Virus varicella-zoster - what is it? Herpes zoster: treatment, causes, symptoms

Chickenpox, or, more correctly, chicken pox, is familiar to almost every inhabitant of the Earth. It is awarded to us by viruses with a melodic name Varicella-Zoster, discovered in 1911. More than a century has passed since that time. Varicella has already been studied along and across, but to defeat it while a person can not. The diseases caused by this virus seem not very serious, because the death rate from them is 1 per 100,000 cases, and even not from them, but from the complications caused by them. Here in these complications lies his cunning. The varicella zoster virus can penetrate the blood, into the lymph, into many body systems. It is impossible to drive him from there. Once in our body, the parasite remains with us forever.

Portrait of a virus

Varicella-Zoster belongs to the genus Varicellovirus, numbering 17 species. Among them there are those that affect only certain animals or birds, and there are purely human. They belong to the species "Zoster" that we are considering. This word means in translation from the Greek "belt", which reflects the picture of the rash, which is observed most often.

It is impossible to infect them from pigs, chickens, dogs and other living creatures. In the international systematics of infectious pathogens, it is called Human alphaherpesvirus of the third type. All viruses are microscopically small, but each has its own unique "face". The microscope shows us that the varicella-zoster are rounded or slightly oval in shape, have a core consisting of DNA, and a shell covered with spines made from complex proteins. Initially hitting the victim's body, the virus causes the disease with chickenpox.

Ways of infection

The varicella-zoster virus infects only humans, mostly pre-school and primary school children. Especially high number of infections in schools, kindergartens, in any large collectives. Ways of spreading are airborne (sneezing, coughing) and contact. On the body of a sick child, bubbles always form in which thousands of thousands of viruses can be counted. When these vesicles burst, pathogens with exudate exit into the environment and can enter the body of a healthy person through dirty hands, objects or with physical contact, such as handshake. Blessed to exist viruses can only in the cells of their victims, so when they are outside, they become defenseless. They can easily be killed with disinfectants, boiling, any detergent.

Symptoms

Penetrates into our body varicella-zoster through the mouth, where it settles on the mucous membranes. Having won the first "bridgehead", the viruses are introduced into the lymphocytes, blood, lungs, nervous and autonomic systems, cells of the spinal cord. Having penetrated into these organs, they start to multiply, and already having become accustomed to the body, cause the disease. From the moment of infection to the first symptoms, it can take 14 or more days. The main feature of chickenpox is the appearance of vesicles in the form of rashes throughout the body. At first they look like reddish knots, but they quickly increase to the size of a match head or slightly less. In them, under thin skin, there is a transparent exudate. When the vesicles burst, the exudate flows out, and the jaundice remains on the skin, turning into crusts when dried.

The temperature of sick preschool children rarely rises to high values and, as a rule, keeps around 37.5 ° C, signs of intoxication are most often not observed, but the child can be capricious, refuse to eat, be listless. Older children (7-12 years old) suffer from chickenpox somewhat more difficult, although they can develop a fairly mild disease with a low temperature and a satisfactory state of health.

With chicken pox, the problem is a rash, which in the patients of any age is very itchy. Children scratch and rip off the crusts, leaving on their skin lifelike marks-pockmarks.

In adults, primarily affected by chickenpox, the disease is more severe. They are noted:

• weakness;
• headache;
• High temperatures;
• An ache in the body;
• sleep disturbance;
• Sometimes nausea before vomiting and stool disruption.

Chickenpox in pregnant and newborns

Among pregnant women, chickenpox is rarely diagnosed (no more than 5%), since most expectant mothers had it in childhood, and the body is able to develop antibodies to varicella-zoster. In a newborn, they also provide protection from this virus for up to 6 months. Therefore, babies with chickenpox virtually do not get sick.

Unfortunately, if the primary infection with smallpox virus happened during pregnancy, there is a risk of infecting them and the fetus (8%). If the disease happened in the first trimester, in 5% of babies various congenital malformations (convulsive syndrome, paralysis, rudimentary fingers, anomalies of appearance and organs) are possible. In case of a disease in the second trimester with deviations, 2% of children are born, and cases with a disease are rare in the third trimester.

But if my mother fell sick with chickenpox five days before the delivery or within two days after them, the chickenpox in newborns is very difficult, even lethal outcomes are possible.

Diagnosis of varicella-zoster, IgG, IgM and other antibodies

Previously, the diagnosis of "chickenpox" was made visually. Now doctors are conducting a series of tests to find out which virus caused the disease and which antibodies are produced in the body. Modern diagnostics include:

• Smear from the oral cavity.
• A blood test for determining the type of virus.
• Exudate from the vesicles.
• The test for antibodies of the IgM group, which are formed almost immediately after the onset of the disease in pre-B lymphocytes, and in the blood are detected on the 4th day of the disease. Later on, antibodies from other groups are detected in patients. The IgG antibody values grow slowly, but also slowly and decrease after the disappearance of visible symptoms and the attenuation of the disease. This is their property used to diagnose the chronic forms of certain ailments.

Treatment

As a rule, patients with chickenpox do not get hospitalized. At home they are given a course of antiviral drugs (Acyclovir, Brivudine, Gerpevir), according to the indications, they are prescribed antipyretic, antihistaminic, and all the rashes are greased with greenery or fucorcin. To strengthen immunity, doctors are also credited with vitamins and diet.

In the body, those who have recovered for life remain antibodies to the varicella-zoster virus, which are a protection against repeated infections. In general, these are antibodies of the IgG group, although groups of IgA, IgM may be present. The level of ATA IgA significantly decreases already by the 4th month after the disease. Basically, they protect the mucous membranes of internal organs and account for 20% of all antibodies. IgM of the total number of immunoglobulins is 10%, and IgG is 75%. They are the only ones able to pass through the placenta (due to their compact size), and give immunity to the fetus in the womb.

Complications

Since, after chicken pox, humans have antibodies to the varicella-zoster IgG virus, they receive lifelong immunity. Complications of the disease in ordinary children can become infections that are included in the combs of papules. Very weak children may have such complications:

• Pneumonia (symptoms: cough, fever, cyanosis of the skin, shortness of breath);
• Encephalitis (symptoms: headache, fever, convulsions, coordination disorder, nausea);
• bursitis;
• arthritis;
• Thrombophlebitis.

In adults, chickenpox can develop:

• laryngitis;
• tracheitis;
• meningitis;
• encephalitis;
• hepatitis;
• arthritis;
• Face;
• Abscesses, phlegmon, streptoderma.

Shingles, causes of appearance

This disease is also called "herpes zoster". Varicella-Zoster, once found in the body, remain in a latent (inactive) state in nerve cells in the spinal cord, in the cranial nerves, in the ganglia (clusters of neurons) of the nervous system. While the immunity of a person is strong, they sit quietly and do not cause trouble. But as soon as the body is weakened, the viruses are instantly activated. As a result, there is no new chickenpox, but a person begins another malaise - shingles, belonging to the category of infectious diseases, and manifested by characteristic rashes on the body.

Causes:

• Transfer of operations, injuries, other diseases, including acute respiratory disease, influenza;
• Nervous stress;
• Poor-quality food;
• Hard work, exhausting the body;
• Poor living conditions;
• Chronic diseases that gave relapses;
• pregnancy;
• Supercooling;
• Organ transplantation;
• Some medicines that depress immunity;
• elderly age.

Symptoms

Shingles are more common in adults, but in weakened children who have had chickenpox, it can also be diagnosed. Its main visual sign are rashes on the body, mainly located where the nerve trunks pass. With herpes near the nose and on the lips, this ailment has nothing in common, since it is caused by another virus, which analysis shows. The varicella zoster virus, having freed itself from the immune system that held them in check, emerges from the nerve cells and rushes along their axons to the tips of the nerves. Having reached the goal, he causes a skin infection. Symptoms-precursors:

• temperature;
• Unexplained fatigue and malaise;
• prostration;
• Loss of appetite;
• Pain and itching (sometimes incomprehensible tingling) in the places of future rashes.

Symptoms at the peak of the disease:

• Rash in the form of blisters with a transparent exudate;
• Increased lymph nodes;
• Neuralgic pain (may be moderate or severe);
• Temperature above subfebrile;
• Signs of intoxication.

The disease lasts from a week to a month.

Classification by type of rash

Varicella-Zoster can affect different parts of the body, in connection with which distinguish such types of shingles:

• Ophthalmic (the eye branch of the trigeminal nerve is affected, which can lead to damage to the cornea). There is pain in the eyes, a drop in vision, a rash on the temples and under the eyes.
• Ramsay-Hunt syndrome (facial musculature is affected, rashes are noted in the oral cavity and auditory passage).
• Motor (affected myotomes and dermatomes, patients complain of severe pain in the muscles of the limbs, forearms).

In the course of the disease, the following types are distinguished:

• Abortive (without pain and rashes);
• Bubble (rashes very large);
• Hemorrhagic (in the exudate of the vesicles there is blood);
• Necrotic (on the place of papules necrosis of the skin occurs);
• Generalized (rash all over the body).

Diagnostics

Clinically and visually, shingles before the onset of rash are often taken for appendicitis, angina, pleurisy and other ailments. If necessary, a laboratory analysis is carried out. Varicella-Zoster is detected by express diagnostics, consisting in the study of samples under a microscope. Immunofluorescent and serological methods are also used. Complex laboratory tests are carried out in the following cases:

• Patients-infants;
• Children in immunodeficiency;
• Atypical herpes;
• Complicated course of the disease.

In babies infected in the mother's womb, antibodies of varicella-zoster IgG and IgM antibodies are found in large quantities. Differentiation is performed by PCR. This reaction also helps to detect viruses in the absence of rash on the skin and its presence on the internal organs.

Treatment of herpes zoster

If the analysis was positive - varicella-zoster is diagnosed with 100% confidence. After that, the doctor determines the treatment algorithm. I must say that in young people, shingles go without medication, but with a sparing diet and a bed rest. Medications can speed recovery and prevent complications, as well as relieve pain and temperature, if any.

Antiviral drugs are prescribed for patients older than 50 years, severely debilitated, having suffered trauma and surgery, suffering from chronic ailments, and children. The prevailing drugs are Acyclovir, Famciclovir, Valaciclovir, and among the pain relievers Ibuprofen, Ketoprofen, Naproksen and analogues. Also, according to the indications prescribed anticonvulsants, antidepressants, corticosteroids. When infected with a varicella-zoster eye and / or brain, the patient is hospitalized.

Complications

There are 28% who have recovered from shingles. Patients complain about:

• Deterioration of vision;
• Hearing loss;
• Frequent and unreasonable headaches;
• Spontaneously appearing dizziness;
• Morbidity of the body after the disappearance of the rash.

Individual patients may develop cardiac and / or renal failure, complication of oncological diseases, blindness or deafness, damage to the tissues of the brain and / or spinal cord.

As a preventive measure, the Zostavax vaccine has been developed. Its effectiveness, established experimentally, is 50%.