- Cytomegalovirus - what is its danger?
Cytomegalovirus (CMV) - a virus with a double-stranded DNA from the group gerpevirusov. This group includes herpes first and second types (those that cause the common cold on the lips and genital herpes, respectively), varicella zoster virus and human herpes virus. In many common cytomegalovirus gerpevirusami with other properties, including gene structure of the virion and the ability to cause chronic and latent infections. In cytomegalovirus the largest genome of all gerpevirusov.
What is cytomegalovirus
The problem of virus infections is considered at the present stage to date. Among viral infections CMV is the most common pathology. The infection has transplacental transmission path that leads to infection of the fetus in utero and development of severe pathology in the postpartum period.
Severity of clinical manifestations is largely determined by the period in which a pregnant woman was infected.
Human cytomegalovirus grows only in human cells and replicate best in fibroblasts. According to health experts, an average of 60% of the population of developed countries vulnerable to cytomegalovirus, 90% of infections occur in people belonging to risk groups (eg homosexual men). In developing countries, most of CMV infected children in developed countries - young people aged 20 to 30 years.
The problem of congenital cytomegalovirus infection
Advances in the study of the influence of CMV infection on the human body have been made possible, thanks to the introduction of methods of serological, virological and culture methods for diagnosis. It was proved that in nature the virus belongs to the group of herpes viruses. Previously it was thought that the disease is caused by cytomegalovirus, can only be innate, since the virus infection occurs in utero. It is now recognized the possibility of a disease acquired character.
Congenital infection occurs due to transplacental transmission of the virus, in most cases it leads to fetal death or the formation of his severe malformations.
Such an effect on the health of the developing fetus necessitates timely diagnosis of the virus in the body of a pregnant woman. In this regard, the program includes a comprehensive survey of women diagnosis of viral infections, as well as other types of pathogens that have a negative effect on the fetus. It is important to conduct a survey at the stage of preparation for the upcoming pregravid pregnancy to be able to carry out complex therapy. This will guarantee the normal course of the pregnancy and the birth of a healthy baby.
Consequences for maternal and child health
Recently, researchers have paid much attention to the study of congenital cytomegalovirus infection. If intrauterine infection has not led to the death of the fetus, it is especially difficult changes at the level of the nervous system, its central departments. The consequences can be very severe and irreversible. Other organs and systems are less vulnerable to the impact of cytomegalovirus, while in the cells of organs will be identified specific changes at the cellular level, it is typical for this type of viral infection of the pathogen.
The defeat of various organs cytomegalovirus occurs differently. The affected organ there is a reduced number of cells, which is related to a cytotoxic effect of the virus on the cells. The virus also affects the process of cell reproduction.
Many researchers are of the opinion that the majority of infants have passive immunity to cytomegalovirus, which they acquire from the mother.
This type of immunity on their data is stored up to three months, and later he disappears. Age newborn three months is considered the most vulnerable period when the child infection can occur.
The development of various forms of CMV viral infection has not yet been fully studied. In some cases, the disease is a consequence of activation of latent infection that occurs on a background of reducing defensive abilities of the body. Viral infection can be characterized by a long asymptomatic virus infection.
Pregnancy helps to activate a viral infection that is independent of the duration of pregnancy and observed in the early and late stages. Once penetrated into the body, cytomegalovirus, as well as the herpes virus, it may continue throughout life. Isolation it occurs in the urine and saliva, in some cases it even is isolated from blood cells (leukocyte). This fact confirms the similarity or tropism of the virus to leukocytes, ie white blood cells are the elements of the blood in which the virus is actively multiplying. White blood cells do not inactivate the virus and make unavailable for exposure to the virus-specific antibodies of the immune system.
Cytomegalovirus can be a long time present in peripheral blood leukocytes, spreading throughout the body and affecting various organs.
This fact is particularly important in terms of understanding the development of pathological changes in the body after infection. The whole complexity of the problem of viral infection is that up to now has not been able to develop effective preventive measures, as well as methods for specific therapy. The use of antibacterial or hormonal methods can not be considered appropriate in some cases, it may cause deterioration of the pathological process and the development of complications.
How dangerous cytomegalovirus
Usually, cytomegalovirus infection is asymptomatic, after which the virus remains latent throughout life. Clinically significant symptoms can cause patients with a weakened immune system, for example, due to HIV, organ transplantation, taking high doses of steroids, antagonists of tumor necrosis factor and other immunosuppressive drugs used to treat conditions such as systemic lupus, rheumatoid arthritis
Arthritis - a variety of forms and complications
Crohn's disease, psoriasis, and others.
Cytomegalovirus can cause further deterioration of patients with AIDS and death, even if they are highly active antiretroviral therapy (HAART). In immunocompromised patients CMV can affect almost any organ of the body and cause a fever of unknown origin, pneumonia, hepatitis
Hepatitis - the scourge of our time
, Encephalitis, myelitis, colitis, uveitis, retinitis, and neuropathy.
By the risk of being infected are people visiting or working in kindergartens, patients who received a blood transfusion, people who have many sexual partners, men who have gay sex, the recipients of infected organs or bone marrow.
How is infection
Cytomegalovirus is spread from person to person through physical contact when an infected person virus is active. It can also be transmitted through the placenta and breast milk.
Cytomegalovirus - a lytic virus cytopathic effect is observed both in vitro and in vivo. Primary CMV infection is defined as an infection in seronegative patients not previously infected. In these patients, antibodies appear 4-7 weeks after infection and persist for 16-20 weeks. Primary cytomegalovirus infection occurs in the form of infectious mononucleosis syndrome, may be accompanied by pneumonia, hepatitis, myocarditis and other complications.
Most of their carriers, however, the virus does not cause clinically significant symptoms. The presence of symptoms with a high probability suggests disorders of the immune system.
Congenital cytomegalovirus infection - one of the diseases, which, along with syphilis, Rubella, toxoplasmosis and herpes virus associated with a greater risk of various defects in newborns.
Clinical signs of congenital CMV include jaundice, splenomegaly, thrombocytopenia, intrauterine growth retardation, microcephaly, and retinitis. Petechiae found in 71% of cases, jaundice - 61%, microcephaly - 53%, is too small for the size of the gestational age - 50%.
Except in patients with weakened immune systems, CMV rarely causes death. However, in infants it can cause defects that are incompatible with a healthy, full life.
Cytomegalovirus in people with normal immunity
In people with normal immunity cytomegalovirus can cause a wide range of infections. Most often these infections affect the lungs, liver, spleen, gastrointestinal tract, central nervous system, circulatory system, or multiple organs or systems simultaneously. Much less CMV infects the kidneys, adrenal glands, salivary glands, pancreas and esophagus.
In most cases, primary CMV infection is asymptomatic or causes mild flu-like symptoms.
More severe symptoms appear within 9-60 days of the initial infection. It is possible to increase the spleen and lymph nodes, so during the differential diagnosis must be deleted infections causing lymphadenopathy. Even after the lab results in the patient normalized, for some time can be saved extreme fatigue and weakness - a common consequence of cytomegalovirus infections.
CMV in people with weakened immune systems
Primary CMV infection in recipients of donor organs can have very serious consequences, because the weakened immune system of these patients, and the body more difficult to fight disease. Quite common pnevmoninya cytomegalovirus, which can lead to serious complications and even death. Transplantation of various organs associated with different levels of immune suppression, and as a result of infection with cytomegalovirus. The highest risk among those that suffered a bone marrow transplantation and lungs. Patients after bone marrow transplantation, cytomegalovirus infection, tend to develop 30-60 days after the operation.
In most cases, cytomegalovirus pneumonia cause symptoms such as shortness of breath and fever. In the differential diagnosis it should be distinguished from diseases such as Pneumocystis pneumonia, viral infections of the respiratory tract and other infections.
CMV pneumonia is difficult to treat, even with the help of modern antiviral drugs.
The mortality rate is still quite high. Particularly high risk of death from CMV pneumonia in patients after transplantation requires a respirator.
CMV infection is also quite common in people with HIV. They cytomegalovirus often affects the entire gastrointestinal tract. Sometimes cytomegalovirus causes HIV-positive patients, diseases of the central and peripheral nervous system.
The aim of drug treatment is not only a cytomegalovirus infection treatment, but also prevention of recurrence, as well as the prevention of various complications. At present, for the treatment of cytomegalovirus infections use multiple drugs; Some drugs are now in clinical trials, and soon likely to become available to a wide range of patients. The latter include, for example, maribavir, which is supposed to be used for the treatment of cytomegalovirus infection in patients undergoing a liver transplant; geksadetsiloksipropil-cidofovir, and leflunomide. Leflunomide has been successfully used for the treatment and prophylaxis of cytomegalovirus in patients after organ transplantation.
Ganciclovir is used for treating cytomegalovirus infections in immunocompromised patients. The drug can cause numerous side effects, including such as anemia, confusion, headache, weakness, nausea and vomiting, neuropathy, paresthesia, pruritus, retinal detachment, skin rash, sepsis.
Foscarnet inhibits replication gerpersvirusov. Tsitomegovirusnyh used to treat infections that are resistant to ganciclovir. Side effects of the drug may be fever, headache, amnesia, anxiety, insomnia, fatigue, alopecia, acne, skin discoloration, nausea, vomiting, diarrhea, anorexia
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, Abdominal pain, constipation, dyspepsia, gastritis, anemia, conjunctivitis.
Cidofovir is used to treat cytomegalovirus infections, including, and in people with AIDS. It may cause side effects such as hypotension, increased sweating, pallor, syncope, tachycardia
Tachycardia - the body to the limit?
, Dizziness, hallucinations, depression, drowsiness, malaise, itching, rash, hyperglycemia, dehydration, stomatitis, hematuria, urinary incontinence, rhinitis, sinusitis, allergic reactions.
Antitsitomegalovirusny immunoglobulin is usually used in the treatment of cytomegalovirus infection complications, for example, if CMV infection is associated pneumonia. It can be used (with ganciclovir) for the prevention of CMV in patients undergoing heart transplantation, lung, kidney, liver and pancreas.
Patients with CMV should be consumed as much as possible fluids to avoid dehydration. Those with weakened immune system, you should pay special attention to the power - it must be balanced, so that the body receives the necessary range of nutrients.
Because of the increased risk of contracting bacterial or fungal infection on the background of cytomegalovirus infection is recommended to do the strengthening of the immune system and / or take medications to prevent infections.
In most cases, the prognosis for patients with cytomegalovirus infection is favorable. The most severe consequences of CMV can cause in people with depressed immune systems, including those who have recently been made organ transplants. So, cytomegalovirus pneumonia in patients after bone marrow transplantation before more than 85% of the cases resulted in death. The use of ganciclovir and other drugs reduce the mortality rate to 30-60%.