What is schistosomiasis?

Schistosomiasis, or bilharzia as it’s also called, is caused by a parasite. This parasite lives in surface freshwater (lakes, rivers and streams) in a number of tropical and sub-tropical regions. The larvae of this parasite enter the body through the skin and find their way via the bloodstream to the intestines or bladder. From here they develop into mature worms and then lay eggs of their own. It’s these eggs that can lead to the illness.

How can you catch schistosomiasis?

You will be exposed to infection if you come into contact with freshwater in which the parasite is present. Such contact can take place through swimming, paddling, washing or showering in contaminated water. Seawater and chlorinated water are safe because the parasite will not be present.

Where can you catch schistosomiasis?

Schistosomiasis occurs in many tropical and sub-tropical regions (Africa, Central and South America, the Middle East and Asia). However, it only occurs in certain parts of the countries in these regions, while other parts of the same countries may not be affected. The KLM Travel Clinic nurses can tell you more about this.

What are the symptoms?

  • itching and a rash on the skin immediately after swimming, which indicates that the larvae has penetrated the skin
  • between two and six weeks after infection you will experience a fever, shivering, muscle ache, coughing, and feeling generally poorly. If it is not treated, serious complications can manifest themselves months or even years after the infection. However, this is relatively rare in western travellers


There is no vaccine against schistosomiasis. You can only protect yourself by avoiding all contact with surface freshwater that might be contaminated. Investigate beforehand whether there is a risk of contracting schistosomiasis in the region you will be visiting. If, after your journey, you think you may have been exposed to schistosomiasis, contact your doctor for further examination.