Cytomegalovirus infections, preventive measures

CMV infections are widespread in the general population and are associated with the risk of intermittent virus excretion. The focus is on (general) preventive measures to protect particularly vulnerable groups of people. These include, above all, seronegative pregnant women, premature babies and immunocompromised persons.

Preventive measures

The expert committee "Viral Infection and Pregnancy" of the German Association for the Control of Viral Diseases, as well as the Society for Paediatric Infectiology (DGPI) recommend preventive measures to avoid CMV infection (measures for contact persons and patients).

The expert committees point out that expectant mothers should have their CMV antibody status determined before the start of pregnancy, if possible. Note: This examination is not a routine service reimbursed by the health insurance funds and is only offered as an individual health service(IGeL).

A vaccine against CMV is currently not available. The administration of CMV hyperimmunoglobulin in pregnant women with primary infections is useful for certain indications (see below Cytomegalovirus infections).

Screening of blood products and organ donors: There is currently no mandatory testing of blood and plasma donations for CMV, as the preparations are considered safe for CMV after mandatory leukocyte filtration. For products that cannot be leukocyte-depleted (e.g. granulocyte and lymphocyte preparations), the Working Group Blood of the RKI recommends CMV testing by PCR analysis.

Contact of seronegative pregnant women with infants

For occupationally exposed seronegative pregnant women (rather rare constellation) with close contact to small children (such as medical staff and governesses), it is very important that consistent, careful hand hygiene is carried out in order to keep the probability of virus transmission as low as possible.

Since the viral infection usually does not cause any symptoms and the virus can be excreted intermittently by children via urine as well as saliva, the risk of transmission is often difficult to identify. In the opinion of the professional societies, it is not necessary to exclude CMV-exfecting children from kindergarten or school attendance. It is also not necessary to isolate these children in hospital, for example in the neonatological area, where the interruption of the most important transmission pathways through consistent basic hygiene and barrier care with general wearing of gloves and protective gowns (so-called glove and gown care) is considered an appropriate preventive measure.

Seronegative pregnant women (rather rare constellation) who have direct contact with infants should be informed about the risk of CMV infection as well as subsequent hygiene measures and follow them without fail, as they are at risk of becoming infected with CMV.

To reduce the risk of transmission, especially in contact with children, it is essential to observe the following hygiene measures:

Thorough hand hygiene should be performed after possible exposure such as diaper changes, washing, feeding, wiping tears, blowing nose, and contact with toys placed in the mouth (hand washes with soap are sufficient). For workers in health care facilities, hands should always be disinfected with an alcohol-based hand sanitizer (with limited virucidal activity).

Kissing contact with the mouth should be avoided, as saliva can transmit the virus. In addition, toothbrushes, towels, and washcloths should not be shared.

CMV is transmitted through breast milk. Breastfeeding is not a problem for mature healthy infants, as these infants process the infection regularly like other postnatally infected individuals. However, preterm infants are at higher risk for infection.

Follow-up examination after congenital CMV infection: Since sensorineural hearing damage in congenital CMV infection may become symptomatic only after years, hearing test checks are useful at certain intervals.