title: Large-scale seroprevalence analysis of human metapneumovirus and human respiratory syncytial virus infections in Beijing, China.
abstract: BACKGROUND
  Human metapneumovirus (hMPV), a recently identified virus, causes acute respiratory tract infections (ARTIs) in infants and children. However, studies on the seroepidemeology of hMPV are very limited in China. To assess the seroprevalence of hMPV infection in China, we tested a total of 1,156 serum specimens for the presence of anti-hMPV IgG antibody in children and adults free of acute respiratory illness in Beijing, China by using hMPV nucleocapsid (N) protein as an antigen. As a control, we used the human serum antibody against the N protein of human respiratory syncytial virus (hRSV), the most important viral agent responsible for ARIs in children.
  
  
  RESULTS
  The seropositive rate for hMPV increased steadily with age from 67% at 1-6 mo to 100% at age 20. However, the rate dropped slightly between 6 mo and 1 yr of age. The seropositive rate for hRSV also increased steadily with age from 71% at 1-6 mo to 100% at age 20. In children aged six months to six years, the seropositive rates for the anti-hRSV IgG antibody were significantly higher than those for hMPV. Additionally, IgG antibody titers to hMPV and hRSV were significantly higher in adults than in young children. Consistent with the seropositive rates, the geometric mean titer of anti-hMPV IgG antibody was lower than that of anti-hRSV IgG antibody in children aged six months to six years.
  
  
  CONCLUSIONS
  Our results indicate that similar to hRSV, exposure to hMPV is ubiquitous in the Beijing population. However, the seroprevalence of anti-hMPV IgG antibody is lower than that of hRSV in children between six months and six years old, which suggests a different number of repeat infections or a different response to infections.
authors.affiliation: State Key Laboratory of Molecular Virology and Genetic Engineering, Institute of Pathogen Biology (IPB), Peking Union Medical College (PUMC) & Chinese Academy of Medical Sciences (CAMS), Beijing 100730, China.
authors.forename: Guilan
authors.initials: G
authors.lastname: Lu
authors.forename: Richard
authors.initials: R
authors.lastname: Gonzalez
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.forename: Guy
authors.initials: G
authors.lastname: Vernet
authors.forename: Gláucia
authors.initials: G
authors.lastname: Paranhos-Baccalà
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Hung
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D029121:Metapneumovirus / Q000276:immunology; D008875:Middle Aged; D019590:Nucleocapsid Proteins; D018184:Paramyxoviridae Infections / Q000453:epidemiology*; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology*; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D019590:Nucleocapsid Proteins