GENEVA -- China is experiencing an epidemic of syphilis, a sexually transmitted disease that the country virtually wiped out in the 1960s, a senior public health official was quoted as saying on Tuesday.

In the WHO Bulletin, a journal produced by the World Health Organization, Xiang-Sheng Chen of China's Center for Disease Control and Prevention said mass migration of rural workers to Chinese cities has been a major factor in the viral spread.

While China nearly eradicated syphilis "through a powerful campaign of propaganda, mass screening, closing brothels and providing free treatment for sex workers," the expert said "the epidemic has re-emerged since the economic boom of the 1980s."

"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 south-eastern coastal areas," Chen said.

The Chinese CDC's deputy director for sexually transmitted disease control said there were 278,215 officially reported syphilis infections in 2008, triple the number from 2004 and a tenfold increase over the past decade.

"On average, syphilis cases are increasing by 30 percent a year across the nation," he said.

MIGRANT WORKERS

Much of the rise has come from unsafe practices of migrant workers, including men who left their wives back in their home villages and solicit sex from prostitutes who do not use condoms, Chen said.

Fears of stigma and a lack of privacy have also kept many patients from going to seek treatment for syphilis and other sexual infections which can make people more likely to catch and spread HIV/AIDS, according to the Chinese expert.

There are no national statistics on how many people in China have both HIV and syphilis.

Globally, the WHO estimates that there are at least 340 million new cases of curable sexually transmitted infections -- such as syphilis, gonorrhea, chlamydia and trichomoniasis -- every year among people aged 15 to 49.

Infection with sexually transmitted infections can cause acute symptoms, chronic infections and delayed consequences including infertility, ectopic pregnancy and cervical cancer.

Michel Sidibe, the head of the U.N. program UNAIDS, and his colleague Kent Buse appealed in a separate WHO Bulletin article on Tuesday for more collaboration between work on HIV/AIDS and sexually transmitted infection worldwide.

Pregnant women and their partners should be offered HIV screening as well as services to prevent sexual infections as part of their regular treatment, they recommended, saying: "The moment is right to take the AIDS response out of isolation."