The death toll from the bird flu strain H7N9 rose to 13 as two more infected people died in Shanghai recently. A total of 11 new cases were reported on Sunday. China has announced a total of 60 infections of the lesser-known strain of avian influenza since February.
Two new cases of H7N9 were reported in the China's Henan province this weekend. One victim, a 34-year-old restaurant chef, is now critically ill in Kaifeng. The other victim, a 65-year-old farmer from Zhoukou, is in stable condition. The two cases are not considered to be connected.
The novel influenza H7N9 appears to be more dangerous than previously observed. The first infections were reported in Shanghai. Two men, ages 27 and 87, were infected in February and died in early March.
State news agency Xinhua reported that 19 people came in contact with the two Henan patients and none of those people have shown any signs of infection.
24 infections and 9 deaths from H7N9 occurred in Shanghai alone. In early April Chinese authorities reported they had killed more that 20,000 birds from a live-poultry trading zone in Shanghai.
The report of a case in Beijing officially expanded the area of infections. Now the Beijing poultry market is shut down, the Shanghai Daily Newspaper reported Saturday.
The Beijing victim, the first H7N9 case reported outside of the Yangtze River delta, is a 7-year-old girl who is in stable condition. Her parents work in the poultry trade.
The World Health Organization (WHO) has repeatedly reported that there is no proof the H7N9 can pass between humans.
Head of WHO in China, Michael O’Leary, said that not everyone infected with the disease was "clustered in one small area with the same source of exposure."
"So we've been expecting new cases to occur ... Furthermore, we still expect that there will be other cases," O’Leary said.
Medscape spoke with Doctors Timothy M. Uyeki and Nancy J. Cox of the Influenza Division of the National Center for Immunization and Respiratory at the CDC, who said the outbreak "is of major public health significance."
Avian flu is transmitted between poultry and humans through a process called zoonosis. But if officials are correct and the disease is not spread from human to human, it appears 60 unconnected Chinese citizens contracted the disease from at least 60 different birds.
"The coming weeks will reveal whether the epidemiology reflects only a widespread zoonosis, whether an H7N9 pandemic is beginning, or something in between," Drs. Uyeki and Cox conclude.