Abstract
Parasites obtain the resources necessary for their reproduction during intimate contact with their hosts. They thus form lasting interactions with the latter, which can potentially harm the health of the host and reduce its survival or reproductive success (Nunn & Altizer 2006). Parasites are generally metazoans (organisms multicellular) and they can be external (fleas and lice), that is to say living on the surface of the host, or internal, present in body cavities (worms). A typical example of a parasite living in the internal body cavity of the host is the schistosome, a trematode worm of the family Schistosomatidae and the genus Schistosoma which lives in the blood system of mammals (humans and animals). It is responsible for Bilharzia (or schistosomiasis), a parasitosis of medical and veterinary importance which occurs in tropical and subtropical regions and which particularly affects African countries. In total, schistosomiasis is endemic in 78 countries around the world, including Benin. Unexpectedly, this disease re-emerged in France in 2014 after more than 45 years of absence (Holtfreter et al. 2014). More than approximately 292 million people are infected with this parasitosis throughout the world. in 2018, 90% of whom live in Africa (WHO 2017). In terms of prevalence, bilharzia is classified as the second parasitic endemic in the world after malaria and the first water-borne disease in tropical and sub-Saharan regions (Chitsulo et al. 2000; Engels et al. 2002). According to the WHO, this parasitosis has economic and health effects considerable and it disables more than kills (WHO 2017). However, it can lead to severe pathology of the liver, intestine, bladder and sometimes even can lead to death (200,000 deaths per year) when the infestation is chronic (Gower et al. 2007).