Cytomegalovirus (CMV) is a double-stranded DNA virus, a member of the betaherpesvirus subfamily. It has been known to man for a little over fifty years - it was discovered in the middle of the 20th century. However, even before this, cells similar to “owl eyes” were described in stillborn babies, which later became clear that they were infected with the virus. 50 years later, the same cells were discovered in patients undergoing organ transplantation.

Cytomegalovirus is a large virus measuring 150-200 nm in size, making it one of the largest viruses known. modern science. Its genome is a double-stranded DNA containing information for the production of more than 230 proteins.

After infection, viral proteins begin to be synthesized in the host cell with viral DNA - this is how CMV spreads and maintains its vital activity.

One of these proteins (DNA polymerase, necessary for the passage life cycle virus) plays the role of a target for currently in use antiviral drugs.

The incidence of the virus is high everywhere. However, this rate varies depending on age, location and socioeconomic status: infection is higher in developing countries and disadvantaged groups. According to survey results, on average in the United States, half of the population from 6 to 49 years of age is infected with CMV. Among 75-80 year old Americans, carriers are already nine out of ten people. In developing countries, among children aged one to five years infected approximately every fifth, and in older people this figure can reach 90-100%.

Because the virus can cause birth defects in children, these numbers have experts sounding the alarm.

How does the virus spread so successfully? It turns out that CMV evolves precisely in such a way as to hide from our immune system and make itself known only at the right moment for it, tells Rich Berry, one of the authors of a study on this topic published in the journal Cell. “However, all is not lost,” continues Dr. Berry, “the immune system is not idle either, it, too, is evolving and rearranging itself in ways that are necessary for the continued survival of our species.” Thus, an evolutionary "arms race" has emerged between the virus and the human immune system, and so far the virus appears to be leading the way.

Who is at risk?

Judging by statistics, almost anyone is at risk of infection. However, serious complications from the virus mainly affect people with reduced immune function: for example, patients with organ transplants, AIDS, or newborns. Especially receptive Premature babies with low birth weight are susceptible to infection because their immune systems are not yet fully developed. Moreover, scientists found out that certain genetic mutations can increase vulnerability to the virus.

The virus can be transmitted through secretions from the body of infected patients: through saliva, tears, urine, feces, breast milk, sperm, etc.

You can also become infected through blood transfusion or organ transplantation. In addition, on some surfaces, CMV remains viable for up to six hours, and therefore may occasionally get infected and through contact with objects.

After the initial entry, CMV remains in the host’s body for life. The manifestations of its presence usually depend on the state of the immune system. “CMV is not like the flu virus, which our immune system can successfully clear from our organs,” comments Peter A. Barry, professor at the University of California, Davis School of Medicine. “Once you are infected, it is forever.”

Healthy people often have no symptoms of infection, and the virus does not make itself felt. However, the virus can be reactivated, and then the disease can manifest itself in complications of varying severity, from nonspecific febrile fever up to even fatal outcome .

Moreover, some scientists consider that in fact the virus is greatly underestimated and is associated with many more complications than can be found in the standard description for doctors.

Clinical diagnosis of CMV can be done in short time conduct in the laboratory, and there are many methods for detecting the virus. Diagnosis of the virus has also improved in pregnant women, although according to the most recent studies, the standard test reveals not all cases of infection. There is currently no approved treatment for expectant mothers. Infants with mild symptoms of infection usually prescribe valganciclovir. Healthy people infected with CMV are most often dont need in treatment. Treatment is usually given to patients with weakened immune systems.

CMV and pregnancy

The main threat CMV poses to children in the womb. Although it is second in popularity to the Zika virus, cytomegalovirus is actually the most common viral cause of disability and birth defects in children in the United States. Intrauterine infection occurs in many forms, including prematurity, intrauterine growth restriction, microcephaly, and hearing loss. Burden of disease in children with lifelong disability due to congenital virus is assessed at $1.86 billion per year.

How notes Amy Armstrong-Heimsoth from Northern Arizona University, only 13% of women had heard of the virus. The researcher learned from a colleague with undiagnosed CMV that its transmission from mother to child can turn into a tragedy.

“Her son now has cerebral palsy and has lost his hearing and vision,” she says.

Particular attention is directed to women with both HIV and CMV, since with such double viral infection the risk of infection of the infant increases significantly. According to research, HIV-infected women with CMV in the urine during childbirth are five times more likely to transmit HIV to infants than women with HIV but without CMV. They are also 30 times more likely infect newborn CMV.

Experts call the best method of combating the virus in the future not drugs at all, but vaccines. They will help control the virus at the population level through universal immunization. First of all, such a strategy would be directed on women of childbearing age to prevent infection of the fetus. However, of course, they are also necessary for patients with organ transplants and hematopoietic stem cells.

Although there is no vaccine yet, researchers appear to already have enough fundamental knowledge to create one.

There are now many developments with different strategies - are engaged even pharmaceutical giants such as Merck and GSK are among them.

It is surprising that the fight against cytomegalovirus has not yet become one of the priorities of international health institutions. Vaccine development could be speed up by attracting public attention to this problem and appealing to political and economic organizations for help. We can only hope that numerous developments by scientists to create an effective and safe vaccine are already close to success - after all, they will relieve many families from the burden of the consequences of infection with the virus and save many lives.

Cytomegalovirus infection (CMVI) is one of the most common infections. According to official WHO statistics, by the end of the first year of life, every fifth child is a carrier of the causative agent of cytomegalovirus infections. At the age of five, cytomegalovirus is detected in forty to sixty percent of children.

Depending on the region of residence, the level of infection of the population with cytomegalovirus infections ranges from fifty to one hundred percent.

A specific feature of CMVI is the variety of its clinical forms. Infectious processes can:

• proceed in hidden forms,
• lead to the development of congenital forms of the infectious process (congenital cytomegalovirus infections),
• occur in the form of lesions of the liver tissue, kidneys, lung tissues, nervous system,
• lead to infertility and miscarriage, etc.

At unfavorable conditions, cytomegalovirus infection can occur in
generalized form.

For reference. Cytomegalovirus infection is a chronic viral infectious pathology caused by cytomegaloviruses and characterized by a variety of clinical manifestations.

When diagnosing cytomegalovirus infection, the identification of specific morphological signs plays an important role:

• cytomegalic cells, similar to owl eyes;
• lymphohistiocytic infiltrates.

Cytomegalovirus infection ICD 10

According to the ICD 10 classification, CMVI is encrypted as:

• B25 – for cytomegalovirus diseases;
• B27.1 – for cytomegalovirus mononucleosis;
• P35.1 – for congenital cytomegalovirus infections;
• B20.2 – for HIV infections with signs of cytomegalovirus pathologies.

Etiological factors of the infectious process

The virus is different:

• specific ability to suppress cellular immunity;
• low level of virulence;
• slow reproduction in cells.

Attention. Cytomegalovirus infection can affect all tissue and organ structures. The virus easily crosses the placental barrier and has a teratogenic effect. It can cause congenital deformities of the fetus, as well as lead to intrauterine fetal death, recurrent miscarriage, miscarriages, etc.

The CMV virus can survive well under conditions room temperature. When frozen or heated above fifty-six degrees, the pathogen quickly loses its activity.

Epidemiological factors of the disease

Cytomegalovirus infection refers to anthroponotic infections, that is, the source of the viruses is either a patient with an active form of cytomegalovirus infection or a healthy virus carrier.

Cytomegaloviruses can be excreted in blood, urine, saliva, cervical and vaginal secretions, tears, semen, breast milk, nasopharyngeal mucus, feces, etc.

In this regard, cytomegalovirus can be transmitted by airborne droplets, parenterally, transplacentally, as well as through household contact and sexual contact.

Attention! Children under one year of age are often infected with CMV when consuming breast milk.

Cytomegalovirus infection during pregnancy

For reference. Congenital cytomegalovirus infections in children are rare.

This is due to the fact that the maximum risk of infection of the fetus is observed only during the mother’s initial contact with cytomegalovirus (according to statistics, primary cytomegalovirus infections in pregnant women are registered in 1-2 percent of cases).

However, with primary infection of the mother, the probability of severe damage to the fetus ranges from thirty to fifty percent.

If activation of a latent virus is observed during pregnancy (the mother previously had CMV infection), the risk of infection of the child is approximately 1-3 percent.

Attention. In approximately ten percent of infected children, congenital forms of the disease occur in a severe form, leading to death.

In other children, the consequences of cytomegalovirus infection can manifest as damage to nerve tissue, neuromuscular disorders, cerebral palsy, mental retardation and physical development, visual impairment, hearing loss, etc.

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For whom does CMV pose the greatest danger?

The infection process is most severe if the patient has:

• immunodeficiency states (according to statistics, approximately forty percent of patients with HIV infection develop generalized cytomegalovirus infection);
• oncohematological pathologies;
• Pneumocystis pneumonia;
• tuberculosis;
• radiation injuries;
• extensive burn injuries;
• the need for long-term treatment with corticosteroid, cytostatic or immunosuppressive drugs;
• severe stress, etc.

In such patients, cytomegalovirus infection can lead to the development of severe hepatitis, obstetric and gynecological disorders, systemic vascular damage, damage to lung tissue, the development of cryoglobulinemia, contribute to atherosclerotic vascular damage, provoke the development of epilepsy, CFS (chronic fatigue syndrome), etc.

Attention. Intrauterine infection can lead to the formation of cerebral palsy.

Cytomegalovirus infection - consequences and pathogenesis of development

Congenital infection

In the development of a congenital infectious process, the degree of viremia (virus circulation in the blood) in the mother plays a decisive role. The presence of active viral particles in the blood contributes to infection of placental tissue, with subsequent infection of the fetus.

Attention. Transplacental infection can lead to delays in the intrauterine formation of tissues and organs, fetal death, and damage to its nervous tissues and organs.

In the presence of viruses in the cervical mucus, infection can occur during childbirth, when the child passes through the birth canal.

Postnatal period

Subsequently, in the postnatal periods, the mucous membranes lining the oropharynx, respiratory tract, gastrointestinal tract, and urogenital tract can serve as entry points for pathogens of cytomegalovirus infection.

After penetration into epithelial cells, viruses begin to actively multiply and then enter the blood, leading to short-term viremia. Fixing in monocyte and lymphocyte cells. cytomegaloviruses spread throughout the body.

For reference. Due to the constant content of the virus in monocyte, lymphocyte, endothelial and epithelial cells, lifelong persistence of viruses in the body is maintained.

In this regard, against the background of decreased immunity, other infectious diseases, exhaustion, etc. cytomegalovirus infection can pass from a latent form to an active one. In this case, the active phase of virus reproduction in tissues begins, viremia and re-distribution of the virus throughout the body.

The severity of clinical symptoms of the disease depends on the degree of decreased immunity.

In severe cases of the disease, cytomegalovirus infection can cause erosive and ulcerative lesions of the mucous membranes of the esophagus, pulmonary fibroatelectasis, cysts and abscesses in the lung tissue, encephaloventriculitis, systemic vasculitis, necrotizing retinitis, etc.

For reference. A characteristic feature of cytomegaloviruses is the outcome of inflammation in organs into massive widespread fibrosis.

Cytomegalovirus infection - symptoms

For reference. The incubation period for CMV infection ranges from two to twelve weeks.

Symptoms of cytomegalovirus infections do not differ between women and men.

Symptoms of congenital infections

Symptoms of congenital cytomegalovirus infections are determined by the timing of infection of the fetus. When infected in the first twenty weeks of pregnancy, severe damage to fetal tissue is observed, leading to the development of congenital deformities, defects incompatible with life, or spontaneous abortion.

With late infection of the fetus, the prognosis is more favorable.

In children infected in the third trimester or during childbirth, symptoms of cytomegalovirus infection may appear:

• hepatosplenomegaly;
• persistent jaundice;
• hemorrhagic rashes;
• severe thrombocytopenia;
• increased activity of liver transaminases;
• hyperbilirubinemia;
• erythrocyte hemolysis;
• prematurity;
• low birth weight and poor weight gain later;
• congenital deafness;
• microcephaly or hydrocephalus;
• convulsive symptoms;
• enterocolitis;
• fibrosis of the pancreas;
• optic nerve atrophy;
• interstitial nephritis;
• congenital cataracts;
• generalized organ damage;
• disseminated intravascular coagulation, etc.

In the future, symptoms of cytomegalovirus infections in children may manifest as developmental delays, mental retardation, sensorineural hearing impairment, convulsive symptoms, paresis, and visual disturbances.

Many viruses can be constantly present in the human body and not manifest themselves symptomatically. In this case, a carrier state of the infection is formed: the patient continues to spread the pathogen unknowingly, but does not have any complaints. The reason for latent carriage is the immune system, which constantly suppresses the virulent activity of the virus. When the functions of the body's defense systems are disrupted, infection occurs. Screening studies make it possible to timely identify hidden pathologies and carry out the necessary preventive measures.

An excellent example of a disease that does not cause symptoms in most people is cytomegalovirus infection. According to epidemiological data, the causative agent of the disease can be detected in 40% of people. The virus is less often detected in children, but the likelihood of latent carriage increases with age. Hazardous properties cytomegalovirus (CMV) infections occur in immunocompromised patients and pregnant women. Intrauterine infection of a developing organism can cause miscarriage or birth defects.

More about the disease

Cytomegalovirus infection is a pathology of a viral nature that affects a variety of organs and tissues. The disease is primarily associated with the salivary glands, but viral particles can also be found in other anatomical structures. In patients with intact immune system functions, the infection occurs in a latent form or manifests itself with nonspecific symptoms, such as fever, joint and muscle pain, increased salivation, weakness and fatigue. The disease poses the greatest danger to pregnant women and patients with reduced immunity.

The significant prevalence of cytomegalovirus can be explained by the lack effective prevention and asymptomatic. The virus is present in the body of many people from the first years of life. Previously, doctors believed that the infection had no clinical manifestations in healthy people, but research recent years proved the hidden danger of the pathogen. In addition to the threat of miscarriage and damage to the fetus, cytomegalovirus infection can negatively affect the cardiovascular system and increase the risk of developing atherosclerosis.

In patients with reduced immunity, CMV can affect almost all organs. The disease is often complicated by encephalitis and. In addition, long-term persistence of the virus in tissues increases the risk of malignant tumor growth. If you have HIV or another condition that affects the body's defenses, timely treatment of such an infection is imperative.

Chemotherapy for malignant neoplasms, immunosuppressive therapy for transplantation internal organs) CMV causes severe illness (damage to the eyes, lungs, digestive system and brain) that can lead to death.

Prevalence and routes of infection with cytomegalovirus

• in everyday life: by airborne droplets and contact - with saliva during kissing
• sexually: contact - with sperm, mucus of the cervical canal
• during blood transfusion and organ transplantation
• transplacental route - intrauterine infection of the fetus
• infection of a child during childbirth
• infection of a child in the postpartum period through breast milk from a sick mother.

Clinical manifestations of cytomegalovirus

The incubation period for cytomegalovirus ranges from 20 to 60 days. The acute phase of the disease lasts from 2 to 6 weeks: increased body temperature and the appearance of signs of general intoxication, chills, weakness, headache, muscle pain symptoms of bronchitis. In response to the initial introduction, immune restructuring of the body develops. After the acute phase, asthenia and sometimes autonomic-vascular disorders persist for many weeks. Multiple damage to internal organs.

Most often, CMV infection manifests itself as:

• ARVI (acute respiratory viral infection). In this case, patients complain of weakness, general malaise, fatigue, headaches, runny nose, inflammation and enlargement salivary glands, with copious secretion of saliva and whitish deposits on the gums and tongue.
• A generalized form of CMV infection with damage to internal (parenchymal) organs. Inflammation of the liver tissue, adrenal glands, spleen, pancreas, and kidneys is observed. This is accompanied by frequent “causeless” pneumonia and bronchitis, which are difficult to respond to antibiotic therapy; There is a decrease in immune status, and the number of platelets in the peripheral blood decreases. Damage to the blood vessels of the eye, intestinal walls, brain and peripheral nerves is common. Enlargement of the parotid and submandibular salivary glands, inflammation of the joints, skin rash.
• Organ damage genitourinary system in men and women it manifests itself with symptoms of chronic nonspecific inflammation. If the viral nature of the existing pathology is not established, the diseases do not respond well to antibiotic therapy.

Pathology of pregnancy, fetus and newborn are the most serious complications of CMV infection. The maximum risk of developing this pathology occurs when the fetus becomes infected during pregnancy. However, it must be remembered that problems often arise in pregnant women with the activation of a latent infection with the development of viremia (the release of the virus into the blood) with subsequent infection of the fetus. Cytomegalovirus is one of the most common reasons miscarriage.

Intrauterine CMV infection of the fetus leads to the development of severe diseases and damage to the central nervous system (mental retardation, hearing loss). In 20-30% of cases the child dies.

Diagnosis of CMV infection

Diagnosis of herpesvirus (HSV and CMV) infections:

1. Diagnosis of HSV and CMV - infections can be diagnosed (especially in low-symptomatic, atypical and latent forms of herpes) only on the basis of detecting the virus in biological fluids of the body (blood, urine, saliva, genital tract secretions) using the PCR method or with special inoculation on cell culture. PCR answers the question: the virus is detected or not, but does not answer the activity of the virus.
2. Cell culture seeding not only detects the virus, but also provides information about its activity (aggressiveness). Analysis of culture results during treatment allows us to draw a conclusion about the effectiveness of the therapy.
3. IgM antibodies may indicate either a primary infection or an exacerbation of a chronic infection.
4. IgG antibodies- they only say that a person met the virus and became infected. IgG in herpesvirus infections persists for life (unlike, for example, chlamydia). There are situations in which IgG has diagnostic value.

Treatment of cytomegalovirus

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Treatment should be comprehensive and include immune and antiviral therapy. Cytomegalovirus quite quickly leaves the periphery and ceases to be released from biological fluids (blood, saliva, breast milk) - the latent phase of infection begins - high-quality immunotherapy activates defense mechanisms organism, which subsequently control the activation of latent CMV infection.

Cytomegalovirus infection (CMVI)

In this article we will look at what cytomegalovirus infection is, how it manifests itself, how to treat it, and much more regarding this infection.

Introduction

Cytomegalovirus infection (CMVI) is a viral infection that can affect one part of the body, such as the eyes, or spread throughout the body.

Before the advent of effective therapy for human immunodeficiency virus (commonly called highly active antiretroviral therapy (HAART)), it was common for people with CMV to develop.

Today, thanks to HAART, cases of cytomegalovirus infection in people with human immunodeficiency virus (HIV) are relatively rare. People with HIV whose CD4 count is below 50 cells/mm 3 are most at risk of developing the disease. Fortunately, treatment for cytomegalovirus infection has improved significantly in recent years.

What is cytomegalovirus infection?

Cytomegalovirus infection or abbr. CMVI is a serious infection caused by a virus called cytomegalovirus or abbr. CMV (lat. Cytomegalovirus, CMV). This virus is related to the herpes viruses that cause chickenpox and infectious mononucleosis (benign lymphoblastosis).

CMV is one of many infections that develop in people living with HIV, referred to as opportunistic infections.

Opportunistic infections only occur when a person's immune system is very weakened and the body becomes vulnerable to infections that would not otherwise affect the person's body.

Most healthy adults carry CMV, but do not know about it, because the virus does not cause any symptoms in them, and in general, does not manifest itself in any way. However, in people with a severely weakened immune system, CMV can cause infectious mononucleosis.

Cytomegalovirus infection can also cause serious illness in various parts of the body, most often in the eye area (see symptoms section below).

Who's at risk CMV ?

People with weakened immune systems due to human immunodeficiency virus (HIV), cancer, long-term use of medications that weaken the immune system, or people with organ or tissue transplants are most at risk of developing cytomegalovirus infection.

People living with HIV are most at risk of developing CMV and typically have the following characteristics:

• CD4 lymphocyte count below 50 cells/mm 3 ;
• not taking or not responding to highly active antiretroviral therapy (HAART);
• have previously had CMV or other life-threatening infections.

Symptoms and signs of CMV infection

The most common complication and manifestation of cytomegalovirus infection is:

• retinitis- This involves inflammation of the light-sensitive part of the eyes, the retina. CMV infects these cells, causing inflammation and death of these cells. Typically, people with CMV retinitis may initially have no or gradually worsen symptoms affecting their vision. Others experience more severe symptoms. Retinitis can cause blurred vision, blind spots, flashes of light and dark spots in the eyes that seem to float in your field of vision, sometimes called “floaters.”

Two-thirds of people initially diagnosed with retinitis have the disease in only one eye; however, without highly active antiretroviral therapy or anti-CMV therapy, most people develop retinitis in both eyes within 10 to 21 days after the first symptoms appear.

If left untreated, retinitis causes permanent blindness within three to six months. If you have problems with your vision, contact your doctor immediately.

Other diseases and symptoms of CMV may include (but are not limited to):

• esophagitis- when a cytomegalovirus infection affects the esophagus (the passage connecting the mouth to the stomach). Symptoms of this complication may include fever, nausea, painful swallowing, and swollen lymph nodes.
• colitis- when CMV affects the colon (the longest part of the large intestine). Symptoms include fever, weight loss, abdominal pain and a general feeling of malaise.
• diseases of the central nervous system (CNS)- when the infection affects the brain and spinal cord. Symptoms include confusion, fatigue, fever, cramps, weakness and numbness in the legs, and loss of bowel and bladder control.
• - if CMV affects the lungs (rarely occurs in HIV-positive people).

A cytomegalovirus infection that has spread throughout the body can make a person feel like they have mononucleosis. When the infection has spread throughout the body, it is called dissemination.

Symptoms of disseminated CMV infection may include unexpected fatigue, joint stiffness, muscle pain, fever, swollen lymph nodes, sore throat and loss of appetite.

Because CMV infection can be life-threatening if not treated early, It is important that you call your doctor as soon as possible if you have HIV and are experiencing any symptoms of CMV, regardless of your CD4 count.

Diagnosis of CMV

Blood and urine tests are often used to detect and measure CMV infection. Confirming a diagnosis of cytomegalovirus infection may require a biopsy (a procedure in which a doctor removes a small piece of tissue that is then examined under a microscope in a laboratory) unless the disease affects the eyes or central nervous system.

If your doctor suspects cytomegalovirus retinitis, he or she will refer you to an ophthalmologist (ophthalmologist). A vision specialist will check your eyes for CMV retinitis.

If you are a pregnant woman and you have CMV, your doctor may recommend a test called amniocentesis to determine whether your baby has CMV. To perform amniocentesis, the doctor inserts a long, thin needle through the abdomen and into the uterus to collect a small amount of fluid from the amniotic sac surrounding the baby.

CMV infection can harm a developing fetus. If the test shows that the fetus does have infections, the doctor will examine your baby after birth to check for birth defects or health problems so they can be treated if possible.