Chapter 15: Disease and Epidemiology Flashcards
Epidemiology
Concerns the geographical distribution and timing of infectious disease occurrences and how they are transmitted and maintained in nature, with the goal of recognizing and controlling outbreaks.
Etiology
The study of the causes of disease.
Morbidity
The state of being diseased.
Morbidity Rate
Can be expressed as the number of diseased individuals out of a standard number of individuals in the population, such as 100,000, or as a percent of the population.
Prevalence
The number, or proportion, of individuals with a particular illness in a given population at a point in time.
Incidence
The number or proportion of new cases in a period of time.
Mortality
Death.
Mortality Rate
Can be expressed as the percentage of the population that has died from a disease or as the number of deaths per 100,000 persons (or other suitable standard number).
Sporadic Diseases
Diseases that are seen only occasionally, and usually without geographic concentration.
Endemic Diseases
Diseases that are constantly present (often at a low level) in a population within a particular geographic region.
Epidemic Diseases
Diseases for which a larger than expected number of cases occurs in a short time within a geographic region.
Pandemic Disease
An epidemic that occurs on a worldwide scale.
Etiologic Agent/Causative Agent
The cause of the disease.
Centers for Disease Control and Prevention (CDC)
Charged with protecting the public from disease and injury.
National Notifiable Disease Surveillance System (NNDSS)
Monitors diseases considered to be of public health importance on a national scale.
Notifiable Diseases/Reportable Diseases
Diseases considered to be of public health importance on a national scale.; must be reported to the CDC.
Reservoirs
Places where pathogens normally reside.
Carrier
An individual capable of transmitting a pathogen without displaying symptoms is referred to as a carrier.
Passive Carrier
Contaminated with the pathogen and can mechanically transmit it to another host; however, a passive carrier is not infected.
Active Carrier
An infected individual who can transmit the disease to others; they may or may not exhibit signs or symptoms of infection.
Incubation Period
Before they show signs and symptoms.
Period of Convalescence
After symptoms have subsided.
Asymptomatic Carriers
Active carriers who do not present signs or symptoms of disease despite infection.
Definitive Host
The parasite’s preferred host.
Contact Transmission
Includes direct or indirect contact.
Person-to-Person Transmission
A form of direct contact transmission; the agent is transmitted by physical contact between two individuals through actions such as touching, kissing, sexual intercourse, or droplet sprays.
Vertical Direct Contact Transmission
Occurs when pathogens are transmitted from mother to child during pregnancy, birth, or breastfeeding.
Horizontal Direct Contact Transmission
Contact between mucous membranes is required for entry of the pathogen into the new host, although skin-to-skin contact can lead to mucous membrane contact of the new host subsequently touches a mucous membrane.
Droplet Transmission
Refers to droplet transmission of a pathogen to a new host over distances of one meter or less.
Airborne Transmission
Transmission over distances greater than one meter.
Indirect Contact Transmission
Involves inanimate objects called fomites that become contaminated by pathogens from an infected individual or reservoir.
Vehicle Transmission
Refers to the transmission of pathogens through vehicles such as water, food, and air.
Waterborne Transmission
Water contamination through poor sanitation methods.
Foodborne Transmission
Food contaminated through poor handling or storage.
Foodborne Transmission
Food contaminated through poor handling or storage.
Aerosols
Dust and fine particles, which can float in the air, can carry pathogens and facilitate the airborne transmission of disease.
Vector
An animal (typically an arthropod) that carriers the disease from one host to another.
Mechanical Vector
An animal that carries a pathogen from one host to another without being infected itself.
Mechanical Transmission
Facilitated by a mechanical vector.
Nosocomial Infections/Healthcare-Associated Infections (HAI)
Infections acquired in healthcare facilities, including hospitals.
Emerging Infectious Diseases
Either new to the human population or has shown an increases in prevalence in the previous 20 years.
Reemerging Infectious Disease
A disease that is increasing in frequency after a previous period of decline.
