HIV infection is on the rise in Hong Kong, with a 30-year high of 513 new cases recorded last year, health authorities say.
The cases marked a 17 per cent rise from 2011, Dr Wong Ka-hing, consultant to the Department of Health's special preventive programme, said yesterday.
In almost half the new cases, the virus was transmitted through homosexual contact between men.
"The increase of HIV transmission among men who have sex with men is a global trend," Wong said.
"It has been increasing in the past decade, first in Western countries, then in Asia."
Homosexual contact between men accounted for 254 of the new HIV cases - the highest number for any year since Hong Kong started records in 1984.
More than 4 per cent of gay men are estimated to have contracted HIV, compared with less than 0.1 per cent in the general population.
Although more people at risk were aware of the need to undergo check-ups, most were diagnosed at a relatively late stage, which made their treatment less effective, Wong said.
"Men who have homosexual contact have a lower awareness of using condoms, regardless of [whether or not they have] fixed partners," he said.
Alice Chan Lai-hing, chief executive of the Society for Aids Care, said men who engaged in homosexual sex were increasingly aware of the need to get regular check-ups for HIV.
Chan called for more promotion and education by the government, and for more resources to be allocated for support services.
The government set up the Aids Trust Fund in 1993 with HK$350 million, to provide assistance to HIV patients and conduct public education on Aids, but had added no new funding since then, she said.
About one-quarter of last year's new cases came from heterosexual contact and another quarter was undetermined.
A small number were caused by intravenous drug use, bisexual contact, blood contact and transmission shortly before or after birth.
Wong called on high-risk groups to undergo regular testing for HIV every six to 12 months.
Such people include men who have homosexual contact, female sex workers and their clients, users of intravenous drugs and spouses or regular partners of HIV carriers.
Since 1984, the city has recorded 5,783 cases of HIV infection. Of that total, 1,353 have developed Aids, which is defined by illnesses such as infections and cancers brought on by lowered immunity.