and summer vacationers visited the park. As a result, the CDC launched an investigation with researchers arriving at the park by the end of May.

Three months later, the CDC released its findings, which indicated that the norovirus outbreak could have come from multiple sources.

According to CDC researchers, five people reported becoming ill before their trips, indicating a “potential for multisource introduction” of norovirus into the park.

In addition, investigations into portable toilets from rafting trips revealed that, while they each tested positive for norovirus, they had two distinct genotypes -- different genetic materials -- meaning they came from other places. Park officials reported the last case of gastroenteritis on June 17.

In all, Arizona’s Family reports that researchers looked into the possibility of 222 people reportedly getting sick within those three months and found more than 80% were visitors.

“We haven’t seen something like this kind of outbreak in about 10 years,” Jan Balsom, a spokesperson for the park, told The Daily Beast in June.

The CDC warns that as norovirus cases increase nationwide, the virus could resurge at the park as visitation levels return to near pre-pandemic levels. Therefore, travelers should practice extra hygiene and ensure they use and consume clean water.

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