title: Seroepidemiology of human bocaviruses 1-4.
abstract: BACKGROUND
  Recently, 3 new members of the genus Bocavirus, human bocavirus 2 (HBoV2), human bocavirus 3 (HBoV3), and human bocavirus 4 (HBoV4), were discovered. HBoV2-4 occur mainly in the gastrointestinal tract but rarely in the respiratory tract, contrary to human bocavirus 1 (HBoV1).
  
  
  METHODS
  To investigate HBoV1-4 seroepidemiology among 195 adults and 252 wheezing children, we conducted immunoglobulin G (IgG) and immunoglobulin M (IgM) enzyme immunoassays with recombinant viruslike particles (VLPs). The children's sera were also tested for HBoV1-4 DNA by quantitative polymerase chain reaction (qPCR).
  
  
  RESULTS
  Both rabbit and human antibodies to HBoV1-4 VP2 VLPs were found to be cross-reactive. After depletion of HBoV1-reactive antibodies, the HBoV2-4 approximate seroprevalences in adults were 34%, 15%, and 2% and in children aged 1-2 years 25%, 10%, and 5%, respectively. After depletion of HBoV2-4-reactive antibodies, the HBoV1 seroprevalence among adults decreased from 96% to 59%. No cross-reactivity of human anti-HBoV IgG was observed with bovine parvovirus1, parvovirus B19 or PARV4. No child was HBoV2-4 viremic.
  
  
  CONCLUSIONS
  HBoV2-4 infect humans less commonly and elicit weaker B-cell responses than HBoV1. In our study HBoV2-4 did not seem to have a major etiological role in wheezing. Cross-reactivity with HBoV2-4 IgG partially accounts for the high HBoV1 seroprevalences previously reported. Correction for cross-reactivity is a prerequisite for VLP-based HBoV seroepidemiology.
authors.affiliation: Department of Virology, University of Helsinki, Finland. kalle.kantola@helsinki.fi
authors.forename: Kalle
authors.initials: K
authors.lastname: Kantola
authors.forename: Lea
authors.initials: L
authors.lastname: Hedman
authors.forename: Jane
authors.initials: J
authors.lastname: Arthur
authors.forename: Abdiwahab
authors.initials: A
authors.lastname: Alibeto
authors.forename: Eric
authors.initials: E
authors.lastname: Delwart
authors.forename: Tuomas
authors.initials: T
authors.lastname: Jartti
authors.forename: Olli
authors.initials: O
authors.lastname: Ruuskanen
authors.forename: Klaus
authors.initials: K
authors.lastname: Hedman
authors.forename: Maria
authors.initials: M
authors.lastname: Söderlund-Venermo
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004279:DNA, Viral / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D056661:Human bocavirus / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D010322:Parvoviridae Infections / Q000453:epidemiology* / Q000821:virology; D016133:Polymerase Chain Reaction; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M