China has seen a tenfold increase in syphilis cases over the past decade, as migrant workers made enough money in the country's economic boom to hire more prostitutes, a senior Chinese health official was quoted as saying Tuesday.

The sexually transmitted disease re-emerged in China during 1980s after being virtually eradicated for two decades, and cases are now growing by 30 percent a year, Chen Xiangsheng said in an interview in the World Health Organization's monthly bulletin.

Last year, 278,215 cases were officially reported, said Chen, the deputy director of China's National Center for Sexually Transmitted Diseases Control.

"We know that the resurgence of syphilis was driven by prostitution, migration of workers and poor health controls," he was quoted as saying by WHO.

"The areas with higher syphilis prevalence are usually places where the economy is booming but where there is also greater economic inequality, such as the southeastern coastal areas," he added.

Syphilis, a bacterial infection that causes rashes and sores, is easily treated with antibiotics, but if left untreated can damage the heart and the nervous system.

Chen told WHO that China is still developing policies for preventing and treating sexually transmitted diseases.

One problem is the stigma and perceived high cost of visiting sexual health clinics, he said. Another is the difficulty of reaching prostitutes who don't work in brothels.

He said promoting condom use, particularly among high-risk groups, would help prevent the spread of syphilis and other sexually transmitted diseases such as HIV.