BIOL 553 Lecture Notes - Lecture 1: Varicella Zoster Virus, Sexually Transmitted Infection, Diarrhea
Document Summary
Acute vs chronic disease: acute diseases. Rapid onset and rapid resolution (usually within three months) Ex: common cold, sore throats, influenza: chronic diseases. The triad of disease causation: three categories explain all causation. Parasite: an organism that lives in or on another organism, and lowers that host organism"s evolutionary fitness. Pathogen: a parasite whose organization is at or below the level of the individual cell (protozoal, bacterial, and viral parasites) Infectious disease: narrowly defined- a disease caused by a pathogen, broadly defined- a disease caused by pathogen or internal multicellular parasite. Nonparasitic environmental causes- too much or too little of non-reproducing agents. Diet- vitamin deficiency, too much or too little caloric intake. Lifestyle- insufficient exercise, smoking: one or more of these categories generally act in concert. An essential cause (primary cause) is necessary for the disease to occur in all patients. Ex: chicken-pox virus (varicella zoster virus) is necessary for singles to occur.
