Technicians deal with test reagents for H7N9 bird flu virus at the Beijing Center for Diseases Control and Prevention in Beijing, China, April 3, 2013. Test reagents for H7N9 virus have arrived in Beijing on April 2. And the city's diseases control and prevention centre along with 55 laboratories in its network are capable of testing the virus. (Xinhua/Li Wen)

A technician holds test reagents for H7N9 bird flu virus at the Beijing Center for Diseases Control and Prevention in Beijing, China, April 3, 2013. Test reagents for H7N9 virus have arrived in Beijing on April 2. And the city's diseases control and prevention centre along with 55 laboratories in its network are capable of testing the virus. (Xinhua/Li Wen)

A technician holds test reagents for H7N9 bird flu virus at the Beijing Center for Diseases Control and Prevention in Beijing, China, April 3, 2013. Test reagents for H7N9 virus have arrived in Beijing on April 2. And the city's diseases control and prevention centre along with 55 laboratories in its network are capable of testing the virus. (Xinhua/Li Wen)

A technician holds test reagents for H7N9 bird flu virus at the Beijing Center for Diseases Control and Prevention in Beijing, China, April 3, 2013. Test reagents for H7N9 virus have arrived in Beijing on April 2. And the city's diseases control and prevention centre along with 55 laboratories in its network are capable of testing the virus. (Xinhua/Li Wen)