Lecture 1 Flashcards
There are 6 steps in which the micro organism need to carry out to set up infection
Attach as enter the body
Local or systemic spread in the body
Multiply
Evasion of host immune defenses
Shred from the body
Cause damage in the host
What is pathogenicity
Ability of an infectious agent to cause disease
Host parasite interaction depend on 3 factors
- No of organisms in or on host
- Virulence of an organism
- Host defence
What is meant by virulence
Degree or intensity of pathogenicity
Virulence depends on 3 factors
Invasive was - ability to spread
Infectivity - ability to form a focal point of infection
Pathogenic potential - ability of pathogen to cause damage
What is meant by Toxigenicity
Pathogens ability to produce toxins, chemical substances which damage the host
As well as toxins what else do pathogens induce
Immunopathology
What is infection
Colonisation of a host
What is a disease
Infection that changes a body function
What is aeriology
Causation of disease
Who proposed germ theory of disease
Louis pasteur
Robert koch
What was Koch postulate
- Suspected pathogen must be present in every case of disease
- Pathogen must be isolated and grown in pure culture
- Cultured pathogen must cause disease when put in a healthy host
- Same pathogen must be re isolated from the diseased experimental host
Steps for infection
Maintain resevoir Transport to host Adhere, colonise or invade host Evade host defenses Multiply Damage host Leave host and return to resevoir
Name 4 sources of how we can get infected
Food
Humans
Animals
Water
Name 4 types of carriers
Active - overt clinical infection
Convalescent - recovered but still harbour large numbers of pathogens
Healthy - harbours pathogen but are not I’ll
Incubatory - harbours pathogens are are not yet I’ll
What are zoonoses
Infection is transmitted from animal to human
How can we get infected from animals
Contract the pathogen by direct contact with diseased tissue
Drinking contaminated milk
Eating contaminated or uncooked meats
Inhale dust from the excreta
What are the 4 transmission routes
Airborne
Vehicle
Vector borne
Contact
What are the categories for infectious diseases
Acute
Chronic
Latent
What is a rapid onset of symptoms for a short time classed as
Acute
If something develops slow and lasts months what could we Categorise it to
Chronic
If a host gets inhibited what could cause their re activation
Decrease in immune response
What 2 routes can parasites kill
Uncontrolled (excess tissue damage)
Immune response can damage the host
What are micro organisms faced with
Host immune defences
