NEW YORK (Reuters Health) - A relatively new sexually transmitted infection has surpassed Neisseria gonorrhea in prevalence among young adults in the US, according to a new study.

Mycoplasma genitalium was first identified in the 1980s. It can cause inflammation of the urethra (the urinary passage from the bladder), in men, and inflammation of the cervix and the lining of the uterus in women, possibly leading to infertility. However, it seems many cases of the infection are symptom-free.

In the current study, researchers at the University of Washington, Seattle, tested 1714 women and 1218 men between the ages of 18 and 27 years participating in Wave III of the National Longitudinal Study of Adolescent Health.

Results of the study are published in the American Journal of Public Health. The investigators found Mycoplasma genitalium infection in 1.0 percent of the participants. In contrast, the prevalence of gonorrhea was 0.4 percent. The prevalence of chlamydia infection was 4.2 percent.

The prevalence of Mycoplasma genitalium infection was 11 times higher among individuals living with a sexual partner, seven times higher among blacks and four times higher among those who use condoms during sex.

None of the genitalium-positive individuals had any discharge.

"Many M. genitalium infections are asymptomatic, like chlamydial infections," principal investigator Dr. Lisa Manhart told Reuters Health. "However, unlike chlamydia, it is probably too soon to recommend widespread screening for M. genitalium."

There are no commercial tests to detect the organism, she explained. Furthermore, she and her colleagues note in their report that it is not clear "whether M. genitalium-infected persons require or benefit from treatment -- and if so, what antimicrobial therapy should be recommended."

SOURCE: American Journal of Public Health, June 2007.

REUTERS