It's difficult talking to sex workers and it's even tougher to get them to sit down and listen to AIDS prevention training, Xu Huifang, a health worker in Guangzhou, capital of south China's Guangdong Province, said with a wry smile.

Over the past eight months, Xu and her colleagues have been visiting the city's entertainment venues, persuading sex workers to use condoms to keep them safe from HIV/AIDS.

"We were not welcomed in the beginning, but we tried hard to get close to them and things got better," said Xu, director of the HIV/AIDS prevention section with the city's center for disease control and prevention.

Xu is a member of a municipal task force, aimed at promoting condom use among the city's sex workers. The task force now has over 180 health workers.

Various ways have been tried to gain the trust of sex workers. "We use their jargon in training to make communication easier. Sometimes we invited them for dinner," Xu said.

The health workers also sought support from managers of the entertainment clubs, who helped persuade sex workers to attend the training.

Health experts estimate that more than 40,000 people have been infected with HIV in Guangdong.

So far, more than 30 free training sessions on HIV/AIDS prevention have been held by Xu and her colleagues with participation of more than 1,000 sex workers. The health workers have also distributed more than 30,000 free condoms in the city.

According to estimates from the health ministry, World Health Organization and UNAIDS, China has about 650,000 people living with HIV/AIDS, including 75,000 who have developed AIDS.

Thirty-seven percent of HIV infections were caused by illegal drug users sharing contaminated needles and 28 percent caused by unprotected sex.

Hao Yang, deputy director of the ministry's Bureau of Disease Control, said transmission through unprotected sex is on rise, with the infection rate of sex workers rising from 0.02 percent in 1996 to one percent in 2005.

Surveys show only 38.7 percent of sex workers use condoms. In an attempt to stop HIV/AIDS spreading from high-risk people to the general public through sexual contact, China is working with the WHO to launch 100 Percent Condom Use Programs in Hubei, Yunnan, Hainan, Jiangsu and Gansu provinces and Xinjiang Uygur Autonomous Region.

In Danzhou, Hainan, the rate of condom use in commercial sex activities rose by 33 percent and the incidence of sexually transmitted diseases such as gonorrhea dropped significantly since the project was introduced.

Dr Wiwat Rojanapithayakorn, HIV/AIDS team leader in the WHO's Beijing office, said providing condoms in entertainment places could curb the spread of HIV.