Wobeser Flashcards
why do we need to understand transmission?
because to control, eliminate or eradicate infectious disease, you have to reduce or stop the occurrence of new cases (reduce or prevent transmission and infection)
what is control of a disease?
reduction of a disease incidence to an acceptable level as a result of deliberate actions
what is the elimination of a disease?
reduction to zero of the incidence of infection caused by a specific agent, in a defined geographical area, as a result of deliberate actions
what is eradication
reduction to zero of the worldwide incidence of infection caused by a specific agent, as a result of deliberate actions
what are the criteria for transmission to occur?
a susceptible individual must have suitable contact with the causative agent which must be in a form and sufficient numbers to represent an infectious dose
agent + host=disease; describe for each of these terms how they can vary
agent: how many what form
+=contact, exposure
host:susceptibility
what is TCID?
tissue culture infectious dose
what does a high TCID mean?
a higher dose of bacteria is required for infection
what is an obligate parasite?
it requires a host to reproduce so the source always begins with an infected individual
what is the source of infection with an obligate parasite?
an infected individual
what is an opportunist parasite?
it is a parasite that does not require a host to reproduce, but can take advantage of hosts when they are available
what is the source of infection for an opportunist parasite?
the source of infection is not from another individual
why is it important to know if the parasite is an opportunist or an obligate parasite?
because they require different methods for eradication or elimination or control
why is it important to know what is the maintenance, spill-over or dead end host?
because if you are dealing with a range of species you want to target the maintenance host
why is it easier to determine who received the infection than who gave it?
because the time when the symptoms appear after contact depend on incubation time (between when contact occurs and the person becomes infection) the time of infectiousness, the contact history etc (discussed it in the class)
