ID1- Flashcards
(23 cards)
Epidemiology
the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health
Infectious(communicable) diseases
are illnesses caused by pathogens that can spread from organism to organism
Virulence
the ability of an agent of infection to produce disease
Contagious
means easily transmitted from one host to another
To spread an infectious disease required:
1) an infectious agent (pathogen)
2) a host
3) a mode of transmission
Zoonoses
describe the example of the spread of a disease from animals to humans
pathogen
is defined as anything able to cause a disease within a host
bacteria, viruses (fungi, protozoa)
A host
is an organism which a pathogen infects
Direct contact
touching the affected area of the infected person -passing pathogen on to non infected person
includes: touching skin, handshake, kissing, sexual contact
Direct contact diseases example
HIV, chickenpox, herpes simplex infection
Indirect contact
Airborne diseases-inhalation of bacterial spores/ droplets
Food and water-eating/drinking contaminated food
Vector -transmission through other organisms that carry the disease
Contaminated articles- articles that become contaminated (food utensils)
Non sterile procedures- all surgeries or caring for wounds require germ free proceedures
Pattern of Infection-
1) Pathogen enters the body
2) Incubation period when the pathogen reproduces, increasing in numbers -host doesn’t show symptoms
3) Host shows symptoms of infectious disease
4) Crisis- the effect on the host is at its most severe stage from which host will either die or recover
5) Convalescence when the host recovers from the infection and the symptoms disappear
An infection
is the detrimental colonisation of a host organism by a foreign species
Fomite
inanimate object that has (the potential to have) an infectious disease
A host cell
a living cell in which a virus reproduces
A primary host
host in which parasite reaches maturity and reproduces sexually
A reservoir host
can hold a pathogen with no ill effects
A secondary (intermediate) host
host that holds the parasite for short time during which some development stage is completed
Endemic Disease
a disease condition that is normally found in a certain percentage of a population
Epidemic Disease
a disease condition that is found in a greater than usual percentage of a population
Pandemic Disease
An epidemic affecting a large geographical area, often on a global scale
Direct zoonosis
the disease is directly transmitted from animals to humans through air, bites.
Reverse zoonosis
when humans infect animals
