PRELIM 05 - Principles of Disease and Epidemiology Flashcards
Studies the cause of disease
Etiology
The scientific study of disease
Pathology
The manner in which disease develops
Pathogenesis
Refers to the disease-causing microorganism
Pathogen
Invasion or colonization of the body by pathogenic microorganisms
Infection
Any change from a state of health due to infection
Disease
Subjective changes not apparent to an observer
Symptoms
Objective changes the physician can observe and measure
Signs
A specific group of symptoms or signs that may always accompany a particular disease
Syndrome
Microorganisms that establish more or less permanent residence but that do not produce disease under normal conditions
Normal microbiota
Ordinarily do not cause disease in their normal habitat in a healthy person but may do so in a different environment
Opportunistic pathogen
Scientist that demonstrated that Bacillus anthracis was always present in the blood of animals that had the disease (anthrax) and not in healthy animals; he did the same for Mycobacterium tuberculosis
Robert Koch
Other name for Mycobacterium tuberculosis
Koch’s bacillus
Type of disease that spreads from one host to another
Communicable disease
Type of disease that is easily communicable
Contagious disease
Type of disease that does not spread from one host to another
Noncommunicable disease
Disease that is occasional and irregular occurence
Sporadic
Disease that is constantly present in a population
Endemic
Disease that is persistent and has high levels of occurence
Hyperendemic
An epidemic that has spread over several countries or continents
Pandemic
An increase, often sudden, in the number of cases of a disease above what is normally expected
Epidemic
Disease where the causative agent remains inactive for a time but then becomes active to produce symptoms of the disease
Latent disease
Disease that develops rapidly but lasts only a short time
Acute disease
Disease that is an intermediate between acute and chronic
Subacute disease
Disease that develops more slowly, may be less severe, but likely to continue or recur for long periods
Chronic disease
Infection where the invading microorganisms are limited to a relatively small body area
Local infection
Infection where the agents of local infection enter a blood/lymphatic vessel and spread to other body parts, where they are confined to specific areas
Focal infection
Infection where microorganisms or their products are spread throughout the body by the blood/lymph
Systemic infection
Systemic infection from the multiplication of pathogens or spread of toxins in the blood
Septicemia/Blood poisoning
3 types of septicemia
Bacteremia, Toxemia, Viremia
Toxic inflammatory reaction to septicemia that can lead to tissue damage and death
Sepsis
Infection which is a result of the pathogen’s presence or activity within the normal, healthy host, and their intrinsic virulence
Primary infection
Infection caused by an opportunistic pathogen in a host with depressed resistance or if they have unusual access to the inside of the body
Secondary/Opportunistic infection
Infection where there is no noticeable illness
Subclinical infection
5 stages of development of disease
Incubation period, Prodromal period, Period of illness, Period of decline, Period of convalescence
Interval between initial infection and first appearance of any signs or symptoms (Stages of development of disease)
Incubation period
Relatively short period that follows the period of incubation in some diseases (Stages of development of disease)
Prodromal period
Most severe; overt signs and symptoms (Stages of development of disease)
Period of illness
Signs and symptoms subside; vulnerable to secondary infections (Stages of development of disease)
Period of decline
Body returns to pre-diseased state (Stages of development of disease)
Period of convalescence
Refers to continual sources of pathogen; provides pathogen with adequate conditions for survival and multiplication
Reservoirs of infection
3 types of reservoirs of infection
Human, Animal, Nonliving
Transmission through physical contact (Type of contact transmission)
Direct contact
Transmission through an intermediate nonliving object, known as a fomite (Type of contact transmission)
Indirect contact
Transmission through droplet nuclei that travel only short distances (Type of contact transmission)
Droplet transmission
Transmission through spread by contaminated water (Type of vehicle transmission)
Waterborne transmission
Transmission through contaminated food (Type of vehicle transmission)
Foodborne transmission
Transmission through droplet nuclei that travel long distances (Type of vehicle transmission)
Airborne transmission
Transmission through passive transport (Type of vector transmission)
Mechanical transmission
Transmission where pathogen reproduces in the vector; part of life cycle in the vector (Type of vector transmission)
Biological transmission
Infections acquired while receiving treatment in healthcare settings
Healthcare-associated infections
Refers to hospital-acquired infections
Nosocomial infections
Is the leading cause of HAIs
Clostridium difficile
Host whose resistance to infection is impaired by disease, therapy, or burns
Compromised host
Are precautions employed to reduce the transmission of microbes in health care and residential settings
Universal precautions
Precautions that are basic, minimum practices designed to prevent transmission of pathogens from one person to another
Standard precautions
Precautions that are procedures designed to supplement standard precautions in individuals with known or suspected infections that are highly transmissible
Transmission-based precautions
Is the single most important means of preventing the spread of infection
Handwashing
Refers to diseases that are new or changing, and shows an increase in incidence in the recent past
Emerging infectious diseases
The use of pathogens or toxins to produce death and disease in humans, animals, or plants as an act of violence and intimidation
Bioterrorism
The science that studies when and where diseases occur and how they are transmitted in populations
Epidemiology
A British physician who is the father of modern epidemiology and conducted a series of investigations related to outbreaks of cholera in London
John Snow
He recorded the number of births and maternal deaths at Vienna General Hospital from 1846 and 1848
Ignaz Semmelweis
A nosocomial infection that begins in the uterus as a result of childbirth or abortion
Puerperal sepsis/Childbirth fever
Puerperal sepsis is frequently caused by __________
Streptococcus pyogenes
3 types of epidemiologic investigations
Descriptive epidemiology, Analytical epidemiology, Experimental epidemiology
Collecting all data that describe the occurrence of the disease under study (Type of epidemiologic investigations)
Descriptive epidemiology
Analyzes a particular disease to determine its probable cause (Type of epidemiologic investigations)
Analytical epidemiology
2 types of analytical epidemiology
Case control method (Retrospective), Cohort method (Prospective)
A group of people with the disease is compared to a group of people without the disease in terms of how many are exposed to the agent (Type of analytical epidemiology)
Case control method (Retrospective)
A cohort group with exposure to the agent is compared to a cohort group without exposure to the agent in terms of how many develop the disease (Type of analytical epidemiology)
Cohort method (Prospective)
Begins with a hypothesis about a particular disease (Type of epidemiologic investigations)
Experimental epidemiology
Testing on humans is called a __________
Clinical trial
Clinical trials include a __________ and __________
Test group, Control group
The number of causes of a specific disease
Morbidity
The number of people affected by a disease in a given period of time in relation to the total population
Morbidity rate
The number of deaths from these diseases
Mortality
The number of deaths resulting from a disease in a population in a given period of time in relation to the total population
Mortality rate
The number of people in a population who develop the disease during a particular time period
Incidence
The number of people in a population who have the disease at a specified time, regardless of when it was first appeared
Prevalence
Prevention of overgrowth of harmful microorganisms by normal microbiota
Microbial antagonism/Competitive exclusion
3 types of symbiosis
Mutalism, Commensalism, Parasitism
Vitamin produced by E. coli
Vitamin K
Diseases that occur primarily in animals and can be transmitted to humans
Zoonoses/Zoonotic disease
Promoted the practice of handwashing to prevent puerperal fever
Ignaz Semmelweis
22 cases of legionellosis occurred within 3 weeks among residents of a particular neighborhood (usually 0-1 per year) (Occurrence of disease)
Epidemic
Average annual incidence is 364 cases of pulmonary TB pero 100,000 population in one area, compared with the national average of 134 cases pero 100,000 population (Occurrence of disease)
Hyperendemic
Over 20 million people worldwide died from influenza in 1918-1919 (Occurrence of disease)
Pandemic
A single case of histoplasmosis was diagnosed in a community (Occurrence of disease)
Sporadic
About 60 cases of gonorrhea are usually reported in this region per week, slightly less than the national average (Occurrence of disease)
Endemic
1 case of smallpox appeared (Occurrence of disease)
Epidemic
