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Key messages

  • Cytomegalovirus (CMV) is the leading cause of congenital infections with a birth prevalence of 0.64-0.7% 
  • CMV is a ubiquitous herpes virus that usually causes only mild disease.
  • Congenital infection can occur during pregnancy or the peripartum period.
  • The timing of infection is important regarding the severity of neonatal illness.

Cytomegalovirus (CMV) is a ubiquitous herpes virus that usually causes only mild disease.

CMV is a congenital infection that can occur during pregnancy or the peripartum period. It is one of a number of organisms that can cause congenital neonatal illness.

CMV is commonly acquired in infancy and childhood through 'saliva sharing', particularly in less developed countries where more than 90 per cent are infected in childhood compared with around 60 per cent in Western countries.

Incidence

The incidence of congenital CMV infection in Australia is estimated at 3.8/100,000 live births.

Clinical features

Clinical features of CMV include the following:

  • Congenital CMV can develop from maternal primary infection or re-activation, with primary infection more likely to result in sequelae.
  • Risk for sequelae is highest after fetal infection during the first trimester.
  • Of the 1 per cent of non-immune women who develop primary CMV in pregnancy, approximately 50 per cent of their fetuses become infected.
  • In women with prior CMV infection, re-activation can occur in pregnancy, with 5 per cent of babies developing infection in utero.
  • Perinatal and postnatal infection can occur through birth canal secretions and breast milk or blood. If affected the clinical syndrome is usually mild and self-limiting.
  • Severe infection can result from transfusion-acquired disease.
  • Use of CMV negative donor blood or deglycerolised frozen blood transfused through a leucocyte filter prevents this transmission.

Effects on babies

The effects on symptomatic babies vary and may include:

  • growth restriction
  • jaundice
  • haemotological problems 
  • thrombocytopenia and purpura (common)
  • anaemia, neutropenia, lymphocytosis (occasional)
  • hepatosplenomegaly
  • lymphandenopathy
  • neurological problems
  • poor tone and poor suck 
  • seizures
  • microcephaly
  • chorio-retinitis
  • cerebral calcification (classically periventricular)
  • deafness (can be a late manifestation and is the most common cause of sensori-neural hearing loss)
  • pneumonitis
  • colitis
  • hepatitis
  • dental defects.

Investigations

A high index of suspicion and investigation is warranted in:

  • babies whose mothers have developed primary infection in pregnancy or have ‘reactivated’
  • growth-restricted infants with low platelet count.

Tests

Tests performed include:

  • IgM assayed from cord/baby blood (these tests have poor sensitivity)
  • urine culture for CMV (the test of choice)
  • throat/saliva swab and NPA sent for PCR (can give a more rapid answer)
  • cerebral ultrasound (hydrocephalus, intracranial calcification although this-insensitive)
  • MRI (intracranial calcification, ventriculomegaly, cerebral atrophy, migrational abnormalities)
  • serial audiology and developmental assessment - 6 monthly until 2 years then annually
  • culture and PCR (should be performed as soon as possible in the first two weeks of life as CMV detected after this time can indicate peri/postnatal infection).

Management

Attention to ‘general’ measures include management of:

  • nutrition
  • haemotological disturbances (low platelets) - FBE & LFT's
  • respiratory disease.

Treatment options: Seek expert advice.

  • A RCT studying IV Ganciclovir started in the neonatal period for 6 weeks in congenitally infected infants with CNS involvement showed normal, stable or improved hearing in treated children at 6 &12 months. Long term outcomes are not available.
  • Valganciclovir at 16 mg/kg/dose, bd is an acceptable alternative.

Long-term follow-up

Long-term follow-up is essential with attention to:

  • management of neurological sequelae
  • serial audiology and developmental assessment - 6 monthly until 2 years then annually
  • opthalmology review annually for first 2 years then close review till 6 years.

Prevention

Two groups require consideration:

  1. Hospitalised newborn infants:
    • Prevention of transfusion-acquired infection is achieved by use of leucocyte filters or CMV-negative blood.
    • Standard precautions and aseptic measures (particularly hand-washing, especially after nappy changing) is important to prevent nosocomial spread of infection.
  2. Potentially 'at-risk' pregnant women:
    • Congenitally infected babies are high CMV shedders for the first years of life. 
    • Testing for viral shedding will not guarantee a baby is not shedding virus at other times.
    • Seronegative staff members have a low risk (around 1-5 per cent) of developing a primary infection.

Attention to prevention of CMV through use of standard precautions is important. Pregnant SCN staff should be aware that SCN babies may be shedding CMV.

It is difficult to advise parents of babies with documented CMV infection as to what to tell friends and family.

Reassurance and explanation about prevention of spread through scrupulous attention to hand-washing after performing baby care is paramount.

More information

Further reading

  • Palasanthiran, P. (et al). 'Management of Perinatal Infections'. Australian Society for Infectious Diseases. 2014
  • Isaacs D, Moxon ER. ‘Handbook of Neonatal Infections - a practical guide’. WB Saunders, London. 1999.
  • Remington JS, Klein JO. ‘Infectious Diseases of the Fetus and Newborn Infant’ 5th edn. WB Saunders, Philadelphia. 2000.
  • Davies EG, Elliman DAC, et al. ‘Manual of Childhood Infections’. WB Saunders, London, 1996.
  • Jeffries DG, Hudson CN. ‘Viral infections in Obstetrics and Gynaecology’. Arnold, London, 1999.

Get in touch

Centre of Clinical Excellence - Women and Children
Safer Care Victoria

Version history

First published: September 2016

Last web update: October 2018

Review by: September 2019

Uncontrolled when downloaded

 

Page last updated: 12 Nov 2020

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