Schistosomiasis

What is schistosomiasis?

Schistosomiasis is a disease caused by parasitic worms called schistosomes. There are 2 major forms of schistosomiasis – intestinal and urogenital – caused by 5 main species of blood fluke.

Schistosomiasis is prevalent in tropical and subtropical areas, especially in poor communities without access to safe drinking water and adequate sanitation. It can be found in Africa, the Middle East, Southeast Asia, and South America.

Intestinal schistosomiasis can result in abdominal pain, diarrhoea, and blood in the stool. The classic symptom of urogenital schistosomiasis is blood in urine. In women, urogenital schistosomiasis may present with genital lesions, vaginal bleeding, pain during sexual intercourse, and nodules in the vulva.

With the rise in eco-tourism, increasing numbers of travellers are contracting schistosomiasis. At times, travellers present severe acute infection and unusual problems including paralysis.

How does it spread?

People become infected when larval forms of the parasite – released by freshwater snails – penetrate the skin during contact with infested water. Transmission occurs when people suffering from schistosomiasis contaminate freshwater sources with their excreta containing parasite eggs, which hatch in water.

Travellers usually contract the disease by bathing, swimming, wading, boating, or rafting in infested waters. Even brief water exposure can lead to infection.

How can you prevent?

Travellers participating in recreational water activities in areas where schistosomiasis is endemic may be at increased risk and should consider the following preventive measures:

• Avoid swimming or wading in fresh water when you are in areas with schistosomiasis. If water exposure cannot be avoided, wear protective footwear and clothing.
  
  
• Drink safe and clean water. Water should be boiled before drinking.
  
  
• Vigorous towel drying after an accidental brief water exposure may help to prevent the parasite from penetrating the skin. You should not rely on vigorous towel drying to prevent schistosomiasis.
  
  

How is it treated?

Praziquantel is the recommended treatment against all forms of schistosomiasis. It is effective and safe. Travellers can consult their doctor for details.