The Clinical Features, Risk of Prolonged Hospitalization and Household Infections of Hospitalized Children for Pandemic 2009 Influenza A (H1N1) Virus Infection in Thailand
Songkiat Udompornwattana MD*,**, Krissada Srajai MD**, Pongsan Suwan MD***, Auchara Tangsathapornpong MD****, Orasi Wittawatmongkol MD*, Wanatpreeya Phongsamart MD*, Nirun Vanprapar MD*, Maneeratn Nuntarukchaikul MD*,********, Pawinee Taeprasert MD*,*********, Sirinthip Sricharoenchai MD*, Surapong Tanchaweng MD*, Pilaipan Phutwattana PhD*****, Walter RJ Taylor MD******,*******, Alan Maleesatharn MBA*, Kulkanya Chokephaibulkit MD*
Affiliation : * Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Pediatrics, Buddhachinaraj Phitsanulok Hospital, Phitsanulok, Thailand *** Department of Pediatrics, Pranungklao Hospital, Nonthaburi, Thailand **** Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Thammasart University, Pathumthani, Thailand ***** Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ****** Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ******* Centre for Vaccinology and Tropical Medicine, Oxford University, England ******** Department of Pediatrics, Prapinklao Hospital, Bangkok, Thailand ********* Department of Pediatrics, Chiang Rai Prachanukhro Hospital, Chiang Rai, Thailand
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).
Material and Method: 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 (> 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 < 18 years.
Conclusion : 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.
Keywords : Pandemic influenza, Pediatric, 2009 H1N1, Thailand
