Researchers from a top Chinese government lab claimed on Wednesday to have traced the source of the rare bird flu strain spreading across the country to migratory birds from South Korea.
Scientists said the strain was created after a virus found in migratory birds mingled with an existing strain of avian influenza carried by ducks and chickens in the Yangtze River delta.
The findings were revealed even as police in southwest China's Guizhou Province said they had detained three people for “fabricating rumors online that the deadly virus had been detected locally.”
So far, China has confirmed 33 H7N9 infections, including nine deaths. Of them, at least 13 cases, including five deaths, were found in Shanghai. Eight cases, including one death, were found in Jiangsu. Two cases, including one death, were found in Anhui. Five cases, including two deaths, were found in Zhejiang,” state media reported.
According to researchers from the Chinese Academy of Sciences' Key Laboratory of Pathogenic Microbiology and Immunology, the “genetic reassortment is likely to have occurred in east China's Yangtze River Delta areas covering Shanghai, Zhejiang and Jiangsu.”
“The researchers found that no genes in H7N9 were traceable to pigs, thus excluding pigs as intermediate hosts for the deadly new strain of bird flu,” the state-run Xinhua said in a Wednesday evening report.
Research revealed that the H7 and N9 gene segments in H7N9 were similar to those in avian influenza samples collected from wild birds from east Asia, while the other six genes are traceable to chickens in China's Shanghai, Zhejiang and Jiangsu.
“As to why the H7N9 is less harmful to the animals than to humans, researchers said it's because of viral mutation, adding that they had monitored the mutation of the N9 genes,” the report said.
Animal experts and scientists have stepped up monitoring of bird migration paths to prevent the H7N9 from spreading, according to the China Wildlife Conservation Association.