Pathogenic microorganisms, including bacteria, viruses, parasites, or fungi, play a role in the development of infectious diseases. As a result of their rapid and unexpected spread, these microorganisms can cause serious mortality in a community.
There are numerous factors that influence health and the origins of infectious diseases which are often beyond the immediate reach of the health sector. These include the travel and tourism industries, as well as other sectors such as sanitation and water supply, environment and climate change, education, agriculture, trade, industrial development, and housing.