Pathogenicity and Epidemiology Flashcards
What is an infectious disease?
Illness caused by microbes (bacteria, fungi, viruses, protozoa)
Most bacterial infections are _______
communicable
What is contagious disease?
Is a subset of extremely communicable diseases.
Whats a pathogen?
Some that makes you feel sick
What is pathogenicity?
a measure of how easily a bug can make you sick
What is a opportunists infection?
when some part of you has broken down - and some thing has got in.
Asymptomatic
you carry but don’t know you have it
Communicable
person to person
Local infection
Sits in one part of your body, and doesn’t get to spread out
Systemic
generalised infection
Acute disease
intensely sick for a short period of time
Chronic disease
slow onset and long duration
Carrier status
not sick with it but you can infect other people.
latent infections
come and go e.g. herpes
How do we measure the capacity of a pathogen to cause disease?
- Transmission
- Invasion and inflammation
- Toxigenicity
How do we determine this?
ID^50 graph: Infectious dose. (Required to make 50 people exposed, infected.
What do we to say how transmissible a disease is?
R naught. Which is the number of people that one sick person will infect. (on average)
How can you catch disease? 8
Respiratory droplets Dust Contaminated water Contaminated objects Contaminated food Contaminated soil Arthropods - biting insects Zoonotic infections
What are the portals of exits? 5
Coughing and sneezing Bleeding wounds and puss Urine Faeces Blood
What are the human to human routes of transmission of infection?
Direct contact (horizontal)
No direct contact
Transplacental (Vertical) mother to baby
Blood borne
What are the non human to human routes of transmission of infection?
Soil Water Food Animals/insects Fomite (bacterial on a object
What is meant by virulence factors?
Super powers that the bacteria have to make them toxic.
Examples of Virulence i.e. fimbriae?
The hairs to burrow through
Virulence: Pili?
Extend out a long tube and send genetic info to other bacteria
Virulence: Capsule?
Cells are to slippery (immune system can’t stick to them).
Virulence: Biofilm formation?
When the bacteria has produced a contiguous mesh over the zone, and it seals the bacteria from your immune system and bodily fluids.
Invasion - enzymes produced by bacteria? examples..
Coagulase - accelerated clotting
2 types of toxin production?
Exotoxin and endotoxin
What is a exotoxin?
Secreted by some living pathogen
What is a endotoxin?
From within the cell wall and doesn’t get out till the bacteria is destroyed. Most lethal.
What is epidemiology?
Where they are from and where they are going
What is endemic?
Confined to one area
Epidemic
spread from one area to another area
Pandemic?
all over the world
What is a sporadic disease?
Comes and goes
Reservoir of infection?
place where you can find that infectious source
Common source?
Coming from a water source.
Nosocomial
Healthcare - got it from the doctors
Zoonosis? From
Animals
What are the 4 stages of infectious disease?
- Incubation
- Prodrome
- Specific illness
- Recovery
What is the incubation of infectious disease?
You are infected but not enough of the bug to create an illness
What is the prodrome?
Some is coming to get you. Feel down, tired ect
Specific illness?
The symptoms being inflicted on you
Nosocomial can be _______ or ________
Local or systemic(whole body)
Example of nosocomial infections?
Communicable disease
Pathogens within the hospital environment e.g. c diff
Normal flora in patients or health care staff
How to control Epidemic disease? 1-5.
- Report
- Identify and attempt to eliminate reservoirs of infection
- immunisation programs
- treat and isolate
- education and sanitation procedures
