Please enable JavaScript.
Coggle requires JavaScript to display documents.
Epidemiology Definitions (Population at risk (Number of susceptible…
Epidemiology Definitions
Case
Diseased, infected or affected animal
-
-
Population at risk
-
May be an area - island, continent, national park etc.
May be an age group, gender etc.
-
Can be very hard to calculate - e.g. in human epidemics when people move around. Very important - denominator to calculate incidence, prevalence etc.
Measuring an outbreak
Mortality
-
-
-
Only easy to calculate if dead animals are easy to find. Difficult to estimate if rural area, esp if small species - method of counting must be defined.
-
-
Prevalence
Number of cases ÷ population at risk at a certain time point. Point in time may be an extended sampling period e.g. a few months, but length of time not defined.
Morbidity
-
Can be hard to calculate - mild cases may not be diagnosed, wild animals may not be found etc.
Need to carefully define how all numbers calculated - e.g. Case mortality - number of animals found dead within certain area within study period ÷ number of animals found ill with same conditions. Be as precise as possible, esp with denominator
-
Spread of disease
Need to consider incubation period, duration of clinical disease and infectious period.