title: Human metapneumovirus reinfection among children in Thailand determined by ELISA using purified soluble fusion protein.
abstract: BACKGROUND
  Human metapneumovirus (hMPV) is a newly discovered paramyxovirus that causes acute respiratory illness. Despite apparent near-universal exposure during early childhood, immunity is transient.
  
  
  METHODS
  An indirect screening enzyme-linked immunosorbent assay using a recombinant soluble fusion (F) glycoprotein derived from hMPV was used to test for anti-F IgG in 1,380 pairs of acute- and convalescent-stage serum samples collected from children in Kamphaeng Phet, Thailand.
  
  
  RESULTS
  Of the 1,380 serum sample pairs tested, 1,376 (99.7%) showed evidence of prior infection with hMPV. Sixty-six paired specimens demonstrated a >or=4-fold rise in titer, for an overall reinfection rate of 4.9%. Two children demonstrated evidence of an initial infection. Forty-eight of the 68 new infections or reinfections occurred in 2000, accounting for 13.2% of all nonflaviviral febrile illnesses in the study population in that year. Of 68 positive cases, 85.3% complained of cough and 66.2% complained of rhinorrhea, compared with 61.4% and 49.0% of negative cases, respectively (P < .01). All positive samples were also tested for an increase in titer of antibodies to respiratory syncytial virus F, and 27% exhibited a >or=4-fold rise.
  
  
  CONCLUSIONS
  These results demonstrate that hMPV reinfections cause illness at a rate equal to that seen for initial infections. hMPV may have a more significant impact in older children than previously realized and may be the cause of significant outbreaks in this population.
authors.affiliation: Department of Microbiology and Immunology, Uniformed Services University, Bethesda, USA. julie.pavlin@afrims.org
authors.forename: Julie A
authors.initials: JA
authors.lastname: Pavlin
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Hickey
authors.forename: Nancy
authors.initials: N
authors.lastname: Ulbrandt
authors.forename: Yee-Peng
authors.initials: YP
authors.lastname: Chan
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Endy
authors.forename: Marina S
authors.initials: MS
authors.lastname: Boukhvalova
authors.forename: Supamit
authors.initials: S
authors.lastname: Chunsuttiwat
authors.forename: Ananda
authors.initials: A
authors.lastname: Nisalak
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Libraty
authors.forename: Sharone
authors.initials: S
authors.lastname: Green
authors.forename: Alan L
authors.initials: AL
authors.lastname: Rothman
authors.forename: Francis A
authors.initials: FA
authors.lastname: Ennis
authors.forename: Richard
authors.initials: R
authors.lastname: Jarman
authors.forename: Robert V
authors.initials: RV
authors.lastname: Gibbons
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Broder
mesh_terms: D000293:Adolescent; D002648:Child; D003710:Demography; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D029121:Metapneumovirus; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000276:immunology; D012008:Recurrence; D013785:Thailand / Q000453:epidemiology
chemical_list: D007074:Immunoglobulin G