Those on the front line of the sex industry are shunning HIV/AIDS prevention services for fear of exposure after a crackdown on prostitution in Dongguan, Guangdong province.
According to the head of the Tianjin Xin'ai Cultural Center - a nongovernmental organisation committed to HIV/AIDS intervention among low-end sex workers in the city - the organisation's work just got a lot more difficult.
"We used to cover more than 700 low-end sex workers in the city and many of them now reject our services," said the NGO head, who did not want her name to be used.
The campaign in Dongguan came hours after a China Central Television programme revealed that high-end hotels in the city were offering sex for sale.
Police have held more than 500 suspects in more than 1,300 cases of organising, soliciting or introducing sex services in Dongguan since Feb 9.
Many other cities have since stepped up efforts to crack down on prostitution.
The women that the Tianjin Xin'ai Cultural Center helps work mostly at massage parlours.
The majority come from impoverished rural areas, have little education and low health awareness, especially regarding STDs, the head of the NGO said.
They are mainly between 35 and 55 years old, she said. "Some can't even read the AIDS prevention brochures we distributed."
Nearly 20 per cent of the sex workers had syphilis, she said, although this number is declining through intervention.
"It's far easier to deliver intervention services at large, high-end parlours, like at those hotels in Dongguan," she said.
Sex workers there are usually younger women who have higher health awareness and are more likely to use condoms with their clients, she said.
In 2012, AIDS control workers tested 1.36 million sex workers nationwide for HIV, and 1,130 tested positive.
"Prostitution definitely played a role in this figure, and sex workers have long been high on our working agenda to curb AIDS," said Wu Zunyou, director of the National Center for AIDS and Sexually Transmitted Disease Control and Prevention.
However, he said, that requires cooperation from public security and health authorities.
In 2010, Dongguan started a programme to help prevent HIV/AIDS among sex workers.
Under the programme, funded by the Global Fund to Fight AIDS, Tuberculosis and Malaria, the disease control and prevention centre in Dongguan conducted HIV/AIDS intervention targeting 12,500 sex workers in the city, according to Guangzhou Daily.
Lin Peng, head of the Guangdong CDC's sexually transmitted disease division, said that by the end of 2012 the number of HIV/AIDS cases reported in Dongguan accounted for 3.8 per cent of the more than 36,000 cases in the province.
In 2012 alone, Guangdong reported 6,454 HIV/AIDS cases, 502 of them in Dongguan.
More than 80 per cent involved heterosexual transmission, higher than the national 70 per cent average, he said.
"Many of the infected were male migrants in the city who lived away from their spouses," he said. He added that 86 per cent of those reported in 2012 were non-locals.
"It's harder to reach migrant workers through intervention efforts," he said.