Experts wait for the big bird flu jump

[Martin]

Experts wait for the big bird flu jump

Pallavi Aiyar

Bejing, May 23 Bird flu has once again raised its deadly head in mainland China. The Chinese Ministry of Agriculture has confirmed that the deaths of 178 migratory birds in the country’s Northwest Qinghai province, have been caused by the avian influenza known as H5N1.
For health experts, this is further confirmation that the virus is now endemic in Asia and many say that it’s not a question of if, but when, the H5N1 mutates into a form that would enable it to spread between humans.

Despite fervent measures to contain the virus since it first appeared in late 2003, including the slaughtering of tens of millions of birds and vaccinating many more, bird flu has continued to spread in Asia. The prospects of eliminating the virus within the next few years now appear to be virtually nil.

‘‘Elimination is a strategy we are no longer looking at,’’ say Maria Cheng, spokesperson for the World Health Organisation (WHO) in Beijing. ‘‘The flu is now established in the region so that eliminating it is not a good possibility.’’ Health experts are trying instead to focus on containment, including the monitoring and vaccination of animals.

Bird flu has affected 11 countries in the region from Japan to Indonesia and WHO says the outbreak is without precedent.

Avian influenza already fulfills 2 out of the 3 conditions for causing a human flu pandemic: the emergence of a new virus to which humans have little or no immunity and the ability of this virus to replicate in humans. The third condition, that the virus must be transmittable from one human to another, is the one standing between the current situation, where the flu is by and large limited to poultry and a possible world wide human flu pandemic of staggering proportions.

Currently, H5N1 is only known to spread between birds and, more rarely, from birds to humans. But as the virus continues to spread there is a distinct possibility that it will mutate in time, enabling human to human transmission.

Says Cheung, ‘‘We have a situation at the moment where both the human influenza virus and avian flu virus are circulating in a region simultaneously.’’

If H5N1 infects a human who is also carrying a human flu virus, the chances of the two strains of virus combining to mutate into a new form are high. Another worry for health officials is the potential for the avian virus to combine with a human flu virus in an intermediary sources like a pig. Already pigs in Java, Indonesia, have tested positive for H5N1.

Last month influenza experts noted a potentially menacing changes in the avian flu virus in Vietnam. Human cases of bird flu in northern Vietnam were found to show an epidemiological pattern and virological features different from those seen in the 2004 cases. They also differed from those currently seen in human cases in southern Vietnam and other Asian countries. These differences could indicate that the virus might already have been transmitted from human-to-human, though this is not proven as yet.

http://www.indianexpress.com/print.php?content_id=70922

 

[Martin]

Frantic race to curb bird flu






May 24, 2005





With bird flu endemic among birds in the Asian countryside, the disease could pose a threat to humans for years. REUTERS



Behind high gray double doors in Hanoi Professor Nguyen Thu Van, a simply dressed woman with black hair held back by a hairslide, has been laboring tirelessly with her team of researchers in a race to avert a pandemic.

Her white-coated co-workers scurried about one recent day in their small, second-floor laboratory in an elegant French colonial building in the Vietnamese capital. Engaged in a drive to perfect a human vaccine against avian influenza, Van, 50, has produced an experimental version and conducted successful tests on monkeys. She and her researchers have volunteered to be the first subjects in human trials, which she hopes will begin this summer despite warnings from the World Health Organization.

Van is at the forefront of a campaign in Southeast Asia to halt the progress of bird flu. International health specialists fear the virus could undergo genetic changes suddenly and become the most deadly disease to strike humanity in modern times. Almost 200 million chickens, ducks and other birds throughout Southeast Asia have died from the virus or been slaughtered to contain it in the last two years.

So far, bird flu has killed 54 people, mostly as a result of close contact with infected poultry. But international health experts say they suspect the virus has also begun to spread among humans.

With bird flu endemic among birds in the Asian countryside, the disease could pose a threat to humans for years. And in an age of global travel, health experts predict that an easily transmitted human strain could move beyond Asia in a matter of weeks and infect tens of millions of people worldwide.

When bird flu began spreading in Southeast Asia, governments in the region initially denied its presence. But a Thai doctor, Prasert Thongcharoen, sounded the alarm, issuing blunt declarations that forced Thailand to acknowledge early last year that the disease was decimating bird populations and beginning to infect people.

In Indonesia, the government has campaigned to vaccinate poultry across the vast archipelago, but tens of thousands of doses sit unused in government refrigerators while farmers leave their birds unprotected. A veterinarian named Suparno patrols the country's most populous island in an ambitious endeavor to prevent the virus from spreading.

Van's eyes gleamed with enthusiasm as she predicted Vietnam could become the first country to develop a human vaccine against the lethal H5N1 bird flu strain endemic among poultry in Southeast Asia. But WHO officials say Van's team has flouted international guidelines, saying that material used to develop the vaccine is potentially contaminated and the planned human tests involve imprudent shortcuts.

``We cannot wait,'' Van responded.


Prasert, 71, one of his country's most eminent virologists, literally wrote the book on influenza in Thailand, published seven years ago. He was a physician fresh out of school when the 1957 Asian influenza pandemic swept through Thailand, flooding his hospital with patients. Later, when an outbreak of Hong Kong flu reached Bangkok in 1968, Prasert was already emerging as a leading researcher.

In the fall of 2003, he learned that tens of thousands of chickens had begun dying in Thailand. The government was insisting the birds had contracted fowl cholera, a common affliction. As the world's fourth-largest poultry exporter, Thailand would suffer an economic blow if other countries learned its flocks were infected with bird flu.

Prasert decided to obtain more information. He visited a Bangkok market, where farmers confided they believed it was something worse.

``They said it wasn't like fowl cholera,'' Prasert recounted. ``If they have chickens that are sick with that, they give them tetracycline and they get better. But these chickens, by the next morning, they're all dead.''

Prasert's suspicions mounted in early December when friends who usually took him six or a dozen eggs after visiting their farm east of Bangkok came back empty-handed.

``They told me the farm is usually full of chickens,'' he recalled, ``but the chickens all died.''

In mid-December, researchers privately showed Prasert results of tests done on chickens revealing they had influenza. Prasert warned officials that urgent action was needed.

``I told them it is a public health concern and I would not close my mouth. I will talk even louder,'' Prasert said.

Senior ministers continued to deny the presence of bird flu throughout much of January 2004, according to Thai and international officials.

But in the first week of January, a six-year-old boy from a province west of the capital developed a high fever, followed a week later by symptoms of severe pneumonia. The boy was admitted to Prasert's hospital, and tests on January 22 came back positive for bird flu. He died three days later.

Prasert told the Health Ministry it was too late for a cover-up, he recounted with an ironic smile and narrowed eyes. The strain had reached humans.

On January 23, the health and agriculture ministers announced that bird flu had arrived in Thailand.


Suparno, the Indonesian government veterinarian, crouched in the cramped backyard of a farmhouse in a central Java village, clad in a tan uniform. He slowly drew the bird flu vaccine from a plastic container into a syringe. Then his fellow animal health officers brought five black hens, one by one, from a barn. Suparno inoculated each one.

There were 20 more chickens running around the farm, but they escaped the needle.

``Too hard to catch,'' Suparno explained before driving off. But by leaving most of the flock unprotected, the exercise was pointless. The remaining chickens could catch avian flu and sick birds, in turn, could infect even those that had been immunized. Vaccinated birds can still become carriers of the disease and transmit it to humans.



Tri Satya Putri Naipospos, Indo-nesia's national director of animal health, said Indonesia turned to vaccination because it was too costly to carry out widespread culling of flocks as Vietnam and Thailand were doing. By the time Indonesian officials acknowledged the presence of the virus, it had already infected much of Java, Bali and the Sumatra islands.

``The announcement of the government came very late,'' Naipospos admitted. ``Our laboratory people knew it already.''

She said senior Indonesian officials delayed acknowledging the disease after the outbreak in August 2003 because of intense pressure from the poultry industry, which was afraid it would hurt sales.



In the neighboring Sragen district, Sri Harjono, a farmer who runs a cooperative that has 23,000 broiler chickens, said he lost more than half of his flock after the initial bird flu outbreak in 2003. He restocked and began vaccinating in October, he recalled.


But no longer. ``It's too much hassle,'' he said, stroking a baby chick. ``You have to go one by one. Can you imagine vaccinating 23,000 chickens over and over?''

Educated partly in the Soviet Union, Van, the Hanoi scientist, later trained at the Centers for Disease Control in Atlanta, where she developed an interest in working on hepatitis. Her efforts to develop a hepatitis B vaccine in Vietnam helped her win appointment as general director of Vietnam's Vaccine and Biological Production Company No1.

As the number of human cases in Vietnam grew last year, a senior colleague suggested that Van try to reprise her success with hepatitis B by developing an avian influenza vaccine.

``It was difficult at the beginning because we did not have the experience,'' she said, but added that Vietnam could not afford to wait for vaccines being developed in the West, which she also feared would be exorbitantly expensive.

Vietnam publicly acknowledged the presence of the disease in January 2004, although Trinh Quan Huan, director general of preventive medicine, said the Health Ministry knew of it five months earlier.

Hospitals in the Hanoi area had already admitted 13 children and an adult with symptoms associated with bird flu, according to WHO. Twelve people had died.

Vietnam's current strategy of poul-try control measures has not tamed the outbreak. The government recently extended a ban on hatching ducks and other waterfowl, but enforcement has been erratic. The raising of all poultry in cities was recently prohibited.


After a study last month discovered that more than 70 percent of ducks and geese sampled in the Mekong Delta tested positive for influenza, the government ordered the slaughter of 1.5 million waterfowl, according to state media.

But experts with the United Nations Food and Agriculture Organization predicted that as long as farmers were offered only a fraction of the birds' value in compensation, they would refuse to cooperate.

Last year, Van's researchers developed the virus strain for the vaccine. The self-administered clinical tests are due to begin as early as August. If they are successful, Van says, she hopes Vietnam can produce about half a million doses by January.

WHO experts visited Hanoi earlier this year and warned that the material used to grow the virus strain in Van's laboratory was not approved by international health agencies. It was grown in cancer cells and could be contaminated, according to Michael Perdue, a WHO influenza expert. Perdue's team also told the Vietnamese that testing the vaccine on researchers rather than on true volunteers would be unethical.

Van's worry is that by the time the vaccine is ready, it will no longer be effective against an influenza virus that easily mutates. If the vaccine cannot be updated, she cautioned, Vietnam would be left vulnerable in the face of a mass killer.

``I'm confident it will work,'' she said, adding, ``I'm 80 percent confident we will succeed.''

http://www.thestandard.com.hk/stdn/std/Focus/GE24Dh01.html

 

[Martin]

Vaccine race to farms as all nature reserves close


May 24, 2005

Yaks in Qinghai province cross a mattress doused in disinfectant as part of aid measures to fight avian flu in the area. - REUTERS

China has closed all nature reserves in the country to visitors and rushed more than three million doses of bird flu vaccine to a remote western province after migratory geese were found dead from the H5N1 strain, which can be fatal to humans.

Poultry across far-flung Qinghai province had become the ``target of a compulsory vaccination campaign,'' said the China Daily Monday. Farms near bird migration routes elsewhere were also ordered to vaccinate poultry.

Scientists linked the deaths of 178 bar-headed geese in a Qinghai nature reserve early this month to the disease, and the media said it is the first report of H5N1 detected in the mainland since last year.

There have been no reports of the virus spreading to humans or domestic fowl, said officials. Qinghai Lake, the area where the dead geese were found the largest saltwater lake in the mainland, had been sealed off for 10 days.

``So far there has not been any human or any other poultry incident that has been reported and there are a lot of measures that have been taken in terms of prevention [and] in terms of vaccination,'' said Noureddin Mona, China representative for the Food and Agriculture Organization.

But World Health Organization spokeswoman Maria Cheng said in Beijing that ``there is still the possibility for this to jump to humans.''

The outbreak came as the Asian death toll in the latest bird flu outbreak rose to 54 Monday when another fatality was reported in Vietnam. The H5N1 strain has now killed 38 Vietnamese, 12 Thais and four Cambodians since it swept across large parts of Asia in 2003.

The WHO said last week the spate of human bird flu cases in Vietnam this year suggests the virus may be mutating in ways that are making it more capable of being passed between humans.

Experts said domestic poultry in China, the world's number two producer after the United States, could also be at risk.

``There is a significant possibility of that, given the fact that wild birds quite often use the same water sources and feeding sources as domestic ducks or domestic geese,'' said University of Hong Kong microbiologist Malik Peiris.

China has been on high alert against bird flu after outbreaks in North Korea and Southeast Asia, which prompted it to tighten quarantine controls. But Qinghai is far from the border and the media said the birds may have migrated from India for the mating season.


The affected area included an island in Qinghai Lake, said Xinhua News Agency, a major tourist attraction that is home to more than 100,000 birds.

Last year, China said it had controlled outbreaks of bird flu through vaccinations, culling and surveillance.


The latest outbreak prompted Malaysia to ban all imports of chicken and meat products from China.

Veterinary Services director-general Hawari Hussein said government departments have also been placed on a high alert, New Straits Times reported.


Hawari said he will be in Beijing later Monday to get more details on the deaths of the migratory birds.

 

[Martin]

Monday, May 23, 2005

U.S. must take avian influenza seriously


Preventing the fire is much easier than putting out a raging inferno
Like an inferno that jumps indiscriminately between adjoining wooden buildings, contagious diseases know no national boundaries. This trait should make international cooperation in fighting the H5N1 avian influenza virus a top priority for our own and every other government.

Just as preventing fires is easier than putting them out, there are concrete steps that should be taken now to delay, contain and mitigate a flu outbreak in Southeast Asia that the World Health Organization (WHO) increasingly fears has the potential to kill millions worldwide.

The bird flu, as the H5N1 virus is commonly known, appears to be adapting and evolving this spring in northern Vietnam. The virus is showing signs of becoming able to spread directly from person to person. Until this spring, virtually all who died caught the virus from infected chickens and ducks. Of 97 known cases, there have been 53 fatalities.

As the virus mutates, it is infecting a wider age range of people, but is killing fewer of those who catch it. Unfortunately, a declining rate of mortality isn’t a particularly good sign, since even a virus that kills one victim out 100 might cost tens of millions of lives around the planet. Killing fewer of those it infects also makes it easier for a virus to spread.

Prompt treatment with new anti-viral drugs has been effective in saving lives. This expensive medicine should be stockpiled and rapidly provided wherever needed in order to surround an outbreak area with a zone of people who have been treated and thus protected — a sort of firebreak.

Similarly, cooperation between technical experts, countries, manufacturers and financial donors is urgently needed to develop, produce and distribute supplies of H5N1 vaccine in currently infected nations. Not only would this save lives in Asia, it would limit the ability of the virus to spread outside that region.

One of the most important steps that can be taken is to vaccinate poultry in Vietnam, Thailand, Cambodia, Indonesia and other affected nations. WHO observes that where the infection in poultry has been controlled or eliminated, human cases no longer occur.

Among other recommendations, WHO also urges steps to increase the sharing of information on suspected outbreaks, as well as technical matters such as adapting the vaccine to counter future mutations of the virus.

The U.S. Centers for Disease Control is playing a valuable role in investigating the H5N1 virus and preparing to combat it. But it is debatable whether American attention and spending is on par with the danger represented by this incipient flu pandemic. We ought to be stamping out the sparks of this disease with all our might, before these sparks turn to flames that spread around the globe.


http://www.dailyastorian.info/Main.asp?SectionID=23&SubSectionID=392&ArticleID=24818