Disease And Epidemiology Chapter 14 Summary

Chapter 14 – Principles of Disease and Epidemiology

Pathology Infection and Disease 1. Pathology is the scientific study of disease – concerned with cause (etiology) and manner in which disease develops (pathogenesis) - Also concerned with structural and functional changes brought about by disease and final effects on the body 2. Infection – invasion or colonization of the body by pathogenic microorganisms 3. Disease – when infection results in change in state of health
Normal Microbiota – 1. Free of microbes in utero, at birth gain lactobacilli in intestine from mothers vaginal canal, E. coli taken through food and inhabits intestine thru life 2. Ten times more bacterial cells than human cells in the body 3. Normal flora – normal microbiota
Septicemia – blood poisoning systemic infection arising from multiplication of pathogens in blood 6. Bacteremia – presence of bacteria in blood, Toxemia – presence of toxins in blood and viremia – presence of virus in blood 7. Primary infection – acute infection that causes initial illness 8. Secondary infection – caused by an opportunistic pathogen after primary weakens defenses 9. Subclinical (inapparent) infection is one that does not cause any noticeable illness e.g. Polio & HepA can be carried but never developed
Patterns of Disease 1. Sequence – must be reservoir of infection as a source pathogen transmitted to susceptible host by contact or vectors transmission followed by invasion (enters host, multiplies) injures host through pathogenesis 2. Despite these effects, occurance of disease generally depends on resistance
Predisposing factors – makes body more susceptible and may alter course of disease 1. Gender – Females more UTI, Men more meningitis 2. Genetic background – sickle cell against malaria 3. Climate and weather – respiratory disease increase in winter 4. Others – nutrition, age environment, lifestyle, habitat, illness, chemo,