4 concepts
Occurrence of a Disease
An occurrence of disease greater than would be expected at a particular time and place is called an outbreak.
Disease Severity and Duration
The severity and duration of diseases vary greatly and are important for epidemiological studies.
Extent of Host Involvement
Host-pathogen interactions are the interactions taking place between a pathogen (e.g. virus, bacteria) and their host (e.g. humans, plants).
Identification of Microbes Based on Molecular Genetics
Modern nucleic acid-based microbial detection methods make it possible to identify microbes that are associated with a disease.