MCB2004 Exam 3 Study Guide Chapters 14 20 Lectures 20 28 Lecture 20 1 Define pathology etiology infection and disease a Pathology The precise study and diagnosis of disease b Etiology The study of the cause of a disease c d Disease An abnormal state in which the body is not functioning normally dis ease Infection Growing and multiplying of pathogens in the host lack of ease Infection Disease 2 Define normal transient microbiota and opportunistic infections a Normal microbiota permanently colonize the host i Probiotics ii Symbiosis is the relationship between normal micrbiota and the host 1 Reestablishment of a healthy host 2 parasitism commensalism mutualism Infectious disease process begins mutualism commensalism parasitism b Transient micriobiota may be present for days weeks or months c Opportunistic infections i In the general realm of biology an opportunist is an organism that is able to sustain its life from a number of different sources but when favorable conditions arise the organism immediately takes advantage of the opportunity to thrive ii Opportunistic microorganisms are typically non pathogenic microorganisms that act as a pathogen in certain circumstances They lay dormant for long periods of time until the hosts immune system is suppressed and then they seize the opportunity to attack iii Sometimes normal microbiota can be opportunistic examples include E coli environmental bacteria or microbiota in immunocompromised hosts 3 Compare and contrast commensalism mutualism and parasitism a Commensalism one organism is benefited and the other is unaffected b Mutualism both organisms benefit c Parasitism one organism is benefited at the expense of the other 4 Understand Koch s postulates and the exceptions a Postulates 1 Microorganisms are isolated from a diseased or dead animal 2a The microorganisms are grown in pure culture 2b The microorganisms are identified 3 The microorganisms are injected into a healthy laboratory animal 4 Disease is reproduced in a laboratory animal 5a The microorganisms are isolated from the animal and grown in pure culture 5b Microorganisms are identified b Rules for the postulates i The same pathogen must be present in every case of the disease ii The pathogen must be isolated from the diseases host and grown in pure culture iii The pathogen from the pure culture must cause the disease when it is inoculated into a healthy susceptible lab animal 1 iv The pathogen must be isolated from the inoculated animal and must be shown to be the original animal c Exceptions i Some pathogens can cause several disease conditions or the same pathogen can cause different disease symptoms ii Some pathogens cause disease only in humans iii Some pathogens need cofactors not all develop disease iv Development of some diseases takes years 5 Understand predisposing factors for disease a Infectious diseases i Noncommunicable disease A disease that is not transmitted from one host to another b Occurrence of disease ii Communicable disease A disease that is spread from one host to another iii Contagious disease A disease that is easily spread from one host to another i Sporadic disease Disease that occurs occasionally in a population ii Endemic disease Disease constantly present in a population iii Epidemic disease Disease acquired by many hosts in a given area in a short time iv Pandemic disease Worldwide epidemic 6 Define reservoir of infection a Continual sources of infection i Human AIDS gonorrhea 1 Carriers may have inapparent infections ii Animal or latent diseases Rabies Lyme disease iii Nonliving Botulism tetanus 1 Soil water 1 Some zoonoses may be transmitted to humans 7 Explain three methods of disease transmission a Contact i Direct Requires close association between infected and susceptible host ii touching kissing sexual intercourse Indirect fomites tissues towels bedding diapers drinking cups toys moneys etc iii Droplet Transmission via airborne droplets b Vehicle Transmission by an inanimate reservoir food water air c Vectors Arthropods especially fleas ticks and mosquitoes i Mechanical Arthropod carries pathogen on feet ex flies transfer pathogens typhoid fever from feces of infected to food ii Biological Pathogen reproduces in vector Lymes WNV 8 Define epidemiology human populations a Epidemiology literally means the study of what is upon the people It applies only to b The branch of science dealing with the spread and control of diseases computer viruses concepts etc throughout populations or systems 2 9 Know the contribution of John Snow Ignaz Semmelweis and Florence Nightingale John Snow 1848 1849 Mapped the occurrence of Cholera in London Ignaz Semmelweis 1846 1848 Showed that hand washing decreased the incidence of puerperal fever Florence Nightingale prominent English nurse writer and statistician 1858 Showed that improved sanitation decreased the incidence of epidemic typhus 10 Identify the function of the CDC a Stands for Centers for Disease Control and Prevention b Collects and analyzes epidemiological information in the United States 11 Define the terms morbidity mortality and notifiable disease a Morbidity incidence of a specific notifiable disease b Mortality the proportion of deaths from a notifiable disease c Notifiable disease any disease that is required by law to be reported to government authorities 3 Lecture 21 1 Define nosocomial infections and explain their importance a A nosocomial infection is any infection that is acquired during the course of stay in a hospital nursing home or other health care facility Joseph Lister 1827 1912 used carbolic acid to prevent nosocomial infections b About 5 to 15 of all hospitalized patients acquire nosocomial infections c d Certain normal microbiota are often responsible for nosocomial infections when they are introduced into the body through such medical procedures as surgery and catheterization 4 e Opportunistic drug resistant Gram negative bacteria are the most frequent causes of f Patients with burns surgical wounds and suppressed immune systems are the most nosocomial infections susceptible to nosocomial infections 2 A compromised host is a patient with acquired or congenital immunologic deficiency at increased risk for infectious disease complications 3 List several methods of disease transmission in hospitals a Nosocomial infections are transmitted by direct contact between staff members and b Fomites such as catheters syringes and respiratory devices can transmit nosocomial patients and
View Full Document
Unlocking...