Intro to Infection Flashcards
What is an infection?
Invasion of a hosts tissues by a microorganism and disease caused by the microbe multiplying, its toxins or the hosts immune response.
How do people get infections?
Source –> patient
Patient –> patient (transfer of microbiota to different site)
Animal –> patient
Intermediary –> patient (air, STI or vector)
Enviroment –> patient (contaminated food, water, air or surfaces)
How do micro organisms cause disease?
Exposure –> Adherence –> Invasion –> Multiply –> Disseminate
To do this they need virulence factors and then by doing this they will either damage the host directly or cause an immune response that leads to disease.
How do we know a patient has an infection?
History: Symtoms, severity, duration and potential exposures
Examination: organ dysfunction tests (O2, urine output), temp, BP, capillary refil, resp rate.
Investigations: FBC, CRP, X Ray, LFT, U+E, MRI, Histopatholgy
Bacteriology- swabs, fluids, tissue samples (CSF or gram stains), cultures, antibiotic suceptibility.
Antigen/ antibody detection
Nucleic acid detection
Who manages infections?
All clinicians but especially health protection workers, GU medics, medical microbiologists and virologists and infectious disease specialists.
List some modes of transport for infection:
Contact- direct, indirect and via vectors
Inhalation- droplets and aerosols
Ingestion- faecal-oral transmission
Vertical- mother to baby before, immediately after or at birth
What factors go in to a resultant infection?
Pathogen: virulence factors, inoculum size, antimicrobial resistance.
Patient: Site of infection, co-morbidities
What new issues are there in infection?
New pathogens
Antimicrobial reisstance
Healthcare related infections
Name changes to established diseases - stay up to date
