Transmission Flashcards
how is chicken pox transmitted?
through skin to skin contact
how is the plague spread?
through flea bites and via URT
how is TB spread?
through feacal matter
how is glandular fever spread?
through genital secretions or transfer of saliva
how is cholera spread?
unsafe water and contaminated food
how is anthrax spread?
contact with spores in infectious animal products
how is giardiasis spread?
via ingestion of contaminated food or water
what is the first line of defence?
non-specific defences against a pathogen
what is second line of defence?
defences specific for bacteria or viruses
what is the third line of defence?
defences specific to a pathogen
what are innate defences?
mechanical barriers and phagocytes
what causes the inflammatory response?
invasion and local multiplication
what are the characteristics of the first line of defence?
present at all times, non-specific, physical and chemical and uses commensal flora
what does lysosome do?
present in tears and dissolves cell walls
what does the skin do to protect?
acts as a physical barrier and produces antimicrobial fatty acids to prevent colonisation
what is the purpose of the second line of defence?
to localise the infection, neutralise toxins and repair damaged tissue
what line of defence is phagocytosis?
second
what are the 5 cardinal symptoms of acute inflammation?
redness, heat, swelling, pain and loss of function
what is involved in the third line of defence?
antibody and cell mediated immunity
what is the infection cycle?
portal of entry into host 1, portal of exit into host 2
what 3 factors does transmission depend on?
number of microorganisms shed, the stability in the environment and number of microorganisms infecting the new host
what is the infective dose?
the number of microorganisms that infect the new host
what are some examples of portal of exit?
ear wax, broken skin, faeces, saliva, urethra
why is a reservoir of infection important?
allows a disease to persist in a community as it gives a continual source of organisms
