Why hikers on the Pacific Coast Trail are coming down with norovirus

MARY LOUISE KELLY, HOST:

Norovirus is a terrible thing to have. It is very contagious and can lead to serious dehydration. It's often associated with cruise ships and day cares and other tightly confined spaces, but it has also been cropping up in the wilderness. NPR's Pien Huang reports on an outbreak on a popular West Coast trail.

PIEN HUANG, BYLINE: Late last summer, Kevin Quinn hiked through a remote mountainous region in central Washington state. He was headed towards Canada on the Pacific Crest Trail when he started feeling sick.

KEVIN QUINN: And at first, I thought it was just a stomachache. But when we got to the campsite, I started throwing up.

HUANG: Quinn was on the Pacific Crest Trail with his daughter, who had left her job so they could hike together. It's a five-month, 2,600-mile trek from the Mexican border up to Canada. After months of hiking, Quinn found himself wiped out at a campsite in the middle of nowhere.

QUINN: You know, I had heard about the norovirus for years, but it was always in the context of, oh, there's a cruise ship in the Caribbean. You don't think about this as being an issue when you're out on the Pacific Crest Trail.

HUANG: But Quinn was one of many hikers last year that caught norovirus on the trail. Robert Henry volunteers at the Washington Alpine Club Lodge to the south. After a stream of sick hikers came through, he closed the lodge and emailed health authorities.

ROBERT HENRY: My concern at the time was, A, to make sure that the hikers on trail didn't get any worse, and, B, to make sure that the volunteers at the Washington Alpine Club didn't contract whatever it was.

HUANG: Arran Hamlet is a disease detective with the CDC. He's based at the Health Department in Washington state, and when he heard about the outbreak, he surveyed hikers. He focused on a 70-mile stretch of the trail. One common rest stop was a log cabin in the meadows.

ARRAN HAMLET: And at this area, there's also a pit latrine and a stream that's used for drinking water.

HUANG: Hamlet and his team hiked out to the cabin and tested water from the stream. They also swabbed the toilets, the door handles, the tabletops - anything people were touching. He says the water was clean.

HAMLET: But every single swab did test positive for human fecal contamination.

HUANG: Shanna Miko, a nurse epidemiologist at CDC, was part of the team, and this wasn't her first norovirus-in-the-woods investigation. Last year, she traced an outbreak at the Grand Canyon among people who were backcountry hiking and white-water rafting. She says these places may seem so remote, but thousands of people pass through in a season.

SHANNA MIKO: Lot of germs can live on environmental surfaces for a long time, specifically norovirus.

HUANG: And with norovirus, hand sanitizer and water filters don't work. Miko says hikers can cut their risks - always wash their hands with soap and water after you defecate and before you eat. Also, make sure to drink and cook with good clean water.

MIKO: Boiling is going to be the best way to kill everything.

HUANG: There are also combinations of water filtering and UV light and chemical treatment that can work. Kevin Quinn thinks he got norovirus because he broke his own rule.

QUINN: We were told not to drink from the standing water, and I did the one time.

HUANG: He was thirsty. He was tired. And soon he knew he'd made a mistake. After a night of being very ill, Quinn and his daughter made a long, slow trek out of the woods.

QUINN: We never made it. We never made the whole trail.

HUANG: When I called him a year later, he still regrets that he didn't take the time to treat the water properly. To other hikers, he says, heed the signs. Wash your hands, and make sure your water is clean. In his experience, it is not worth the risk.

Pien Huang, NPR News.

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