systems: Veterinarians’ role & Zoonoses

week 1 pre work

zoonosis

any disease or infection that is naturally transmissible from vertebrate animals to humans

infectious agent

agent that causes infection and/or disease including viruses, bacteria, fungi, protozoa, and helminths

horizontal: direct transmission

transfer of infectious agent through an intermediate biological host or can be food-borne, water-borne, via transfusions or aerosol transmission (large transmissions)

vector

an organism, usually an arthropod, which transmits an infectious agent to a new host. arthropods which act as vectors include houseflies, mosquitoes, lice and ticks

biological vectors: infectious agent either replicates here or undergoes a necessary agent either

droplet

inhalation of large droplets (diameter > 5 μm) that travel shorter distances than aerosols. SARS CoV-2 & Mycobacterium tuberculosis

reservoir host

in which an infectious agent normally lives and multiplies, and is thus a common source of infection to other animals eg. cattle as reservoirs for Bluetongue virus Birds as reservoir for WNV, EEE

amplifier host

host animals, such as pigs, that can become infected with the virus and produce a higher viral load, potentially leading to increased transmission to other hosts, including humans

incidental host or dead and hosts (also sometimes termed accidental host)

host animals, like humans and horses, that do not support significant replication of the agent or concentration in their bloodstream, making them unlikely sources of further transmission. these are hosts that are not integral to the infectious agents’ transmission cycle