Hepatitis C Virus (HCV)
Antivirals

A virus is a microscopic biological parasite that can multiply inside the living cells of the host. Outside the host cells the viruses consists of virions that may range in different size and forms. Some of the virions are so small that their size does not exceed the size of ribosomes, while the viruses such as vaccinia virus that are much larger than the most of the bacteria. Each virions consists of capsid that has a protein origin. The capsid helps to protect the contents of the viruses, determines what type of the host cells can attach and affect. Some of the viruses also contain lipids and carbohydrates that are compounds of the host cells. The interior core consist of the genetic material(DNA and RNA chains).

Virals infection begins when the virion attaches to the specific receptors on the surface of the host cells. For example HIV viruses binds to the CCR5 located on the lymphocytes. Then the virus penetrates into the cells and begins to reproduce. The virus replicates the genome and produces new proteins that form new cores and capsids.

Currently there are known more than 2000 of different viruses that may cause a viral infection. The viruses are spread in different ways. Some viruses are spread by insects, usually blood-sucking insects. Other such as influenza are spread through the air from one person to another. There are viruses that are transmitted through the blood, by the faecal-oral route(norovirus) and during sexual intercourse(HIV).

The preparations that are used for the treatment of virals infections called antiviral agents. The most known of them are Zovirax(acyclovir) and Valrex(valacyclovir). These medicines fit into the viral DNA(genetic material) and block its replication. As a result the viruses are unable to replicate and infection goes away. Zovirax and Valtrex are effective against Herpes simplex type 1 and 2, Varicella zoster(Chickenpox).

The transmission of viruses can also be prevented through the vaccines that contains the weakened or dead virions. Vaccines help the organism to produce antibodies that neutralizes viruses. Unfortunately, there are not available vaccines for the all types of viruses. For example, the vaccine for the HIV viruses is still not found.

Some people think that viruses can also be treated by antibiotics. However, antibiotics are used only for the treatment of the infections caused by bacteria and are useless for the viral infections.