Infect Chemother.  2010 Apr;42(2):76-81.

Clinical Characteristic of Respiratory Tract Infections in Children during Pandemic Influenza (H1N1 2009) in Korea

• Kim KH
• Park HJ
• Kim DS

Abstract

BACKGROUND
Since initial emergence on pandemic influenza (H1N1 2009) in Mexico on March 2009, the first case of pandemic influenza (H1N1 2009) occured on 2 May 2009 in Korea. We describe the clinical characteristics of childhood patients from pandemic influenza (H1N1 2009) and other concurrent respiratory pathogens during early phase of the pandemic influenza in Korea.
MATERIALS AND METHODS
We have retrospectively studied 959 patients under age of 15 years who have visited Department of Emergency Medicine for a diagnostic test of pandemic influenza (H1N1 2009) or treatment of flu-like illness between May and September of 2009. The pandemic influenza (H1N1 2009) was detected via real-time RT-PCR and other respiratory viruses were detected via multiplex RT-PCR.
RESULTS
A total of 959 patients visited Department of Emergency Medicine at Severance Hospital. Of them, 562 were tested; 124 (12.7%) were positive for pandemic influenza (H1N1 2009). Confirmed patients of pandemic influenza (H1N1 2009) were relatively older than non-H1N1 patients (7.5 years of age vs 4.6 years, P<0.001). Among histories or symptoms of patients with flu-like illness, contact history (80%) with another patient with pandemic influenza (H1N1 2009) was an important clue of the infection in early phase of pandemic. Comparing with hospitalized patients with respiratory tract infections due to other causes, lower ESR (32.9+/-23.5 mm/hour vs 11.5+/-9.2 mm/hour), hyperkalemia (4.2+/-0.3 mmol/L vs 5.2+/-3 mmol/L) and hyponatremia (137.2+/-2.5 mmol/L vs 124+/-40.5 mmol/L) were significant laboratory finding and higher cholesterol and GTP were noticed in pandemic influenza (H1N1 2009). Ten confirmed patients with pandemic influenza (H1N1 2009) were hospitalized due to pneumonia and all of them were resolved without any complication.
CONCLUSIONS
Respiratory tract infections were caused not only by pandemic influenza (H1N1 2009) virus but also various respiratory viruses. Hospitalized patients, confirmed as pandemic influenza (H1N1 2009), showed a good prognosis. Age and contact history were distinct features and could be an important clue to differentiate causes in patients with febrile respiratory symptoms.

Keyword

Children; Pandemic influenza (H1N1 2009) virus; Korea; Respiratory tract infection

MeSH Terms

Child
Cholesterol
Diagnostic Tests, Routine
Emergency Medicine
Guanosine Triphosphate
Humans
Hyperkalemia
Hyponatremia
Influenza, Human
Influenza A Virus, H1N1 Subtype
Korea
Mexico
Multiplex Polymerase Chain Reaction
Pandemics
Pneumonia
Prognosis
Respiratory System
Real-Time Polymerase Chain Reaction
Respiratory Tract Infections
Retrospective Studies
Viruses
Cholesterol
Guanosine Triphosphate

Figure

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  Figure 1 The number of patients with flu-like illness increases in warm and hot seasons and that of confirmed pandemic influenza (H1N1 2009) cases increases simultaneously. H1N1, pandemic influenza (H1N1 2009)

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  Figure 2 Various respiratory pathogenic viruses circulated during early phase of pandemic. Rhinovirus and adenovirus caused the respiratory infection in children at the same time with pandemic influenza (H1N1 2009) virus. ADV, adenovirus; PIV, parainfluenza virus; hRV, human rhinovirus; hBoV, human bovca virus; H1N1, pandemic influenza (H1N1 2009)

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