Chronic infection

Definition

A chronic infection is a persistent infection caused by pathogens that can evade the host's immune system, leading to prolonged disease. Such infections often result in continuous or recurrent symptoms over an extended period.

5 Must Know Facts For Your Next Test

1. Chronic infections are typically caused by viruses that integrate their genome into the host's cells, such as HIV and hepatitis B.
2. These infections can persist for months, years, or even a lifetime without being completely cleared by the immune system.
3. Chronic viral infections often involve latent phases where the virus remains dormant before reactivating.
4. Immune evasion mechanisms of chronic infections include antigenic variation and downregulation of MHC molecules.
5. Effective treatment of chronic infections often requires antiviral drugs that target specific stages of the viral life cycle.

Review Questions

• What mechanisms allow pathogens to maintain chronic infections in hosts?
• Name two viruses commonly associated with chronic infections and explain how they persist in the body.
• How do antiviral treatments work against chronic infections?

Related terms

Latent Infection: A type of infection where the virus remains dormant within the host cells and can reactivate later.

Antigenic Variation: The process by which pathogens alter their surface proteins to evade detection by the host's immune system.

Viral Life Cycle: The series of steps a virus follows to replicate within a host cell, including attachment, penetration, replication, assembly, and release.