Reassortment

Definition

Reassortment is a process where segmented viruses exchange genetic material during co-infection of a host cell, leading to the generation of new viral strains. This genetic mixing can significantly alter viral properties such as virulence, transmissibility, and resistance to antiviral drugs, impacting viral evolution and disease emergence.

5 Must Know Facts For Your Next Test

1. Reassortment is most commonly observed in segmented RNA viruses, such as influenza viruses, where two or more strains infect the same cell.
2. This process can lead to the emergence of pandemic strains, as seen in the 2009 H1N1 influenza outbreak, which was a result of reassortment between swine and human flu viruses.
3. Reassorted viruses may exhibit altered pathogenicity and transmissibility due to changes in their surface proteins, impacting how the immune system recognizes them.
4. The ability to undergo reassortment allows viruses to adapt quickly to changing environments, including shifts in host immunity or antiviral pressures.
5. Public health monitoring of viral strains is crucial to detect reassorted viruses early, which can inform vaccine development and outbreak response strategies.

Review Questions

• How does reassortment contribute to the genetic diversity of segmented viruses?
  • Reassortment contributes to the genetic diversity of segmented viruses by allowing different viral strains to exchange genetic segments when they co-infect the same host cell. This mixing of genetic material can produce novel combinations of traits, leading to variants that may have enhanced abilities to infect new hosts or evade existing immune responses. Consequently, this process plays a vital role in the evolution of viruses and their adaptation to changing environments.
• Discuss the implications of reassortment for public health and vaccine development.
  • The implications of reassortment for public health are significant because it can lead to the emergence of new viral strains that may not be adequately covered by existing vaccines. When reassorted viruses exhibit altered surface proteins, they may escape recognition by the immune system. Therefore, continuous surveillance and monitoring of viral strains are essential for timely updates to vaccines and effective public health responses to potential outbreaks caused by these novel strains.
• Evaluate the role of co-infection in reassortment and its impact on viral emergence and re-emergence.
  • Co-infection is a critical factor in reassortment as it provides the necessary conditions for multiple viral strains to exchange genetic material within a single host cell. This exchange can lead to the emergence of novel strains with distinct characteristics that may increase their transmissibility or virulence. The ability of viruses to rapidly adapt through reassortment poses challenges for controlling viral diseases, as it can result in sudden outbreaks or re-emergence of previously controlled infections, highlighting the need for vigilant monitoring and adaptive strategies in public health.

Related terms

Segmented Genome: A type of viral genome composed of multiple distinct segments of RNA, which allows for reassortment during co-infection.

Antigenic Shift: A major change in the antigenic properties of a virus, often resulting from reassortment, that can lead to new strains capable of evading immune responses.

Co-infection: The simultaneous infection of a single host cell by multiple viral strains, which is necessary for reassortment to occur.