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Rapid Molecular Detection and Differentiation of Influenza Viruses A and B
Published on: January 30, 2017
Clinical features and outcomes of influenza by virus type/subtype/lineage in pediatric patients
Seung Beom Han1,2, Jung-Woo Rhim1, Jin Han Kang1,2
1Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Insights
Influenza B virus infection may be more severe in children under two years old compared to Influenza A. Clinical differences between pediatric influenza A and B infections are otherwise minimal.
Area of Science:
- Pediatric Infectious Diseases
- Virology
- Epidemiology
Background:
- Four influenza virus types circulate globally: A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata.
- Limited data exists on clinical distinctions among pediatric influenza cases caused by these four strains.
Purpose of the Study:
- To compare clinical features of pediatric influenza patients infected with different circulating influenza virus strains.
- To identify potential differences in disease severity and symptoms based on influenza type and subtype.
Main Methods:
- Retrospective review of medical records for pediatric patients (<20 years) diagnosed with influenza (2014-2019).
- Comparison of clinical features between influenza A (FluA) and influenza B (FluB) infections.
- Further comparison based on dominant circulating FluA subtypes (H1N1pdm09, H3N2) and FluB lineages (Victoria, Yamagata).
Main Results:
- 1,588 FluA and 964 FluB cases analyzed.
- FluB patients were older and more likely to report sore throat than FluA patients.
- No significant differences in symptoms, diagnoses, or outcomes overall, except in children ≤2 years where FluB was linked to more lower respiratory tract infections and hospitalizations.
Conclusions:
- Pediatric influenza cases show minimal clinical differences across the four main circulating virus types.
- Influenza B infection may present with increased severity in very young children (≤2 years) compared to Influenza A.
Background:
Recently, four influenza viruses are circulating worldwide: A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata. However, information on the clinical differences among pediatric patients infected with four recently circulating influenza viruses is sparse.
Methods:
Medical records of pediatric patients (<20 years of age) diagnosed with influenza between the 2014-2015 and 2018-2019 influenza seasons were retrospectively reviewed. Clinical features were compared between (I) patients infected with influenza A (FluA) and influenza B (FluB) viruses, (II) patients infected with FluA when A(H1N1)pdm09 and A(H3N2) circulated dominantly, and (III) patients infected with FluB when B/Victoria and B/Yamagata circulated dominantly.
Results:
A total of 1,588 patients infected with FluA and 964 patients infected with FluB were included in this study. Patients infected with FluB were older (P<0.001) and more likely to report sore throat (P=0.002) than those infected with FluA. Otherwise, there were no significant differences in the clinical symptoms, diagnoses, and outcomes between patients infected with FluA and FluB. Overall, clinical features of influenza patients were similar regardless of the dominantly circulated subtype and lineage of the virus. In children aged ≤2 years, patients infected with FluB were more like to experience lower respiratory tract infection (P=0.034) and hospitalization (P=0.001) than those infected with FluA.
Conclusions:
There were no significant clinical differences among pediatric patients infected with four recently circulating influenza viruses, except that FluB infection tended to be more severe than FluA infection in children aged ≤2 years.
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Classification
Acute pharyngitis can be categorized based on its underlying cause: