Many of us associate the concept of "herpes" with a rash on the lips and do not attach much importance to it. However, the family of these viruses is quite numerous and insidious. To date, scientists have identified about a hundred types of herpes that parasitize in living organisms. The man "got" eight of them, including type 6 herpes. This virus is present for life in 9 out of 10 people on our planet, but it manifests itself mainly in children.
Human herpes virus family
All eight herpes viruses are remarkably similar in appearance. Sometimes even under a microscope it is difficult to distinguish them. They can be distinguished into separate groups only by the reaction to certain antigens of their virion proteins, by the so-called antigenic properties of proteins, and also by the degree of homology (similarity) of their DNA. Some researchers distinguish groups of herpes viruses by the presence or absence of a large envelope. However, this method is not completely accurate. The human herpes virus type 6, in addition, has 2 subtypes, A and B. Since their DNA is 95% similar, they were previously defined as varieties of the sametype, but in 2012 they were separated into separate species. In addition to 5% dissimilarity in DNA, they have other differences, in particular, clinical manifestations. However, it is difficult to accurately identify them in laboratories.
Type A
To date, it is known that herpes type 6 A is considered more neurovirulent, that is, it is more common in those who have diseases of the nerve fibers, such as multiple sclerosis. This disease is absolutely not related to the age of a person. It occurs with equal frequency in both the elderly and the young. There are cases of detection of multiple sclerosis even in infants. One of the causes of the disease is called infection with the herpes virus 6A of the nerve tissues of the brain and spinal cord. However, there are other causes that are not related to herpes. The clinical manifestations of the disease depend on the site of infection, the stage of the disease, and many other factors. In addition, herpesvirus 6A is thought to be more common in people with HIV. In laboratory conditions, it was found that in the bodies of macaques, it dramatically increases the development of the disease AIDS. HIV viruses cannot enter he althy cells until the herpes viruses type 6A have settled in them and prepared the conditions for them. This feature is adopted by scientists developing treatments for AIDS.
Type B
Herpes 6 type B has been studied more extensively. According to the results of numerous studies, it has been established that it is the cause of such a disease as children's roseola. It is also called the sixth disease,pseudorubella or exanthema. This disease occurs exclusively in children, and most often in babies under two years of age. In adults, the body develops immunity to viruses. In the human body, viruses begin to react with immune factors, and once they enter the skin with blood, they damage tissues. The main symptom of the disease is a high temperature without any symptoms of a cold. In some children, it reaches 40 degrees and above. Sometimes the patient has an increase in lymph nodes. On the 3rd or 4th day a rash of red or pink color appears on the back, abdomen and chest, blanching on pressure. Within a short time, the rash spreads to the rest of the body. There is no itching and pain, the temperature subsides. A day later, less often after a couple of hours, the rash disappears without leaving any traces.
Herpes type 6 in adults
Most often, infection with the herpes virus 6B occurs in childhood. In adults, it is present in an inactive state, but under certain conditions, its activity can resume. In particular, after organ transplantation, some patients may experience complications such as encephalitis or pneumonitis. Encephalitis is inflammation of parts of the brain. Pneumonitis is damage to the walls of the alveoli in the lungs, which makes breathing difficult. Some researchers have associated bone marrow suppression with the 6B virus, leading to shortness of breath, anemia, and more serious consequences. In addition, this virus is believed to be responsible for the occurrence of chronic fatigue,manifested in weakness, apathy, depression. Herpes type 6 has been linked to hepatitis, high sensitivity to antibiotics, cancer, and more. However, all this has not yet been finally proven.
Mechanism of action of the virus
Herpes simplex virus type 6 has a dense shell with receptors. The main component for them is the CD46 protein, which is located on the surface of almost all cells. Therefore, the virus so quickly and so easily “settles down” in the body. Once in the human body, it tries to penetrate CD4+ cells, which differentiate into T-lymphocytes. The latter are able to suppress the immune response. Viruses, using this property, induce the phenotype of T-lymphocytes and bind to the CD46 protein. Since this protein works in all cells except red blood cells, it is easy to imagine the possibilities of this herpes virus in our body. It was first discovered in 1986 in adult patients with HIV. A couple of years later, it was also isolated from infants with roseola. After a series of studies, the herpes virus type 6 was found in people on all continents in almost every country.
Routes of infection
Because herpes type 6 is present in the vast majority of the world's population, it is very easy for the uninfected to become infected with it. Most often this happens in infancy (from about the 3rd month of life), when the mother's antibodies stop working in the child's body. A small percentage of children are infected at birth if the motherthe newborn picked up this virus in the last months of pregnancy. If the child's parents have herpes, they can infect the baby through direct contact. Herpes 6 is known to be present in saliva. Therefore, the easiest way of infection is airborne. You can infect a baby by kissing him or talking to him, bending over his face. Transmission of the virus through breast milk is not possible.
In addition, herpes 6 can be transmitted from a sick person to a he althy person directly with blood. Cases have been recorded when infection occurred through injections or when examining a patient with non-sterile instruments.
Virus Diagnosis
Unfortunately, in a primary infection, it is difficult to detect and accurately recognize a virus of this group. It is even more difficult to detect it during the inactive stage. It is determined in the laboratory. There are several methods for determining, depending on the manifestation of the infection. They all come down to immunological, biochemical and microbiological studies.
For example, they are used for myocarditis, which can be fatal. It has been established that it is also caused by the herpes virus type 6. There are no symptoms, unlike myocarditis caused by other causes. With this disease, the virus is identified in a biopsy taken from the heart muscle or in the blood. If the results are doubtful, additional studies are carried out. With pneumonitis, the virus is determined in sputum and blood serum, and the reason for assuming its presence may beprovide chest x-ray data. For hepatitis caused by a virus, liver biopsy and serum tests are performed. For various tumors and swollen lymph nodes, special monitoring and serological tests are carried out, as well as blood PCR. This test is widely used in the reactivation of the virus and its inactive form.
Treatment
It is impossible to completely get rid of the herpes virus of any kind. The same can be said about herpes type 6. Treatment in this case is to prevent the occurrence of relapses and maintain the virus in an inactive state. The course and methods of treatment depend on the clinical manifestations of the disease. If it is baby roseola, then special antiviral drugs are not prescribed. If the child has a high fever, they are given antipyretics such as ibuprofen or paracetamol and drink plenty of fluids. Children with depressed immunity are sometimes prescribed Foscarnet or Acyclovir. The latter drug is currently considered not quite effective, so they began to replace it with Ganciclovir. A very big disadvantage of baby roseola is that it is often confused with ordinary rubella and appropriate drugs are prescribed, although they are absolutely not needed.
Prevention
As you can see, the herpes virus is quite unpleasant. However, there is one positive point - the human body is able to develop immunity against it. Antibodies to this virus are produced during the first few days after infection. In the future, their number changes, but they are present inbody constantly. They are able to contain herpes type 6. Symptoms of virus reactivation occur when a person has problems with the immune system or the body is weakened by other diseases. Therefore, the main preventive measure is to strengthen the immune system in every possible way. These are physical activity, and the right lifestyle, and rational nutrition, and vitamin complexes. Another important point of prevention is personal hygiene.
