What is an infection?
An infection is the invasion of a host’s tissues by micro organisms
How do people get infections?
Explain by means of a diagram
Identify 3 mechanisms that manifest as disease
- Microbial multiplication
- Toxins
- Host response
Identify and describe the modes of horizontal transmission
- Contact: direct, indirect, vectors
- Inhalation: droplets, aerosols
- Ingestion: faecal-oral route
What is vertical transmission?
Vertical transmission is transmission from mother to child, before or at birth
Describe how microbiota can cause infection
- Microbiota are micro-organisms carried on skin and mucosal surfaces
- Normally harmless / even beneficial unless transferred to other sites
Identify and provide an example for the different mediums for getting infections
- Physical contact e.g. STI
- Airborne spread e.g. Chickenpox
- Animal vector e.g. mosquito for malaria
Describe how one can get an infection from one’s environment
- Ingestion of contaminated food or water
- Inhalation of contaminated air
- Contact with contaminated surfaces
State the first 5 steps that lead to disease caused by micro-organisms
- Exposure
- Adherence
- Invasion
- Multiplication
- Disemmination
Virulence factors are involved in the second step that leads to disease caused by micro-organisms.
Identify some examples
Virulence factors:
- Exotoxins – cytotoxic, AB toxins, superantigens, enzymes
- Endotoxins
What is the last step that leads to disease caused by micro-organisms?
Direct host cellular damage
Identify the disease determinants for pathogens
Pathogen:
- Virulence factors
- Inoculum size
- Antimicrobial resistance
Identify the disease determinants for patients
Patient:
- Site of infection
- Co-morbidities
What 4 overlying questions should one ask when treating a patient with a potential infection?
- Is there an infection?
- Where is the infection?
- What is the cause of the infection?
- What is the best treatment?
What history should one take when treating a patient with a potential infection?
- Symptoms
I. Local / systemic
II. Severity
III. Duration
- Potential exposures
What examination should one perform when treating a patient with a potential infection?
Examine organ dysfunction
Which two investigations should one perform when dealing with a patient with a potential infection?
- Specific investigations
- Supportive investigations
Provide 5 examples of supportive investigations
- Full blood count
- C reactive protein
- Liver and kidney function tests
- Imaging: X-ray, ultrasound, MRI
- Histopathology
Which specimen types are used in bacteriology?
- Swabs
- Fluids
- Tissues
Identify the 5 steps involved in bacteriology
- Microscopy
- Culture (patient and bacteria cells)
- Antimicrobial susceptibility
- Antigen detection
- Nucleic acid detection
Outline the three steps involved in virology
- Antigen detection (the virus)
- Antibody detection (the patient’s response)
- Detecting viral nuclei acid (DNA or RNA)
Identify 4 key considerations regarding infection
- New pathogens
- Antimicrobial resistance
- Healthcare infections
- Re-labelling of established diseases as infections
All clinicians encounter patients with infections.
However, identify the specialities whose primary interest is infection management
- Infectious diseases
- Medical microbiology and virology
- Genitourinary medicine
- Health protection
Which measurements are included in a full blood count?
- WBC count
- WBC differential
- RBC count
- Haemoglobin
- Haematocrit
- Mean corpuscular volume
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S1) Infection Overview33
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S2) Introduction to Microbes19
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S2) Infection Model13
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S3) Acute Sepsis in the Emergency Department19
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S3) Innate Immune System31
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S4) Antimicrobials and Resistance30
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S4) Antimicrobial Stewardship5
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S5) Hospital Acquired Infections24
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S5) Adaptive Immunity31
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S6) Surface Infections17
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S6) Beta-Haemolytic Streptococci17
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S7) Infection Prevention19
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S8) Blood Borne Viruses – HIV25
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S8) Blood Borne Viruses – Hepatitis23
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S9) Travel-related infections42
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S10) The Immunocompromised Host37
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Clinical Conditions24
