MANY restaurants have failed to vaccinate food handlers against hepatitis A but have invested in expensive fish tanks to stave off far less infectious cholera bacteria, the Community Health Education Foundation said. The foundation called for all food handlers to be vaccinated against the liver disease to protect diners. ''We would like to see the Government endorse the vaccination of food handlers and ultimately set up a vaccination programme,'' a spokesman said. ''But we know this is likely to take some time and so, in the immediate future, education of food handlers is the key to increase vaccination on an individual basis.'' Although both diseases can be transmitted by contaminated food, hepatitis A is about 1,000 times more infectious than cholera. While there have been 31 cases of cholera this year, there were 422 cases of hepatitis A in only the first six months. The World Health Organisation has said the food service industry should be advised the vaccine was available. But the Health Department said it was not routinely recommending it. A cost-benefit study of the vaccine in Hong Kong found that the average cost of treatment for hepatitis A was more than $7,000 per person, while the course of three injections, which offers protection for 10 years, costs about $1,000. With fewer than five per cent of people contracting the disease in Hong Kong in any one year, the study found that vaccination of the entire population would not be cost-effective. However, researchers backed the vaccination of high-risk groups, including food handlers, as being a worthwhile investment. The president of the Federation of Hong Kong Restaurant Owners, William Mark, said some big restaurants had vaccinated their employees, but smaller businesses would need to be educated to do this. ''All restaurants are very hygiene-conscious and most food is cooked properly in temperatures high enough to kill all germs, but I still think vaccination against hepatitis A is a good idea,'' he said. ''Although I think the Government should do more in this area because it has the responsibility to make sure the standard of hygiene in restaurants is improved.''