Chapter 9: Principles of Infectious Disease and Epidemiology Flashcards
Define: pathogen
-cause disease (viruses, prions, protozoans, fungi, helminths, bacteria)
Define: opportunistic pathogen
-pathogens that cause disease in a weakend host (weak immune system/HIV/AIDS)
Define: endemic
- an infection that is routinely detected in a population or region (common cold)
Define: epidemic
-widespread disease outbreak in a particular region during a specific timeframe
Define: pandemic
-epidemic spreads to numerous countries or througout the world
Define: emerging pathogen
-newly identified agents/pathogens that previously only caused sporadic diseases
Define: reemerging pathogen
-infectious agent that was once under control but is now resurfacing (antibiotic resistant bacteria)
Define: zoonotic disease
-diseases spread from animals to humans
Define: noncommunicable
-do not spread from human to human
Define: communicable
-spread from human to human
Define: contagious
-easily transmitted from one host to the next
Define: signs
-objective indicators of disease that can be measured or verified (fever, rash, blood in stool)
Define: symptoms
-sensed by the patient rather than precisely measurable (pain, fatigue, nausea)
Define: latent disease
-asymptomatic
Define: chronic disease
-slow onset and progression
Define: acute disease
-rapid onset and progression (quick resolution)
Define: noninfectious disease
-illnesses not directly caused by pathogens
Define: infectious disease
-illnesses caused by pathogens
Define: susceptible host
-host that can develop a disease in question
Define: obligate intracellular pathogen
-pathogens that only replicate inside a host cell and therefore cannot be grown as independent pure cultures
(viruses, certain bacteria, protozoans)
Define: reservoir
-animate or inanimate habitat where a pathogen is naturally found
Define: source
- disseminate infectious agent from the reservoir to new hosts
Define: endogenous source
-pathogen came from hosts own body
Define: exogenous
-pathogen is from external to host
Define: vector
-organisms such as arthropods and rodents that spread infectious agents to other susceptible hosts
Define: morbidity
-existence of disease in a population
Define: prevalence rate
-morbidity in a given population during a specified time
Define: incidence rate
-number of new cases in a defined population during a defined time frame
Define: duration
-how long the infection lasts
Define: epidemiology
-monitoring and controlling disease occurrence to promote public health
Define: HAI
-healthcare acquired infection
Define: localized infection
-infection restricted to a specific part of the body
Define: systemic infection
-infection widespread throughout the body
Define: virulence factor
-ways pathogens overcome our defenses
Kochs Postulates
- the same organism must be present in every case of disease
- the organism must be isolated from the diseased host and grown as a pure culture
- the isolated organism should cause the disease in question when it is inoculated into a susceptible host
- the organism must then be re-isolated from the inoculated, diseased animal
Infectious Disease Transmission (know mechanisms)
Know figure 9.1
5 stages of infectious disease
incubation period: time between infection and the development of disease symptoms
prodromal phase: patient has mild symptoms
acute phase: patient experiences full blown symptoms
period of decline: pathogen replication decreases
convalescent period: elimination of the pathogen from the hosts body
Know the epidemiological triangle(what can be done to stop the spread of infection?)
- education
- quarantine
- vector control
Importance of CDC and WHO?
- the CDC is a federal health agency that serves as a central source of epidemiological information
- the WHO is importance for the global governance of health and disease
What is the MMWR?
- MORBIDITY AND MORTALITY WEEKLY REPORT
- updates health officials and care providers on U.S. health issues
- provides summaries of health watches and a running report for selected notifiable diseases
What is an HAI (nosocomial)? Why are they a problem?
Most common HAIs?
Prevention?
- HAIs are healthcare acquired infections
- 1 in 25 hospitalized patients develop an HAI
Prevention
- hand washing
- personal protective gear
- environmental sanitation
- equipment sterilization
- limiting patient transport
- patient isolation
What is the NNDS?
-surveillance for nationally notifiable diseases
Examples of vaccine preventable diseases:
