The aim of this module is introduce third year students to the main clinically relevant parasite classes, it will consider their lifecycles, the human/veterinary pathology caused and the treatment methods both of the primary and where applicable intermediate hosts and environment. It will give an understanding of vector borne disease. The module will consider the interaction and evasion methods used by parasites in respect to the immune system and chemical control. It will consider the evidence of possible benefits gained by parasitism. Finally it will demonstrate examples of host:parasite coevolution and consider the likely changes in parasite risk the UK in the light of environmental change.