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Grand Canyon reports 118 cases of gastrointestinal illness, norovirus found in several park visitors


More than 100 cases of gastrointestinal illnesses have been reported at the Grand Canyon, with cases cropping up among Colorado River visitors and backcountry campers, park officials say.

Northern Arizona National Park issued a gastrointestinal illness alert on May 20 citing “increasing reports” that month.

At least 118 cases have been reported since June 10, said Joelle Baird, public affairs specialist at Grand Canyon National Park.

Symptoms match those of norovirus, which the Centers for Disease Control and Prevention describes as a contagious virus that causes vomiting and diarrhea, with symptoms including nausea, stomach cramps and pain.

Baird said some visitors have tested positive for norovirus.

Norovirus, which can be spread through infected people and contaminated food and water or by touching contaminated surfaces, causes “sudden vomiting and diarrhea” that lasts one to three days, the park said.

“We have had positive confirmation that a number of associated river trips have tested positive for norovirus. It is difficult to say if all the cases are related to norovirus, but we currently understand that at least in the trips that have been tested, it is very likely to be norovirus,” she said.

A first peak of cases appeared in May, with a majority of cases reported in May and June.

After Kristi Key called for help, a helicopter with park rangers rescued one of the hikers with symptoms resembling a gastrointestinal illness.Kristi’s Key

“We’ve kind of plateaued in terms of the number of reported cases, especially in the last three to four weeks,” Baird said.

Kristi Key, an Arizona hiker who frequents the Grand Canyon, recalled calling for help after seeing a hiker throw up while hiking Boucher Trail in mid-May.

She passed four hikers on the Hermit Boucher Loop and noticed one didn’t look well. She offered to use the SOS button on her satellite communicator and tracking device to call for help, but they refused.

When she returned, she found the group and this time they asked her to call for help.

The group took refuge under a tree and set up a tarp to keep the sick hiker cool.

“He just lay down and slept and got up every once in a while to throw up and drink some water,” Key said.

She said it wasn’t until park rangers arrived and whisked the sick hiker to safety in a helicopter that she learned of the norovirus.

Grand Canyon reports 118 cases of gastrointestinal illness, norovirus found in several park visitors
To help the sick hiker, friends and Key set up a tarp to keep him cool in the shade while they waited for his rescue in the Grand Canyon.Kristi’s Key

“They were, like, it could either be the creek [water] or it could be norovirus, because norovirus strikes [the area] pretty bad right now,” she said.

She later learned that at some point during their trip, each of the four hikers she helped had fallen ill.

Other visitors with her in the shuttle back to their cars said they also knew people who had fallen ill with similar symptoms of diarrhea and vomiting.

“Suddenly there were all these people saying, ‘My friend has been saved,'” she said. “A lady said, ‘I was on a trip there this week and several, maybe five, people got sick on that trail. “”

Key said she’s walked hundreds of miles in the Grand Canyon, and while people are being rescued “all the time,” it’s usually because of the heat or lack of water, not for those symptoms.

The park noted that norovirus can spread quickly at campsites and on rafts along the Colorado River, which are usually home to dozens of people.

Baird said norovirus is “highly contagious” and could spread to areas with high visitor traffic, saying: “It’s more of direct contact with people exposed to and carrying the virus itself.”

Visitors are encouraged to wash their hands properly and to drink water that is not only filtered, but also chemically disinfected or boiled.

The cause of the cases is not yet known, and the National Park Service Office of Public Health, along with the CDC and Coconino County, Arizona, Health and Human Services, are investigating.

Baird said there have been outbreaks of gastrointestinal illness in the park before, but “it’s been several years.”

“Research was conducted several years ago for something similar to a massive population of Colorado River users, impacting multiple river trips, [who] have been contracted by the norovirus,” she said.

“So it’s not uncommon for this to happen. However, the fact that it’s impacted so many different river journeys is concerning.”

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