1. Disease

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

4. Disease A pathological condition of a part, organ, or system of an organism Infection Genetic Environmental stress

5. Infectious disease Clinically evident illness resulting from the presence of pathogens Virus Bacteria Fungi Protozoa Parasites prions

6. Non-living pathogen

7. Opportunistic pathogen Immunosuppressed

8. Infectious disease Can be slow or fast when it spreads Can be transferred through different vectors

9. Disease vs infection Which is which? Type of Diseases Genetic Age Infectious

10. Manner of infection Entrance to the host body Adhere to specific host cells Invade and colonize Multiply between host cells or body fluids Tissue damage Production of toxins or destructive enzymes

11. Germ Theory Microorganisms can cause diseases Infectious disease is caused by an infectious agent

12. Koch’s Postulate Series of experimental steps to determine the cause of a disease

13. Koch’s Postulate The 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.

14. Koch’s postulate

15. Modes of Infection Direct contact Indirect contact fecal oral route Airborne (droplet infection) Vector

16. Body Defense Non-specific Specific Humoral Cell-mediated

18. Other terms Lysosome cilium/cilia Mesosome flagellum/flagella Piliperoxisome Plastid glyoxisome Leucoplast/amyloplast Chromoplast Cytoskeleton Microtubule microfilament