Hong Kong has been invaded by sushi. The fashion is especially prevalent among Hong Kong's youth who flock to the discount sushi bars springing up all over the city. Japan has been playing a leading role in influencing the tastes and ideas of Hong Kong youth for some time, quietly usurping the more distant, alien and non-Asian trends from Europe and North America. Sushi is also attractive because of its sophisticated, expensive image. The preparation of good quality sushi in Japan is considered an art form. Shokunin - sushi chefs - serve an apprenticeship of at least seven years before they are considered competent. In Hong Kong such skilful practitioners are only found in expensive Japanese restaurants and exclusive hotels. The sushi served at the Genroku, Genki and Genwa chains is not prepared by shokunin but by employees with, at best, a very basic training in culinary technique. The reasons for this are obviously economic. Sushi entrepreneurs rely on the low cost of their product, together with the image inherited from the upmarket origin to produce their profit. And profits must be good because these three companies are all preparing to open more outlets. Another factor in sushi's success is a perception that it is good for health. The Japanese diet is low in cholesterol and heart disease is uncommon. The Japanese take pride in their fastidious cleanliness and the quality and freshness of their food. But in August, this confidence was dealt a deadly blow. The outbreak of food poisoning which killed 11 and produced dangerous symptoms in 9,400 has left concerned parents unsure how best to feed their children safely. The culprit, E-coli 0157:H7 colon bacillus bacteria, has made its home in a variety of food stuffs. Since the outbreak was first reported the 0157 bacteria, as it came to be known, has been associated with raw meat, beef offal, cooked eel, rice, radish sprouts, chicken, noodles, bean paste jelly and raw fish. Most sushi consists of cooked, cooled rice and raw fish. Bacteria multiplies in raw fish unless it is stored at regulated temperatures. Infections can be passed on by unhygienic handling and sushi production is certainly a hands-on business. Recent Health Department surveys have found that 25 per cent of the sushi tested in Hong Kong had bacteria levels above acceptable levels. When it comes to raw fish the price of a fashionable lifestyle could be a spell in the infectious diseases ward. Traditionally southern Chinese eat little raw food, even in these days of refrigerators and freezers there seems to be a lingering fear of disease. Retailers are understandably reluctant to talk about health scares and the food stuffs that they are selling. None, however, reported any decline in sales as a consequence of the Japanese bacteria alert or the Government's Health Department findings. Seibu, which has a counter serving sushi next to its Coo food hall reported no change although staff were 'too busy' to back this up with figures. The Grand Hyatt's highly regarded Japanese restaurant, Kaetsu, says business has increased in the past few months because customers have confidence in their hygiene standards and their well-trained chef. As far as the lower end of the market was concerned we have to rely on empirical evidence because responses to enquiries were not forthcoming. The branch of Genroku Sushi next to Times square in Causeway Bay was packed with young diners plucking raw fish and rice from the eye-level conveyor belt and the queue of eager youngsters stretched into the street. In these days of automated, industrialised food production, special care has to be taken to ensure it remains safe, healthy and uninfected. No one is saying this is ignored in Hong Kong, but if it ever were the consequences could be grave.