Medical microbiology, also known as clinical microbiology, is the study of microorganisms (parasites, fungi, bacteria, viruses, and prions) capable of infecting and causing diseases in humans. As with other specialties in medicine, the evolution of medical microbiology is essentially a response to clinical needs. At its core is the study of the pathogenesis and epidemiology of these microorganisms, and its practical applications lie in the form of diagnostic and therapeutic guidance – intrinsically a supportive role in clinical practice. Today, virtually all tertiary hospitals worldwide will have an in-house microbiology laboratory to provide diagnostic services for infectious diseases.