Cytomegalovirus (CMV) is a type 5 herpes virus. Like most herpes viruses, it often occurs in a latent form. Its danger lies in the fact that it can seriously damage internal organs in certain situations. Below we will talk about why cytomegalovirus is dangerous, as well as how CMV is transmitted, about the treatment of cytomegalovirus and the reasons for its manifestation.
Features of the virus
Human cytomegalovirus is a DNA virus from the herpesvirus family.
Other members of this family are the causative agents of herpes, chickenpox, mononucleosis and other diseases. CMV develops in connective tissue cells and often spreads throughout the body. Replication of viral particles occurs in leukocytes: the pathogen enters the cell, introduces its own genetic information into the nucleus and triggers the assembly of the necessary protein components. After replication, virions leave the affected cell and attack other leukocytes, affecting external receptors. The mechanism of transmission of the virus has not been thoroughly studied, but experts know that CMV can be present in almost all biological fluids, including saliva, semen, urine and blood. It is believed that the infection is most often transmitted through kissing and sexual contact. Due to its moderate contagiousness, infection requires close contact with a carrier of the virus.
In the external environment, the virus quickly loses its virulent properties, so the household route of transmission is not so common. CMV is easily inactivated by ethanol and exposure to high temperature. After entering the body, the virus is not destroyed by the immune system, however, lymphocytes are able to secrete immunoglobulins that remain in a person throughout life.
What it is?
Cytomegalovirus is a genus of viruses in the herpesvirus family.
This virus is quite common; cytomegalovirus antibodies can today be found in approximately 10-15% of adolescents and 40% of adults. Unfortunately, it is not immediately possible to recognize the presence of cytomegalovirus - this disease has an incubation period that can last up to 60 days. During this period, the disease may not manifest itself in any way, but after that there will certainly be an unexpected and sharp outbreak, which in most cases can be triggered by stress, hypothermia or a general decrease in the immune system.
Unfortunately, cytomegalovirus is often confused with such ailments as acute respiratory infections and acute respiratory viral infections, since this virus is quite similar in its symptoms: body temperature rises, headache, and general weakness appear. If cytomegalovirus is not recognized in time, the consequences can be more than serious: pneumonia, arthritis, encephalitis, etc.
Transfer methods
For cytomegalovirus to invade the body, contact with an infected biological fluid is necessary. It is believed that the largest number of viral particles is contained in saliva, so the infection is most often transmitted through kissing. The airborne mechanism of transmission of the disease implies a risk of infection even when talking with a carrier of the virus, since saliva can enter the oral cavity.
Other infection options:
- Sexual transmission: The virus is transmitted through vaginal mucus, lubricant and semen.
- Transmission of the disease from mother to child through the placenta. Infection of a newborn is also possible during childbirth.
- Organ transplantation and blood transfusion.
The risk of intrauterine transmission of CMV increases if a woman first becomes infected with the infection during pregnancy. In children and adults, pathogen invasion can occur even with minor contact: a person touches their eyes and lips with dirty hands after contact with a carrier of the infection.
Pathogenesis
Once infected, CMV enters the bloodstream and spreads throughout the body. Initially, humoral immunity responds to infection with the formation of immunoglobulin M - this reaction is maintained for two months. Approximately six months after infection, immunocompetent cells secrete specific immunoglobulin G, which remains in the host’s body throughout life. Lymphocytes (CD8 and CD4) are also responsible for suppressing the activity of the virus. In patients with reduced immunity, CMV immediately begins to show its virulence.
Most healthy people infected with cytomegalovirus after birth have no symptoms. In rare cases, a clinical picture resembling infectious mononucleosis develops: a mild form of hepatitis, fever and sore throat. These pathological signs quickly pass, after which the virus does not manifest itself in any way until reactivation.
Regardless of the form of the disease, CMV affects the body's tissues. The so-called cytomegaly develops, characterized by a significant increase in cells. Such morphological changes can be explained by the destruction of the cytoskeleton and the active synthesis of viral particles that become cellular inclusions. During a histological examination of the affected tissue, a specialist can detect fibroblasts that resemble an owl's eye in appearance.
Risk group for developing active infection:
- newborns;
- aged people;
- patients with leukemia;
- HIV-infected;
- people with congenital immunodeficiency;
- patients with cancer;
- patients who require hemodialysis or immunosuppressants.
In HIV-infected patients, the manifestation of cytomegalovirus infection may indicate the development of acquired immunodeficiency syndrome (AIDS), since in this case the number of T-lymphocytes decreases.
Decoding the analysis for pregnant women
Interpretation of diagnostic data for pregnant women has its own characteristics.
A significant increase in the titer of immunoglobulin G indicates an intensive fight of the body against the virus.
Additional diagnostics are required to confirm the active phase of the disease.
If a woman takes tests after 4 weeks from the start of pregnancy, a negative result does not guarantee the safety of the fetus.
The virus could have entered the body earlier than 12 weeks, and the immune response is still weak.
If a high titer of immunoglobulin M and low G are detected, the pregnant woman should be prescribed treatment.
It requires constant monitoring and observation followed by repeated diagnostics.
Pregnant women whose tests have confirmed the absence of an acute form of the disease should undergo regular examinations and monitor their condition.
Maintaining immunity at the proper level will help maintain the health of the fetus until birth.
Immunodeficiency disease
Cytomegalovirus infection manifests itself symptomatically in most HIV-infected people. The virus can infect the brain, lungs, liver, heart, bone marrow, genitals and other anatomical structures. The first stages of the pathology are characterized by the appearance of night sweats, fever, insomnia and muscle pain.
Forms of organ damage
- Pneumonia is inflammation of the lung tissue. In this case, the virus is detected not only in the lung parenchyma, but also in the bronchoalveolar fluid. In immunocompromised patients, this pathology can lead to death.
- Hepatitis is an inflammation of the liver tissue. Manifested by an increase in the level of bilirubin and hepatocellular enzymes. In rare cases, jaundice develops.
- Inflammation of the gastrointestinal tract. Doctors include diarrhea, abdominal pain and the formation of ulcerations in the mucous membranes as features of this complication.
- Inflammatory process in the retina of the eye. There is a progressive decrease in visual acuity. Irreversible blindness often develops.
- Nephropathy, manifested by impaired renal function.
Other dangerous complications of the disease include damage to the central nervous system and increased bleeding.
Congenital form
In most cases, intrauterine infection of a child does not lead to the development of symptoms. If a pregnant woman encounters cytomegalovirus invasion for the first time, the risk of developing a congenital disease in the newborn increases.
Signs and complications of congenital infection:
- Liver damage, manifested by organ enlargement, jaundice and increased bleeding.
- Intrauterine growth retardation and prematurity.
- Microcephaly and retinitis.
- Enlarged spleen.
The probability of death from congenital infection reaches 30%. The negative consequences of cytomegalovirus infection subsequently become the cause of human intellectual disability.
Conservative therapy
Information regarding how to treat CMV infection should only be provided by a doctor based on diagnostic results.
Currently, there are no drugs that can completely rid the body of the pathogen. According to methodological recommendations, uncomplicated CMV infection does not require treatment. In other cases, it is aimed at getting rid of unpleasant symptoms. To eliminate intoxication, you must drink at least 2.5 liters of pure still water per day.
In most cases, treatment of CMV infection in adults is carried out with the drug Ganciclovir. This is an antiviral drug that is prescribed only when the immune system is weakened. It is available in the form of tablets and solution. Injections are indicated for patients with severe forms of the disease.
In the treatment of pathology in people with immunodeficiency, the drug Foscarnet has shown the greatest effectiveness. But it can also cause serious complications, and therefore should be taken with caution and according to a strict regimen drawn up by a doctor.
During treatment, you do not need to adhere to any diet or specific daily routine.
Diagnostics
The necessary examinations can be completed by an infectious disease specialist. The doctor will ask the patient about complaints, carefully review the medical history to identify risk factors, and conduct a general examination. An active infection in immunocompetent people is manifested by symptoms of mononucleosis, so to clarify the diagnosis, a specialist will need the results of laboratory and instrumental studies.
Prescribed diagnostic procedures:
- Blood test for immunoglobulins. In the first weeks after infection, IgM antibodies are detected in patients. Also, the presence of these antibodies may indicate an exacerbation of a chronic disease. A high concentration of IgM in a pregnant woman indicates a risk of damage to the fetus. If the patient has IgG antibodies, the doctor suspects viral carriage without clinical manifestations.
- Polymerase chain reaction - detection of viral DNA in biological fluids and patient tissues. An assessment of the number of viral particles allows us to draw a conclusion about the severity of the pathology.
- Examination of organs for active infection. The doctor prescribes visual diagnostics and additional tests, such as a biochemical blood test to detect liver failure.
If primary CMV infection is detected in the body, it is recommended to undergo screening for HIV infection to exclude complications. Also, patients at risk necessarily require regular monitoring.
Possible complications
The negative consequences of the disease are very diverse. The following disorders are most often diagnosed in patients:
- hepatitis;
- stomach and duodenal ulcers;
- esophagitis;
- pancreatitis;
- diabetes;
- significant deterioration of vision up to its complete loss;
- low blood pressure;
- anorexia;
- hyperpigmentation of the skin;
- mental and neurological disorders;
- deafness;
- pathologies of the cardiovascular system.
The above disorders are only part of the possible complications. It is impossible to predict which organ will be affected. In this regard, when a CMV infection is detected, the recommendations of the attending physician should be followed regularly. In addition, it is necessary to periodically donate blood to timely detect the transition of the pathogen to the active phase.
Treatment
Drug treatment of infection involves the use of various antiviral agents. Clinical guidelines instruct physicians to prescribe cytomegalovirus immunoglobulin, ganciclovir, foscarnet, or cidofovir to patients. The specific treatment regimen depends on the symptoms of the disease and the patient’s condition.
Description of drugs
- Cytomegalovirus immunoglobulin is a specific class G antibody that can fight the virus. The drug blocks the ability of the virus to influence cell signaling systems and stimulate the assembly of virions. This medicine is used as primary therapy in combination with other antiviral medicines or prescribed to prevent the disease. The use of immunoglobulin can significantly reduce the risk of complications of the disease.
- Ganciclovir, foscarnet and other drugs block viral replication. Side effects of these drugs include increased bleeding, kidney damage, and gastrointestinal dysfunction. In case of renal failure, such medications are used as a last resort.
Timely implementation of prevention allows you to suppress the infectious process and gives the patient the opportunity to avoid taking dangerous drugs.
How to treat cytomegalovirus
No matter what the doctors did, what therapeutic measures they did not carry out, they were unable to achieve a complete recovery of the clinical patient. Treatment of cytomegalovirus infection is aimed at strengthening the immune system, preventive measures and reducing the number of relapses of the underlying disease. Doctors know what CMV is, but they don’t even know how to cure it. The approach to the problem is comprehensive and involves taking the following medications:
- Antiviral drugs: Panavir, Ganciclovir, Forscanet.
- Interferons: Viferon, Cycloferon, Leukinferon.
- Immunoglobulins: Megalotect, Cytotect.
- Symptomatic treatment: according to medical indications.
In children
If a child is sick, the choice of intensive care depends on his age category. Children under 6 years of age can only eliminate cold symptoms using conservative methods, and older children can take antiviral drugs to reduce the activity of a dangerous infection. In the latter case, it is important to recall that such medications have a toxic effect and have side effects. Before treating cytomegalovirus with medication, you need to consult with your local pediatrician.
Prognosis and prevention
In immunocompetent people, carriage of the virus does not affect the quality of life. Only a few studies indicate the risk of developing atherosclerosis with long-term persistence of CMV in the body. The prognosis for immunodeficiency depends on the clinical manifestations of the disease and the timeliness of treatment. The highest mortality rate is characterized by cytomegalovirus pneumonia.
Prevention methods:
- compliance with personal hygiene rules (You must wash your hands regularly);
- separate meals with the child;
- regular cleaning of any objects that have come into contact with the child’s urine or saliva (This is especially true for toys);
- using a condom;
- regular examinations for HIV positive status and other conditions that negatively affect immunity.
- drug prevention of infection during organ transplantation and use of immunosuppressants.
Thus, cytomegalovirus infection is a viral disease that can affect human organs and tissues when the immune system is impaired. First of all, this pathology is dangerous for pregnant women and children, so screening for CMV must be carried out in advance.
Epidemiology
HCMV is found in almost all parts of the globe and is common among all socioeconomic groups; for example, about 50-80% of the US population is infected, as evidenced by the presence of antibodies among the majority of the population.
According to serological tests, 58.9% of people aged 6 years and older are infected with CMV. In the group of 80 years and older, 90.8% of the population are seropositive.
HCMV infection is most common in developing countries and communities of low socioeconomic status, and represents the most common cause of viral birth defects.
