A heat wave is rolling over the capital: temperatures of over 30 degrees are expected in Berlin and Brandenburg at the weekend. The numerous bathing spots, open-air baths, and beach baths in the capital provide cooling off. But what about the water quality of urban lakes and rivers?

The Berlin State Office for Health and Social Affairs (Lageso) has put together a map for this. It not only gives an overview of Berlin’s bathing areas but also shows how clean the water is at the relevant point at the moment. The latest data paints a pleasing picture: each of the 39 bathing resorts is marked in green on the map. The water quality is good, and Berliners can go swimming without restrictions.

Berlin bathing waters: Skin irritation due to cercaria possible

However, one thing could still cloud the bathing pleasure at the weekend, as the Lageso announced shortly before the weekend: cercaria. These are larvae of flukes that live in ducks or other waterfowl.

The worm eggs get into the water via the bird droppings and infect snails living in the bank area as intermediate hosts. In these, the cercaria form, and swarm out when the water temperatures are warm to look for their definitive host.

This is usually a water bird, but it can also happen that a human is accidentally infested. The larvae then burrow under the skin, where they die after a short time. This can lead to uncomfortable itchy skin infections in those affected.

Bathers should pay attention to this

According to Lageso, it is difficult to detect cercaria in water. An increased occurrence of the larvae is very variable in terms of time and space. In addition, cercaria would often only appear briefly in some of the strongly warmed waters.

The Lageso recommends the following measures:

Avoid riparian areas rich in aquatic plants
Visit open water zones
Avoid longer stays in the shallow water area (especially children are at risk)
Use waterproof sunscreen
After bathing, rub vigorously with a towel to prevent cercaria from penetrating the skin
Take off wet swimwear
If the symptoms are more severe, a doctor should be consulted.
Waterfowl should not be attracted by feeding
Report to the local health authority

In recent years there have been indications of cercariae in Berlin bathing waters. The Schlachtensee, the Krumme Lanke, the Jungfernheideteich, the Große and the Kleine Müggelsee, the Halensee, the Unterhavel (Große Steinlanke) and the Große Wannsee were all affected.