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    STD Trichomonas May Be More Common Than Thought

    Study Shows 8.7% of Women Test Positive for the Sexually Transmitted Disease

    Symptoms of Trichomonas

    Trichomonas vaginalis, also called trichomoniasis, is a parasite. Both men and women can be infected. In women, the vagina is most often infected. In men, the urine canal is the most common infection site.

    The infection is spread sexually, either through penis-to-vagina intercourse or from vulva-to-vulva contact.

    Those infected are often not aware, Gaydos tells WebMD. "Fifty percent [of women] may not have symptoms," she says. That may also apply to men, she says, but data are lacking.

    Some infected men report an irritation inside the penis or slight burning with urination or during ejaculation.

    Infected women may report a smelly vaginal discharge. The infection can also cause itching in the genital area and burning with urination.

    Antibiotics given in a single dose are the usual treatment, Gaydos says. It is usually successful, but people can be reinfected if they have sexual contact again with an infected person.

    Infection with Trichomonas vaginalis is linked with premature labor and low-birth-weight babies in pregnant women. The infection can increase susceptibility to HIV infection if a woman is exposed to that virus.

    Testing for Trichomonas

    Gen-Probe, a company based in San Diego, got clearance from the FDA in April for its new APTIMA test for Trichomonas vaginalis.

    The new test, Gaydos says, is more accurate than other tests, such as those that examine a sample under the microscope. She says the new test is close to 100% sensitive. It is a nucleic acid amplification test. It works by replicating the nucleic acid found in the organism.

    The cost of the new test is expected to be about $50 to $100 for consumers, she says, and insurance may cover it. The test can use the same test samples as those received for chlamydia or gonorrhea.

    An estimated 7.4 million new cases of trichomoniasis occur each year in women and men, according to the CDC.

    The new data may dispel the thinking that all STDs are most common in teens and young adults, Stoner tells WebMD.

    It may also boost awareness. "It's a disease that flies under the radar," he says. "It's been perceived as [only] a nuisance by public health officials."

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