The cytomegalovirus (CMV) is widespread worldwide. Many people become infected unnoticed in the course of their lives. But once acquired, the pathogen remains in the body and can become a danger: in the case of immune deficiency for the affected person, in pregnancy for the unborn child. CMV belongs to the large group of herpes viruses that can cause not only the well-known cold sores, but also chickenpox, shingles and Pfeiffer glandular fever.
Virus remains in the body for life
What they all have in common is that they remain in the body for life, usually without becoming noticeable. Only when the immune system is weakened do they come back to life. This can be caused by stress and fever (for example, in the case of cold sores), but also serious infections, cancer or organ transplants. Then the viruses are particularly dangerous because they can trigger serious diseases.
Distribution of cytomegaloviruses.
It is estimated that 50 to 80 percent of adults are infected with the virus. This means that the risk of becoming infected is almost impossible to banish. This is all the more true because most people do not know they carry CMV, as the initial infection usually goes unnoticed or manifests itself only in mild flu-like symptoms. The pathogens are found in body fluids such as saliva, blood, urine, semen or the mucus of the cervix – their transmission occurs through the skin and mucous membranes as a result of smear or droplet infection. The unborn child can become infected via the placenta, and the infant via breast milk during breastfeeding. The latter is problematic in premature infants because the virus may still cause brain damage in them.
Symptoms of cytomegaly
In most cases, the initial infection is unproblematic with no or few symptoms. However, if immunocompromised individuals become infected or if reactivation of the already lurking virus occurs in them, life-threatening clinical pictures may occur. Therefore, in case of suspicion, a blood test must be performed to detect the virus at an early stage and to initiate therapy. If this is not done, the first symptoms after a few days are fatigue, fever, muscle and joint pain similar to flu. In the further course, various organ systems can be affected by the virus – typical are, for example, inflammations of the lungs, the heart muscle, the kidneys, the liver, the brain and the retina (retinitis). The bone marrow can also be affected, which can lead to disturbances in blood cell production and thus to a further weakening of the immune defenses and increased risk of infection, for example by fungi. In about one-third of cases in which women first become infected with CMV during pregnancy, the virus is transmitted to the unborn child. Symptoms vary from liver and spleen enlargement to life-threatening illness. Complications may include hearing and vision loss and mental developmental disorders. If pregnant women were previously infected, the rate of transmission of infection to the child is only one percent, with usually no symptoms or disorders to worry about.
Diagnosis of cytomegaly
CMV infection is detected by various blood tests. On the one hand, the virus can be directly detected quantitatively. This involves determining how high the “viral load” is, that is, how many viruses are in the body. This procedure is important for checking whether a drug is effective. On the other hand, the infection can be detected indirectly by the presence of certain antibodies. The latter also indicate whether the infection is acute or has been present for some time.
Prevention and therapy of cytomegaly.
Patients with weakened immune systems must be protected from CMV infection or reactivation. Affected individuals include:
- HIV-infected
- Cancer patients especially under chemotherapy
- Transplant recipients. CMV infection is one of the most common complications of transplantation, specifically retinitis a common complication in HIV patients.
For efficient prophylaxis, it is first assessed how high the individual risk is and the treatment or controls are adjusted accordingly. If it is high, the affected receive a virus-inhibiting agent (virustatikum) before the virus can multiply in the blood at all.If it is lower, they are regularly monitored by means of blood tests and – in the case of viral replication – therapeutic measures are initiated if necessary before symptoms appear. Depending on the case, the drugs are available in the form of infusions or as tablets or capsules.
