Swimmer’s itch, otherwise known as cercarial dermatitis, is an irritating rash that can occur after swimming or wading outdoors. Swimmer’s itch is the result of an allergic reaction to microscopic parasites. It is most common in freshwater lakes and ponds but occasionally occurs in salt water. While the parasite’s preferred hosts are usually birds, it can and will burrow into the skin of human beings.
What Kind of Parasite Is Involved?
The parasites responsible for swimmer’s itch are the larval stages or cercariae of flatworms. They emerge from aquatic snails during hot, summer months. Once infected, snails shed cercariae for the remainder of their lives.
Flatworms swim in search of their next host, using their forked tails to grab onto their prey. The usual targets are ducks, geese, gulls, muskrats, and beavers. If the cercariae invade the right host, they mature into adult worms and produce eggs that escape from the host’s feces, causing them to multiply rapidly.
How to Control the Problem
Swimmer’s itch flatworms are very difficult to monitor in a natural setting without harming fish and other organisms. Although people are not suitable hosts, the microscopic larvae can burrow into the swimmer’s skin and cause uncomfortable allergic reactions. Swimmer’s itch rarely leads to complications, but it can become infected and cause severe tingling, burning, and itching.
Nevertheless, swimmer’s itch is a problem that must be treated to avoid the occurrence of skin infections.
1. Use Copper Sulfate
Copper sulfate is a granular algaecide ideal for eliminating parasites in bodies of freshwater. It is an effective algae control product that also helps relieve swimmer’s itch and leech issues. A large area must be treated with the pesticide to ensure the death of most of the snails. Although effective, it is not the most environmentally-friendly way to remove parasites since it can accelerate the death rate of fish and other freshwater organisms. It’s advisable to take immediate action once traces of water contamination is found to avoid having to use higher concentrations of copper sulfate, which may present water quality concerns.
2. Modify Snail Habitats
Snails highly prefer moist, shady areas. That’s why they hang underneath plants all day. It helps to keep the soil cultivated and free of weeds. Eliminating weed beds will reduce snails from populating and lessen the formation of swimmer’s itch flatworms. It also helps to have a few frogs lying around since they love to eat mollusks.
3. Shoo Away Waterfowls
Getting rid of a gang of geese and other waterfowls is often a simple matter of scaring them away. There are many tactics to shoo away birds that might’ve managed to find its way into private lakes. They fear sudden loud noises which might indicate danger. Using an air horn, letting a car’s alarm go off, or firing a hunter’s rifle produce unexpected noises that often drive birds away.
Another factor that confirms noise as an effective tactic is the fact that birds prefer a stable environment. Sudden changes will often scare them away even before they begin to nest. It also helps to avoid leaving food around since it attracts birds in general.
Those who swim or wade in infested waters may be at risk. Further preventive measures include avoiding lakes and ponds where swimmer’s itch is a known problem and areas where snails and waterfowls thrive.