Cytomegalovirus – Infection, Transmission & Diseases


The cytomegalovirus is a herpesvirus and mostly affects humans. The transfer from person to person takes place via a smear and droplet infection as well as parenterally. A healthy person has no symptoms. The body is infected for life.

What is cytomegalovirus?

Cytomegalovirus is a common virus that can infect almost anyone. About 80 percent of 30-year-olds in industrialized countries are carriers of this virus. It has double-stranded DNA and multiplies very slowly. Most infected people are asymptomatic and unaware of the virus.

Only pregnant and immunocompromised people have a reason to worry. Since this virus is a herpes virus, the body retains this virus for life. It only becomes noticeable when the immune system is weakened by illness . Its host spectrum is limited to humans. It spreads through bodily fluids such as saliva, urine, semen and blood.

If the patient is pregnant and develops an active infection, she can transmit the virus to the fetus via the placenta . The infected human cells enlarge microscopically and are called owl’s eye cells. There are no curative drugs for cytomegalovirus, only for the weakened immune system.

Meaning & Function

Structurally, the cytomegalovirus does not differ from other herpesviruses. In principle, it can affect all organs, but mainly the ductal epithelial cells of the salivary glands . The cells of the mammary glands, lungs and kidneys follow . The infected cells are magnified under the microscope. 

The cytoplasm contains protein aggregates. These are deposits of viral proteins that are produced in excess. Since the affected cells look like owls’ eyes, they are called owls’ eyes cells. Herpesviruses persist for a lifetime in the host’s body and are highly associated with the cells. In most cases, the host remains asymptomatic even during the initial infection, but sheds the virus for a year. Existing or newly developed diseases that weaken the immune system can lead to serious illnesses.

Upon reactivation, the virus spreads to bodily secretions such as urine, saliva , breast milk , semen , and the cervical fluid of the vagina. The mononuclear cells, i.e. all cells with a cell nucleus, carry the latent virus genome. The early gene viral RNA transcriptases can be detected in these cells. The progenitor cells in the bone marrow of the myeloid cells may be the primary site of latency.

Once their progeny have been activated to differentiate into tissue macrophages, the virus can enter the replication cycle. This leads to the activation and multiplication of the virus. If the virus is present in body fluids, it can be transmitted through close contact. Sexual intercourse , breastfeeding , blood transfusions or organ transplants are possible transmission routes. CMV infection is one of the most common infections after kidney transplantation. The cytomegalovirus can cross the placenta and infect the unborn child.

Dangers, disorders, risks & diseases

CMV is a worldwide and widespread virus that can infect almost anyone. In most cases, healthy children and adults have no symptoms. In rare cases, otherwise immune-strong and healthy people become very ill. 

These can develop mononucleosis. Symptoms of these include a sore throat , swollen glands and tonsils , fatigue and nausea . Other typical symptoms are fever , unclear elevated liver values ​​and possibly pneumonia . Intestinal complications such as diarrhea , fever and abdominal pain can also occur. A variety of neurological complications resulting from this viral infection in the nervous system have been observed.

This can be inflammation of the brain . The virus can cross the placenta and cause serious illness. Hepatomegaly and jaundice may occur. A general disability is not uncommon. In the worst case, newborns with CMV infection can suffer hearing loss or eye malformations. The latter can develop into central vision loss, scarring of the retina, inflammation of the light-sensitive layer of the eye, or swelling.

Intellectual disability , lack of coordination, seizures , and even death can also occur . In the case of already existing immunodeficiency diseases, such as HIV , the symptoms are serious. The complications are much stronger and last longer. High fever, pneumonia , encephalitis , retinitis , esophagitis , pancreatitis , and hepatitis are possible. Encephalitis is often fatal. Also for leukemia patients, tumor patients who are treated with cytostaticsare treated and transplanted, the CMV can have devastating consequences. Blindness, transplant rejection, and colitis can be potential complications.

The cytomegalovirus cannot be removed with medication, only the symptoms can be alleviated. It persists in the body. The virus is not always in the active form. Only in the active form is it present in body fluids and highly contagious.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.