The H5N1 strain of influenza - often referred to as bird flu - is first known to have jumped from chickens to humans in 1997. Since 2004 it has ripped through poultry and wild bird populations across Eurasia, and had a 53% mortality rate in the first 147 people it is known to have infected. Health authorities fear this strain, or its descendent, could cause a lethal new flu pandemic in people with the potential to kill billions.
Flu has been a regular scourge of humanity for thousands of years. Flu viruses each possess a mere 10 genes encoded in RNA. All of the 16 known genetic subgroups originate in water birds, and especially in ducks.The virus is well adapted to their immune systems, and does not usually make them sick. This leaves the animals free to move around and spread the virus - just what it needs to persist.
But sometimes a bird flu virus jumps to an animal whose immune system it is not adapted to.
The ministry said on its Web site that by Thursday, 9,830 ducks had died of the outbreak in Guangzhou's Panyu District.
Initial tests by provincial officials showed that the birds had died of the highly pathogenic H5N1 virus, which can be transmitted to humans, the ministry said.
... authorities had culled nearly 33,000 ducks to contain the outbreak.
With the world's biggest poultry population and millions of backyard birds roaming free, China is at the centre of the fight against bird flu.
What separates this BBC documentary/drama from others, such as the excellent National Geographic piece from 2005 and the 2006 ABC TV movie "Fatal Contact - Bird Flu in America," are the videos. I had never seen still photos or video of the dying/dead tigers at the Bangkok Zoo in 2006, nor had I ever seen the actual die-off at China's Qinghai Lake in April-May 2005, nor had I ever seen actual newsreel footage of post-Spanish Flu sufferers of encephalitis lethargica. The photos and videos are outstanding. Also chilling are the words from Los Alamos National Laboratory scientist and forecaster Dr. Catherine Macken. Dr. Macken's words should be taken very seriously. She recounts how, in the aftermath of 9/11, the US government charged Los Alamos to come up with the most plausible bioattack upon Americans. Homeland Security was expecting anthrax, or maybe smallpox, or some other pathogen. Instead, LANL told Homeland the most likely scenario was an H5N1 pandemic.
The U.S. Geological Survey's Alaska Science Center tracked the odyssey of the bird as part of an ongoing collaborative effort with colleagues in California and New Zealand. The scientists were hoping to better understand potential transmission of avian influenza by migratory birds.
E7 departed Miranda on the North Island of New Zealand and flew non-stop to Yalu Jiang, China, completing the 6,300-mile-long flight in about eight days. There she settled in for a 5-week-long layover before departing for the breeding grounds.
On the evening of May 1, she headed east out over the Sea of Japan and the North Pacific, eventually turning northeast towards Alaska, crossing the end of the Alaska Peninsula en route to her eventual nesting area on the Yukon-Kuskokwim River Delta in western Alaska. This flight was also accomplished non-stop, covering some 4,500 miles in five days.
Nearly 10,000 ducks that died of bird flu at farms near Guangzhou's Panyu district had been vaccinated against the disease, sparking fears the deadly H5N1 virus may have mutated.
Straw contaminated with the H5N1 strain of bird flu was the likely source of an outbreak of the disease at a poultry farm in southern Germany that resulted in 160,000 birds being slaughtered, an official said Monday.
Ottmar Fick, the chief veterinarian in the Erlangen district of northern Bavaria, said it remained unclear how the straw, which was stored on the farm, became infected, although wild birds were a possible source.
German authorities said Friday that more than 200,000 ducks would be slaughtered at two farms in Bavaria after tests indicated the presence of the H5N1 strain of bird flu.
The head of Bavaria's state office for health and food safety, Volker Hingst, said the slaughter was "a purely precautionary measure," taken after "laboratory indications of H5N1" were found. The birds were not visibly sick, he said.
The two farms are located near Schwandorf, east of Nuremberg, and have a total of 205,000 ducks. It was not immediately clear how the virus might have gotten there.
However tests of the Friedrich Loeffler Institute would have resulted in that it acts with the found viruses around completely different strain than in Erlangen.
The above reports describe three geographically and/or genetically distinct H5 outbreaks on Bavaria. The initial report involved highly pathogenic H5N1 that was first noted in dead or dying ducks. Those positives led to additional testing at farms that had commercial ties to the initial outbreak. High path H5N1 and antibodies was found there in ducks that were not visibly sick. Those positives were followed by additional testing at additional farms, where low path H5 was detected. As expected, the low path H5 was genetically distinct from the high path (Qinghai) H5N1 found earlier at the other Bavarian locations.
H5 in Europe has been circulating for some time. Usually it does not produce significant mortality in waterfowl. In contrast, Qinghai H5N1 can produce significant mortality, as seen in the initial outbreak, as well as dead or dying wild birds throughout Europe. In 2006, Germany had over 300 confirmed cases of Qinghai H5N1 in wild birds, which was followed by a similar number in central and southern Germany this year.
However, Qinghai H5N1 does not always produce fatal disease in waterfowl. The outbreak at Qinghai Lake in May, 2005 was followed by an outbreak in and around Chany Lake in July, 2005. The Russian outbreaks also involved the Qinghai strain, which was isolated from a healthy crested grebe. Sequence of all eight gene segments had the characteristic Qinghai markers and was very similar to H5N1 from wild bird and poultry outbreaks in Russia and neighboring regions in Kazakhstan.
Similarly, Qinghai H5N1 sequences were detected in a healthy teal in the Nile Delta in December, 2005. Although the PCR positive sample failed to yield H5N1 virus, repeated RNA extractions led to HA and NA sequences which were clearly Qinghai and most closely related to H5N1 isolated from an asymptomatic cat in Austria in early 2006.
Moreover, H5 antibodies have been routinely detected in wild birds in Russia in 2005, 2006, and 2007, providing additional evidence for non-fatal Qinghai H5N1 infections in wild birds.
The above findings create significant sensitivity issues in surveillance programs world-wide. Many of these programs focus on H5 detection in swabs from healthy wild birds. These programs have failed to detect Qinghai H5N1 in regions where Qinghai H5N1 virus is isolated from dead or dying wild birds, indicating these assays do not have the sensitivity to detect H5N1 in healthy wild birds. Extensive testing of captive birds can yield positives by PCR, but detection of H5 antibodies is more common, and such assays are actively avoided in most of the surveillance programs.
Thus, the recent results from Germany demonstrates widespread H5 infections in domestic waterfowl in Germany, suggesting widespread H5 in wild birds which is largely missed by H5 PCR tests on live wild birds. The testing of the live birds should include tests for H5 antibodies, which signal the presence and spread of low and high path H5 in wild birds.
The bottom line is that if they do not want to find high path H5N1 (HPAI),
they will not do the type of testing that would provide the results should this
virus actually be present in these birds. You have to be motivated to find it .
Can you imagine the reasons for NOT wanting to find positive results?
There are many governments and business that would be significantly impacted
by positive results, and that is why this is a political/economic issue as well as a public health issue.
Public health is taking a back seat with regards to this testing.
The public does not have a clue. They are only told that tests have failed to find the
highly pathogenic virus, but they do not know the real reasons for why it has not been found.
This is what is happening in North America right now as well as in Europe.
Chinese bird flu vaccination attempts have been very controversial and have inadvertently put the entire world at risk of infection. Just last year, the disclosures came that the Chinese government had mixed the M2 inhibitor Amantadine with its H5N1 poultry vaccine. This, of course, led to H5N1's acquired resistance to Amantadine, the first antiviral used against influenza A some 20+ years ago. Amantadine prevents influenza's M2 protein coat from dissolving.
Just not any more: Seasonal influenza is Amantadine-resistant, but China's unwise mass use of the drug in chickens and ducks guaranteed that H5N1 would develop resistance prematurely. So a front-line antiviral, cheap and plentiful, was summarily taken off the table by the Chinese. Thanks, guys. And we thought The Return of Lead Paint in Toys was bad!
And more "good" news:
H5N1 gains a measure of resistance to the vaccine; it is allowed to "drift" and mutate, which concerns Dr Ho Pak-leung, an infectious diseases expert at Hong Kong University. He stated there were worries the virus had mutated or the vaccine had not been effective. This either means the vaccine was ineffective, or the virus has drifted beyond the vaccine's ability to protect. Either way, it is not good news.
From Effect Measure with permission of the author:
Bird Flu in Vaccinated Ducks in Guangdong, China
10,000 ducks in Guangdong Province in the south of China have died of bird flu and 100,000 more culled in an attempt to stop the spread of the disease. Massive bird flu outbreaks are not exactly a novelty these days but the Chinese incident is noteworthy because it is now reported the ducks were in vaccinated flocks:
According to Guangdong Animal Epidemic Prevention Center director Yu Yedong, the 9,800 ducks that died at Sixian village had been vaccinated. But he added the first vaccination could only be 65 percent effective, while a second shot would have made it 90 percent. He believed the birds were infected after the first shot. The deaths led to a mass culling of 32,600 ducks on Friday in an attempt to contain the outbreak.
Health workers have been spraying disinfectant on every passing vehicle and duck farms around the village. (The Standard [Hong Kong])
Vaccinating poultry has been touted as both the answer to the bird flu problem and a dangerous practice because it masks the fact of infection in poultry that can still become infected and shed virus. There has thus always been a question as to whether it is effective and this report suggests it isn't even working to keep the birds asymptomatic (which from the public health perspective is actually a good thing because it allows us to become aware the flock is harboring the virus). Whether this is the result of a change in the virus that allows it to escape the protective effects of the vaccine or whether the vaccine was never very effective in the first place or requires multiple applications or whether the vaccination program itself is at fault with records showing birds as being properly vaccinated when they weren't or some combination of these factors or something entirely different we don't know. But so far no one strategy has stopped this virus.
Both H5N1 and SARS started in Guangdong, which is the part of the mainland closest to Hong Kong. China is the world's largest poultry producer and has officially reported 25 human cases and 16 deaths. If you think that's all there has really been, I have a used car to sell you. and some prime real-estate in Florida. Oh, yeah. The bridge in New York. I say this because disease surveillance and detection in China is manifestly inadequate to have a realistic chance of full ascertainment of cases. Given China's past record on disease reporting and the fact they are hosting the 2008 Summer Olympics in Beijing, however, I am not discarding the idea there has been some cover-up of cases. I just don't know, but it is a suspicion the Chinese authorities have brought on themselves.
The virus, like a clever computer hacker, finds ways to get around our firewalls. Let's hope we don't have to reboot the human species.
The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.
In Guangzhou, reporters and editors were told not to cover the outbreak themselves, but to use only the version provided by the official New China News Agency. In Hong Kong, some media chafed at the restrictions.
"Alarm Bells Are Ringing," Hong Kong's Mingpao newspaper editorialized Tuesday, a day after the city suspended chilled and frozen duck imports from Guangdong.
The paper said that birds began to die in large numbers in Panyu on Sept. 5, but that it wasn't until last Wednesday that local officials told the Panyu government of the outbreak and not until Thursday that Guangdong provincial authorities learned of it.
And this may explain why we're not hearing from China's own H5N1 experts.
China's southern city of Guangzhou has destroyed 153,320 domestic fowls in the wake of an outbreak of bird flu, local authorities said on Tuesday.
The extermination of 134,384 ducks, 18,786 chickens and 150 doves was carried out in nine villages within a radius of three kilometers from the site of the outbreak, an official with the Panyu district government said.
A total of 68 poultry farmers in Panyu district who have had close contact with ducks killed by bird flu have taken blood tests and medical checkups, and were found to be in good condition.
The Panyu district government announced on Tuesday the suspension of all poultry markets within a 13-kilometer-radius surveillance zone.
China has a major problem looming on its horizon, and it is found at the intersection of the 2008 Summer Olympics and H5N1. Simply put, the Chinese know that any ill-timed outbreak of H5N1 in poultry -- coupled with any simultaneous human infections, particularly tourists and/or athletes -- could irreparably harm the nation's economy if it occurs during the run-up to the games, or, even worse, during the Games themselves.
Over 1,052 birds have so far been culled in Panda Development Area of Nasarawa State in the wake of Avian Influenza (Bird Flu) that affected the area just as the people of the area were commended for reporting early signs of the flu.
UNICEF field officer for Avian Influenza, Alhaji Bala Hassan who visited the affected area from their headquarters in Bauchi said the efforts of the people of the area in reporting cases of sick or dead birds as well as their contributions towards the depopulation exercise was commendable.
He particularly advised parents to keep their children away from sick or dead birds and advised them to always imbibe the culture of washing their hands whenever they come in contact with sick or dead birds to avoid the spread of the flu.
We have never had a pandemic in the 21st Century, and we dodged a huge bullet with SARS (and its extremely scary 10% Case Fatality Rate). We have no idea how IT will operate in the wake of 20%+ absenteeism and in the era of the Just-in-time economy. But we all know that no entity can operate without IT. It might as well try to conduct its operations by gaslight. IT is the fuel that drives the modern economy, the modern government, the modern everything. That is one major reason I strongly advocate government data center people being classified as "second responders" for purposes of antivirals. Without IT, governments will lose their ability to effectively serve their citizens within 24 hours. That is because in a pandemic, after medical help, citizens will demand sustenance. The assistance will come in the form of checks, drafts, and warrants, usually via direct deposit. The era of people with green eyeshades, writing checks manually, does not exist anymore. And to move that money requires data centers, with mainframes and server clusters working overtime to produce the ones and zeros necessary to convert digital cash into real cash. Try to do THAT in the midst of a major pandemic.
Katrina showed us what happens when government cannot complete its most essential tasks in the most urgent time frame. Imagine what will happen if/when governments fail to take care of their citizens' most basic needs. Those needs include unemployment compensation; aid to families with dependant children; emergency food stamps (although whether or not there will be food to buy in a JIT-failed supply chain is debatable); and housing subsistence. Without those direct deposits/swipe cards/ checks, people will invariably resort to other, more drastic measures to survive.
BioCryst was the deliverer of bad news Wednesday. Phase II human trials of its Peramivir injectible neuraminidase antiviral were not statistically any better in human tests than the placebo. BioCryst postulates that such issues as the subjects' BMI (body mass index) and needle length were factors, but the press is reporting nonetheless that the tests did not go well at all. headlines such as "Flu Drug Misses Goal in Mid-Stage Study" (http://www.clinicaspace.com/news_story.aspx?NewsEntityId=70432) abound. It is difficult to imagine using calipers to measure body fat and requiring inch-and-a-half needles for injections during a pandemic, but you see where this is going. It's back to the drawing board for BioCryst.
Category: Bird flu * Infectious disease * Public health preparedness
Posted on: September 21, 2007 7:18 AM, by revere
We've talked here fairly often... that the way and how far influenza virus spreads isn't understood or known precisely. That seems to be a big surprise, not only to the public but to many in the public health community who should know better. That's why I was pleased to see that this dirty little secret is finding its way into the public press (hat tip from one of our many readers in Oz, RobT):
It was a simple question: how far could a virus spluttered out of someone's mouth travel?
When Professor Lidia Morawska went looking for an answer, she was staggered to find little research on this important health issue. Only three studies existed. "And the results were contradictory."
So her team at Queensland University of Technology built a machine to measure the distance a droplet moves in air before drying out, depending on whether people are coughing, spitting or laughing.
It had been thought that if you were an arm's length from an infected person you were safe, Professor Morawska says. "But we found the droplets evaporate quickly and the dried residue can travel large distances." (Sydney Morning Herald)
This doesn't mean an influenza virus can travel long distances and remain replicable. This was (apparently) a question about the fate and transport of large droplets that are coughed or breathed. At what point in the change in volume of the droplet is the virus no longer viable? Maybe the answer is very quickly or maybe it is that the virus remains viable long after the droplet reaches a size where it can remain suspended for hours or days and can be breathed deeply into the respiratory tract. You'd think we would know the answer to this by now.
But we don't.
The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.
indigo girl
5,173 Posts
China
China is admitting to a big outbreak of H5N1 in ducks. The local press
was calling it "duck plague", but now they are saying bird flu.
http://www.flutrackers.com/forum/showpost.php?p=100834&postcount=1