Hidden chlamydia epidemic found in China

Researchers at the University of North Carolina at Chapel Hill School of Medicine have helped identify a large, undetected epidemic of the sexually transmitted disease chlamydia in China. The new findings appear in the Journal of the American Medical Association. The collaboration involving UNC, the University of Chicago and researchers in China points to a chlamydia epidemic that developed in that country during the last 20 years ? and represents the first nationwide study of its kind to combine reported behavior with physical evidence of the consequences of sexual activity.From the University of North Carolina at Chapel Hill School of Medicine :Hidden chlamydia epidemic found in China by joint research team

By LESLIE H. LANG
UNC School Of Medicine

CHAPEL HILL — Researchers at the University of North Carolina at Chapel Hill School of Medicine have helped identify a large, undetected epidemic of the sexually transmitted disease chlamydia in China.

The new findings appear Wednesday (March 12) in the Journal of the American Medical Association. The collaboration involving UNC, the University of Chicago and researchers in China points to a chlamydia epidemic that developed in that country during the last 20 years ? and represents the first nationwide study of its kind to combine reported behavior with physical evidence of the consequences of sexual activity.

Easing of restrictions on prostitution and a subsequent burgeoning sex worker industry, along with upper-income men traveling away from home on business, have all contributed to the epidemic, the authors said.

“The prevalence of chlamydia across China is exactly what it is in many developed countries, including the United States,” said study co-author Dr. Myron Cohen, the J. Herbert Bate professor of medicine, microbiology and immunology at UNC. “And in some urban areas, the chlamydia prevalence is extremely high, especially among women whose husbands are high earners and who are out of the home a number of days each month.”

The study found 14.6 percent of high-income men who had sex with prostitutes have chlamydia. The study found that 5.6 percent of the partners of those men also were infected. Chlamydia was highest in the rapidly developing coastal region of the nation’s south, where 16 percent of men and 9.9 percent of women are infected. Overall, disease prevalence (2.1 percent for men and 2.6 percent for women) is similar to that in developed countries.

The report pointed out that China’s health system tracks eight sexually transmitted diseases, but does not record chlamydia statistics largely because the disease typically is not associated with symptoms.

“A failure to confront the epidemic could have serious consequences,” said study lead author Dr. William Parrish, a sociologist and Centennial professor in Chinese studies at the University of Chicago. Because it is a “silent” epidemic, chlamydia infection can cause many women to be infertile, to have ectopic (outside the womb) pregnancies and be at greater risk of HIV infection, he said.

“There are two giant issues here,” said Cohen. “Given the one-child policy in China, chlamydia infection in women can be a life-devastating event. In China, a women’s fertilility is traditionally perceived as her most precious commodity because it is expected that she bear a child. Women who can’t do that are subject to great social stigma and tremendous duress.

“Second, since we use chlamydia as a biomarker of high-risk sexual behavior, we’re greatly concerned about the HIV epidemic. At least 1 million people in China are infected with HIV. In the absence of any interventions, that figure may climb to 10 million by 2010, and there exists a risk for an epidemic in that nation to affect 100 million.”

The study was based on interviews from August 1999 to August 2000 with 3,813 men and women, all of whom were asked to provide a urine sample. The researchers relied on social workers in China to interview the respondents, who were selected randomly from 60 communities throughout the country, except from the sparsely populated far west. Hong Kong and Tibet were not included.

Interviews were conducted at sites outside the respondent’s home and were aided by a laptop computer, which most interviewees used for a portion of the survey.

The study recommended education campaigns to promote awareness of chlamydia infection and stressed the value of condom us to limit its spread. Such strategies have worked elsewhere, particularly in Thailand, the authors reported.

Support for the study came from the National Institute of Child Health and Human Development and the Fogarty International Center of the National Institutes of Health.

In addition to Cohen and Parrish, other co-authors included Edward Laumann, the George Herbert Mead distinguished service professor at the University of Chicago; Dr. Heyi Zheng of Peking Union Medical College; Irving Hoffman, research instructor in the department of medicine at UNC; and Tianfu Wang and Kwai Hong Ng, both of the University of Chicago.

The role of UNC globally in AIDS research is exemplified by its international efforts, which include extensive HIV prevention and treatment work in Malawi and China. Over the past decade Cohen and his colleagues have received many millions of dollars of support for their work from the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes, Digestive and Kidney Diseases, the NIH Fogarty International Center and the U.S. Agency for International Development.

UNC is a China Fogarty Center and helped organize the first Sino-USA Conference on AIDS at the NIH in 2002.

“There’s a 23-year relationship between the UNC faculty and China,” Cohen said.

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