Infectious disease

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

1. Pathogenicity refers to the ability of a microorganism to cause disease in a host.
2. Virulence factors are molecules produced by pathogens that enhance their ability to cause disease.
3. The incubation period is the time between exposure to the pathogen and the appearance of symptoms.
4. Modes of transmission include direct contact, indirect contact, droplet transmission, and vector-borne spread.
5. Antibiotic resistance occurs when bacteria change in response to the use of medicines, making infections harder to treat.

Review Questions

• What are virulence factors and how do they aid in pathogenicity?
• Describe at least three modes of transmission for infectious diseases.
• Why is understanding the incubation period important in controlling infectious diseases?

Related terms

Pathogen:

A microorganism that can cause disease.

Host: An organism that harbors a pathogen, providing it with nutrients and shelter.

Vector:

Any agent (person, animal, or microorganism) that carries and transmits an infectious pathogen into another living organism.