Infection Flashcards
(35 cards)
Define a pathogen
A disease causing microorganism
Name three types of microorganism which can cause infectious disease
Bacteria, viruses and fungi
Describe the bodies ‘microbiome’
The microbiome refers to the parts of the body which are connected to the outside environment and become colinised by microbes soon after birth. These microbes are harmless.
Define ‘free living’
Something which can live successfully outside of the body
Do bacteria have a nucleus?
No they are prokaryotic. However they do carry DNA which is coiled.
Give three examples of common bacteria and the infections they cause:
E coli- diarrhoea, UTI’s, respiratory disease, sepsis
Staphyloccocus Aureus- skin infections, pheumonia, sepsis, endocarditis
Clostridium dificile: diarrhoea, colitus
Bacteria are free living - true or false
True
Viruses are free living- true or false
False
Viruses can also be known as…
Intracellular parasites
How do viruses multiply?
They invade body cells which allow for them to replicate
Funghi are free living - true or false
True
How do fungi cause damage?
By invading body tissues and releasing digestive enzymes
Protozoa are free living true or false?
Both- some are free living but others rely on body cells and are important parasites of humans
Name the 6 stages in the chain of infection and briefly describe each stage.
- Organism: the pathogenic microorganism
- Reservoir: the source of the infection e.g. dirty door handle
- Portal of exit: how the microorganism leaves the body of the host e.g. vomiting or sneezing
- Transmission: how the microorganism is passed on e.g. airborne transmission, direct contact
- Portal of entry: how the microorganism enters the body of the host e.g. wound, bite, catheter
- Vulnerable host: the individual who becomes susceptible to the microorganism
Give two ways in which invading microorganisms may cause injury:
By targeting the bodies own immune system leading to immunodeficiency
By releasing toxins
What are the 5 stages of illness?
- Incubation period: pathogen begins to replicate but symptoms are not yet visible
- Prodromal phase: initial appearance of vague symptoms e.g. tiredness
- Acute stage: maximum impact of infection. Symptoms are obvious and usually specific.
- Convalescent period: Infection is contained and progressively eliminated.
- Resolution: Pathogen is eliminated from the body.
Define Sepsis
A life threatening organ dysfunction caused by an unregulated immune response to infection
Give 5 risk factors for developing sepsis
- age >65 years
- alcoholism
- diabetes
- recent surgery
- IV drug user
- pregnancy or recent pregnancy
- haemodialysis
Which three things are activated following initial infection within Septic patients?
The coagulation system, complement activation and the activation of neutrophils and monocytes.
How does organ failure occur in septic patients?
The endothelium of body cells allows for increased vascular permiability and vasodilation leading to excessive fluid loss from the blood and therefore blood volume reduction. This causes a low blood pressure meaning that bodily organs are unlikely to be receiving the amount of oxygen they need to perform their specific functions.
What is included in the sepsis 6 bundle?
- Give oxygen- to increase O2 saturations
- Take blood cultures- to determine infection present
- Give IV antibiotics- to target infection
- Give IV fluids- to increase blood pressure
- Measure lactate levels- to monitor O2 therapy and IV fluid
- Monitor urine output- to monitor response to treatment
What is the definition of a commensal microorganism?
A microorganism which usually lives harmlessly on our bodies
What does CRP stand for and what does it measure?
C-reactive protein. A blood test which measures levels of protein which are released upon inflammation or infection.
What does ESR stand for and what does it measure?
Erythrocyte sedimentation rate. A blood test which measures how quickly red blood cells settle. They quicker the settling rate, the higher the inflammation within the body.
