Norovirus on the Colorado River in Grand Canyon National Park
(The following is from Brian Bloom, River District Ranger and addresses the
problem of norovirus spread and cnntamination)
BACKGROUND: Norovirus is a very contagious virus that infects over 20 million
people in the US every year. You can get norovirus from an infected person,
contaminated food and water, or by touching contaminated surfaces. Norovirus
causes sudden-onset vomiting and diarrhea that lasts about 24-48 hours. On rafts
and in camps, norovirus can spread quickly. The best way to prevent norovirus is
to practice proper hand washing and general cleanliness.
Each season, there are multiple river trips that are affected by norovirus. So
far in 2012, the number of infected trips is about average. Large outbreaks of
norovirus can be prevented if you do the following:
BEFORE AN OUTBREAK: Trip participants may bring norovirus from home or from
their travels. Many people who carry norovirus do not have symptoms. You may not
be able to prevent the first case of norovirus on your trip, but you can prevent
its spread by practicing good health habits from day one.
Handwashing: Explain and enforce good handwashing habits in your group. Use
hand sanitizer post-wash.
Food service: Offer hand sanitizer on the boat before serving snacks. If you are
sharing something from a common bag or box (e.g. trail mix), have everyone pour
the contents into their hands, rather than reaching into the bag/box. At meals,
encourage everyone to wash their hands before eating.
Drinking water: Make sure no one touches the nozzle of water dispensers. Wipe
the nozzle with bleach solution twice a day. If you are filtering water from the
river, remember that norovirus is tiny and can pass through filters. Treat
drinking water (2-5 drops of bleach per gallon of water) and set aside for at
least 30 minutes before using.
Setting up camp: When you enter a camp, observe whether it appears to have been
occupied by ill people recently. Cat-holes, vomit, etc., may indicate a sick
trip before you. Be careful about where you set up your tents, toilets, chairs,
and kitchen. Avoid setting up sleeping camps in questionable areas. Assume that
norovirus contamination may be present at all beaches and take appropriate
Wear eye protection (e.g. sunglasses) and two pairs of disposable gloves. Before
putting on gloves squirt a small dollop of hand soap on the back of one of your
hands for hand washing afterwards
Don’t use toilet brushes. They carry contamination.
Keep bleach solution in the toilet kit to disinfect the toilet seat, toilet box,
and handles. Don’t use the same bottle for your dish-wash/potable water – have a
separate bleach bottle for toilets.
After you properly store the toilet seat in a separate plastic bag in the toilet
kit and place the toilet lid back on the toilet, remove and discard the outer
pair of disposable gloves.
Wipe down the hand soap, toilet “key”, toilet paper container, etc. with the
bleach solution, using a disposable paper towel.
Lastly, take off your gloves, and use the dollop of soap on the back of your
hand to wash hands thoroughly at the hand wash station followed by a hand
IN THE EVENT OF ILLNESS
Supplies: If someone is sick, make a bleach solution (5-25 tablespoons per
gallon of water) each day. Do not use this for food surfaces or hand-washing. It
is for cleaning contaminated non-food surfaces only.
“Spill” clean-up: Try to avoid putting vomit or feces in the river. Don’t leave
vomit or feces on a beach, and don’t bury it. Put it in a toilet or trash
container. If you use a trash container, use extra trash bags to close and seal
the vomit away. If you use a toilet, reserve that toilet for sick people only.
If you don’t have room to carry all the vomit or feces with you on the rest of
the trip, scoop it into a five-gallon bucket, and saturate it with the bleach
solution as specified above. After 15-20 minutes, throw it into the main current
of the river and rinse the bucket with the bleach solution, This is meant to be
last resort if a trip is incapable of containing it otherwise. (Try to limit any
damage to resources during clean-up, especially if you’re in an archeological
Isolate ill individuals and gear: Have ill people sit on the same boat or same
area of a rig. Wash the boat and other potentially contaminated equipment
frequently with the bleach solution. If clothing is soiled with vomit or feces,
store it in a dry, labeled bag. Paco pads, tents, etc. must stay with the people
who were sick for the rest of the trip. Have sick people stay in the same area
of camp, if possible.
Toilets: Consider taking extra disposable toilet bags (“wag bags”) to provide
for participants to use in camp or in case of sudden emergency. If you have
day-tripper ammo cans, consider creating an additional one (or two) for sick
Set up a “sick” toilet and hand-washing area for those who are ill or recovering
If feces or vomit are on the toilet seat or on the outside of the toilet box,
clean with a bleach wipe, discard it in the toilet, and then rinse the surface
with the bleach solution. Wipe with a disposable paper towel and dispose in
Never wash off fecal material in the river or side tributaries. Get it into a
Food preparation: If you have an ill participant, enhance food prep safety.
Make every effort to have only people who have not been sick in the previous two
weeks prepare food. Wash your hands more frequently followed by a hand
sanitizer. Wear non-latex disposable gloves. Have someone who does not have
symptoms serve all food so only one person touches serving utensils. Serve sick
people separately. Do not save unused food. Wipe down the outsides of
condiment containers with a weak bleach solution (1-2 teaspoons of bleach per
gallon of water).
Reporting: Please report any trip with gastrointestinal illness to the National
Park Service after the trip, using the form in your private trip regulations,
12 to 25 Day Noncommercial River Trips: Lees Ferry to Diamond Creek - Grand Canyon National Park
Reporting will help the National Park Service learn more about norovirus and how
to prevent it for future river runners. If you rented gear from a private trip
outfitter, tell them that you had illness on the trip so they can take extra
care in cleaning your returned gear.
After the trip: The National Park Service may ask you to hold your toilets for
testing at the end of the trip. Sanitize all equipment using the bleach solution
or hot water > 140 degrees. Launder sleeping bags and other soft goods in hot
water and hot dry. Don’t forget to clean all items that have hard surfaces, such
as the ammo can that holds your library.
GCPBA RiverNews is a service of Grand Canyon Private Boaters Association.
Support GCPBA - visit our all new website: Grand Canyon Private Boaters Association | To ensure the ability for all to obtain an opportunity to experience a float trip through the Grand Canyon while protecting the resource.
We are on FaceBook - Welcome to Facebook - Log In, Sign Up or Learn More