Cytomegalovirus (CMV)

Cytomegalovirus (CMV)
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In this article

What is Cytomegalovirus?

Il cytomegalovirus is a very widespread virus belonging to the family of herpesvirus which infects humans, especially school-age children. Once contracted, this virus disappears in the body For all life, but in many cases it remains dormant. However, a weakening of the immune system could reactivate the agent, causing symptoms light (fever, fatigue, etc.) or, in severe cases, infections which affect organs such as eyes or lungs.

When a person contracts the virus for the first time, it is calledprimary infection, when instead the subject undergoes a reactivation (with consequent new infection) of the virus we speak ofnon-primary infection.

In most cases, however, the immune defenses keep the cytomegalovirus at bay. It is estimated that 40 to 80% of the population in industrialized countries and almost all of the population in developing countries come into contact with this virus, often without any obvious consequences. In Del Paese 70-80% of the population is positive for anti-Cytomegalovirus antibodies (source: National Institute of Health).

Read also: Dictionary of pregnancy

How it is transmitted

Transmission of infection can be asymptomatic or similar to one flu syndrome and occurs through contact with body fluids such as blood, urine, saliva, seminal fluid, vaginal secretions and breast milk.

The woman who contracts Cytomegalovirus infection during pregnancy can pass it on to the fetus via the placenta: the risk to the health of the unborn child is higher the earlier the gestational period in which the passage occurs but, in 90% of cases, the disease does not produce any consequences. In one case out of 10, however, they occur damage to the nervous system, developmental delay e prematurity.

The test of greed

Among the first trimester tests, it is possible to search in the maternal blood for antibodies directed against the virus that are indicative of an infection before or acquired during pregnancy. In particular, the exams look for two types of immunoglobulin:

  • le IgM (which indicate if the disease is ongoing)
  • and IgG they are (they tell us the disease has been contracted in the past and antibodies have been developed).
Read also: Cytomegalovirus in pregnancy


Usually the subjects contract the cytomegalovirus during the childhood or the adolescent phase and the great majority he does not feel any symptoms. In the low percentage of cases in which it is felt fever, enlarged lymph nodes o malaise generic then, very often we end up confusing the infection for diseases with similar symptoms (eg: mononucleosis).

The question concerning individuals is different immunosuppressed, in which the virus could trigger a more violent reaction that can affect all organs and cause pneumonia, encephalitis e retiniti with impaired vision.

Cytomegalovirus in pregnancy

Women who first contract cytomegalovirus during pregnancy run the risk of passing it to the fetus through breastfeeding or childbirth. In these cases we speak ofcongenital infection.

In Del Paese, the incidence of similar situations varies between 0,57% and 1% and within this series, it is estimated that the risk of transmission to the fetus for primary infection can vary between 30% and 40% in first and second trimester and between 40% and 70% during the third quarter. However, even in the presence of a congenital infection, it is not automatic that the fetus will develop consequences. However, the few cases that encounter complications may be very dangerous.

In fact, the greatest risk of symptoms and consequences concerns primary infections, especially if manifested during the first trimester of pregnancy. In this case, a cytomegalovirus infection can also cause a premature birth or even a miscarriage.

85-90% of infants with congenital infection are however asymptomatic and about 10% of these will have late repercussions, often including a sensorineural hearing defect which can be more or less severe. On the other hand, 10-15% could develop full-blown symptoms at the time of birth. Such symptoms which can be transient or permanent:

  • Transients: hepatosplenomegaly, pneumonia, jaundice, petechiae, convulsions, birth with an underweight baby.
  • Permanent: Sensorineural deafness, visual impairment, mental retardation, psychomotor retardation, microcephaly, movement coordination deficit, epilepsy. Permanent disabilities are more likely to occur when symptoms appear at birth.


There is currently no therapy that can prevent infection - albeit a Vaccine is in development - so the only thing to do is to adopt some precautions how to avoid contact with too many children during pregnancy, maintain scrupulous personal hygiene, do not share cutlery with the baby and never put his pacifier in his mouth.


Questions and answers

How long do cytomegalovirus symptoms last?

Most cases have no symptoms, but when they do, they can last 5-10 days (even longer in childhood).

What are the symptoms of cytomegalovirus?

Fever, malaise, body aches, swollen lymph nodes. In severe cases, serious organ infections may arise (e.g. pneumonia, retinal infections ...)

How is cytomegalovirus transmitted in pregnancy? 

During childbirth, breastfeeding or following organ transplants.

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