LEGISLATORS plan to pressure the Government to improve its handling of cholera as the number of cases has reached its highest level for 30 years. The number of cases for the year so far is 34, the highest since 1964 when there were also 34 cases. Three cases have been reported in the past two days, bringing this month's figure to 10 and the number now in hospital to five. Councillors say the Government should step up efforts to stop the bacterium getting into food, particularly from dirty harbour water. Polluted water used to keep fish in restaurants was blamed for a single outbreak among 12 people in Aberdeen in June. Only five of the several dozen restaurant water suppliers have requested permits to enter Sai Kung Country Park to collect water from the site recommended by the Environmental Protection Department, according to the Agriculture and Fisheries Department. An Urban Services Department representative said it could not stop water trucks taking water from the polluted harbour, despite recommending that restaurants avoid such suppliers. There have been no prosecutions under by-laws requiring restaurant water to meet certain standards. Weekly meetings of the inter-departmental working group on cholera control, comprising heads of departments and led by Secretary for Health and Welfare Elizabeth Wong Chi'en Chi-lien, ended on July 30 after no cases had been reported between July 10 and 21. Yesterday a 42-year-old man was admitted in fair condition to Yan Chai Hospital. He was thought to have contracted cholera while travelling in China. But two people admitted on Wednesday, a 61-year-old woman from Tsuen Wan and a 75-year-old man from Kwai Chung, were both in poor condition in Yan Chai and Princess Margaret hospitals. Both cases were contracted locally. The woman's 22-year-old daughter was found to be a symptomless carrier of the bacterium and was being treated with antibiotics. The World Health Organisation has warned health services worldwide of the presence of cholera in Hong Kong. Geoff Davis, senior consultant at Australia's Department of Health in Canberra, said he was warning travellers to take extra precautions with what they ate and drank during their Hong Kong holiday. ''We would certainly say there are foods you should avoid if you are not confident about them - think seriously about seafood,'' he said. Department of Health principal medical and health officer Leung Ting-hung stressed that after routine testing of the patients' food, home and family, all the cases were found to be isolated. He stressed that people must wash their food and cook it thoroughly, and keep themselves clean to avoid catching the disease. But legislator Albert Chan Wai-yip said he would keep pushing for a change in the Water Control Ordinance to make it an offence to take water from the water controlled zone. ''The situation is definitely not satisfactory,'' he said. Following the publicity during the Aberdeen outbreak, he had seen no major policy change from the Government. ''This is normal government practice. They take some action but when [the problem] dies down they just wait for another crisis.'' He said the Legislative Council health panel should ask for a report from the cholera working group to check the effectiveness of its measures. Health care legislator Michael Ho Mun-ka said that using harbour water for fish ''must be stopped'' and a public grading system of restaurant hygiene, proposed by Mrs Wong and ''under consideration'' according to the Urban Council, should be introduced. ''A lot of things have been progressing slowly or not progressing at all,'' he said.