Thursday, 25 April 2013

Bird flu jumps the border

New bird flu strain 'more easily caught by humans' than 2003 outbreak
WHO official says H7N9, which has infected more than 100 people in China, is one of most lethal flu viruses



24 April, 2013

A new strain of bird flu that has killed 22 people in China is "one of the most lethal" of its kind and is more easily transmissible to humans than an earlier strain that has killed hundreds around the world since 2003, a top World Health Organisation (WHO) official has said.

The H7N9 virus has infected 108 people in China since it was first detected in March, according to the Geneva-based WHO. Although it is not clear exactly how people have been infected, WHO experts see no evidence so far of the most worrisome scenario – sustained transmission between people.

An international team of experts led by the WHO and the Chinese government conducted a five-day investigation in China, but said they were no closer to determining whether the virus could become transmissible between people.

Keiji Fukuda, WHO's assistant director general for health security, said at a briefing: "The situation remains complex and difficult and evolving. When we look at influenza viruses, this is an unusually dangerous virus for humans." Fukuda also named the previous H5N1 strain that killed 30 of the 45 people infected in China between 2003 and 2013.

Although the H7N9 strain in the current outbreak has a lower fatality rate to date, he added: "This is definitely one of the most lethal influenza viruses that we've seen so far."

Fukuda stressed that the team was still at the beginning of its investigation and that "we may just be seeing the most serious infections" at this point.

The team of experts said what was mystifying about the latest virus was the absence of visible illness in poultry, "making it harder to track and control".

Fukuda also said that based on the evidence, "this virus is more easily transmissible from poultry to humans than H5N1", which has killed 371 people globally since 2003.

Ho Pak-leung, an associate professor in the department of microbiology at the University of Hong Kong, noted in the British Medical Journal that in the two months since it was first detected, the H7N9 flu had already resulted in almost twice as many confirmed infections in China as H5N1 caused there in a decade.

Besides the initial cases of H7N9 in and around Shanghai, others have been detected in Beijing and five provinces.

Samples from chickens, ducks and pigeons from poultry markets have tested positive for the H7N9 virus, but those from migratory birds have not, said Nancy Cox, director of the influenza division at the US Centers for Disease Control and Prevention.

"At least we can now understand the likely source of infection is poultry," Cox said.

The experts also looked at poultry samples from farms but found nothing, said Malik Peiris, a clinical virologist at the University of Hong Kong.

Liang Wannian, the director general of the office of health emergency at the National Health and Family Planning Commission, warned that more sporadic cases would probably emerge "before the source of infection has been completely confirmed and effectively controlled".

There has been a "dramatic slowdown of cases" in the commercial capital of Shanghai, which has recorded most of the deaths, said Anne Kelso, the Melbourne-based director of the WHO Collaborating Centre for Reference and Research on Influenza.

"This is very encouraging at this stage of the outbreak," she said.

After Shanghai closed down its live poultry markets in early April, "almost immediately there was a decline in detection of new cases", Kelso said.

"The evidence suggests that the closing of the live poultry markets was an effective way to reduce the risks of infection of the H7N9 virus," she said.

Even so, the WHO's China representative, Michael O'Leary, issued figures last week showing that half of the patients analysed had no known contact with poultry.



China's Bird Flu Jumps The Border As First Case Confirmed In Taiwan



24 April, 2013


While precious little space has been dedicated in the US media to what remains an uncontained epidemic of the H7N9 bird flu in China, cases continue to spread even as the number of deaths mount, taking at least 22 reported lives at last check. Things just got from bad to worse, as the bird flu is now following in the footsteps of the 2003 SARS breakout, with the first reported case outside of China hitting newswires overnight.




The SCMP reports that: 

"Taiwan on Wednesday reported the first case of the H7N9 bird flu outside of mainland China. The case involves a 53-year-old man, who had been working in the eastern Chinese city of Suzhou. He showed flu symptoms three days after returning to Taiwan via Shanghai, the Centres for Disease Control said, adding that he had been hospitalised since April 16 and was in a critical condition." Considering the lack of transparency of the Chinese government one can only guess, literally, at what the true morbidity and mortality statistics of the flu epidemic are, which is perhaps the main reason this ongoing story for the past two months has so far evaded major coverage. However, as more and more cases are reported outside of China, the world will have no choice but to start paying attention, especially with the WHO announced that "This is one of the most lethal influenza viruses we have seen so far."


From NBC:

A new type of bird flu that has killed 22 people in China since March is one of the most deadly strains of influenza known, international health experts said on Wednesday.
"This is one of the most lethal influenza viruses we have seen so far," said Dr. Keiji Fukuda, the World Health Organization (WHO)’s Assistant Director-General for Health Security. "We are at the beginning of our understanding of this virus."
The H7N9 strain appears to spread more easily to humans than SARS, another type of bird flu that started killing people in Asia a decade ago, experts said.
"This is an unusually dangerous virus for humans," added Fukuda, who was speaking in Beijing alongside leading flu experts from around the world. 
The group of experts made an impressive display of international cooperation, but at the same time admitted just how little is known about the virus that has infected 108 people since March.
"We are at the very early stages of this investigation," said Dr. Nancy Cox, who heads Influenza Division at the Center for Disease Control and Prevention in Atlanta. "There's a lot to be learned.”
He said a few family clusters have been found, which could be the result of exposure to the same source of virus, or limited person-to-person transmission.
But he said: "'Evidence so far is not sufficient to conclude there is person-to-person transmission. Moreover, no sustained person-to-person transmission has been found.”
The experts concluded that live poultry markets were the most likely source of infection.
The experts praised the swift action of Chinese authorities in closing live poultry markets, and said it was "encouraging" that there have been no new cases in Shanghai since its markets were shuttered.
And they called for continued international cooperation against a virus that doesn't recognize borders.
"The risks of an outbreak situation are shared in a globalized world, where we are all interconnected," said Fukuda.


Taiwan, already paranoid about China's microbial exports, would beg to differ.


No comments:

Post a Comment

Note: only a member of this blog may post a comment.