Dozens of Havasupai Falls Hikers Reportedly Contract Mystery Stomach Bug

Dozens of hikers in the Grand Canyon’s Havasupai Falls have reported falling ill with an unknown gastrointestinal (GI) illness in recent days. Reported symptoms range from fatigue to diarrhea and projectile vomiting. Some evacuated the canyon via helicopter, too weak to hike out under their own power.

Hiker Erin Entringer told AZCentral on Thursday that roughly 170 people were waiting in line for a helicopter ride out of the canyon when her group was evacuated (due to a leg injury on Entringer’s part and sickness among some other group members), and that many of the people waiting were vomiting.

As of June 13, the Havasupai Tribe said that just 15 people were confirmed to have contracted an unknown illness between June 8 and June 11, with reported symptoms including nausea, vomiting, and diarrhea.

Havasupai Falls is a popular hiking destination. Although the number of visitors is controlled by a permit system issued by the Havasupai Tribe, resources and infrastructure at the remote location are limited. In a recent public health statement, the Tribal Council reminded tourists to “(i) take responsibility for their personal hygiene while visiting and (ii) properly dispose of trash by hauling it out.”

Additionally, as the region has been experiencing excessive heat in recent days and heat illness can cause symptoms like nausea and vomiting, the Tribe has advised visitors to properly hydrate and consider supplementing drinking water with electrolytes before, during, and after visiting the canyon. A water station will be set up along the trail near Little Navajo Falls to aid hikers and campers in the excessive heat.

The Tribe has been meeting with the Indian Health Service (IHS) and Coconino County Health and Human Services to investigate the uptick in reported illnesses. “What the Tribe has learned from these meetings is that a gastrointestinal illness is currently being experienced in the northern Arizona region, not only at the Havasupai Campground.”

The Tribe is hiring additional staff to more frequently clean and disinfect the composting toilets in the campground and is testing Fern Spring, the campground’s drinking water source, every two weeks for water quality. The most recent test on June 6 indicated that the water remains safe to drink. Additional hand sanitizers and other protective supplies will be made available at the campground. In conjunction with the IHS, the Tribe also plans to track new cases for follow-up.

This is not the first time the Grand Canyon region has experienced a large surge in GI-related sicknesses. Over 200 people fell sick in a suspected norovirus outbreak in Grand Canyon National Park in 2022. GI illnesses can be highly contagious and often spread due to inadequate hand washing. 

Per a health advisory from the Supai Health Station:

“Sharing toilet stations is an inevitable part of the camping experience and a high risk area for picking up germs. Please remember to practice good hygiene while in the toilet stations and wash well upon exiting. The best way to protect yourself and others from any potential viruses is to properly wash hands, handle food safely, and properly package and remove your trash. Washing with soap and water whenever possible is highly recommended.”

Hand sanitizer alone is often not enough to eliminate some viruses, like norovirus. Anyone with a gastrointestinal illness should avoid swimming for 48 hours after symptoms resolve. According to the Havasupai Tribe, the IHS medical clinic is available for campers who get sick during their visit.

Featured image: Havasu Falls pictured in 2015. Photo: Brent Sisson