Over the last 13 years the idea of central slaughtering for chickens has gone from being seen as the solution to the threat of bird flu, and necessary to prevent the spread of dangerous diseases, to being seen now as no longer needed at all. Officials have shelved it - and ensured the survival of the live-chicken trade - because they say the current risk of bird flu is low. That may be true at the moment. But the death from bird flu of a woman on the mainland this week serves as a timely reminder that the virus may return to our city at any time. There is no room for complacency. Everything must be done to keep the risk low, especially the enforcement of prevention measures. It is disturbing, therefore, that contrary to rules and guidelines put in place to safeguard public health, many traders of live chickens refuse to abandon their old ways. The reduced risk is due in part to a drop in the number of live-chicken stalls from more than 800 to 133 in two years, and a big switch to consumption of chilled and frozen birds. Apart from a ban on keeping chickens overnight, the remaining stalls are also supposed to follow tougher hygiene rules and guidelines aimed at preventing an outbreak among their birds. A day after the government shelved central slaughtering, observation of stalls and markets in Kowloon and on Hong Kong Island suggested that few vendors were adhering to the rules or guidelines. Many slaughtered chickens with their bare hands, without washing afterwards. Some kept them in overcrowded cages, some cages were not the required 30 centimetres above ground and at least two stalls kept birds of different species together. In the wake of the discovery of the virus in wet markets, the rules were drawn up to safeguard public health pending the opening of a central slaughterhouse. If we are not to get one because the risk is now perceived as low, that is no reason to relax enforcement, or leave compliance to the discretion of people in the trade, who tend to dismiss the risk. On the contrary, we now depend on such measures to keep us safe. There may have been no outbreaks among poultry in the city since 2008. The World Health Organisation may have confirmed only 11 cases of H5N1 infecting people in Asia this year to the end of April. But the highly contagious virus is far from controlled. Past experience shows it can easily catch us off-guard. The deadline for establishing a central slaughterhouse was repeatedly delayed because of opposition from the poultry trade and residents near potential sites. The government shelved the plan after considering a consultant's report that it was no longer financially viable. That does not alter the fact that it would have safeguarded us from bird flu by ending the live-chicken trade and preventing human contact with birds that may be carrying such viruses. Hong Kong was the first city to suffer a human outbreak of the disease, when six people died in 1997. The live-chicken trade was implicated then, as it was in the appearance of the virus in wet markets. Secretary for Food and Health Dr York Chow Yat-ngok says the shelving of central slaughtering will not necessarily be permanent as the virus itself and the risk could change. We trust that if the idea has to be revived the government will act more decisively in the public interest. Its past record of dithering does not inspire confidence. Meanwhile, the public is entitled to reassurance that officials will not relax their vigilance, and will redouble their efforts to ensure compliance with rules and guidelines to safeguard our health.