title: Clinical and genetic features of human metapneumovirus infection in children.
abstract: BACKGROUND
  Human metapneumovirus (hMPV) is one of the main pathogens responsible for respiratory tract infection in children.
  
  
  METHODS
  From 2011 to 2013, nasopharyngeal aspirates were obtained from Korean children and tested for hMPV on reverse transcription-polymerase chain reaction (RT-PCR). The genotype of hMPV in each sample was identified on PCR-restriction length polymorphism analysis of the fusion gene. We divided patients into three groups according to degree of fever. Patients with fever peaking at >39.5°C or lasting >7 days were classified as the high fever (HF) group; those with fevers peaking at <38.5°C and lasting <72 h were classified as the low fever (LF) group; and the other subjects were classified as the moderate fever group.
  
  
  RESULTS
  Among 457 samples positive for hMPV, hMPV genotype was able to be identified in 399 (87.3%); of these, A2a was found in 97 (24.3%), B1 in 186 (46.6%), and B2 in 116 (29.1%). Clinical features of hMPV infection were compared between the HF and LF groups. We classified 80 subjects into the HF group and 84 subjects into the LF group. Mean absolute neutrophil count (5625 ± 4418 vs 4072 ± 3076/μL, P = 0.010) and C-reactive protein (2.39 ± 3.39 vs 0.96 ± 1.77 mg/dL, P = 0.001) were higher in the HF group. Wheezing (5.0% vs 32.1%, P < 0.001) and dyspnea (2.5% vs 15.5%, P = 0.010) were more frequently seen in the LF group. Genotype distribution was similar in the two groups.
  
  
  CONCLUSIONS
  Two distinct clinical presentations of hMPV infection were identified in this study.
authors.affiliation: Departments of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Departments of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Ki Wook
authors.initials: KW
authors.lastname: Yun
authors.affiliation: Neuroscience and Behavioral Biology, Emory College of Arts and Sciences, Emory University, Atlanta, Georgia, USA.
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Lim
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Mi Kyung
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Departments of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: In Seok
authors.initials: IS
authors.lastname: Lim
authors.affiliation: Departments of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Eung Sang
authors.initials: ES
authors.lastname: Choi
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D029121:Metapneumovirus / Q000235:genetics*; D009305:Nasopharynx / Q000821:virology*; D018184:Paramyxoviridae Infections / Q000453:epidemiology / Q000235:genetics / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics*; D056910:Republic of Korea / Q000453:epidemiology; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000235:genetics / Q000821:virology*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012367:RNA, Viral
keywords: Korea; children; fever; genotype; human metapneumovirus