Biomed: Epidemic Disease Occurrence

what has to happen for an epidemic to occur?

an agent and susceptible host are present in adequate numbers and agent can be efficiently conveyed from a source to a susceptible host

can obesity and diabetes be described as epidemics even though they are not infectious diseases?

yes

is syphilis a vector borne disease?

no

how many incubation periods are there in a propagated outbreak?

more than 1

can epidemics have features of both common source epidemics and propagated epidemics?

yes

what is another name for the baseline of a disease?

endemic

what are some diseases that would warrant an epidemiological investigation even if there is only one occurrence of the disease in the population?

rabies, polio, plague

how can you further describe common source epidemics?

point, continuous, intermittent

what type of curve do you have when you plot an epidemic over time? it typically has a steep upslope and a more gradual downslope

epidemic curve

in what type of outbreak does the range of exposures and range in incubation periods flatten and widen the peaks of the epidemic curve?

continous

what are epidemics called that have features of both common source and propagated epidemics?

mixed

define: persistent high levels of disease occurrence

hyperendemic

define: disease that occurs infrequently and irregularly

sporadic

define: epidemic that has spread over several countries, usually effecting a large number of people

pandemic

define: often sudden increase, in the number of cases of a disease than what is normally expected in that area, but often used for more limited geographic area

outbreak

define: constant presence and/or usual prevalence of a disease or an infectious agent in a population within a geographic area

endemic

define: often sudden increase, in the number of cases of a disease than what is normally expected in that area

epidemic

define: aggregation of cases, grouped in a place and time that are expected to be greater than the number expected

cluster

define: the range of exposures and range of incubation periods tend to flatten and widen peaks of epidemic curve (people exposed over a period of days, weeks, or longer)

continuous common source outbreak

define: if a group is exposed over a brief period so everyone that becomes ill does so within one incubation period

point source outbreak

define: group of people all exposed to an infectious agent or toxin from the same source

common source outbreak

define: pattern of common source outbreak followed by a secondary person-to-person spread

mixed epidemic

define: transmission from person to person

propagated outbreak

list the 5 situations that may cause an epidemic to occur:

recent increase in the amount of virulence of the agent

recent introduction of an agent into a setting where it hasn’t been before

enhanced mode of transmission so more susceptible people are exposed

change in susceptibility of the host response to agent

factors that increase host exposure or involve introduction through new portals of entry

list the 4 ways that epidemics can be classified according to their manner of spread through a population

common source

propagated

mixed

other