Brief overview
- Symptoms: Predominantly asymptomatic infection; in neonates, symptoms include jaundice, retinitis, organ swelling with severe disability as a consequence; in immunocompromised individuals, severe symptoms possible
- Causes and risk factors: Infection with human cytomegalovirus HCMV (HHV-5); transmission through all body fluids; risk for pregnant women and immunocompromised individuals.
- Diagnosis: Medical history, based on symptoms, antibody detection in blood, PCR examination for virus genome
- Treatment: Usually no treatment necessary; in severe cases virus-inhibiting drugs (antivirals); administration of antibodies
- Prognosis: In more than 90 percent of cases without consequences; severe consequences possible in case of infection before birth with permanent damage; if left untreated with immune deficiency, fatal course possible
- Prevention: No vaccination possible; immunocompromised and uninfected pregnant women avoid contact with small children (among other things, occupational ban for nursery school teachers); administration of antibodies.
What is cytomegaly?
After the CMV infection has healed, these viruses remain in the body for life. This is what experts call latency or persistence. If the immune system is severely weakened by another serious illness, for example, it is possible that the viruses will reactivate from their latency. Then it is possible that they will cause a symptomatic clinical picture of cytomegaly. In the vast majority of cases, however, infection with CM virus is completely asymptomatic.
The cytomegaloviruses are distributed worldwide. There is a correlation between the level of infection and the prosperity of the population. In so-called developing countries, more than 90 percent of the population have antibodies against cytomegaloviruses. In the industrialized countries of the western world, the rate of infection in children up to the age of six is between five and 30 percent and rises from puberty with an increase in sexual contacts to up to 70 percent in adulthood.
What is cytomegaly in pregnancy?
With 0.3 to 1.2 percent of newborns affected, cytomegaly is the most common congenital viral infection. Transmission already takes place from the mother to the child via the placenta. However, this mainly occurs when the mother first becomes infected with the pathogen during pregnancy. It also occurs when a latent infection is reactivated by weakening of the immune system during pregnancy. In the case of initial infection, the risk of transmission is much higher (20 to 40 percent in the first and second trimesters, 40 to 80 percent in the third versus one to three percent in the case of reactivation).
Only one in ten children born with an already congenital cytomegalovirus infection show symptoms. However, four to six out of ten symptomatically infected children sometimes suffer serious late sequelae, including severe disabilities.
However, malformations are possible in the first two trimesters of pregnancy, and the risk of premature birth is also increased.
What are the symptoms?
The symptoms of cytomegaly vary greatly from person to person. The strength of the body’s own immune system is the decisive factor. In most cases, immunocompromised infected persons do not show any symptoms at all. In the case of a congenital cytomegalovirus infection, severe disabilities are sometimes possible as a consequence.
Thus, a distinction is made depending on the time of infection and the age of the affected person:
Congenital (connatal) cytomegalovirus symptoms.
If unborn children become infected with cytomegaly in the womb, 90 percent of them are asymptomatic at birth.
However, there is a risk, especially if infection occurs in the first two trimesters of pregnancy, of severe malformations in the fetus. This affects, for example, the cardiovascular system, the skeleton and other areas. The risk of premature birth also increases with CMV infection during pregnancy.
In ten percent of cases, symptoms appear from birth, in some cases not until weeks or months after birth. Ten to 15 percent of all connatally CMV-infected persons only show late damage such as hearing disorders later in life.
- Low birth weight
- Jaundice (icterus)
- Enlarged liver and spleen (hepatosplenomegaly)
- Coagulation disorders
- Hydrocephalus
- Retinitis (inflammation of the retina)
- Mircocephaly (skull too small)
- Hemorrhages in the brain
Later in life, children often have mental and physical disabilities such as learning disabilities or hearing problems. Visual impairments are also possible permanent consequences.
Symptoms in healthy children
In healthy children, CMV infection is usually asymptomatic. This means that there are usually no signs of illness at all.
Symptoms in healthy adults
In otherwise healthy adults, cytomegalovirus infection is asymptomatic in more than 90 percent of cases, or patients complain of uncharacteristic flu-like symptoms such as:
- Fatigue for weeks
- Swollen lymph nodes (lymphadenopathy)
- @ Mild inflammation of the liver (hepatitis)
Symptoms in immunocompromised patients
- Fever
- Muscle and joint pain
- Severe pneumonia (lung infection)
- Liver inflammation (hepatitis)
- Biliary tract inflammation (cholangitis)
- Brain inflammation (encephalitis)
- Retinitis (inflammation of the retina)
- Colitis (inflammation of the large intestine)
- Kidney inflammation (especially after transplantation)
Causes and risk factors
The cytomegalovirus (CMV) is the cause of cytomegalovirus. It is a pathogen consisting exclusively of an envelope with a capsule and genetic material contained therein. If the virus enters the body through smear infections, sexual contact, blood products or the respiratory tract, it penetrates individual cells and multiplies in them. In the process, these cells are damaged and develop into giant cells. This gave rise to the name of the disease: the Greek word “cytos” means “cell”, and “megalo” stands for “large”.
The cytomegalovirus attacks almost all organs, preferentially the salivary glands. The location in the body where the viruses remain for life has not yet been conclusively determined. It is likely that some of them survive in blood-forming stem cells.
Since the virus usually remains in the body of infected persons for the rest of their lives, it is in principle possible for viruses to be excreted and thus transmitted at any time. The exact mechanisms of viral latency have not yet been conclusively clarified.
Risk factors for cytomegaly
Pregnancy is a special risk situation: When a woman is infected with the cytomegalovirus for the first time during pregnancy, the unborn child becomes infected in 40 percent of cases. It is true that 90 percent of affected children are asymptomatic at birth. However, ten to 15 percent of these children develop late complications such as hearing disorders in the course of their lives. The remaining ten percent of children born with cytomegaly show half unspecific, mild symptoms at birth, the other half severe signs of the disease.
Examinations and diagnosis
To make the diagnosis of cytomegaly, your doctor will ask you in detail about your medical history (anamnesis). For example, he or she will ask you the following questions:
- How long have you felt ill?
- Are you pregnant?
- Do you have an underlying disease, such as cancer or AIDS?
- Do you breathe well?
- Do you feel pressure in your upper abdomen?
During the physical exam that follows, the doctor will listen to your lungs and palpate the lymph nodes in your neck and your abdomen. In addition, the back of your eye will be mirrored (fundoscopy/ophthalmoscopy) to detect any retinitis.
Sample examination
In addition, the doctor will take a sample of your body fluid, which will be examined for the cytomegaloviruses in the laboratory. Blood, urine, bronchial fluid, amniotic fluid or umbilical cord blood are suitable for this. The blood is examined to determine whether it contains the genetic material or surface proteins of the cytomegaloviruses or antibodies against them. The viral genetic material is detected by PCR (polymerase chain reaction) in the laboratory.
Hearing tests in children
Children who have contracted cytomegalovirus during pregnancy ideally undergo hearing tests at regular intervals, as hearing disorders can sometimes be diagnosed late.
Examinations during pregnancy
In pregnant women who have not yet had a CMV infection (i.e., are seronegative), it is possible to test the blood for antibodies regularly during pregnancy. However, this is usually an additional service that is not covered by statutory health insurance.
Possible malformations in the fetus as a result of CMV infection during pregnancy can be detected during standard ultrasound examinations.
Treatment
How cytomegalovirus is treated depends primarily on the strength of the immune system and the severity of symptoms. Healthy adults with a well-functioning immune system and, accordingly, usually only uncharacteristic signs of illness such as fatigue are usually not given any medication.
Patients with a weakened immune system are given virustatics and hyperimmunoglobulins.
Virustatics
Cytomegaly is treated with the viral drug ganciclovir. It has strong side effects because it has a toxic effect on the kidneys and bone marrow. Depending on how well ganciclovir responds, other viral drugs are used as alternatives. These include valganciclovir, which is the preferred treatment for retinitis, cidofovir, foscarnet, and fomivirsen. Often, physicians combine different antivirals to prevent resistance.
Pregnant women and nursing mothers are usually not treated with these drugs. Newborns who have cytomegaly are treated only in special facilities that have experience with the disease.
Hyperimmunoglobulins
A hyperimmunoglobulin consists of antibodies (bioengineered) that are effective against a specific pathogen. In the case of cytomegaly, CMV hyperimmunoglobulin sera are used. These are used both in immunocompromised patients and in pregnant women suspected of having contracted CMV for the first time.
Course of the disease and prognosis
The time between infection and the outbreak of cytomegaly (incubation period) is about four to eight weeks. Cytomegaloviruses remain in the body for life after the disease has been overcome. Therefore, especially if the immune system is weakened, the disease may break out again and again.
Patients with an intact immune system have a good prognosis, and cytomegaly usually heals without consequences. In all other patients, the outcome of the disease depends on the type and severity of symptoms that occur.
For example, cytomegaly in newborns often heals without sequelae, but in some cases leads to blindness, hearing impairment, or mental retardation. In immunocompromised patients, generalized infection (i.e., infection of many different organ systems) may be fatal. Pneumonia in the context of cytomegalovirus infection is particularly dangerous: it ends in death in about half of the cases.
Prevention
Course of the disease and prognosis
The time between infection and the outbreak of cytomegaly (incubation period) is about four to eight weeks. Cytomegaloviruses remain in the body for life after the disease has been overcome. Therefore, especially if the immune system is weakened, the disease may break out again and again.
Patients with an intact immune system have a good prognosis, and cytomegaly usually heals without consequences. In all other patients, the outcome of the disease depends on the type and severity of symptoms that occur.
For example, cytomegaly in newborns often heals without sequelae, but in some cases leads to blindness, hearing impairment, or mental retardation. In immunocompromised patients, generalized infection (i.e., infection of many different organ systems) may be fatal. Pneumonia in the context of cytomegalovirus infection is particularly dangerous: it ends in death in about half of the cases.
Prevention
Pregnant women who have not previously contracted cytomegalovirus are advised to maintain strict hand hygiene when in contact with young children. Children excrete cytomegaloviruses in their urine or saliva, often without showing signs of illness. Washing hands with soap or alcohol-based hand disinfection can minimize the risk of infection. In addition, doctors give the following tips to seronegative pregnant mothers of infected infants:
- Do not kiss your children on the mouth.
- Don’t use the same silverware or dishes as your children.
- Do not use the same towels or washcloths.
- Disinfect your hands after wiping your child’s nose or touching toys they have previously had in their mouths.
Taking these steps will reduce the risk of contracting cytomegalovirus for pregnant women.
