Answer:
Infectious disease epidemiology (which includes the epidemiology of viruses) is the study of the complex relationships among hosts and infectious agents. Epidemiologists are interested in virus spread or transmission, with or without disease.
There are different types of pathogens, but we're going to focus on the four most common types: viruses, bacteria, fungi, and parasites.
Bubonic and Pneumonic Plagues. Perhaps the most notorious of all infectious diseases, the bubonic and pneumonic plagues are believed to be the cause of the Black Death that rampaged through Asia, Europe and Africa in the 14th century killing an estimated 50 million people.
Explanation:
Common examples of contagious viral diseases include the flu, the common cold, HIV, and herpes. Other types of viral diseases spread through other means, such as the bite of an infected insect.