Session 1 - Introduction to infection Flashcards
What is an infection?
• Invasion of a host’s tissues by microorganism causing disease
What is disease caused by in an infection?
- Microbial multiplication
- Toxins
- Host response
What are commensals?
- Micro-organisms carried on skin and mucosal surfaces
- Normally harmless or even beneficial
- Transfer to other sites can be harmful
Outline three general modes of horizontal transmission
- Contact
- Inhalation
- Ingestion
Outline three different methods of contact based horizontal transmission
- Direct
- Indirect
- Vectors
Outline two different methods of inhalation based horizontal transmission
- Droplets
* Aerosols
What is vertical transmission?
• Mother to child transmission
What are the five stages of micro-organism disease causing?
• Exposure • Adherence • Invasion • Multiplication Dissemination
Outline three disease determinants of a pathogen
- Virulence factors
- Inoculum size
- Anti-microbial resistance
Outline two disease determinants of a patient
- Site of infection
* Co-morbidities
What are the four main questions to ask if you suspect a patient of having an infection?
- Is there an infection?
- Where is the infection?
- What is the cause of the infection?
- What is the best treatment
What are the three procedures which must be dealt with to work out whether a patient has an infection?
- History
- Examination
- Investigations
What do you explore in the history of a supected infected patient?
• Symptoms
○ Focal, systemic
○ Severity
○ Duration
Potential exposure
What do you examine in a patient with suspected infection?
• Organ dysfunction
Name four supportive investigations which can be performed to confirm an infection
• Full blood count ○ Neutrophils and lymphocytes • C reactive protein • Blood chemistry ○ Liver and kidney function • Imaging
