Week 1 Intro To Infection/ Infection Model Flashcards
what are the mechanism of infection? eg contiguous
contiguous- direct spread inoculation- trauma- stabbing- taking bacteria in ingestion- faecal- oral transmission inhalation- droplets, aerosols heamatogenous vector horizontal transmission- mother to child
Define infection?
Invasion of a hosts tissues by micro-organisms
And
Disease caused by: multiplication, toxins, host response
Give an example of a situation that puts someone at increased risk of direct spread infections?
Surgery- skin bacteria gets into wound
What are the two methods of inhalation spread and give an example of both?
Droplet spread-
Aerosols- smaller particles that remain suspended in the air- TB
Give an example of vector transmission?
Mosquito bite- malaria
what comes under the subcategory of management in the infection model?
history, examination, investigation, treatment- specific, supportive infection prevention
what comes under the person subcategory of the infection model?
age
sex
physiological state- stress- start with cold
pathological state- diabetic, smokers, pregnancy
social factors
How do you diagnose an infection?
History
- symptoms- focal, systemic, severity, duration
- potential exposures
Examination
- organ dysfunction
Investigation
- specific
- supportive
what are the specific and supportive treatment options?
specific
- antimicrobials- kill pathogen
- surgery- physical removal- drainage, debridement, dead space removal
supportive
- pain/ symptom relief
- physiological restoration
Name some possible supportive investigation in infection diagnosis
Full blood count- neutrophil, lymphocytes
C reactive protein- acute phase protein- measure of inflammation
Liver/ kidney function test
Imaging
Histopathology
What is the difference between an endotoxin and exotoxin and give an example of each?
Endotoxin contained within ordinary bacteria and only released when bacteria broken down- can cause immune response
Eg LPS
Exotoxin is a toxin released from bacteria into the surrounding area in order to cause disease
Eg diphtheria toxin
How can you detect a virus?
Antigen detection- virus
Antibody detection- host response
Viral nuclei can acid- DNA/RNA
What is a bacteriophage?
Virus that infects bacteria- way of transmitting DNA that encodes for toxins from one bacteria to another
What is the difference between an aerobe, obligate aerobe, anaerobe and obligate anaerobe?
Aerobe- can survive in presence of O2
Obligate aerobe- require O2 for survival (necrotic tissue)
Anaerobe- can survive in a sense of O2
Obligate anaerobe- requires O2 free environment- unless creates spores
State some Mechanism of bacterial pathogenesis (virulence factors)?
Host entry
Adhesion to host cell- pili, fimbriae
Invasiveness- enzymes- collagenase
Iron sequestration- gain nutrition from environment
