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Not Forgotten

WHO says avian infuenza remains a major concern


January 10, 2008
By Jim Knisley


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The near panic and high profile that avian influenza generated a couple
of years ago has quieted. But it is neither gone nor forgotten.

12The near panic and high profile that avian influenza generated a couple of years ago has quieted. But it is neither gone nor forgotten.

The relentless run of news as AI – commonly referred to as bird flu – spread from China to southeast Asia into Africa and reached then into Europe has been replaced by episodic reports of the latest outbreak. Most recently this was the outbreak on a turkey farm in Britain.

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That outbreak was quickly controlled and put down.

In much of the world it seems that what had been near panic is being replaced by preparedness. There has been a continuing relentless drive to gain greater understanding of the disease, how it spreads and how it can be controlled.

There has been progress on all fronts. For example, biosecurity is the watchword  across North America and Europe. Gaining entry to most poultry barns is like breaking into a bank except banks don’t make you shower in and shower out, they don’t require you to wear sanitized coveralls and booties and they don’t have big signs scattered around advising that the area is a biosecurity zone.

On the science front, the AI genome has been broken down and analyzed with subtle mutations noted.

Mathematical modelers have worked out how the disease spread from barn to barn and farm to farm in past outbreaks.

A lot of work has been done on the best ways to dispose of infected birds to prevent further spread of the disease.

A human vaccine has been licensed, poultry vaccines are available and recommended in areas where the disease is endemic, tamiflu has been shown to be effective if given as soon as the infection has been identified and not just as a prophylactic, and governments are stockpiling the drugs.

But as much progress as has been made AI remains a major international health concern. It persists in Indonesia and southeast Asia. It is in Egypt and parts of Eastern Europe.

The World Health Organization diligently tracks the disease case by case day by day.

Last year ended with reports of outbreaks in Korea and Vietnam. The Korean outbreak was reported Nov. 22, the first outbreak since 2004, while on Dec. 19 the first Vietnamese outbreak in four months was reported in unvaccinated poultry.

The year ended with Egypt reporting its 16th, 17th and 18th human cases. The Egyptian viruses showed a mutation that gave the disease “moderately reduced susceptibility to oseltamivir,” the treatment recommended by the WHO.

This year began with Indonesia reporting its 75th, 76th and 77th human cases of the disease. Through the first four months of the year Indonesia reported four additional confirmed human cases with Indonesia’s Ministry of Health reporting that additional human cases continue to occur.

Since the start of the year, Egypt has reported more than a dozen confirmed new cases while Nigeria reported its first confirmed human case.

Meanwhile, Japan, Thailand, Vietnam, Hungary, Russia and the United Kingdom all reported H5N1 in poultry in January. In February, Pakistan, Turkey, Laos, Afghanistan, Kuwait, and Myanmar reported the disease in poultry.

In March, China reported finding H5N1 in poultry for the first time in six months and Bangladesh reported its first-ever case.

In April, Saudi Arabia reported its first case and Cambodia reported its first case in seven months. With the reports on new or additional outbreaks the WHO cautioned against complacency in late April.

Jean-Marc Olive, the WHO representative in Manila, said the mass culling of poultry must be accepted in order to prevent a human pandemic and governments should boost their capability to prevent the spread of the disease, strengthen surveillance and prepare for any outbreak.

Olive said that a pandemic could infect at least one billion people and cause the death of between two and seven million, in a matter of weeks.

The WHO prediction is based on models derived from previous flu epidemics, he said.

He added that even a modest pandemic lasting over one year might cause losses as high as three per cent of Asia’s gross domestic product and 0.5 per cent of the world’s gross domestic product.

The WHO says that since 2003, a total of 172 people have died from the H5N1 strain of bird flu, with most of the deaths in southeast Asia.

Virtually all those infections were a direct result of contact with infected birds.

However, the fear is that the virus could mutate and allow human-to-human transfer and WHO says that threat cannot be predicted. n