Ep 133 Parvoviruses: Who let the dogs (and their viruses) out?
Jan 16, 2024
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Explore the world of parvoviruses beyond dogs, including their biology, history, and pandemic spread. Learn about the role raccoons played in the emergence of canine parvovirus. Discover the latest research on parvoviruses and gene therapy. Discuss the symptoms, transmission, and complications of parvovirus B19. Delve into the distinctions between human and animal parvoviruses and the naming and discovery of parvo viruses. Understand the impact of parvovirus on puppies and kittens and the importance of vaccination.
Parvoviruses infect a variety of animals and humans, causing different symptoms and disease manifestations.
Parvoviruses can be transmitted through respiratory droplets or fecal-oral route, with varying evolution and adaptation abilities.
Vaccination is crucial in preventing the spread of parvoviruses, especially in vulnerable populations like puppies and kittens.
Certain variants of adeno-associated viruses (AAVs), a type of parvovirus, have shown potential in gene therapy but require further investigation regarding disease severity.
Deep dives
Discovery of Parvoviruses
The history of parvoviruses began with the discovery of rat virus in 1959, leading to its classification as a Parvovirus. In the 1960s, similar viruses were found in rodents and arthropods, and the name Parvovirus was officially adopted. In the 1970s, human Parvovirus B19 was identified, initially associated with asymptomatic infections, but later recognized for causing various diseases in humans.
Manifestations in Humans
Parvovirus B19 can cause a range of symptoms in humans, from mild infections to severe manifestations. In children, it often presents as erythema infectiosum, also known as fifth disease, which is characterized by a slapped cheek rash. In adults, it can cause joint pain and inflammation. Parvovirus B19 can also lead to transient aplastic crisis and severe anemia. In pregnant women, it can result in fetal infection and hydrops fetalis. Additionally, the virus can cause chronic red cell aplasia in individuals with pre-existing blood disorders.
Animal Parvoviruses
Parvoviruses are a family of viruses that infect a variety of animals. They primarily target rapidly dividing cells, with specific tropisms for different cell types. Animal parvoviruses, such as canine parvovirus and feline panleukopenia virus, cause gastrointestinal symptoms and can be transmitted fecal orally. These viruses have different pathogenicity and transmission patterns compared to human parvoviruses.
Naming and Research
The naming of Parvoviruses was subject to some debate, with suggestions such as Picodenoviruses being proposed but ultimately rejected. The name Parvovirus was adopted for the family of small DNA viruses that infect various species. Research on Parvoviruses focused on studying different manifestations in humans and animals, identifying causative agents and transmission patterns. The discovery of Parvoviruses and their association with specific diseases has contributed to our understanding of these viral infections.
Overview of Parvoviruses
Parvoviruses are a diverse group of viruses that infect humans, animals, and even plants. One well-known parvovirus is human parvovirus B19, which causes the common childhood illness known as fifth disease. Parvoviruses are small, single-stranded DNA viruses that have a tendency to infect rapidly dividing cells. They can cause a wide range of symptoms depending on the specific virus and the host it infects. In the case of human parvovirus B19, symptoms include fever, rash, and joint pain. Parvoviruses can also have significant impacts on animal health. Canine parvovirus and feline panleukopenia virus are two examples that can cause severe illness and even death in dogs and cats. These viruses primarily affect young animals and can lead to symptoms such as vomiting, diarrhea, and dehydration. Vaccines are available to help prevent infection and effective treatment typically involves supportive care and management of symptoms. While the focus of this summary is on parvoviruses, it's important to note that there are many different species of parvoviruses that continue to be studied and researched.
Evolution and Transmission of Parvoviruses
The evolution and transmission of parvoviruses can vary depending on the specific virus and host involved. Some parvoviruses, such as human parvovirus B19, are primarily transmitted through respiratory droplets, while others, such as canine parvovirus and feline panleukopenia virus, are spread through fecal-oral transmission. Parvoviruses have the ability to evolve and adapt to new hosts, as seen in the case of canine parvovirus type 2, which likely originated from a variant of feline panleukopenia virus. The ability of parvoviruses to survive outside the host can also contribute to their transmission, as they can remain stable on surfaces and objects for extended periods. Vaccination is a key method of preventing the spread of parvoviruses, especially in vulnerable populations such as puppies and kittens.
Gene Therapy Potential and Recent Discoveries
Adeno-associated viruses (AAVs), a type of parvovirus, hold promise in the field of gene therapy. AAVs have been extensively used as gene therapy vectors due to their efficient infection and integration into the host cell genome. Recombinant AAVs can be engineered to deliver specific genes and have been employed in the treatment of various genetic conditions. However, recent discoveries have shown that certain AAV variants, such as AAV2, can be associated with severe outbreaks of hepatitis in children. The exact relationship between AAV infection and disease severity is still being studied. These recent findings emphasize the ongoing nature of parvovirus research and the need for further investigation into their biology, transmission, and potential therapeutic applications.
This one’s not just for the dogs. It’s also for the cats, the raccoons, the wax moths, the birds, the mice, and so many other critters. Oh, and of course the humans. Even though most of us may be familiar with parvovirus through our canine friends, the world of parvoviruses is much larger. In this episode, we explore that world, focusing first on the biology of these tiny DNA viruses and how they make us sick before tracing the history of their discovery and the pandemic spread of canine parvovirus just a few short decades ago. We are joined by the amazing Dr. Steph Horgan Smith who acts as our veterinary tour guide through the animal world of these viruses and why vaccination against them is so incredibly important. Finally, we round out the episode with some of the latest research on these viruses, featuring some very cool, very promising work on using the dependoparvoviruses as a tool for gene therapy. Tune in to learn where Fifth disease got its name, what role raccoons may have played in the emergence of canine parvovirus, and so much more.
