Journal List > Pediatr Allergy Respir Dis > v.21(4) > 1033137

Pediatr Allergy Respir Dis. 2011 Dec;21(4):269-276. Korean.
Published online December 31, 2011.
Copyright © 2011 The Korean Academy of Pediatric Allergy and Respiratory Disease
Comparisons of Clinical Features among Influenza A (H1N1) and Seasonal Influenza A and B during 2009 to 2010 at a Single Institution
Tae-Gon Kang, MD,1 Mi-Jin Kim, MD,1 Byoung-Gwon Kim, MD,2 Hye-Sung An, MD,3 Hyun-Jin Yun, MD,4 Eun-Jeong Choi, MD,4 and Jin-A Jung, MD1
1Department of Pediatrics, Dong-A University College of Medicine, Busan, Korea.
2Department of Preventive Medicine, Dong-A University College of Medicine, Busan, Korea.
3Department of Pediatrics, Good Moonhwa Hospital, Busan, Korea.
4Department of Pediatrics, Ilsin Christian Hospital, Busan, Korea.

Corresponding author (Email: )
Received October 06, 2010; Revised July 19, 2011; Accepted July 25, 2011.



This study was performed to compare the clinical features of pediatric patients who were diagnosed with influenza A (H1N1) or seasonal influenza A and B during 2009 and 2010 at a single institution.


Among children who visited the Dong-A University Hospital with fever (>37.8℃) and acute respiratory symptoms from September 2009 to February 2010, 1,004 children who were diagnosed with influenza A (H1N1) or seasonal influenza A and B by reverse transcription-polymerase chain reaction (RT-PCR) were enrolled. Monthly incidence, fever duration before diagnosis, symptoms (fever, cough, rhinorrhea, sore throat, headache, vomiting, abdominal pain, diarrhea, seizure, and dyspnea) and signs (rales, wheezing) were reviewed retrospectively in each group based on medical records.


Influenza A (H1N1) was detected in 944 patients (94.0%), followed by seasonal influenza A in 42 (4.2%) and seasonal influenza B in 8 (1.8%). The positive rate of influenza infection was highest in November 2009 (n=557, 55.5%). Mean duration of fever before RT-PCR was 1.6 days (range, 1.5 to 1.8 days). Except fever, cough was the most common symptom (n=792, 78.9%), followed by rhinorrhea in 407 patients (40.5%). Rales and wheezing were detected in 16 patients (1.6%) and 19 (1.9%), respectively. Significant differences were observed for the number of patients who had cough, headache, vomiting, and wheezing among the three groups (P<0.05).


Although the incidence of cough, headache, vomiting, and wheezing differed significantly among the three groups, the number of patients in each group was too different to compare the results.

Keywords: Influenza A (H1N1); Seasonal Influenza A; Seasonal Influenza B


Table 1
Monthly Distribution of the Influenza Viruses
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Table 2
Age, Sex Distribution and Fever Duration before Reverse Transcription-Polymerase Chain Reaction
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Table 3
Percentage of Symptoms and Signs in 3 Groups
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