The Frequency of Subtypes of Respiratory Influenza Viruses Isolated in Busan during 2013 Season
Seok Hyeon Moon, Man Kyu Huh

Abstract
A better understanding of human influenza seasonality is useful to inform the timing and composition of vaccine recommendations and monitor the emergence of new virus variants. In 2013 season, we analyzed influenza virus specimen in 1,504 hospitalized children to identify three kinds of respiratory influenza virus A (FluH1N1, and FluH3N2) and FluB. Identification of viruses was used the indirect fluorescent test (IFA) with FITC-conjugated anti-mouse immunoglobulin and hem agglutination inhibition test (HI test). We analyzed the positive rate, annual frequencies according to the retrospective review of medical records. Positive respiratory viruses were isolated in 132 (8.8%) out of 1,504 patients examined. Of 848 influenza virus A samples, 82 (8.8%) had positive. Of 82 positive influenza A virus samples, number of influenza H1N1 subtype was 9 (2.6%) and number of influenza H3N2 subtype was 73 (14.5%). The positive influenza virus B was 7.6% (50/656). Positive respiratory viruses on February and March were detected 18.6% and 16.3%, respectively. The frequencies of detection rates between males and females were similar to each other. As for the age distribution, the high detection rates were indicated in children at the age of two to five. Whenever children are together, there is a chance of spreading infections.

Full Text: PDF     DOI: 10.15640/aijb.v3n1a7