Overview

An infection occurs when a microorganism or chemical enters a person’s body and causes harm.
The microorganism uses that person’s body to sustain itself, reproduce, and colonize. These infectious microscopic organisms are known as pathogens, and they can multiply quickly. Examples of pathogens include:
  • bacteria
  • viruses
  • fungi
They can spread in several different ways, including through:
  • skin contact
  • the transfer of bodily fluids
  • contact with feces
  • ingesting contaminated food or water