The resurgence and spread in China of syphilis, an infection eliminated there from 1960 to 1980, represents a rapidly increasing epidemic calling for urgent intervention, according to authors of a new report documenting rising infection rates.
"Syphilis has returned to China with a vengeance. The data demonstrates a syphilis epidemic of such scope and magnitude that it will require terrific effort to intervene," said Dr. Myron S. Cohen, the J. Herbert Bate distinguished professor of medicine, microbiology and immunology, and public health, and director of the Center for Infectious Diseases at the University of North Carolina at Chapel Hill School of Medicine.
Cohen and co-authors from China collected and assessed data from China's national sexually transmitted disease (STD) surveillance system and sentinel site network. The total incidence of syphilis in all of China's counties increased from less than 0.2 cases per 100,000 people in 1993 to 6.5 cases per 100,000 in 1999, the study shows. Of the three categories of disease - primary, secondary and tertiary - the first two represented 5.7 cases per 100,000 people in 2005. This latter incidence is substantially higher than in most developed countries, including the U.S., which reported 2.7 cases of primary and secondary syphilis in 2004, the researchers note.
The results appear in the Jan. 13, 2007 issue of the journal Lancet. The research was supported by special funding from the National Institutes of Health Fogarty-Ellison Fellowship and the UNC Center for AIDS Research.
Also alarming is the rate of congenital syphilis, Cohen said, which has increased from 0.01 cases per 100,000 live births in 1991 to 19.68 cases in 2005 - an average yearly rise of 71.9 percent. Congenital syphilis occurs when a pregnant woman with syphilis passes the infection to her baby in the womb. Many cases result in miscarriage or stillbirth, and surviving babies may have serious problems of the brain, liver, and other organs.
The study authors link the rise in syphilis infection rates to economic reforms and globalization in China. These changes have led to income gaps and a cultural climate that favors re-emergence of prostitution due to a substantial majority of men and a large migrant population of male workers, the report says. Changing social practices such as people experimenting with sex at earlier ages and before marriage, as well as increasing costs of individual health care, also contribute.
Syphilis was first recognized in mainland China in 1505. By the time the Communist party assumed power in 1949, "the Chinese were suffering one of the biggest syphilis epidemics in human history," the authors said. Mao Zedong and his government made syphilis treatment and prevention a priority and launched a prolonged campaign beginning in 1952 to eliminate STDs, Cohen said. By 1964, syphilis was rare and the infection virtually eliminated until China opened its international borders in the early 1980s.
The virtual absence of syphilis in China for 20 years means the general
population of young, sexually active individuals has no natural immunity to the disease, according to the authors. "Sexually active individuals would be completely susceptible to this infection," the report states. Cohen also notes that syphilis also increase the risk of both transmitting and getting infected with HIV, the virus that causes AIDS.
Cohen, who has worked in China since 1979, designed and planned the research along with co-author Dr. Xiang-Sheng Chen of the National Center for STD Control in Nanjing. Cohen said the development of longstanding collaborations with the center helped make the report possible.
"This report helps to demonstrate the openness with which China is trying to approach epidemics of infectious diseases. The data we now have provides important clues as to where the authorities in China should put their resources," Cohen said.
A "formal and aggressive" China Syphilis Working Group has formed through partnerships involving UNC, China's National Center for STD Control, the World Health Organization, the United Nations Center for Disease Control and the London School of Hygiene, Cohen said.
Other co-authors with Chen and Cohen are Drs. Zhi-Quiang Chen, Guo-Cheng Zhang, Xiang-Dong Gong, Xing Gao, Gua-Jun Liang, Xiao-Li Yue and Mr. Charles Lin, all from the National Center for STD Control, Chinese Academy of Medical Sciences and Peking Union Medical College. Lin is also a student at the University of California, San Francisco School of Medicine and an NIH Fogarty-Ellison Fellow funded through UNC-Chapel Hill.