CMV is the most common congenital infection, and the most common viral cause of mental retardation, but also the main non-genetic cause of neuro-sensitive deafness.
In the US, about 30-50% of women are not infected with CMV, and 1-4 of 100 women who have not been infected with CMV do primoinfection during pregnancy. The risk of fetal transmission is 30-40%.
Centers for Disease Control and. Prevention. Cytomegalovirus (CMV) and congenital CMV infection. Http://www.cdc.gov/cmv/transmission.html.
The Primoinfection is accompanied by repeated viral infections, CMV being able to pass transplacentaly.
If primoinfection occurs before the woman becomes pregnant, the risk of transmitting cytomegalovirus to the fetus is 1%.
In developed countries, the congenital CMV infection has an incidence of 0.3-2.4 cases at 100 births.
Of Pregnant women with confirmed CMV infection, only 10-20% of foetuses will have clinical manifestations at birth.
Mothers who are seropositive before pregnancy may transmit the CMV to the fetus during the reactivation of the existing virus in latent form in the body (especially in the salivary glands) or reinfection with a new strain. The infections transmitted thus are usually asymptomatic and less severe, both for the mother and expecially for the fetus, causing sequelae in the case of 0.2 to 2% of children.
Boppana SB, Rivera LB, Fowler KB, Mach M, Britt WJ. Intrauterine transmission of cytomegalovirus to infants of women with preconceptional immunity. N Engl J Med. 2001; 344 (18): 1366-71.
The age of pregnancy at the time of Primoinfection has an important effect on intrauterine transmission and on symptoms at birth.
Riscul transmiterii intrauterine a infecției CMV și simptomatologia la naștere
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* The study was conducted on a number of 248 pregnant women infected with CMV and untreated.
Enders G, Daiminger A, Bader U, Exler S, Enders M. Intrauterine transmission and clinical outcome of 248 pregnancies with primary cytomegalovirus infection in relation with gestational age. J Clin Virol. 2011; 52 (3): 244-6.
Although the risk of CMV transmission to the fetus is high in the third quarter, newborns are asymptomatic both at birth and later.
Overall, 80-90% of CMV-infected newborns are asymptomatic at birth.
Of those asymptomatic, 10-15% will exhibit developmental disorders, especially deafness. Correlating with the age of pregnancy at which primoinfection occurred, neurological sequelae will be developed in 30% of newborn from mothers infected in the first trimester, and in 15% of newborn from mothers infected later during pregnancy.
Pass RF, Fowler KB, Boppana SB, Britt WJ, stagnate S. Congenital cytomegalovirus infection Following first trimester maternal infection: Symptoms at birth and income. J Clin Vriol. 2006; 35 (2): 216-29.
Symptomatic CMV infection occurs in 50% of cases with isolated splenomegaly, jaundice and/or petechiae, and the remaining 50% of cases occur with the classic “Newborn Cytomegalic Incidence Disease” including plurivisceral and neurological signs and symptoms.
W, Britt, Remington JS, Klein JO, Wilson CB, et al. Cytomegalovirus. In: Infectious Diseases of the Fetus and Newborn Infant, 7th ed. Elsevier Saunders, 2011. P. 706.
Tipurile de manifestări din infecția CMV simptomatică la naștere
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The prognosis is poor for symptomatic newborn babies: mortality is approximately 30%, and 80% of survivors manifest sequelae: deafness, ocular impairment, intellectual disabilities, retardation in psychomotor development.
Neuro-sensitive deafness is detected in over 60% of newborns with symptomatic congenital CMV infection, being progressively up total.
Children with symptomatic congenital CMV infection should be monitored periodically by conducting screening tests for hearing, vision and psychomotor development.
The transmission of the infection during childbirth is very rare and is either asymptomatic or manifested with a syndrome similar to infectious mononucleosis.
Clinical studies:
In Japan, in a batch of pregnant women CMV seropositive at a rate of 95.7%, the risk of congenital infection with CMV was 2.1% in preterm newborns (6/289) and 1.8% (3/165) in full-term newborns.
(Yamamoto AY, Mussi-Pinhata MM, Pinto PC, et al. Congenital cytomegalovirus infection in preterm and full-term newborn infants from a population with a high seroprevalence rate. The Pediatric Infectious Disease journal. 2001 Feb 1; 20 (2): 188-92).
A recent study has tested premature newborns for CMV. Of 1200 tested newborns, 37 (3.08%) were positive for CMV. In the case of 346 of them the collection was carried out over 2 or more weeks after birth. In the case of newborns in which the collection was achieved up to 2 weeks, 2 cases (0.3%) of CMV infection were identified.
(Pitlick MM, Orr K, Momany AM, et al. Determining the prevalence of cytomegalovirus infection in a cohort of preterm infants. Journal of neonatal-perinatal medicine. 2015 Jul 31; 8 ( 2): 137-41).
A risk of congenital CMV infection of 4.1% in newborns was described in another study in which, in the tested pregnant women group, 83.5% were positive for cytomegalovirus and 82.9% for herpes simplex.
No case of congenital infection with herpes simplex has been detected (Festary A, Kourí V, Correa CB, et al. Cytomegalovirus and herpes simplex infections in mothers and newborns in a Havana maternity hospital. MEDICC Review. 2015 Mar; 17 (1): 29-34.).
About Corneliu Zaharia
