Viruses are microorganisms that multiply only in living cells and cause infections in plants, animals, and humans. In the past, the term __ampersandsignldquo;virus__ampersandsignrdquo; has been used to refer to various pathogens, especially unknown agents. After the French scientist, L. Pasteur proved the role of bacteria in the origin of several diseases, the concept of the virus began to be used as a synonym for the word __ampersandsignldquo;microbe__ampersandsignrdquo;. When we test viruses in the laboratory, they break down at the expense of amino acids in the cytoplasm, and it needs several amino acids. When we look at a set of virus molecules under a microscope, they look like crystals or X-cells. It is believed that their reproduction can take place around them. When we studied viruses, we found that they spread in several different ways. Studies have shown that most viruses are spread by airborne droplets. One of the main principles of combating infectious diseases is early detection and prevention of the spread of the disease. This is a very complex job and largely depends on the experience and qualifications of the specialist. In addition to the traditional methods used in other areas, some special methods are used in the detection of infectious diseases.