An elder consults at the specially-established fever clinic at Hefei No. 1 Hospital in Hefei, capital of east China's Anhui Province, April 3, 2013. Authorities in some Chinese regions have ordered health institutions to step up monitoring of H7N9 bird flu as four more cases were reported Tuesday. The order comes after seven people in east China's Jiangsu Province and Shanghai have been been confirmed as being infected with the lesser-known H7N9 bird flu. (Xinhua/Yang Xiaoyuan)

A doctor works in a specially-established fever clinic at Hefei No. 1 Hospital in Hefei, capital of east China's Anhui Province, April 3, 2013. Authorities in some Chinese regions have ordered health institutions to step up monitoring of H7N9 bird flu as four more cases were reported Tuesday. The order comes after seven people in east China's Jiangsu Province and Shanghai have been been confirmed as being infected with the lesser-known H7N9 bird flu. (Xinhua/Yang Xiaoyuan) 

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)