Schistosomiasis (Blood fluke)

Schistosomiasis haematobium (also known as bilharzia or blood fluke) is an infection caused by several parasitic worms belonging to the grouping of Schistosomes. Over 200 million people are estimated to be infected worldwide. This parasite occurs mainly in Africa, south of the Sahara desert, but also on the Caribbean islands, China and in northern South America.

Life cycle The

Infection is spread by contaminated urine and feces that carry the eggs, once released into fresh water such as streams and lakes the eggs hatch and the larvae infect snails, fish and humans penetrating the skin of people who, for example, bathe or fish in lakes (a small splash on the skin can be enough). Inside the body, the larva settles in large vessels next to the intestine where it reproduces and lays eggs that spread with the blood circulation to the intestine and bladder as well as to other parts of the body. An adult worm can live for about 3 – 10 years.

Symptoms

Where the larva penetrated the skin in connection to contact with infected water, problems with itching often occur however it is not until the adult worms resides inside the blood vessel and has started to produce eggs that symptoms occur to a larger extent (approx. 1 to 8 weeks after contact with infected fresh water). More common symptoms associated with blood fluke infection is; severe inflammatory reaction in the skin with small red blisters or sores, swollen abdomen, diarrhea/bloody diarrhea, fever, blood in the urine and in some cases also tumor development.

Precautions

• Avoid swimming completely in fresh water such as lakes, lagoons, hot springs and waterfalls if you travel to tropical countries where infection with blood flukes occur. Visit the country’s tourist information provided online and review the contagious infections that occur in the country  where you are going to travel to.

• Do not drink tap water when traveling outside the EU or USA. 

• Good hand hygiene in connection with toilet visits.  

Sources: FOHM, Health care