Clinical characteristics of patients with laboratory-confirmed influenza A(H1N1)pdm09 during the 2013/2014 and 2015/2016 clade 6B/6B.1/6B.2-predominant outbreaks

Yu-Chia Hsieh, Kuo-Chien Tsao, Ching-Tai Huang, Kuang-Yi Chang, Yhu-Chering Huang, Yu-Nong Gong
2018 Scientific Reports  
A novel pandemic influenza A(H1N1)pdm09 virus emerged in 2009 globally, and it continues to circulate in humans. The National Influenza Surveillance Network in Taiwan identified five A(H1N1)pdm09predominant seasons, representing the a retrospective cohort study (which enrolled 639 infected patients during the five seasons) was conducted at Chang Gung Memorial Hospital to explore the risk factors associated with influenza A(H1N1)pdm09-related complications. A phylogenetic analysis of
more » ... ysis of hemagglutinin (HA) sequences showed that the circulating A(H1N1)pdm09 virus belonged to clades 1, 2, and 8 in 2009/2010; clades 3, 4, 5, and 7 in 2010/2011; clades 7 and 6C in 2012/2013; clades 6B in 2013/2014; and 6B/6B.), those infected in 6B/6B.1/6B.2 seasons (2013/2014 and 2015/2016) were at higher risk for influenza-related complications (adjusted odds ratio [aOR]: 1.6, 95% confidence interval [CI]: 1.0-2.8), pneumonia (aOR: 1.78, 95% CI: 1.04-3.04), mechanical ventilation (aOR: 2.6, 95% CI: 1.2-5.6), and acute respiratory distress syndrome (aOR: 5.5, 95% CI: 1.9-15.9). For the increased severity of infection during the influenza A(H1N1)pdm09 clade 6B/6B.1/6B.2 seasons, aspects related to the antigenic change of A(H1N1)pdm09 virus, immune response of the host, and environmental factors required further investigation.
doi:10.1038/s41598-018-34077-4 fatcat:22cnbmxhwbccday37czgljuuyu