Swimmer's Itch

What about swimmer’s itch?


Several years ago the Wexford County Department of Public Works (DPW) commissioned a study with Hope College to determine the exact source of our swimmer’s itch. That study showed that waterfowl were to blame, mostly the ducks and geese that stay all summer. For many years the DPW applied tons of copper sulfate, which is biologically dangerous, to combat swimmer’s itch on Lake Mitchell. Now, as a result of the study, the County DPW instead inoculates the waterfowl through feeding, and copper sulfate is no longer needed. We can all do our part by not feeding the waterfowl. Artificial feeding of waterfowl leads to unnaturally high numbers of waterfowl on our lake, which makes the swimmer’s itch problem worse.

Although there are still cases of the itch reported every year, the incidence is much lower than it used to be. The parasite that causes swimmer’s itch uses ducks and snails as hosts before infesting humans. Children, often are most affected, because their skin may be more sensitive, and they spend time playing in shallow water where the swimmer’s itch parasites are more concentrated.


Infected swimmers may notice red spots within a half-hour of leaving the water. These spots may enlarge for the next 24-30 hours and may itch for a week. Toweling off may help. Others find protection by applying baby oil before swimming or taking a shower after leaving the water.


History shows that the incidence of swimmer’s itch may range from few cases a season to widespread problems. Variables affecting swimmer’s itch include:

  • Distribution and number of snails and ducks.
  • Numbers of hours that people stay in the water.
  • Wind direction.


What can be done to prevent or reduce swimmer’s itch?


  • Avoid swimming for long periods in shallow water.
  • Avoid swimming where swimmer’s itch is a problem.
  • Towel off immediately after leaving the water and shower.
  • Onshore winds may push parasites in toward shore.
  • Do not feed the ducks.
  • Inoculate ducks with an antihelmintic drug to remove the adult worms from bird hosts. This has been done in recent years to ducks on Lake Cadillac.

To find out more about swimmer’s itch go to: www.hope.edu/swimmersitch.