As part of your systematic review of a micro-organism species or group of species (e.g. Enterobacteriaceae) , knowledge about the ‘epidemiology‘ is essential,  the second element in the ORGANISM knowledge proforma.

“Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.” [ref1]

In your reading or when asked during a viva examination to “describe the epidemiology” of an organism or disease, concern yourself with a few basic questions- always a lot to say about most bugs! :

• What disease(s) does it cause? What are the reservoirs of the organism? – human, animal, environmental etc
• Who (age, sex) gets colonised ? Who gets infected? Natural history of colonisation and disease.
• Where – geographical determinants,
• When – Are there seasonal differences in disease incidence?
• Why/how- how is it transmitted?  Is it an obligate pathogen or an opportunist? Risk factors  for disease – immune status, healthcare exposure etc

For an excellent online course see the self learning package from CDC (USA).   Knowledge of epidemiology is essential for pathologists, physicians and others.

Reference

1. Last JM, editor. Dictionary of epidemiology. 4th ed. New York: Oxford University Press; 2001. p. 61.