Monthly distribution of test-positive virus in the PKU People' hospital from June 2010 to May 2011.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028786#pone-0028786-g001" target="_blank">Figure 1A</a> shows the number of respiratory specimens testing positive for influenza, by influenza type and positive rates of respiratory virus. Panel B shows the smaller number of other viruses. The rate of positive cases of the virus gradually increased from August to October, slowly decreased in November, and then increased again in January 2011. The peak of the positive rate occurred in January 2011 and influenza was the predominant virus between August 2010 and March 2011. Particularly in August, September and October 2010, and March 2011, all infections were caused by FLU only( <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028786#pone-0028786-g001" target="_blank">Figure 1B</a>). The number of positive cases of influenza virus increased rapidly in September and peaked in January 2011, following which it then decreased to normal levels in March 2011. Influenza A(H3) was the predominant viral etiological factor and was only observed from July to December 2010, and again, in January 2011, Influenza A(H3) were replaced by 2009 H1N1. 2009 H1N1 peaked in January 2011. Most influenza viruses were in fact influenza A, with influenza B virus only observed in April 2011. In June, multiple infections predominated. Each identified ILI was caused by a single virus except in June, July and November 2010 and January and February 2011: two FLU-A in August, eight FLU-A in September and in October each, eight FLU-A and one HRCV229E/NL63 in December, four FLU-A in March 2011, one FLU-A, two FLU-B and one ADV in April 2011, No virus was detected in May 2011. On the other hand, two of the three identified ILI samples in June were mixed infections, HRSV and HRV. Other double infections included: One HRCV/FLU-A in July, one FLU-A/HRV in November, two HRSV-A and FLU-A and one HRSV-A and HRV and FLU-A in January 2011, one HRSV-A and HRV and FLU-A in February 2011.