Number of new H.I.V. infections at record high
Of the 438 cases emerging last year, 43 per cent resulted from infections via male homosexual activity, health department report says
The 438 new cases last year marked an increase of 12.6 per cent from 389 in 2010.
Overall, HIV prevalence in the city is estimated at under 0.1 per cent - low by international standards, which define infections to be widespread if more than 1 per cent of the general population is affected.
Infections through male homosexual contact was a prevailing trend, said Dr Wong Ka-hing, a consultant with the department's Centre for Health Protection.
"The rise in infections in men having sex with men has been obvious since 2005, being the highest among all high-risk groups," Wong said. "The trend is also seen in other parts of Asia."
There were 188 such cases last year, a 12.6 per cent rise from 2010. This mode of transmission made up 43 per cent of the 5,270 cumulative HIV infections last year. HIV prevalence in the group is about 4 per cent.
HIV, or human immunodeficiency virus, is the cause of acquired immune deficiency syndrome (Aids), which is characterised by clinical complications such as infections and cancers due to a suppressed immune system. The most common Aidsrelated illnesses in Hong Kong are pneumonia and tuberculosis.
Wong said more gay men sought to test for HIV, which was a good sign.
In fact, more people had undergone the test in recent years. The proactive approach explained the high overall infection number, Wong said, but it was disappointing that the declines posted in 2009 and 2010 did not continue.
He warned people not to delay the diagnostic test, citing the finding that 95 per cent of 82 new Aids cases last year were patients diagnosed with HIV less than three months ago.
"This shows that many people have been infected for a long time before being diagnosed," he said. "They are not alert enough to get tested and this is not good for treatment."
Without treatment, about half of HIV patients would progress to Aids within 10 years, he said.
Recent international studies found early treatment more effective, contrary to previous advice, he said. It would also help prevent disease, as treatment decreases the amount of the virus in body fluids, thus reducing the chances of transmission.
A cocktail of drugs is the mainstream treatment. But it only suppresses the virus, so taking medication is a lifelong necessity. It was effective; more than 90 per cent of patients who took the medication regularly were able to suppress the disease, he said.
He urged high-risk groups, such as people engaged in homosexual activities, sex workers, and drug users using syringes, to undergo regular check-ups. Safe sex using condoms was the most effective preventive method, he said.