These are ideal habitats for snails and swimmer's itch parasites. Although not scientifically proven, some people believe the use of a fragrant suntan oil may reduce the risk of getting swimmer's itch. Swimmer's itch shows up in Manitoba lakes every summer. Manitoba Environment receives reports of swimmer's itch from approximately four to twelve lakes per year. Swimmer's itch usually starts showing up in Manitoba lakes in June-warm water accelerates its development.
Wind can concentrate swimmer's itch parasites in shallow beach areas.
Where outbreaks have been confirmed, the provincial departments of Environment, Health, and Natural Resources work cooperatively to ensure that swimmer's itch advisory signs are posted to warn other beach users. Some pesticides kill the snail host which carries the parasite. However, this is not always practical or legal and can also cause ecological damage.