Parvovirus

Definition

Parvovirus refers to a group of small, single-stranded DNA viruses that primarily infect animals and are known for their ability to cause disease. In humans, the most notable member is the human parvovirus B19, which is associated with conditions like fifth disease, characterized by a distinctive rash and flu-like symptoms. Parvoviruses have a unique structure and replication strategy that distinguishes them from other DNA viruses.

5 Must Know Facts For Your Next Test

1. Parvoviruses are among the smallest DNA viruses, measuring only about 18-26 nanometers in diameter.
2. These viruses can only replicate in actively dividing cells, which is why they often cause severe disease in rapidly growing tissues like the bone marrow.
3. Parvovirus B19 is primarily spread through respiratory secretions, blood, or from mother to fetus, especially during pregnancy.
4. In healthy individuals, parvovirus B19 infections are usually mild and self-limiting, but they can cause serious complications in people with weakened immune systems or underlying health conditions.
5. In veterinary medicine, parvoviruses can cause severe gastrointestinal diseases in dogs and cats, leading to high mortality rates if not treated promptly.

Review Questions

• What are the main clinical manifestations of human parvovirus B19 infection, and how do they vary among different populations?
  • Human parvovirus B19 infection commonly presents as fifth disease, characterized by a 'slapped cheek' rash in children and mild flu-like symptoms. In adults, the infection may result in arthralgia or arthritis. Pregnant women face higher risks as the infection can lead to fetal complications such as hydrops fetalis or anemia. The severity of symptoms varies based on the individual's immune status; healthy individuals often experience mild symptoms while those with compromised immune systems can face serious health challenges.
• Discuss the unique characteristics of parvoviruses compared to other DNA viruses, particularly in terms of their structure and replication.
  • Parvoviruses are notably smaller than most other DNA viruses, containing a single-stranded DNA genome rather than the double-stranded DNA seen in many other viral families. They require host cell machinery for replication and can only replicate in actively dividing cells. This dependency on rapidly dividing cells limits their ability to infect certain tissues. Additionally, their simple structure allows for a high mutation rate, which can lead to variations that help them evade host immune responses more effectively than some larger DNA viruses.
• Evaluate the implications of parvovirus infections on public health and veterinary medicine, considering both human and animal impacts.
  • Parvovirus infections pose significant public health challenges, particularly with human parvovirus B19 impacting vulnerable populations like pregnant women and individuals with hemolytic anemias. The mild nature of most cases can mask potential outbreaks, complicating surveillance efforts. In veterinary medicine, canine parvovirus is notorious for causing severe gastrointestinal illness and high mortality rates in unvaccinated populations. Effective vaccination programs have reduced incidences in pets, highlighting the importance of understanding these viruses to mitigate their impacts on both human and animal health.

Related terms

Human Parvovirus B19: A specific type of parvovirus that infects humans, causing diseases such as fifth disease and can lead to complications in pregnant women and individuals with certain blood disorders.

Adenovirus: A group of medium-sized viruses with double-stranded DNA that can cause a variety of illnesses in humans, including respiratory infections and conjunctivitis.

Viral Replication: The process by which a virus produces copies of itself within a host cell, which is crucial for the virus's survival and propagation.