Homosexual sex has been blamed for the highest number of new HIV cases in 30 years.
An expert said unless men who have sex with men, or MSM, consistently practice safe sex, there will be another record high this year.
The Centre for Health Protection said yesterday that homosexual or bisexual exposure was responsible for 295 of the 559 newly reported cases last year, with 137 infections through heterosexual contact.
The 559 new cases was the highest for a single year since records were first kept in 1984 and marked an 8.9 percent rise on the 513 cases in 2012.
The new cases take the cumulative total of HIV infections reported locally since 1984 to 6,342.
Center consultant Wong Ka-hing acknowledged that increasing infections among gay and bisexual men make prevention and control "increasingly important and increasingly difficult."
Government and non-governmental organizations have been trying hard to contain the rising epidemic among these men, Wong said.
"We have to face the reality and the MSM community has to be aware of this and take all the necessary precautions to try to prevent infection," he said.
Wong said conveying the message across the MSM community to wear condoms "consistently and correctly" is sometimes difficult and "harder still to make them buy the idea." He called for more effort, publicity and education.
AIDS Concern yesterday urged individuals who had unprotected sex to take the HIV antibody test as soon as possible to learn about their infection status.
Its chief executive Andrew Chidgey is concerned that people with HIV who have not received treatment are putting their health at risk and should reach out for medical assistance.
Free, anonymous and confidential HIV tests can be obtained by calling the Department of Health's AIDS hotline 2780-2211.