Transcription
I'm being sarcastic. What I really mean is they can affect the adults, kids, and even the pets in the household. They'll do so in really fun ways too. Well, maybe not fun for those who are infected.
In addition, the humans affected by this virus family are, in some ways, short-changed on viral infections compared to our pets, as you'll find out at the end of this lesson on the parvoviridae virus family.
Viruses in this family are small and icosahedral in shape. They are not enveloped and are therefore very resistant to environmental destruction. Their genome consists of single-stranded DNA.
Something really cool about the viruses in this family, the parvoviruses, is that they are some of the smallest DNA viruses known to humankind. This shouldn't come as a surprise since the term "parvus" means small in Latin.
The viruses in this family that are of human concern are primarily spread by direct contact or through the respiratory route. Those of you who love dogs should be aware that dogs have a very severe form of parvovirus that affects their digestive tract, leading to potentially deadly vomiting, often bloody diarrhea, and other symptoms of infection.
Therefore, transmission of these viruses can also occur by way of contact with surfaces or objects contaminated with infected fecal material. This is especially likely if your dog decides to stick its nose or mouth in infected fecal matter.
If you're a fan of cats, then you should know that cats are also not out of the danger zone when it comes to parvovirus infections. Cats can also get a type of parvovirus commonly referred to as feline panleukopenia. This virus can easily kill a kitten due to some of the same reasons as canine parvovirus, but can also kill with no warning at all.
Feline panleukopenia virus is also transmitted through feline bodily secretions and is, like all parvoviruses, highly contagious. Regardless of the organism, be it human, dog, cat, or something else, the viruses of this family are extremely contagious, and you're unlikely to escape their wrath if you are near an infected individual.
However, you won't get parvovirus from your dog or cat, as the canine and feline parvoviruses I talked about are not zoonotic, meaning these same viruses aren't contagious to humans. Since you're not a dog or a cat, you don't have to worry about catching a parvovirus from your pet.
But, and there is a big but here, you do have to worry about catching something known as parvovirus B19 from another human. Parvovirus B19 is a virus that causes a condition called fifth disease. Fifth disease is characterized by a rash, stereotypically on the face and cheeks, that is most common in children.
The more technical term for fifth disease is erythema infectiosum, and it can be easily remembered. The term "erythema" refers to the reddening of the skin associated with this disease. "Infectiosum" refers to the ease of infectivity that is so characteristic of parvoviruses.
The suffix "osum" means that something is full of or prone to something; in this case, it means prone to infection. In very rare scenarios, women who have never been infected with this virus but are infected during pregnancy may pass this virus onto their unborn child.
These cases may result in a condition called hydrops fetalis, which is a condition whereby large amounts of fluid accumulate in two or more compartments of a fetus or newborn, such as the chest, abdomen, heart, and so on.
In addition, parvovirus B19 has been associated with a myriad of other issues, ranging from arthritis to anemia in patients with AIDS. Unfortunately for children and adults, there is no vaccine that can be given to prevent infection with parvovirus B19.
This is in contrast to dogs and cats, which have a vaccine available for the prevention of infection of their specific parvovirus.
The AAV has a linear single-strand DNA genome of approximately 4.7 kilobases in length, with two 145 nucleotide long inverted terminal repeats. The AAV genome does not encode a polymerase and instead relies on cellular polymerases for its replication.
Its entire genome only encodes viral replication and capsid genes. These two genes encode all non-structural and structural proteins for replication regulation and capsid structure, respectively.
The capsid proteins of the AAV assemble into a near-spherical protein shell of 60 subunits. AAV was first discovered in 1965 as a contaminant of adenovirus preparation, which is subsequently how it got its name.
At a size of approximately 22 nanometers, the AAV is one of the smallest non-enveloped capsid viruses discovered. AAV is also exceptional for its very low pathogenicity in comparison to its universal distribution in the human population.
This virtually non-existent pathogenicity of AAV can be attributed to its inability to replicate on its own. It requires a co-factor to be able to replicate and cause a productive infection in the body.
Even then, at worst, the adeno-associated virus causes a very mild immune response, as seen with receptor-mediated endocytosis. This is a niche hydrosphere as we had fly sets from endosome.
This core particles select when the AAV infects a human cell alone. Its gene expression program is auto-repressed, and latency is ensued by integration of the virus into a two-kilobase region of human chromosome 19 called AAVS1.
This allows the virus to stay in a lysogenic or dormant state in the cell or infected tissue until a helper virus, such as adenovirus, is brought into the infected cells.
Once the helper virus is introduced, AAV can enter a lytic cycle and replicate along with the adenovirus. E1A, E1B55K, E2A, E4, ORF6, and viral-associated genes from the adenovirus are the known helper genes required for AAV replication.
In the updating height from half a virus, virus proteins can integrate into the cellular genome. Here in orange text, once the helper virus is introduced, AAV can enter a lytic cycle and replicate along with the adenovirus.
This is done by the autonomous power done via these fryer's dry street and therefore in this region and prevented by us. Strong here identity status was perceived by the autonomous terminal here as up here.
The vote here is out here in a molecular production.