The normal, cellular PrP (PrPC) is converted into PrP(Sc) through a post-translational process this leads to the progress of prion disease in different species of animals including humans. The formation of the infectious agent is unknown, but with cascades of molecular mechanisms that cause degeneration of the nervous system the disease is manifested by spongiform encephalopathies. The diseases can be transmitted within and between species by several mechanisms, including ingestion, iatrogenic transmission, mother to offspring and blood transfusion. Schistosomiasis is a chronic debilitating infection of humans and animals, and hence the disease is of public health importance. Different species of schistosomes can be found in animal populations, such as Schistosoma rodhaini in wild rodents and antelope, and S.bovis in domestic cattle which is one of the major veterinary problems. Animal populations can also serve as reservoirs for schistosomes that more commonly infect humans, including S. Japonicum and S. Mansoni.