Hong Kong builds strong bird flu defense -- with the `Birdy Song'

To the tinkle of one of the most irritating pop songs ever written, Hong Kong has built up the world's most elaborate defense mechanisms against bird flu and made itself a role model for the region.

Public service announcements using the 1980s hit The Birdy Song by The Tweets as a backdrop have blared out of radios for more than two years, carrying advice on avoiding bird flu which it now seems neighboring countries would have done well to tune into.

The broadcast alerts poultry sellers to mandatory monthly "rest days" when they must close and disinfect market -- a measure introduced to fight H5N1 which Hong Kong has been battling for more than six years.

Until this year, the former British colony was the only location where the H5N1 had made that crucial jump across the species barrier and killed humans.

In 1997, 18 people in Hong Kong became the first recorded human victims of the virus. Six of them died. The outbreak caught everyone -- scientists and medical experts included -- by surprise, and officials had the entire poultry population culled.

The move was criticized at the time as extreme but it succeeded in halting the spread of H5N1 and experts have since praised the quick reaction, saying it prevented the virus from mutating into something much more deadly to humans.

The scare was real enough to make Hong Kong take the virus seriously and while the rest of Asia -- and the world -- moved on, the territory began to look more closely at the virus and put into place a set of measures to try to ensure it never happened again.

Four rest days a month were introduced in markets to break the virus cycle and bio-security was increased in farms. This included the vaccination of all chickens and the "bird-proofing" of farms to prevent the introduction of the virus from wild birds.

Chickens are also tested for antibodies to ensure the vaccine is effective while those imported from the mainland have to be vaccinated and come from registered farms which are closely monitored. In addition, the government also monitors any unusual deaths of both in farms, markets and in wildfowl.

At the market, different kinds of birds are segregated to prevent different avian viruses mixing -- as was the case in the 1997 outbreak which proved fatal to humans after mixing with goose and quail viruses.

Even humans have not escaped and hospitals and clinics now take part in an influenza surveillance programme which monitors flu and respiratory illness trends.

Hong Kong is now also the base for some of the world's top experts in avian flu while the experience of SARS added much weight to the feeling about taking viruses very seriously.

It is not surprisingly therefore when stories began emerging of a deadly bird flu virus in Vietnam, Hong Kong reacted quickly. While countries like Thailand -- which avoided SARS last year -- sat back and feasted on chicken dinners served with generous amounts of complacency, Hong Kong stepped up preventative measures.

So far, the measures have worked and Hong Kong appears to be a refuge in a troubled sea of Asia. Professor Roger Morris, an expert in avian flu from Massey University in New Zealand said as a result of the controls "the risk [of an avian flu outbreak] was lower than anywhere else in the world."

But for how long? Past experience has shown vaccination and surveillance is not 100 percent effective. There have been four other outbreaks since 1997, though none of these spread to humans.

There are concerns that vaccination is not the ideal solution. The Dutch-made vaccine currently in use in Hong Kong is around 80 percent effective against the 1997 strain on which it is based. But any mutation of the virus could drastically reduce its effectiveness, say experts.

More alarmingly, a report in the latest edition of the British journal, New Scientist, claims the current strain originated in southern China.

The article suggests it spread because the vaccination used was not a good match to the current strain. As a result, chickens infected appeared healthy and were exported carrying the virus all over Asia.

Earlier this week Hans Wagner of the UN Food and Agriculture Organization (FAO) said: "We don't like vaccination," while the WHO expressed dismay at the announcement by Indonesia that it is tackling its outbreak with vaccinations not culling.

On Thursday in Hong Kong legislator for the medical sector Lo Wing-lok appealed to Asian countries infected to instigate mass culling, saying the territory had learnt from experience that it was the most effective way of trying to curb its spread.

"I am quite worried about the situation.," Lo said.

"It appears to be getting out of control. Culling must be done and it must be carried out quickly and boldly."

Controlling the spread by watching imports of chickens, is ineffective from an air attack which could come from migrating wildfowl birds who are known to carry the virus.

Speaking at a crisis meeting of Asia's leaders in Bangkok earlier this week, Hong Kong Health Secretary Yeoh Eng-kiong said: "The preventative and surveillance measures introduced have reduced the risk of occurrence of large-scale avian outbreaks in Hong Kong."