Infections Flashcards
What is an infection?
Invasion of a host's tissues by microorganisms AND Disease caused by: Microbial multiplication Toxin release Host response
Microbiota are also known as … bacteria
Commensal
What is a microbiota?
Ecological community of Commensal, symbiotic and pathogenic microorganisms that inhabit our body space
How do aerosols spread infection?
Aerosols are nuclei droplets of water that contain microorganisms. These remain in the air and are inhaled or can remain on surfaces and spread via contact.
Describe a “vector” in regards to infection.
A vector is an organism which spreads the pathogenic microorganism. Eg mosquitos are the vectors for plasmodium falciparum
What is vertical transmission in regards to infection?
Transfer of a microorganism between mother and child, either in utero, during birth or during breast feeding
Describe the term “virulence factor”
Virulence factors are the characteristics of a microorganism which confer pathogenicity. Eg endotoxins, exotoxins, capsules, etc.
What is contiguous spread?
Contiguous spread is the local spread of microorganisms within a tissue. This can include haematogenous or lymphatic spread
What are the 5 stages that lead from microorganism infection to disease?
Exposure Adherence Invasion Multiplication Dissemination
What are the 2 categories of disease determinant?
Name the factors that contribute to each category.
Pathogen-related:
Virulence factors
Inoculum size
Antibiotic resistance
Patient:
Site of infection
Co-morbities
What do we look for in a history when determining if there is an infection?
Symptoms:
Focal/systemic
Severity
Duration
Potential exposures:
Geography
Animals
Environment (including social)
What do we look for in an examination when determining if there is an infection?
Inflammation
Dysfunction
Pus
Foreign bodies
Name some supportive investigations when determining if there is an infection.
FBC - WBCs (neutrophils and lymphocytes) C Reactive Protein (acute phase protein) Blood chemistry - lover and kidney function tests Imaging - X-ray, ultrasound, MRI Histopathology
What kind of specimen types can be taken for bacteriology?
Swabs
Fluids (pus/urine/CSF)
Tissues (biopsy)
What does M, C and S refer to when determining if there is an infection?
Microscopy (inc. gram stain)
Culture
antibiotic Susceptibility
