Health Information

Cercariae In The Water 

Cercariae appearing in the water can happen at any time and is not connected to water quality. When temperatures reach 20°C, the larvae leave their hosts, in this case freshwater snails, in search of a new host. They tend to be found close to the shore where there are water plants and can survive without a host for around 48 to 60 hours.

Unfortunately it is not possible to predict when larger numbers of cercariae can be found in the water. 

Cercariae can cause skin irritations.

To help prevent this, please observe the following:

  • Use waterproof suncream and make sure it is well rubbed into your skin. Suncream can help prevent cercariae coming into contact with your skin.
  • Don't feed ducks or any other aquatic birds.
  • Shower after swimming as well as before
  • Remove wet swimwear immediately after swimming/showering and dry your skin vigorously with a towel.


Cercariae and skin irritation (PDF) - Information from the State Office For Health & Social Affairs