Session 1 - Introduction Flashcards
What is an infection?
Invasion of a host’s tissues by micro-organisms and disease caused by microbial multiplication, toxins and host response
How do people get infections from microbiota?
Micro-organisms carried on skin and mucosal surfaces are normally harmless, but when transferred to other sites can be harmful
What is an example of a infection spread via physical contact?
Sexually transmitted infection
What is one example of infections spread via airborne spread?
Chickenpox
What is one example of infections that need vector to be spread?
Mosquito for malaria
What are the 2 main types of transmission?
Horizontal and vertical
What are the 3 forms of horizontal transmission?
Contact, inhalation and ingestion
What is vertical transmission?
Infection spread from mother to child, before or at birth
What are the 5 processes micro-organisms undergo to cause disease?
Exposure to host Adherence to mucosal membranes Invasion into tissues or interstitial space Multiplication of microorganism Dissemination into bloodstream
What are virulence factors?
Chemicals that enhance survival of microorganisms and their reproduction within the host
What are the 5 disease determinants of how serious the infection is?
Virulence factors Inoculum size Antimicrobial resistance Site of infection Co-morbidities
What is inoculum size?
Amount of microorganism present
What are the 3 things you need to know if patients have an infection?
History
Examination
Investigation
What are the 4 things to ask about history when deciding whether a patient has infection?
Focal or systemic symptoms
Severity of symptoms
Duration of symptoms
Potential exposure
What are the 2 types of investigations?
Specific and supportive
What are specific investigations?
To identify causative organism of infection
What are supportive investigations?
Prove that patient is suffering from infection
What are 5 tests to do when doing supportive investigations?
Full blood count Liver function test Kidney function test Imaging Histopathology
What does a high value of neutrophils mean?
Bacterial infection possible
What does a high value of lymphocytes mean?
Viral infection possible
What does high amounts of C-reactive protein suggest?
Prove there is an inflammatory process
Why do we do liver and kidney function tests?
To find out how body manages infections and also affects dosage of medicine to give
What kind of infection is histopathology good at showing?
Fungal
What are the 4 things we have to do to find out if patient has a bacterial infection?
Collect specimen
Microscopy
Culture
Antibiotic susceptibility test
