May 22, 2003 -- The most common sexually transmitted bacterial infection may be even more common than previously believed. Although often considered primarily a woman's health problem, a new study by British researchers suggests that chlamydia may also afflict one in 10 young men -- a rate at least five times higher than noted in some previous research.
What's more, in studying infection rates of chlamdyia among 800 army recruits, the researchers found that nearly 90% of those who tested positive for chlamydia showed no obvious symptoms. In other studies in both the U.S. and U.K., only about half of infected men, along with three in four women, displayed no symptoms.
"The clear message is that most men with chlamydia have no symptoms," says the study's lead researcher, Gordon Scott, FRCP, of Edinburgh Royal Infirmary, whose findings appear in the May 24 issue of The Lancet. "Many studies have shown about one in 10 women are infected, and now we have some evidence that shows, not surprisingly, that men are just as likely to be infected."
What is surprising, however, is that his study participants -- men in their late teens and 20s -- reported having an average of only one sexual partner in the previous six months, the typical rate for other men living in the U.K. The highest rates of infection are usually seen in persons with multiple sex partners and not using barrier contraception. "This confirms that you don't have to have a lot of partners to pick up a chlamydia infection," Scott tells WebMD.
But it does indicate the importance of wearing condoms -- and being screened regularly for the infection, which is caused by the Chlamydia trachomatis bacterium and spread through unprotected sex. Chlamydia infects about 3 million Americans each year -- occurring 30 times more often than syphilis and six times more frequently than genital herpes, according to the CDC.
"While chlamydia doesn't carry the same serious consequences for men as HIV or some of the other sexually transmitted diseases, it's further assurance that condoms should be utilized in sexual activity," says Martin Resnick, MD, president of the American Urological Association and chairman of urology at Case Western Reserve School of Medicine.
Scott's finding also suggests that men with even minimal symptoms -- including burning while urination or a clear or mucous-like discharge or itching -- shouldn't "write off" these signs as a passing problem, says Resnick. "There are many men who are carriers of chlamydia that are totally asymptomatic," he tells WebMD. "Even if you have mild symptoms, or none at all, you should get screened if you are sexually active."
Two years ago, the U.S. Preventive Services Task Force made a formal recommendation that sexually active women -- especially those under age 25 -- be regularly screened for chlamydia. But that recommendation didn't address screenings for men. In the U.S., statistics indicate that women contract the infection five times as often.
When detected early, chlamydia can easily be treated with antibiotics. Sexual partners must also be treated to avoid recurrence of the infection. But untreated, it can cause several health problems in both sexes. In women, untreated chlamydia can lead to pelvic inflammatory disease, infertility, and ectopic pregnancies. In men, untreated chlamydia typically causes a less serious urethral infection, but it can lead to epididymitis, which results in testicular swelling and severe pain.
Chlamydia can also infect unborn children. Each year, about 180,000 American babies born to infected mothers suffer pneumonia or conjunctivitis, an inflammation of membranes in the eye that may lead to blindness.
"What's nice about this study is that since we've focused on asymptomatic infections in women over the last several years, looking at the role of asymptomatic infections in men is a useful addition to our epidemiological data," says Carolyn Deal, PhD, chief of the Sexually Transmitted Diseases Branch of the National Institute of Allergy and Infectious Diseases. "However, this was a select group, and you must always be cautious about translating data from one group to another for a variety of reasons."