PMB: Introduction Flashcards
What is the germ theory of disease theory known as?
Kochs postulates
What are Koch’s postulates?
- The responsible microrganism must be present in all case
- The organism must be able to be isolated and grown in pure culture
- The organism must be able to infect a healthy individual when injected with the pure culture
- The organism must be recoverable from an animal which has been experimentally infected
What types of microorganisms is there?
- Bacteria
- Virus
- Fungi
- algae
- protozoa
What are general properties of microorganisms?
- Bacteria:
- Prokaryote
- No nucleus
- No organelles
- Protozoa/ fungi
- Eukaryote
- Nucleus (multiple)
- Organelles e.g. mitocondria, hydrogenosomes
- Viruses
- incapable of Independent life - need a host for replication
What are the definition refering to disease states across the world
- Endemic - constantlypresent at low incidence
- Epidemic - occur when an incidence in abnormally high
- Pandemic - global epidemic
Why does not everyone respond in the same way to the same infection?
It is possible for some people to be asymptomatic and others to find the disease near life threatining
- Pregnancy
- nutriational factors
- Age
- Elderyly - weakened immune response
- Baby - poorly developed immune system
- Immune status
- Genetic differences
- mode and level of infection
What is a disease resivioir and what is its properties?
- A location where an organism lives
- The organism must be able to reamin alive there and freshly infect people
- There is 3 classes
- What is the first disease reservoir?
- Why is this disease reservior difficult?
- What types is there?
- Other people
- Some people can have the disease but be asymptomatic
- Types:
- Acute infection - people fully recover and become non-carriers gain
- Chronic infection - people appear to recover but remain indefinite carriers
What is the 2nd disease resevior?
What ways can the infection be transmitted via this resevior?
- Other animals - animals can be a source of infection
- Via direct contact with infected animal e.g. fur
- By consumption of infected product e.g. meat
- via another source acting as a vector e.g. insect
- Sometimes the infection must go through an intermediate phase/ animal before infecting another human
What is the 3rd disease reservoir?
What are examples?
Non-living sources
- Contaminated drinking water
- faecal material
- Soil
- obects able to break skin e.g. injections or glass
Some organisms can survive for a log period when outside host whereas others cant
What 2 ways can pathogens be transmitted?
Directly or indirectly
Give some examples of how pathogens can be transmitted directly
- Respiratory pathogens:
- Sneezing
- Coughing
- Being in close proximity to someone talking
- Sexually transmitred disease
- Requires to be closley incontact with someone
- Soe organsims are sensitive to drying out
What are examples of indirect transmission of pathogens?
- Via a vector e.g. mosquito
- TO new in hospital patients e.g. via bedding
What techniques are used to combat diseas?
- Irradiation
- Autoclaving
- antimicrobials
Describe irradiation
- UV irradiation - uses wavelengths around 254nm
- OTher wavelnegths - IR and microwave
