Chinese health officials have reported the first human infection by the H10N8 bird flu virus. In a development called "worrisome" by a World Health Organization (WHO) spokesperson, the Chinese Center for Disease Control and Prevention confirmed that a 73-year-old woman, who died of respiratory failure on Dec. 6 in the city of Nanchang, Jiangxi Province, was carrying the H10N8 virus. This is the second new strain of bird flu, previously undetected in humans, confirmed in China within the past year. During March, the WHO first heard reports of the H7N9 bird flu virus jumping the species barrier and infecting humans. Since then, there have been a total of 145 people infected with H7N9 and of these patients, 45 have died.

Referring to the new strain, University of Hong Kong microbiologist Yuen Kwok-yung, an expert on bird flu, flatly told Hong Kong Cable TV, "It has never been detected in humans before." Xinhua, the official news agency of China, notes that the provincial health agency did not state whether her death was connected to the bird flu virus. Earlier this week, China’s National Health and Family Planning Commission notified WHO of two new laboratory-confirmed cases of avian influenza A(H7N9) virus. One patient, a 39-year-old man from Guangdong Province, was admitted to the hospital on Dec. 11 and is currently in critical condition. A second patient, a 65-year-old woman also from Guangdong Province, was admitted to the hospital on Dec. 15. She had been directly exposed to live poultry and is currently in critical condition. China has controlled the H7N9 outbreak by closing many of its live animal markets. WHO maintains that there is no evidence of sustained human-to-human transmission and scientists have assumed infections have been transferred directly from live birds to humans.

In the new case of H10N8, the Associated Press reported the elderly woman suffered from high blood pressure, heart disease, and other underlying health problems that lowered her immunity, according to the Jiangxi health department. She had a compromised immune system. Then, when she had visited a local live poultry market, health officials noted that people who had come into contact with her showed no signs of the disease so far, though they were continuing to be monitored. Before dying in the Nanchang hospital on Dec. 6, the woman developed severe pneumonia.

Timothy O'Leary, spokesman for WHO’s regional office in Manila, told the AP that the bird flu source remains unknown and health officials from his organization were working closely with Chinese health authorities to better understand the new virus. O’Leary stated it would not be surprising if another human case were detected.