Bird flu vigilance can never waver

PUBLISHED : Thursday, 22 December, 2011, 12:00am
UPDATED : Wednesday, 06 May, 2015, 4:39pm


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Bird flu remains the single biggest threat to public health in Hong Kong, the site of the first outbreak of the deadly disease among humans in 1997. The reappearance of the H5N1 virus in our live-chicken market has prompted health authorities to implement drastic precautionary measures. As a result of the mass slaughter yesterday morning and a 21-day ban on wholesale and retail supply, there will be no live birds for family's winter solstice celebrations. Health minister York Chow Yat-ngok rightly makes no apology for the disappointment and losses to the poultry trade. Our city's elaborate defences have, once again, been breached. Even if only a single bird is implicated, no effort can be spared to prevent and control the spread of the virus.

It is just over a year since the last bird flu scare - the infection of a 59-year-old woman who had recently been to the mainland. It is three years since an incident comparable with the latest alert - the discovery of the virus in dead chickens at a Yuen Long farm. A worry then, as now, is that birds supposed to have been protected by vaccination were affected, raising concerns that the effectiveness of the vaccine was fading.

Meanwhile, bird flu has killed more than 330 people around the world, with Indonesia the worst hit. Infection almost always occurs from direct contact with infected birds, since the virus still does not pass easily from person to person. But that could give rise to a false sense of security. Dutch scientists commissioned by the US National Institutes of Health to study how the virus might mutate to become more transmissible between humans not only created new strains that spread more easily, but made a worrying finding - it appeared easier than they had thought for it to evolve in a way that lets it spread easily among at least some mammals.

The government has raised its bird-flu response level from 'alert' to 'serious' and launched sweeping preventive and precautionary measures. These include checks on the market, stalls selling live poultry, local farms and mainland poultry suppliers. This is a well-tried response on which we continue to rely, since the government abandoned plans for a central slaughtering system after a consultant reported that it was not financially viable. Central slaughtering would end the live-chicken trade, which was implicated in the initial 1997 outbreak of H5N1 in humans that killed six people.

The government relied on expert advice about the threat level. Any evolution of the virus should give cause to reconsider, while the the reappearance of H5N1 in markets is also reason enough for a rethink. Sadly, so long as Hong Kong people believe the risk does not warrant forsaking a culinary preference, they will have to be prepared for it to be put off-limits from time to time for the sake of public health.