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21 Cards in this Set
- Front
- Back
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What is disease transmission a result of?
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It is the result of the interaction between the host, agent and environment.
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Why is knowing the mode of transmission important?
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It is more important than identifying the specific agent especially when facing an outbreak of a newly emerging disease
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What is a reservoir?
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Habit in which an infectious agent normally lives, grows and multiplies
Reservoirs maintain pathogens overtime from year to year or generation to generation |
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What is a portal of exit?
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The route by which an agent leaves an infectious host.
Usually corresponds to the site which the agent is localized Examples: blood, saliva, feces, urine, respiratory aerosol, skin, percutaneous |
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What are carriers?
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Host that are infectious but are not symptomatic
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What is an incubatory carrier?
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One that sheds the disease during the incubation period
Ex) HIV? |
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What is a convalescent carrier?
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A host that is clinically recover that shed disease during recovery
ex) chicken pox |
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What is a latent carrier?
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Host that has a persistent infection
Ex) herpes simplex virus |
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What is a chronically affected carrier?
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Sick animals shedding sporadically or continuously
Ex Bovine TB |
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What is vertical transmission?
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Transmission from host to its offspring
Congential- some pathogens can cross the placenta, infect eggs Perinatal - during parturition, via colostrum |
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What is horizontal transmission?
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Transmission from host to another host
Direct - directly from the infectious host to a new susceptible host Indirect - via and sort of intermediary, living (vector) or inanimate (vehicle) |
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What are examples of direct horizontal transmission?
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Skin to skin contact, mucous membrane, direct contact with soil or vegetation harboring infectious organisms
short range aerosol |
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What are examples of indirect horizontal transmission?
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vehicle
vector |
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What is a vehicle?
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An inanimate object which serves to communicate disease.
Ex water, food, fomites |
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What is a vector?
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A living organism that serves to communicate disease
Ex arthropods |
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What is a mechanical vector?
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The agent does not multiple or undergo part of its life cycle in or on the living organism
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What is a biological vector?
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The agent undergoes changes or reproduces which in the vector host
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What is development transmission of biological vectors?
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Essential phase of development that occurs in the vector
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What is propagative transmission of biological vectors?
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Pathogen multiplies in a vector (viruses)
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What is cyclopropagative transmission of biological vectors?
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The parasite undergoes cyclical changes and multiplies within the vector
there are both developmental changes and multiplication of the parasite |
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What is common vehicle transmission?
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Mode of transmission of infectious pathogens from a source that is common to all the cases of a specific disease
ex) blood transfusion |
