title: Absence of novel human parvovirus (PARV4) in Danish mothers and children.
abstract: BACKGROUND
  The recently discovered human parvovirus 4 (PARV4) is found most frequently in injection drug users, HIV-positive patients, and in haemophiliacs. Studies from Ghana report the finding of PARV4 in plasma from 2 to 12% of children without acute infection, and in nasal secretions and faecal samples. Studies of PARV4 in children from industrialized countries are few.
  
  
  OBJECTIVE
  We aimed to describe the occurrence of PARV4 in a population-based birth cohort of 228 Danish mothers and their healthy children who previously participated in a study of respiratory tract infections in infancy.
  
  
  METHODS
  Children were included over a whole calendar year and were monitored through monthly home visits through the first year of life. Plasma samples for the present study were available from 228 mothers, 176 newborns, and 202 12-months-old children. All samples were analysed for the presence of PARV4 antibodies by enzyme immunoassay, and samples with detectable antibodies were in addition studied by real-time PCR.
  
  
  RESULTS
  One (0.4%) of 228 mothers had PARV4 IgG exceeding the cut-off absorbance level and another had borderline IgG reactivity. No mother among these two had an acute infection, as they were IgM and PARV4 DNA negative. All blood samples from newborns and one-year-old children had IgG and IgM reactivity below cut-off.
  
  
  CONCLUSIONS
  PARV4 is rare in Danish mothers and infants. Further studies are needed, in both rural and urban settings, to investigate the epidemiology and clinical significance of this novel human parvovirus.
authors.affiliation: Department of Paediatrics, Hvidovre University Hospital, Copenhagen, Denmark. Electronic address: linstow@dadlnet.dk.
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: von Linstow
authors.affiliation: Department of Paediatrics, Hvidovre University Hospital, Copenhagen, Denmark.
authors.forename: Vibeke
authors.initials: V
authors.lastname: Rosenfeldt
authors.affiliation: Department of Virology, Statens Serum Institut, Copenhagen, Denmark. Electronic address: eor@ssi.dk.
authors.forename: Ellinor
authors.initials: E
authors.lastname: Lindberg
authors.affiliation: Department of Virology, Statens Serum Institut, Copenhagen, Denmark. Electronic address: lise@dadlnet.dk.
authors.forename: Lise
authors.initials: L
authors.lastname: Jensen
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland; Helsinki University Hospital, Helsinki, Finland. Electronic address: Lea.hedman@helsinki.fi.
authors.forename: Lea
authors.initials: L
authors.lastname: Hedman
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland. Electronic address: xuemengli2005@gmail.com.
authors.forename: Xuemeng
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland. Electronic address: elina.vaisanen@helsinki.fi.
authors.forename: Elina
authors.initials: E
authors.lastname: Väisänen
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland; Helsinki University Hospital, Helsinki, Finland. Electronic address: Klaus.hedman@helsinki.fi.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hedman
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland. Electronic address: norjap@gmail.com.
authors.forename: Päivi
authors.initials: P
authors.lastname: Norja
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D009035:Mothers; D010322:Parvoviridae Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D017992:Parvovirus / Q000276:immunology*; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D060888:Real-Time Polymerase Chain Reaction; D016036:Seroepidemiologic Studies
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Children; Denmark; Infants; PARV4 antibodies; Parvovirus