The Centre for Health Protection's senior medical officer, Raymond Ho Lei-ming, warned that if the trend continued, this year could see a record number of new cases of the virus, which can lead to full-blown Aids.

The new cases took the total number of infections to 2,914. Of these patients, 799 have Aids. Seventeen people with HIV developed Aids in the first three months of this year.

Of the new HIV infections, 52 were contracted from sexual contact and eight from drug use. The cause of infection of the other 29 was not known.

Dr Ho blamed the high rate of infections on over-optimism for treatment for the virus and a lack of awareness of the need to practise safe sex.

'People think cocktail drug therapy can delay the progress to full-blown Aids and can help control their illness, and such an attitude lures them into continuing to engage in high-risk activities,' he said. He warned that while cocktail drug therapy can improve the lives of patients, there was still no cure for Aids.

The chief executive of Aids Concern, Loretta Wong Wai-kwan, urged the government to put more resources into public education, especially for cross-border travellers, about the risks of contracting HIV. 'There is little information about what they do on the mainland. Their condom usage rate is not known, nor do we know if they have unsafe sex. And their mobility is very high.

'This group of people threatens an Aids epidemic in Hong Kong.'

Ms Wong said the lack of information about travellers hindered efforts to prevent the spread of HIV. 'If we can learn more about them, then we can conduct campaigns which target their needs and help them more effectively,' she said.

Dr Ho also expressed concern over the increasing burden on government medical expenditure of HIV/Aids treatment.

'Every year the government spends about $100,000 on each patient just for buying drugs,' he said. Antiretroviral drug therapy was provided to HIV sufferers at almost no cost, he said.

Ms Wong said many patients were worried the government might pass the cost of treatment onto them. 'We hope the government will continue to offer subsidy and the policy will not be affected by medical reforms. As long as Aids patients can stay healthy with the help of medication, they can also work and make an economic contribution to society,' she said.

'The most important thing is, every patient should have a chance to receive treatment regardless of their financial background. This principle should be applied to all patients in Hong Kong, no matter what diseases they have.'