Changes

Analytic epidemiological studies aim to investigate and identify factors associated with the presence of disease within populations. These factors can be classified as one of the components of the 'epidemiological triad' of:<br>

Analytic epidemiological studies aim to investigate and identify factors associated with the presence of disease within populations. These factors can be classified as one of the components of the 'epidemiological triad' of '''Host, Agent and Environment'''

Host<br>

Agent<br>

Environment<br>

 

==Host factors==

==Host factors==

These include unchanging characteristics of the host animal such as sex, breed or species, as well as more variable characteristics such as age, nutritional status and stage of pregnancy.

These include unchanging characteristics of the host animal such as sex, breed or species, as well as more variable characteristics such as age, nutritional status and stage of pregnancy.

==Agent factors==

==Agent factors==

Features of the agent which affect the levels of disease within an infected population  

Features of the agent which affect the levels of disease within an infected population include

==Environment factors==

==Environment factors==

==Analytic studies==

==Analytic studies==