Emergency surveillance and viral etiology of flu like patients after the first case of human bird flu reported in Beijing, 2009.

Objective To investigate the viral etiology of acute respiratory infections during an emergency surveillance after the first case of human bird flu confirmed in Beijing,2009,and provide evidences for generating the preventive strategies of acute respiratory infections.Methods 1 936 influenza A virus(H1N1)rapid screening test negative throat swabs were examined for influenza A virus by RT-PCR or real-time RT-PCR testing.A package of 12 frequently isolated respiratory viruses were tested simultaneously for 400 H1N1 rapid screening negative throat swabs by multiplex RT-PCR tests.Results 996(51.45%) rabid screening negative throat swabs were influenza A virus positive by RT-PCR or real-time RT-PCR testing.60(15%) rabid screening negative throat swabs were positive for other respiratory viruses,which had the highest positive rate(17.98%) in the population under 15 years old.RSVB was the mostly detected virus besides influenza H1N1.Conclusion The sensitivity was low for the influenza H1N1 rapid screening test used in the emergency surveillance.Influenza A virus was the main pathogen leading to the acute respiratory infections for the period in Beijing,followed by RSVB in the population under 15 years old.