Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
An infectious disease is a disorder caused by pathogenic microorganisms such as bacteria, viruses, fungi, or parasites. These diseases can be transmitted directly or indirectly from one individual to another.
5 Must Know Facts For Your Next Test
Pathogenicity refers to the ability of a microorganism to cause disease in a host.
Virulence factors are molecules produced by pathogens that enhance their ability to cause disease.
The incubation period is the time between exposure to the pathogen and the appearance of symptoms.
Modes of transmission include direct contact, indirect contact, droplet transmission, and vector-borne spread.
Antibiotic resistance occurs when bacteria change in response to the use of medicines, making infections harder to treat.