Bilharzia, commonly known as schistosomiasis, is a parasitic disease that plagues the tropics and subtropics, mainly in Africa. It is caused by parasitic worms and can cause severe infection and severe disability. It is a global public health issue, since it is the second parasitic endemic after malaria.

Bilharzia kills between 20 and 000 people each year, according to the World Health Organization, which treated more than 200 million people in 000. The WHO then estimated the number of people requiring preventive treatment at more than 60 millions. Bilharzia is present in Latin America, the Middle East and Asia, but the African continent concentrates 2014-250% of cases. (80) Bilharzia is considered a neglected tropical disease, i.e. a disease widespread and confined to developing regions (often referred to as NTD for Neglected Tropical Disease). This could change because several cases have occurred in Europe since 2011, in particular in Corsica, raising fears of the emergence of this parasitosis in Europe. (2)

The first signs of an infection are a rash, followed a few weeks later by fever, cough, and muscle pain. There are 2 main forms of schistosomiasis:

• Intestinal schistosomiasis: diarrhea, blood in the stool and abdominal pain are common signs. In its chronic form, the complications are an increase in the size of the liver and spleen (hepatomegaly and splenomegaly).
• Urogenital schistosomiasis: The presence of blood in the urine is often indicative of urogenital schistosomiasis, which can cause damage to the bladder, urethra and kidneys.

Growth and cognitive development delays are observed in affected and untreated children.

Bilharzia is caused by parasitic worms of the genus Schistosoma. Three species of worms are responsible for most of the transmission of bilharzia to humans: Schistosoma haematobium (bilharziose urogeÌ ?? nitale), Schistosoma mansoni et Schistosoma japonicum (intestinal bilharziose).

Bilharzia is rife in populations in the tropics and subtropics living in contact with stagnant water. Fishermen, women washing clothes and children playing games are particularly exposed.

The larvae of the parasite develop in freshwater gastropods and enter the human body through the skin. They are drained by the blood to the intestines and the bladder where they produce eggs which will damage the tissues and provoke the inflammatory reaction of the body. The water is contaminated by the feces of people carrying the parasite.

Praziquantel is an effective drug against all forms of schistosomiasis, safe and inexpensive. Repeated large-scale treatment of populations at risk can cure the early stages of the disease and reduce the number of people infected. The fight against endemic disease also involves cleaning up stagnant water, combating gastropods which are vectors of the parasite, as well as prevention among populations in endemic areas. As for travelers in the tropics and subtropics, they should avoid swimming in lakes, ponds and rivers.