The world is full of viruses. Some can be successfully fought, while others cause serious diseases. The following text will explain why this is so. DNA viruses are viruses whose genome consists of DNA (genetic material).
What are DNA viruses?
A virus in general is an infection carrier that consists of one strand of genetic material. This may consist of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). The strands are wrapped in a protein coat. A DNA virus is a virus whose genetic material consists of deoxyribonucleic acid. The genetic material is called the genome. The genome may be double-stranded or single-stranded. The strands themselves consist of one piece (non-segmented) or may be distributed among different pieces (segmented). A DNA genome has the ability to occur in a ring (circular) or in an open strand (linear). Unlike RNA viruses, DNA viruses are less variable. Consequently, they are often stable against environmental influences. The reason for this is their higher chemical stability and lower mutation rate. Their enzymes that serve to amplify DNA, the DNA polymerases, have their own proofreading function. This means that incorrectly inserted DNA is recognized and removed. As a result, mutations occur less frequently. The viruses are not capable of independent metabolic processes. For this, they need a host cell into which their own genetic material is inserted. Researchers count many different viruses and divide them into 20 virus families. The following list includes the six most important types of viruses:
- Herpes viruses
- Human papillomaviruses
- Parvoviruses (Parvoviridae)
- Human adenoviruses
- Smallpox viruses
- Hepadnaviruses
Meaning and function
If an infection of the body by viruses occurs, the entire body is on alert. Due to the ability of DNA viruses to not be able to build their own metabolism, they rely on infecting a cell. They use the body’s own cells as hosts. They introduce their own genetic material into these invaded cells. Subsequently, from this point on, the infected cell uses the foreign genetic material to create new viruses. When the viruses are released, the cells die. The viruses cause the cells to self-destruct. The immune system of the human body tries to prevent the cells from being attacked. Scavenger cells are sent out to destroy the DNA viruses and diseased cells. The defense reaction results in typical symptoms of the disease, such as fever, weakness and loss of appetite. If the body survives an attack by the viruses, there is subsequently immunity to these viruses. The immune defense system has created memory cells that can recognize the enemy when it attacks again. As a result, people contract chickenpox, mumps or measles only once in their lifetime. In the context of protective vaccinations, weakened viruses are used for immunization. These cause the body to develop defenses. In the event of a possible infection, the immune system can fight the viruses directly. In the Western world, vaccination has succeeded in achieving the near eradication of chickenpox. However, there are infections that cannot be treated by vaccination. These include the HI virus, which attacks the body’s own immune cells and renders prior vaccination obsolete. Viruses are very dangerous for humans and animals. They are extremely adaptable and changeable. The genetic material of DNA viruses continues to change through mutation. They can change their surface, on the basis of which they are recognized by the body’s own defense system. They outsmart the antibodies that have been formed, as these can no longer dock onto the surface of the viruses. The antibodies can no longer recognize and destroy the viruses due to the altered surface. For this reason, new vaccines against influenza viruses are used for vaccinations every year.
Diseases and ailments
DNA viruses also have the ability to jump from one species to another. They can pass from animals to humans to replicate on their new host. This is extremely dangerous because existing defenses are largely ineffective. The host is thus highly infectious and rapid spread can occur. This happened with swine flu or bird flu.For the animal virus to function at all in humans, more than just a mutation is required. Two different viruses mix to form a new virus. To limit the risk of pandemics, many viral diseases are therefore notifiable. DNA viruses pose a further danger because they can remain in the body for years without causing symptoms. The infection only leads to cell damage and a noticeable illness when other triggers are added. Herpes viruses are among the most common DNA viruses. The herpes simplex virus in particular is widespread. Infection can be recognized by blisters on the face, lips, oral mucosa, or eyes.
