**2. The diseases**

### **2.1 Schistosomiasis**

Schistosomiasis is native in many countries in Africa, South America, and Asia with an estimated number of 200 million infected people and with 800 million being at risk according to Doumenge et al. [4], but considering the population increase since then, the number of humans currently at risk must be well over a billion [5]. According to latest available information somewhere between 230 and 250 million people are actually infected [6, 7]. People become infected by contact with water harboring schistosome-infected intermediate host snails (**Figure 2**). The snails release cercariae into the water that contact and penetrate human skin.

The schistosomes belong to the trematode order Diplostomida, superfamily Schistosomatoidea and Schistosomatidae. The genus *Schistosoma* contains 23 recognized species and at least 7 of these are of medical and veterinary importance [8].

