title: The clinical features, risk of prolonged hospitalization and household infections of hospitalized children for pandemic 2009 influenza A (H1N1) virus infection in Thailand.
abstract: OBJECTIVE
  To evaluate the clinical features, risk of prolonged hospitalization, and household infection in Thai children hospitalized with 2009 pandemic influenza A/H1N1 virus (pH1N1).
  
  
  METHODS
  The authors conducted a retrospective chart review of children hospitalized in four Thai tertiary care hospitals between June 1 and September 30, 2009, with reverse-transcriptase-polymerase-chain-reaction confirmed pH1N1. Household contact data were obtained by telephone.
  
  
  RESULTS
  Pediatric admissions numbered 115, 58 were females (50.4%). Median age was 5.2 (range 0.5 to 15) years. Fifty-one (44.4%) children had underlying diseases, most commonly asthma 17 (14.8%). Median preadmission illness duration was two days (range 1 to 10). Sixty-one (53.0%) children had lymphopenia. Chest X-ray infiltration was detected in 89 (77.4%) children. Oseltamivir was prescribed in 104 (90.4%) children; 47(45.2%) within 48 hours of illness. 70 (60.9%) children received antibiotics. The median hospitalization was three days (range 1 to 94). Independent (multivariate analysis) factors associated with prolonged hospitalization (> or = 7 days) were aged five to nine years (OR 7.4; 95% CI 1.1-48.9, p = 0.037) and having an underlying disease (OR 5.9; 95% CI 1.5-23.3, p = 0.01). Five (4.3%) children required mechanical ventilation; two (1.7%) children died. Household data showed that 63 of 109 (57.8%) patients had contact with a suspected or confirmed pH1N1 case. There were 39 (15.7%) of 249 household contacts who were probable secondary cases: 23 suspected and 16 confirmed pH1N1 of whom 25 (64.1%) were aged < or = 18 years.
  
  
  CONCLUSIONS
  Most pH1N1 infected hospitalized children had pneumonia, an uneventful short hospitalization, and a low in hospital mortality. Half of the patients were household acquired. Secondary household cases affected mostly children.
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Songkiat
authors.initials: S
authors.lastname: Udompornwattana
authors.forename: Krissada
authors.initials: K
authors.lastname: Srajai
authors.forename: Pongsan
authors.initials: P
authors.lastname: Suwan
authors.forename: Auchara
authors.initials: A
authors.lastname: Tangsathapornpong
authors.forename: Orasi
authors.initials: O
authors.lastname: Wittawatmongkol
authors.forename: Wanatpreeya
authors.initials: W
authors.lastname: Phongsamart
authors.forename: Nirun
authors.initials: N
authors.lastname: Vanprapar
authors.forename: Maneeratn
authors.initials: M
authors.lastname: Nuntarukchaikul
authors.forename: Pawinee
authors.initials: P
authors.lastname: Taeprasert
authors.forename: Sirinthip
authors.initials: S
authors.lastname: Sricharoenchai
authors.forename: Surapong
authors.initials: S
authors.lastname: Tanchaweng
authors.forename: Pilaipan
authors.initials: P
authors.lastname: Phutwattana
authors.forename: Walter R J
authors.initials: WR
authors.lastname: Taylor
authors.forename: Alan
authors.initials: A
authors.lastname: Maleesatharn
authors.forename: Kulkanya
authors.initials: K
authors.lastname: Chokephaibulkit
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy; D007902:Length of Stay; D008297:Male; D011014:Pneumonia / Q000453:epidemiology; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D013785:Thailand / Q000453:epidemiology