It’s almost as inevitable as the sun coming up on a summer day. Swimmer’s itch is back at a couple of Manitoba’s lakes.
Cases of swimmer’s itch have been confirmed in the past week at both Winnipeg Beach and Moose Lake.
But don’t panic. These things happen when humans choose to swim where animals and plants live.
"It’s a natural phenomenon, it happens fairly regularly in a number of Manitoba lakes so it’s really not unusual. It happens every year," said Nicole Armstrong, director of Manitoba Conservation and Water Stewardship’s water science and management branch.
There are swimmer’s itch reports from three to 17 lakes per year in Manitoba.
Advisory signs have been posted at both locations and will remain for the rest of the summer.
"We can’t test for swimmer’s itch so it’s impossible to know if it has completely cleared the area. So, we find the signs give the public some basic information," Armstrong said, noting the provinces’ protocol is is to post advisory signs when even just one case has been confirmed by a medical professional such as a doctor or a public health nurse.
Moose Lake Provincial Park is in southeastern Manitoba, approximately 150 kilometres from the city.
Swimmer’s itch is an irritating, red rash that shows up on your skin after you have gone swimming in water where the parasite that causes it is present.
The parasite is a worm which originates in the intestines of waterfowl and aquatic mammals (such as beaver). Its eggs are passed into the water through the host creature’s feces. After a short stay with snails, the eggs hatch into worms that seek out the waterfowl or aquatic mammal host. You get swimmer’s itch when these worms, or cercariae, penetrate your skin.
Gross, yes. Uncommon, no.
Swimmers itch usually starts showing up when the heat hits as warm water assists in the parasite’s development. It is more common near areas in lakes where there is a lot of aquatic plants since that’s the home of the parasite-carrying snails.
That’s why Armstrong said it is a more rare occurance in Lake Winnipeg.
"We don’t typically see swimmer’s itch in large Winnipeg beaches where there are not aquatic plants because snails really like weeds and aquatic plants and they are a critical part of the life cycle (of the parasite). If we don’t have snails, we don’t have swimmer’s itch," she said. "I understand there are some areas of weedy vegetation along the shoreline of Winnipeg Beach so it could have been contributed from that type of a source."
To prevent swimmer’s itch, you can avoid going in the water if you know swimmer’s itch has occurred there. But if you are going in anyway, rinse off right after being in the water and vigorously towel the water from your skin.
There are showers available on many Manitoba beaches, such as Winnipeg Beach and Grand Beach.