Cytomegalovirus (HHV 5) (synonyms: CMV; CMV infection; cytomegalovirus; cytomegaly; inclusion body disease; salivary gland viral disease; cytomegaly; cytomegalovirus; ICD-10 B25.-: Cytomegaly) are DNA viruses that represent a subgroup of the herpes viruses (human herpes viruses, HHV). Humans currently represent the only relevant pathogen reservoir. Occurrence: Infection occurs worldwide. Infestation of the adult population is up to 50 % in Europe and about 90 % in developing countries. In 0.5-4% of pregnancies, a woman first becomes infected with cytomegalovirus shortly before or during pregnancy. The contagiousness of the pathogen is high. The disease occurs more frequently in summer. Transmission of the pathogen (route of infection) occurs mainly via body fluids such as saliva, blood or seminal fluid. Diaplacental transmission (“via the placenta“) and in the context of organ transplants or blood transfusions is also possible.Depending on the gestational age (age at pregnancy), there is a maternofetal transmission rate (transmission from mother to unborn child) of up to 70%. Human-to-human transmission: Yes
The incubation period (time from infection to onset of disease) averages 1-2 weeks (2-35 days), but cannot be more precisely determined due to the usually asymptomatic courses. The duration of the disease is usually about 8 days.
The following forms of cytomegalovirus infection may occur:
- Prenatal infection – infection of the unborn child via the mother before birth (= intrauterine infection).
- Perinatal infection – infection of the child during birth via the mother; the risk of abortion (miscarriage) and malformations is increased; most children are born healthy
- Postnatal infection – infection (after birth) in children and adults; in CMV-positive mothers, the virus is also detectable in breast milk
Symptoms – complaints
In 80% cases, infection of immunocompetent pregnant women with cytomegalovirus is asymptomatic, that is, without causing symptoms.Approximately 20% of pregnant women present with flu-like or mononucleosis-like symptoms. The disease may present with the following symptoms:
- Fever
- Lymphopathy
- Headache and pain in the limbs
- Hepatitis (rare)
- Polyneuritis (rare)
The virus persists for life, which means that once infected, the virus remains in the body for life and can lead to re-infection if the immune system weakens.
Special features during pregnancy
The disease is usually harmless to adults but can cause severe damage to an unborn child, especially in the first and second trimesters of pregnancy. In about 40% of cases of initial infection during pregnancy, the virus is transmitted to the unborn child. Possible consequences of cytomegalovirus infection are:
- Premature birth
- Retardation – reduced fetal (child) growth.
- Numbness
- Damage to the
The child can also become infected with the virus after birth, either immediately during the birth process or afterwards through breastfeeding.Signs of infection may also appear weeks or even months after birth.These include:
- Nerve deficits
- Hepatitis (jaundice)
- Pneumonia (pneumonia)
- Petechiae – bleeding into the skin, due to vascular wall damage.
- Blood clotting disorders due to thrombocytopenia (platelet deficiency).
- Hepato- and splenomegaly – abnormal enlargement of the liver and spleen.
For about 30% of infected children, the disease is fatal.Of those children who survive the infection, about 90% show late sequelae, which in turn kill 30% of children.The following sequelae or late effects occur:
- Deafness
- Damage to the eyes up to blindness
- Mental and motor damage
- Changes in the brain – seizures, paralysis.
Approximately 10% of asymptomatically infected newborns develop unilateral or bilateral sensorineural hearing loss.
Diagnostics
Blood tests can be used to determine whether the mother carries newly emerged antibodies to cytomegalovirus (CMV), that is, has developed.Laboratory parameters 1st order – obligatory laboratory tests.
- Cytomegalovirus antibodies of the IgG type.
Blood testing should be performed in early pregnancy (1st-4th month).If no antibodies are detectable, a control examination is recommended in the 20th-24th week of pregnancy. Furthermore, an ultrasound examination of the unborn child can be performed in order to determine any damage that may already have occurred to the child in the event of positive findings in the mother (= evidence of cytomegalovirus infection). Likewise, an amniocentesis (examination of amniotic fluid), umbilical cord blood or a chorionic villus sampling can be performed to determine or exclude an infection of the child.Infected children are treated with a virostatic agent (anti-viral agent) and also receive antibodies. However, it is still unclear whether this can prevent damage to the brain.Treatment in the womb is not yet possible. Vaccinations are also not currently available.
Benefits
If you already have antibodies to the disease, the risk of your child becoming infected is very low. In the case of a first-time infection, on the other hand, it can be determined early on whether the infection has also been transmitted to the unborn child.
