What is a virus and what are the symptoms of a viral infection
A viral infection is caused by a virus. Just about everyone has been infected with a virus at some time. A virus is a microscopic package containing DNA. Since a virus cannot reproduce on its own, it infects living cells (like human, animal cells or even plant cells and microscopic organisms) and uses them to replicate their DNA. There are millions of different types of viruses, causing a very wide range of viral infections. In this OneHowTo.com article, we will explore what are viruses and what are the symptoms of a viral infection.
Viruses are fascinating things. There is a debate as to whether the virus is alive or not. Some argue that viruses must be alive as they possess genes, they evolve, and they reproduce. Others argue that since they cannot reproduce on their own, they can't be considered living. Similarly, different theories exist explaining the origins of the virus. It is possible that the virus was one of the first forms of life, therefore existing since the beginning of time. Yet, it is also possible that viruses evolved from life.
Basically, a virus is made up of an envelope which can bind to a host cell, a genome containing genes, and some enzymes.
The life cycle of a virus is perhaps the most fascinating aspect of this agent. Basically, the virus is a bit like a pirate.
Like a pirate, the virus' capsule first binds to a host cell (either human, animal or plant). This is called the attachment phase. The capsule of the virus contains special agents that bind and fuse to living cells.
The second stage of the viral cycle is called penetration. This is when the virions enter the invaded cell, a bit like the crew of pirates entering a ship.
The next step in the viral life cycle is called replication. This is when the virus uses the host cell machinery to reproduce itself, creating a bunch of replications of the viral genome. Also produced are the proteins and other structures of the virus.
Next, the new 'baby' viruses are assembled. This way, several new viruses are formed, and are ready to infect new host cells.
Lastly, the viruses are released from the cell. Just as a pirate would exit a ship that it has looted, the viruses exit the cell by bursting it and obviously killing it.
As mentionned above, there are millions of different types of viruses. And, although they have similar life cycles, different viruses infect different types of cells and can cause varying amounts of harm.
The HIV virus, for example, targets immune cells, weakening the immune system and making the body more prone to other infection.
The common cold, or rhinovirus, is also a viral infection. This particular virus attacks the cells of the upper respiratory tract. This is a virus with a high degree of mutation, which is why we could catch it over and over again. Obviously, this virus is more easily eliminated by the immune system which is why it isn't very dangerous.
Other common viruses include:
Depending on the virus, the symptoms and severity of a viral infection will differ dramatically. Although a few vaccines exist to prevent certain types of viral infections, there remains no cure for viruses. It is important to note that antibiotics are targeted toward bacteria and are completely useless against viruses.
This article is merely informative, oneHOWTO does not have the authority to prescribe any medical treatments or create a diagnosis. We invite you to visit your doctor if you have any type of condition or pain.
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- Consult your doctor for diagnosis and appropriate treatment.