The number of new HIV cases recorded in the city is set to hit a record high for the fourth year running and may pass 600 for the first time, a government consultant says.
Some 304 new cases were diagnosed in the first half of the year, Dr Wong Ka-hing said, well up on the 262 new cases reported in the same period last year. There were 559 new HIV cases in the whole of last year.
The figures, and the fact many young people were among those affected, have raised concerns that the message on the importance of safe sex is not getting through.
Wong, a Health Department consultant, said that gay men made up the biggest group of new patients, in line with international trends.
"It is worrying. It is likely that the annual figure will surge past 600, which will be the highest figure in Hong Kong history," Wong said yesterday.
Of the 150 new cases reported between April and June, more than 80 per cent were men, of whom more than half had had sex with other men. Some 16 per cent of cases involved heterosexual sex, while 2.7 per cent were contracted through injections. More than a quarter had an undetermined cause.
A department survey last year found that only 70 per cent of gay men wore a condom during sex, compared to 90 per cent for female sex workers, another high-risk group.
"The trend for HIV to infect men who have sex with men has increased significantly in recent years, while the figure for the heterosexual group remains stable," Wong said.
Last year's figure of 559 was a nine per cent increase on the 513 cases in 2012.
The new cases this year bring the total number reported since records of HIV cases began in 1984 to 6,646.
Two Aids concern groups expressed particular concern at the number of young people contracting HIV; 59 of the 150 patients diagnosed in the second quarter were aged 29 or younger.
Aids Concern said the number of young HIV patients was "alarming". It plans to conduct 60 sex-education workshops for young people.
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Jim Hoe, programme manager for the organisation's youth work, said he believed the increase was partly down to deficiencies in sex education - and where women had been infected - the mistaken belief that only men had a say on whether a condom was used in sex.
The Hong Kong Aids Foundation said it would step up education to promote safe sex, especially among young gay men, and encourage those who had unprotected gay sex to take HIV tests.
Without treatment, about half of those who contract HIV will go on to develop Aids within 10 years. Receiving treatment reduces the possibility of developing Aids by 90 per cent.
Aids is characterised by major clinical complications related to suppressed immunity.
There were 40 new Aids cases reported between April and June, bringing the overall number of cases to 1,497 since 1984.