In human cytomegalovirus (HCMV) (synonyms: Human herpes virus 5 (HHV 5), cytomegalovirus (CMV), or cytomegalovirus/cytomegalovirus (CMV) designated; CMV infection; cytomegalovirus; cytomegaly; inclusion body disease; salivary gland virus disease; cytomegaly; cytomegalovirus; ICD-10-GM B25.-: Cytomegalovirus) is an enveloped, double-stranded DNA virus that belongs to the Herpesviridae family. Humans currently represent the only relevant reservoir of the pathogen. Occurrence: The 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 (CMV) shortly before or during pregnancy. Contagiousness (ability of the pathogen to infect or transmit) is high; however, pathogenicity (ability to cause disease) is low in immunocompetent patients. Seasonal accumulation of the disease: Cytomegaly occurs more frequently in the summer. Transmission of the pathogen (route of infection) occurs primarily through body fluids such as saliva, blood, or seminal fluid. Transmission is also possible diaplacentally (“across the placenta“) and in the context of organ transplants or blood transfusions.Depending on gestational age (age at pregnancy), the maternofetal transmission rate (transmission from mother to unborn child) was 30% in the first trimester (third trimester), increasing to 38 and 72% in the second and third trimesters. 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 determined more precisely because of 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 (risk for premature infants with birth weight < 1,500 g)
Note: CMV is the most common causative agent of congenital (congenital) infections.Primary infection usually occurs in early childhood. Frequency peak: predominantly children.
Duration of infectivity (contagiousness) is from 2-3 days before and during symptoms; virus detection in stool up to several weeks
Germany is considered a CMV low prevalence country (definition: 50-70% CMV seroprevalence) (percentage of patients tested serologically positive).The seroprevalence of pregnant women in Germany is 42%. The virus persists for life, meaning that once infected, the virus remains in the body for life and can lead to re-infection if the immune system is weakened. Immunity is type-specific. Course and prognosis: Most infections are asymptomatic, i.e. without causing symptoms, or mild. However, infection of pregnant women and immunodeficient (immunocompromised) persons occupies a special position, in whom infection can lead to severe disease and even death. Notice:
- Maternal primary infection (“initial maternal infection) is associated with transmission rates (“transmission of the pathogen”) of up to 70%. This is, regardless of the course of infection, equivalent to infection of the fetus (see below “Symptoms – complaints/Maternofetal transmission risk depending on the timing of maternal primary infection”).
- Cytomegaly is the most common intrauterine maternally acquired disease, affecting approximately 1% of all newborn infants.
- CMV is one of the most common triggers of pneumonia (CMV pneumonia) after lung transplantation (due toImmunosuppression) in addition to bacteria.
A vaccination against cytomegaly is not yet available. In Germany, the disease is not reportable under the Infection Protection Act (IfSG).
