title: Genotype distribution, viral load and clinical characteristics of infants with postnatal or congenital cytomegalovirus infection.
abstract: BACKGROUND
  Congenital cytomegalovirus infection is a leading cause of long-term sequelae. Cytomegalovirus is also frequently transmitted to preterm infants postnatally, but these infections are mostly asymptomatic. A correlation between cytomegalovirus genotypes and clinical manifestations has been reported previously in infants with congenital infection, but not in preterm infants with postnatal infection.
  
  
  OBJECTIVE
  The main objective of this study was to investigate cytomegalovirus genotype distribution in postnatal and congenital cytomegalovirus infection and its association with disease severity.
  
  
  METHODS
  Infants admitted to the neonatal intensive care unit of the University Medical Center Utrecht, The Netherlands between 2003-2010 and diagnosed with postnatal or congenital cytomegalovirus infection were included. Classification of cytomegalovirus isolates in genotypes was performed upon amplification and sequencing of the cytomegalovirus UL55 (gB) and UL144 genes. Clinical data, cerebral abnormalities, neurodevelopmental outcome and viral load were studied in relation to genotype distribution.
  
  
  RESULTS
  Genotyping results were obtained from 58 preterm infants with postnatal cytomegalovirus infection and 13 infants with congenital cytomegalovirus infection. Postnatal disease was mild in all preterm infants and all had favourable outcome. Infants with congenital infection were significantly more severely affected than infants with postnatal infection. Seventy-seven percent of these infants were symptomatic at birth, 2/13 died and 3/13 developed long-term sequelae (median follow-up 6 (range 2-8) years). The distribution of cytomegalovirus genotypes was comparable for postnatal and congenital infection. UL55 genotype 1 and UL144 genotype 3 were predominant genotypes in both groups.
  
  
  CONCLUSIONS
  Distribution of UL55 and UL144 genotypes was similar in asymptomatic postnatal and severe congenital CMV infection suggesting that other factors rather than cytomegalovirus UL55 and UL144 genotype are responsible for the development of severe disease.
authors.affiliation: Department of Neonatology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Joppe
authors.initials: J
authors.lastname: Nijman
authors.affiliation: Department of Virology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Femke S
authors.initials: FS
authors.lastname: Mandemaker
authors.affiliation: Department of Neonatology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Malgorzata A
authors.initials: MA
authors.lastname: Verboon-Maciolek
authors.affiliation: Department of Virology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Aitken
authors.affiliation: Department of Virology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Anton M
authors.initials: AM
authors.lastname: van Loon
authors.affiliation: Department of Neonatology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Linda S
authors.initials: LS
authors.lastname: de Vries
authors.affiliation: Department of Virology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Schuurman
mesh_terms: D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000473:pathology* / Q000821:virology; D003587:Cytomegalovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000151:congenital / Q000401:mortality / Q000473:pathology* / Q000821:virology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008137:Longitudinal Studies; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D009426:Netherlands; D012720:Severity of Illness Index; D016019:Survival Analysis; D014759:Viral Envelope Proteins; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics
chemical_list: D008562:Membrane Glycoproteins; C119624:UL144 ORF protein, Human herpesvirus 5; C546870:UL55 protein, human cytomegalovirus; D014759:Viral Envelope Proteins; D014764:Viral Proteins