Transmission Of Disease Flashcards
What must pathogens be able to do to persist and live on?
- Leave infected host.
- Survive transmission in environment.
3 enter susceptible persona or animal. - Develop/multiply in newly infected host.
What does the spread of infection require?
- Agent (pathogen)
- Reservoir (human, animal, food)
- Exit (coughing, vomit, breaks in skin)
- Mode of transmission (contact, droplets)
- Portal of entry (cuts, mouth, nose)
- Susceptible host (weakened immune system, babies, elderly).
What type of disease transmission is from mother to child?
Vertical
What type of disease transmission is from person to person?
Horizontal
Examples of direct transmission?
Touching
Kissing
Oral secretion
Body lesions
Intercourse
Examples of indirect transmission?
Vehicles; Air/droplets, Water, Soil, Food, Blood, Saliva.
Vectors; living organisms such as insects, fleas, flies.
What are fomites?
Objects or material which are likely to carry infection (bed, computer keyboard, phone)
How is infection spread to blood and bodily fluids?
Blood or fluid from infected person come into contact with mucous membrane or bloodstream of uninfected individual.
How is diseased transmitted through air/droplets?
- Droplets from respiratory system of infected person (sneezing, coughing, talking), enter upper and lower respiratory tract of a host.
What must organisms be capable of if transmitted through air and droplets?
Capable of surviving outside of body and resistant to drying out.
What is meant by preventing ingress?
What defences do we have as humans to prevent microbes from entering system.
What is meant by dealing with ingress?
Defence mechanisms which deal with microorganisms once they have gained ingress.
Examples of preventing ingress
- Mucocillary escalator
- Skin
- Fatty acids and salts
- Saliva
- Gingival crevicular fluid
- Blood
- Blood brain barrier
What is the mucocillary escalator?
Mucous and cilla lining the respiratory tract. The mucous traps the microbes and the cilla beats to remove mucous from lungs.
Continual processes that trap and sweep away particles up the epiglottis to be swallowed.
What do the glands in the skin secrete to prevent ingress?
Fatty acids and lysozyme (kill bacteria)