Herpes diseases are diverse and manifest themselves in many different ways. The best-known herpes virus is manifested by burning blisters, usually at the corners of the mouth. They are unpleasant and often return despite professional treatment. However, there is not only one herpes virus, but many different herpes viruses.
What are herpes viruses?
Persistent herpes viruses can be divided into three groups. Alpha, beta, and gamma herpesviruses cause diseases of the skin and mucous membranes, the eye, or the nervous system. They can also be responsible for tumor formation. Eight herpes viruses are threatening to humans. Especially in the case of first infections, it can happen that the affected person does not attribute his illnesses to herpes viruses, because they manifest themselves in an untypical way. It is also possible to carry the virus within oneself without it breaking out and expressing symptoms typical of the disease. Worldwide, 85 percent of the population carry the HSV-1 virus. Herpes viruses have a double-stranded DNA and a size of about 150- 200 nm in diameter. They have been evolving for 200 million years and are therefore an ancient family of viruses. They infect not only humans but also animals. The viruses are spread by droplet infection.
Significance and function
In the primary infection of alpha-herpesviruses, epithelial cells, that is, skin and mucous membranes, are infected first. The affected cells die while the virus spreads widely throughout the body. Now the immune system kicks in, trying to contain the viral infection. Before this happens, however, the HSV viruses have already infected nerve cells, the ganglion cells. The immune system now manages to bring most of the viruses under control and the infection heals. However, some viruses remain in the nucleus of the neurons, where the immune system cannot fight them. Because they have never left the body, reactivation of the infection is possible at any time. Thus, when symptoms occur, a distinction is made between initial infection and reactivation of the herpes viruses. Once the viruses have reached the dorsal root ganglia, they remain there for the entire life of the host. Reactivation is often triggered by stress, fever, lack of sleep and UV light. If the affected person carries a herpes virus without any outbreaks of disease, this is called latent infection; the viral genome is silent. Herpes viruses are responsible for a variety of diseases that can threaten human health. They are broad-spectrum and can interact with other pathogens, causing serious illness. Many people become infected with the viruses during childhood. While symptoms that occur can be treated and the infection contained, it is as yet impossible to banish the herpes viruses from the body. In the course, a new outbreak can then be expected at any time.
Diseases and symptoms
Herpes viruses often make themselves felt by the formation of blisters. These can occur on the lips and nose, but likewise on the genitals, buttocks, eye conjunctiva, oral mucosa, or face and cheeks. In very severe cases, the viruses can lead to death. However, since it is not the intention of the virus to kill its host, deaths occur relatively rarely. Viral diseases can also affect the liver and [[brain]], where they trigger autoimmune processes. The HHV-1 virus, which usually appears in the form of vesicles, is one of the most harmless. However, in extremely rare cases, it can cause paralysis, seizures, fever and coma, which, if left untreated, lead to death in 70 percent of cases. Genital herpes, HHV2, runs without complications in healthy people and the risk of infection is lower than that of HIV. HHV-6 is also associated with multiple sclerosis. It infects T cells, altering the central nervous system. If it now comes into contact with other pathogens, multiple sclerosis can develop. HHV-6 is found particularly frequently in people who suffer from an autoimmune disease of the connective tissue. Other diseases triggered by herpes viruses are chickenpox and shingles. If they occur in the form of chickenpox, some viruses migrate to the vicinity of the spine, where they remain in nerve cells and are usually reactivated only in adulthood.The infection that now occurs is shingles, which manifests itself with a slight fever and reddened spots as well as nodules, some of which are accompanied by considerable pain. Pfeiffer’s glandular fever is also caused by one of the various herpes viruses, the Epstein-Barr virus. During the infection, the body forms antibodies, which prevents a new infection because the body has become immune. Typical symptoms of Pfeiffer’s glandular fever are swelling of lymph nodes in the neck and throat, fever, difficulty swallowing, fatigue and difficulty concentrating. Epstein-Barr virus is the HHV4 herpes virus. Herpes viruses are often associated only with blistering, but their true extent is much greater.
