Types of viruses, infectious diseases and pathogens

What a virus is made of?

Viruses are relatively simple. They consist of one or more molecules and are sometimes surrounded by a protein shell. The molecules contain the genetic material - that is, the DNA or RNA - with the information for their reproduction.
virus particle outside of cells is called a virion (plural viria, virions). Virions are particles that consist of nucleic acids.

Unlike bacteria, viruses do not consist of a cell of their own, nor do they have their own metabolism. They have no own energy production and no possibility for protein synthesis. Therefore, strictly speaking, viruses are not living beings.
Viruses are tiny, only around 20 to 300 nanometers in size. That is why you cannot see them under an ordinary light microscope, it requires an electron microscope. Viruses come in many different forms. Some viruses almost look like tadpoles with a long tail, others are round or rod-shaped.

Table of contents:

Do all viruses make you sick?
Where do viruses occur?
How do viruses multiply?
What works against viruses?
How do viruses ensure their survival?
What viral diseases out there?


Do all viruses make you sick?

Not all viruses in our environment affect humans. And not all viruses that affect humans actually make us sick. Because often our immune system reacts quickly and successfully fights the intruders. However, there are important diseases that are caused by viruses.

Where do viruses occur?


Viruses penetrate animal, plant or human cells. They use these living cells as "host cells". In the area, too, they can sometimes last very long and remain contagious. However, if they don't find a new host cell, they will die sooner or later.

How do viruses multiply?


Viruses also need host cells to reproduce. As soon as the pathogens penetrate our body - so we got infected - the viruses begin to multiply. The virus docks onto the host cell and lets it produce the necessary building blocks. Once the genetic makeup of the virus is released, the host cell is forced to produce numerous virus particles and assemble them into new viruses. Then the host cell dies and thousands of viruses are released, which immediately start looking for a new host cell. For example, red and white blood cells can serve as host cells, but also liver cells, muscle cells and others. As long as we are ill, we eliminate the pathogens, often for some time afterwards.

What works against viruses?


It is not easy to fight viruses with medication. Antibiotics, for example, have no effect on viral diseases. There are so-called antiviral drugs, but they only help against certain types of virus. In many cases, however, when our body's defense has dealt with the pathogen, we are immune to this virus. We cannot then get infected with the same pathogen a second time.

How do viruses ensure their survival?


Viruses are flexible: The flu virus (influenza virus), for example, is constantly changing its face, making it easier for it to get past the body's defenses. That is why the flu vaccine only protects for one year, because with the next wave of influenza, the quick-change artist may have changed his appearance again. The vaccine is adapted annually to the properties of the flu viruses that are currently on the move or are expected.

What viral diseases are there?


Viruses can trigger harmless diseases such as a banal cold or cold sores. Most of the gastrointestinal infections in Germany are also caused by viruses. But serious infections such as HIV / AIDS or inflammation of the liver (hepatitis) are also caused by viruses. Viruses also cause many of the so-called classic childhood diseases such as chickenpox, measles or rubella.

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