Infection control (SA5) Flashcards
What are the stages of the chain of infection?
- Pathogen
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible host
What is a convalescent carrier?
- Recovered from disease but still sheds into environment
What is a healthy carrier?
- Exposed to organism but doesn’t become ill
- Usually because immune system has fought disease previously
What is an open carrier?
- Continuously shed organism
- Usually weeks-months
- Can be life long
What is a closed carrier?
- Doesn’t normally shed disease
- Shedding triggered by stress or steroids
Where is MRSA found?
- Within naso-oral cavity
What is an infectious disease?
Caused by microorganism capable of invading and replicating within a host
What is a contagious disease?
- Can be passed from one animal to another
- Via direct or indirect contact
- Spread through contagions
What is a zoonotic disease?
- Can be passed from vertebrate animals to humans
- immunosuppressed, young, old and pregnant most at risk
What is contamination?
- Presence of microorganisms on body surface or inanimate object
What is colonisation?
- Presence of microorganisms with no clinical signs
What are pathogens?
- Disease producing microorganisms
- May live in or on the host
- Disrupts normal physiological function
What is a facultative anaerobe?
- Will grow whether oxygen is present or not
What is an epidemic?
- Increase in number of cases of a disease
- Above what is normally expected in that population
What is a pandemic?
- Epidemic of worldwide proportions
- Increase in number of cases of a disease worldwide above normal expectations
What is an endemic?
- Disease that permanently exists is particular populations
- At normal levels and is predictable
- What is an epizootic?
- Epidemic of an animal disease
- Increase in number of cases of an animal population above normal levels
What are the causal agents of infectious diseases?
- Bacterium
- Virus
- Protozoan
- Fungus
- Prions
- Ecto/endo-parasites
What are viruses?
- Tiny intracellular parasites
- Can only replicate within a host cell
- Can only attach to compatible cells
What is the structure of a virus?
- Each virus particle
- Core of nucleic acid (RNA or DNA)
- Surrounded by protein coat (Capsid)
- Together known as nucleocapsid
- Some viruses are enclosed in an envelope
What are virus envelopes made from?
- Lipoprotein and glycoprotein
- Some have glycoprotein spikes to help them attach to host cells
What is the name for spherical viruses?
Icosahedral