Two people in China have died after being infected with H7N9 avian influenza and a third person is in critical condition with a virus that had not previously been transmitted to humans, Chinese officials said Sunday.
The men, aged 27 and 87, both fell ill with the H7N9 strain in February and died some weeks later in March, according to Chinese news agency, Xinhua.
The 87-year-old man who fell ill on February 19 and died on March 4, followed by a 27-year-old man who contracted the disease on February 27 and passed away on March 10. The third case involves a 35-year-old woman from a nearby Chinese province of Anhui who became ill on March 9 and is now in critical condition.
China's National Health and Family Planning Commission said the details are still not clear as to how the three got infected with the virus. The H7N9 strain had not been transmitted to humans before, it added. All three of them displayed initial symptoms of coughing and fever, which later developed into pneumonia and difficulty breathing.
H7N9 bird flu is considered a low pathogenic strain that cannot easily be contracted by humans. The overwhelming majority of human deaths from bird flu have been caused by the more virulent H5N1, which decimated poultry stocks across Asia in 2003.
Meanwhile, The World Health Organization (WHO), said in an statement that there was no evidence of human-to-human transmission in the three reported cases.
China is considered one of the nation's most at risk from bird flu because it has the world's biggest poultry population and many chickens in rural areas are kept close to humans.