Chain of Infection: 2-6 Flashcards
List the major reservoirs for infectious disease
Humans
Animals
Environmental - Soil, Water
Example of disease from human resevoir
UTI - E.coli
Example of disease from an animal
Disease from animals are called ‘zoonoses’
eg SARS and Ring worm / Tinea Corporis
Example of disease from soil
Tetanus or Gas Gagrene
Example of disease from water
Giardiasis and Hepatitis
Define portal of exit
Is the path by which an infectious microorganism leaves the resevoir
Define portal of entry
Is the path of which an infectious microorganism gains entry to a new host
List the main portal of exits
Excretion
Secretion
Droplets
Respiratory System, Urinary System, Digestive System
List the main portal of entry
Endogenous - derived from a source from within the body
Exogenous - derived from a source outside the body
Standard precautions that aim to break the portal of exit and entry link
Use of PPE
Respiratory and cough etiquette
Waste management
Hand Hygiene
Disease transmission categories
Contact
Common Vehicle
Vector
3 forms of Contact transmission
Direct - Close or intimate touch
Indirect - indirect touch eg door handle
Droplet - droplets falling less than 1 meter
3 forms of Common Vehicle and an example for each
Airborne - organisms in the air for more than 1 meter. Must be able to survive outside of the host
eg Rubeola (Measeles)
Waterborne - faecal contamination of water
eg Hepatitis A
Foodborne - poor hygiene, lack of sanitation and/or poor handling of food
eg Salmonella
2 forms of Vector Transmission
Mechanical - Passive transport of microorganisms on the exterior of the body
Biological - Requires both vector and host to complete its life cycle
eg Malaria / Plasmodium
5 Strategies for prevention of transmission
- Sanitisation
- Hygiene Practices
- Isolation
- Immunisatin
- Treatment
Susceptible Hosts may include:
Young children Elderly Chronically Ill People People receiving treatments such as chemo People with open wounds
How can we protect these susceptible hosts
Ensure effective use of Standard Precautions
Treat their underlying disease or condition
Ensure appropriate nutrition
Vaccination
Why are antibiotics better than antimicrobial drugs
Selective Toxicity. This means they are otxic to only selected types of cell, they cause much greater harm to microbes than to the uhuman host cells.
Limitations on the use of antibiotics
Not effective against viruses, some have toxic side effects, normal flora living on the human tissue are destroyed which can cause infection such as thrush
Main causes of antibiotic resistance
Rapid multiplication of bacteria
The more antibiotics are used, the more likely antibiotic resistance will occur
Susceptible bacteria die off, leaving resistant bacteria to multiply
