Persistent infection

Definition

A persistent infection is a type of viral infection that continues over a long period, often without causing acute symptoms. Unlike acute infections that resolve quickly, persistent infections can lead to chronic health issues and allow the virus to evade the host's immune response. This means the virus can remain in the body and may reactivate later, affecting various organ systems.

5 Must Know Facts For Your Next Test

1. Persistent infections can occur in various organ systems, such as the liver with hepatitis viruses or the nervous system with herpesviruses.
2. The immune system often struggles to eliminate viruses in persistent infections due to mechanisms like viral mutation or immune evasion strategies.
3. Some persistent infections can lead to serious complications, such as cancer, especially when the virus integrates into the host genome.
4. Treatment for persistent infections may involve antiviral therapies aimed at controlling the virus rather than completely eliminating it.
5. Examples of viruses that can cause persistent infections include HIV, hepatitis B and C, and Epstein-Barr virus.

Review Questions

• How do persistent infections differ from acute infections in terms of their impact on the host's immune response?
  • Persistent infections differ from acute infections in that they often allow viruses to evade the host's immune response over an extended period. While acute infections typically elicit a strong immune reaction that clears the virus quickly, persistent infections can exploit immune evasion strategies. This leads to ongoing viral presence in the body, resulting in chronic health issues and potential complications over time.
• Discuss the role of viral latency in persistent infections and its implications for treatment.
  • Viral latency plays a crucial role in persistent infections, as it allows viruses to remain dormant within host cells while avoiding immune detection. This characteristic complicates treatment efforts because antiviral therapies may not effectively target latent viruses. As a result, understanding latency is essential for developing strategies that can address both active replication and latent reservoirs, ensuring better management of persistent viral infections.
• Evaluate the potential long-term consequences of untreated persistent infections on different organ systems in the body.
  • Untreated persistent infections can have severe long-term consequences on various organ systems. For instance, chronic hepatitis B or C can lead to liver cirrhosis and hepatocellular carcinoma. In the nervous system, herpesviruses may cause neurological disorders due to inflammation or reactivation events. Additionally, HIV can progressively damage the immune system, making individuals susceptible to opportunistic infections and other diseases. The impact of these persistent infections highlights the importance of early detection and intervention.

Related terms

Latency: A stage in which a virus remains dormant within host cells, often reactivating under specific conditions.

Chronic Infection: A type of infection that persists for a long time, characterized by the continuous presence of the virus and ongoing tissue damage.

Viral Shedding: The release of virus particles from an infected host, which can occur even when the host is asymptomatic.