This article originally appeared on Backpacker
When you're spending weeks at a time on the trail, it's not unusual to have a little bit of stomach trouble. From trouble adjusting to calorie-dense, lightweight backpacking fare to indigestion after chowing down on a burger and fries at a town stop, there are all sorts of plausible reasons a thru-hiker might feel their stomach rumbling, most of them benign. But after more than 20 people came down with diarrhea and vomiting on the same Washington stretch of the Pacific Crest Trail in 2022, the Centers for Disease Control and Prevention (CDC) were alarmed enough to send an investigator to find out why. Now, their findings are out--and there's a lesson in them that hikers need to learn.
The incident began in late August last year, when hikers suffering from gastrointestinal illness began trickling into the Washington Alpine Club Lodge near Snoqualmie Pass. According to NPR, the glut of sick backpackers alarmed a volunteer enough that he closed the lodge and sent a warning to the Washington State Department of Health, where Arran Hamlet, an officer with the CDC's Epidemic Intelligence Service, received it.
In an attempt to determine the source of the illness and gauge its spread, Hamlet posted a survey in a popular Washington PCT Facebook group, as well as at trailheads along the 73-mile stretch of trail where most of the cases had begun, and asked sick hikers to fill it out. Hamlet and his fellow investigators wrote in a CDC report last month that 27 hikers responded with usable answers, and two who were still in Washington sent stool samples to a state laboratory. Both tested positive for norovirus.
Norovirus is one of the most common causes of gastroenteritis, and it spreads easily via person-to-person contact and contaminated surfaces. Several widely reported outbreaks have taken place on cruise ships over the past decade, but cases can multiply anywhere that infected people are sharing space. With between 800 and 1,000 people completing this trail every year--and thousands more hiking its most popular stretches--the PCT certainly qualifies.
When Hamlet and his colleagues visited pit toilets and a cabin along the suspect stretch of trail, every single surface they tested--from door handles to toilets to the tabletops where hikers were eating their lunches--came back positive for "human-specific fecal contamination." (Tests of nearby water sources, on the other hand, all came back negative--a good thing too, since most water filters can't remove norovirus.)
"Although the REDCap survey identified only 27 ill hikers, social media reports indicated that the true size of the outbreak was likely substantially larger, with 27 reports with a date of onset, and numerous others without further chronologic information apart from the year," the team wrote.
How did one or two sick people manage to balloon into dozens? In their report, Hamlet and his coauthors have one gross guess: Hikers aren't very good at washing their hands. Without running water, backpackers often opt to use alcohol-based hand sanitizers after doing their business. That's true for newbies and veterans alike, and outdoor journalists aren’t exempt: In an in-house poll, 57 percent of Outside staffers said they primarily used sanitizer after going to the bathroom on the trail, while another 27 percent said they were equally likely to use sanitizer as they were to wash their hands. Just 17 percent said they always washed their hands with soap and water after going to the bathroom on a hike.
The problem is that while hand sanitizer effectively kills germs like E. coli and SARS-CoV-2, the same isn't true for norovirus. Numerous studies over the past 15 years have found that alcohol, the active ingredient in sanitizers, doesn't significantly reduce the number of virus particles on users' hands. The issue, researchers believe, is that norovirus is non-enveloped, meaning it lacks the lipid envelope that surrounds the virus particles. Alcohol-based hand sanitizers work by attacking that protective layer, which deactivates the virus. This works for viruses like the flu, but when it comes to norovirus, which lacks that layer, there's little that sanitizers can do.
While norovirus rarely causes major complications and generally passes quickly--most of the backpackers in the 2021 outbreak recovered after two to three days--it's more than serious enough to tank a trip. Fortunately, the CDC says, there's one easy way to cut down on your risk: Get in the habit of washing your hands after you use the bathroom and before you eat. Scrubbing your paws with soap and water can help remove the persistent norovirus--and any other sickening pathogens--from your hands. Because while taking the extra minute or two to lather up may not be as quick as slapping on some sanitizer, it'll slow you down a lot less than losing a long weekend to the trots.
Lightweight Handwashing Gear
You won't even know these hygiene essentials are in your pack.
This half dollar-size case holds 50 leaves of dehydrated soap, each one good for a wash. (Pro tip: Make sure your hands are dry when removing a sheet or you'll risk melting them together.)
Tired of drying your hands on your clothes? Consider swapping your neck gaiter for this quick-drying square hand towel, which pulls double duty as a kerchief.
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