More than 85 percent of new cases of HIV and AIDS in Guangdong province resulted from unprotected sex, a senior health official has revealed.

The figure has risen sharply from 57.4 percent just two years ago, and is well up on the 37.6 percent of 2008, according to the Guangdong Center for Disease Control and Prevention.

"The steady growth in HIV and AIDS is a serious threat," said Lin Peng, head of its HIV/AIDS prevention center.

He called for measures to help slow the spread.

Guangdong, which borders the Hong Kong and Macao special administrative regions, recorded 1,708 new cases of AIDS in 2012, a year-on-year increase of 12.1 percent, and 4,746 cases of HIV in 2012, up 10.2 percent.

"About 17 percent of AIDS victims detected in the previous year were citizens aged over 50. That figure has steadily grown every year since 2007," Lin said.

He said more than 60 percent of the province's HIV and AIDS patients were drug addicts or homosexual men infected through intravenous injections or blood transfusions before 2009.

From 1986 until the end of June, Guangdong reported 12,736 registered AIDS patients and 36,763 HIV carriers. More than 10,000 have died.

More than 80 percent of new cases were found in Yangjiang, Shenzhen, Guangzhou, Jiangmen, Dongguan and Yunfu.

Wang Longde at the Chinese Academy of Engineering, previously a vice-minister of health, said sex is now the major channel for the spread of HIV and AIDS on the mainland, taking over from blood transfusions and illegal drug use.

He urged authorities to improve AIDS prevention awareness among residents to combat the spread nationwide.

"HIV and AIDS patients should also be well cared for and should not be discriminated against," the academic said in a lecture last month.

He said the mainland has more than 500,000 registered HIV and AIDS patients, and estimated there are another 300,000 who are undiagnosed.

HIV/AIDS prevention workers distribute condoms to migrant workers at a Foxconn factory in Shenzhen on Nov 24 to promote the use of protection measures. Chen Wen / China News Service