Infection 1 Intro To Infection Flashcards
Infection definition
Invasion of a host’s tissues by microorganisms
An infection is a disease caused by…
Microbial multiplication
Toxins
Host response
Ways people get infections
Patient to themselves
Other organisms
Environment
How do patients get infections from themselves ?
The normally harmless microbiota transfer to other sites which are harmless
E.g. harmless on skin but damaging if enter into bloodstream via a cut
Microbiota meaning
Microorganisms in particular place??
How do other organisms cause infections
Direct e.g. STIs (other people) - HIV, chlamydia
Indirect e.g. air-chickenpox, influenza, covid
vector-malaria
How does the environment cause infections?
- Ingestion of contaminated food or water e.g. cholera, salmonella
- Inhalation of contaminated air
- Contact with contaminated surfaces e.g. hep B, sharing needles/ medical instruments
Horizontal transmissions of infection
Contact: direct, indirect, vectors
Inhalation: droplet, aerosols
Ingestion
Vertical transmission of infection
Mother to child
Before or after birth
Via placental blood vs breast feeding
How to microorganisms cause disease?
1- exposure
2- adherence of microorganisms to cell surface
3- invasion
4- multiplication
5- dissemination
Dissemination meaning
Spreading
What are virulence factors?
Chemical products of the pathogen that allow it to successfully survive and reproduce in a host - harming them
What are endotoxins?
Part of cell wall in lipopolysaccharide protein complexes in gram negative bacteria
What do endotoxins do?
Cause host cell damage
Either directly or due to a virulence factor which causes damage
What is a specific investigation for?
To identify organism causing infection
