Sexually transmitted diseases more common in women age 40

Johns Hopkins expert calls for testing and mandatory reporting

A Johns Hopkins infectious disease expert is calling for all sexually active American women age 40 and older to get tested for the parasite Trichomonas vaginalis after new study evidence found that the sexually transmitted disease (STD) is more than twice as common in this age group than previously thought. Screening is especially important because in many cases there are no symptoms.

"We usually think of STDs as more prevalent in young people, but our study results clearly show that with trichomonas, while too many young people have it, even more, older women are infected," says senior study investigator Charlotte Gaydos, M.S., Dr.P.H.

Results of a study to be presented July 12 at the annual meeting of the International Society for STD Research, in Quebec City, Canada, by Gaydos and her co-investigators show that among 7,593 U.S. women between the ages of 18 and 89, women 50 and older had the highest trichomonas infection rate, at 13 percent. Women in their 40s were next, at 11 percent. The study, which collected test samples from women in 28 states, is believed to be the largest and most in-depth analysis of the STD ever performed in the United States, complementing periodic national surveys of adolescents and individual city reports.

"Trichomonas infections are quite treatable with antibiotics," says Gaydos, a professor at the Johns Hopkins University School of Medicine." And these high numbers really warrant older women getting screened by their family physicians and gynecologists during routine check-ups to make sure they are not infected and are not inadvertently spreading it to others."

Overall, the survey results showed that 8.7 percent of all women tested positive for the STD. Previous estimates, using older, less reliable tests had indicated an overall infection rate of less than 4 percent. In the new study, the infection rate was 8.5 percent in women ages 18 and 19, dropping slightly to 8.3 percent for women in their 20s.

Gaydos says testing is needed to prevent transmission of the parasite because some infected women and most infected men show no signs of the disease, such as liquid discharge from the vagina or penis, irritation while urinating and genital itching. Left untreated, trichomoniasis can lead to severe health problems. Trichomonas infection is closely tied to co-infection with HIV, easing transmission of the virus that causes AIDS. Gaydos says trichomoniasis can also lead to inflammation of the vagina, urethra and cervix and to pelvic inflammatory disease, and in pregnant women, the infection has been known to cause premature labor and result in more low-birth-weight babies.

The public health threat of trichomonas is compounded, Gaydos adds, by the fact that, unlike other common STDs, such as the bacteria Chlamydia trachomatis and Neisseria gonorrhoeae, confirmed cases of parasitic trichomonas infection do not have to be reported to local public health officials and the U.S. Centers for Disease Control and Prevention.

"What we are really witnessing with trichomonas, especially in older women, is that no one ever looked, no one ever tested and diagnosed, and no one is really getting treated, so the infection persists year after year," says Gaydos. She says that in addition to encouraging women to get tested, federal agencies should make trichomonas a reportable condition, as are chlamydia and gonorrhea, so that public health officials can screen, track and develop better methods to halt infections.

Among the study's other key findings were that infection rates were highest among black women of all ages, at 20 percent, almost twice what earlier estimates had suggested and more than three times the rate in whites, at 5.7 percent. Gaydos says this finding mirrors results of other health surveys tying increased STD infection rates - such as chlamydia and gonorrhea, too -- to high levels of poverty, unemployment, and lack of education in different racial and ethnic groups.

Such social and economic disparities, she says, also help explain why the infection rate in jails, in which a large proportion of the prison population is African American, was 22.3 percent; and why women in the relatively poorer Southeast United States have the highest regional trichomonas infection rate, at 14.4 percent, whereas women in the more affluent Northeast had the lowest, at 4.3 percent.

"This survey information is vital to tailoring our efforts to get women, especially black women and women in jails, tested, diagnosed and treated," says Gaydos.