Human parasitology o Human parasitology is the study of those organisms which parasitise humans. According to the very broad definition of parasitology. parasites should include the viruses, bacteria, fungi, protozoa and metazoa(multi-celled organisms) which infect their host species. However, for historical reasons the first three have been incorporated into the discipline of microbiologyHuman parasitology ⚫ Human parasitology is the study of those organisms which parasitise humans. According to the very broad definition of parasitology, parasites should include the viruses, bacteria, fungi, protozoa and metazoa (multi-celled organisms) which infect their host species. However, for historical reasons the first three have been incorporated into the discipline of Microbiology