A disease is defined as any change that interferes with normal body functioning. The Germ Theory of Disease states that infectious diseases are caused by specific infectious agents like viruses, bacteria, fungi, or parasites. Koch's postulates provide a method to determine if a specific pathogen causes a particular disease by finding the microorganism in diseased subjects but not healthy ones, being able to isolate and grow it in culture, and using the cultured version to reproduce the disease in a healthy subject. Diseases can spread through direct or indirect contact, fecal-oral transmission, airborne droplets, or vectors. The body defends against disease through non-specific and specific immune responses.
2. A disease is defined as any change (other than an injury) that interferes with the normal functioning of the body. The Germ Theory of Disease states that an infectious disease is caused by a certain agent.There are different types of infectious agents which cause specific symptoms from which the disease may be identified.
3. Koch’s postulates is a set of rules that is used to determine whether a specific pathogen is the cause of specific disease.There are various ways in which diseases are spread.The human body has specific and non-specific mechanisms that defend the organism against infectious diseases
10. Manner of infectionEntrance to the host bodyAdhere to specific host cellsInvade and colonizeMultiply between host cells or body fluidsTissue damageProduction of toxins or destructive enzymes
13. Koch’s PostulateThe microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy animals.The microorganism must be isolated from a diseased organism and grown in pure culture.The cultured microorganism should cause disease when introduced into a healthy organism.The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.