Bird flu evolves

Bird flu spreads to Hunan province: 23 dead

China on Saturday reported its first case of H7N9 bird flu in the southern province of Hunan, the latest sign the virus that has killed 23 people in the country is continuing to spread.

Reuters,

27 April, 2013

The official Xinhua news agency said the patient was a 64-year-old woman from Shaoyang city who developed a fever on April 14, four days after having contact with poultry. Her condition had improved with treatment, it added.

The flu was first detected in March. This week, the World Health Organization called the virus "one of the most lethal", and said it is more easily transmitted than an earlier strain that has killed hundreds around the world since 2003.

None of the 41 people who had come into contact with the newly-confirmed Hunan patient, identified only by the surname Guan, had shown symptoms, Xinhua said.

A 54-year-old man who fell ill in Jiangxi province was also being treated in Hunan, where he was diagnosed with H7N9, Xinhua said.

The Hunan cases come a day after the eastern province of Fujian reported its first case and during the same week that a man in Taiwan become the first case of the flu outside mainland China. He caught the flu while travelling in China.

Chinese scientists confirmed on Thursday that chickens had transmitted the flu to humans.

H7N9 may mutate 8 times faster than regular flu

The new bird flu could be mutating up to eight times faster than an average flu virus around a protein that binds it to humans, a team of research scientists in Shenzhen says

South China Morning Post,

17 April, 2013

Dr He Jiankui, an associate professor at South University of Science and Technology of China, said yesterday that the authorities should be alarmed by the results of their research and step up monitoring and control efforts to prevent a possible pandemic.

With genetic code of the virus obtained from mainland authorities, the team scrutinised haemagglutinin, a protein that plays a crucial rule in the process of infection. The protein binds the virus to an animal cell, such as respiratory cells in humans, and bores a hole in the cell's membrane to allow entry by the virus.

The researchers found dramatic mutation of haemagglutinin in one of the four flu strains released for study by the central government. Nine of the protein's 560 amino acids had changed. In a typical flu virus, only one or two amino acids could change in such a short period of time, He said.

"It happened in just one or two weeks. The speed may not have caught up with the HIV, but it's quite unusual for a flu."

The fast mutation makes the virus' evolutionary development very hard to predict. "We don't know whether it will evolve into something harmless or dangerous," He said. "Our samples are too limited. But the authorities should definitely be alarmed and get prepared for the worst-case scenario."

The origin of the virus was puzzling due to its novelty, but He's research suggested some clues that differ from the mainland authorities' theories.

His team compared the new virus strain to all other H7N9 viruses identified in Europe and in other Asian countries that were cited by the Ministry of Agriculture as possible origins of the new bird flu, but found them all very different.

In fact, the new bird flu was quite similar to some familiar domestic viruses such as H9N2, H11N9 and H7N3 found in Zhejiang and Jiangsu.

He said researchers could not rule out the possibility that the new virus was carried into China by wild birds, but it was more likely to be of local origin.