by Colette Bouchez
A gynecological infection known as bacterial vaginosis may be more widespread than previously believed, even in women with no history of sexual activity.
In a study of almost 2,000 women who entered basic training for the U.S. Marines, doctors from the University of California, San Francisco (UCSF) report that bacterial vaginosis (BV) was present in more than one of every four. Eighteen percent of those infected were virgins.
The research appears in the November issue of Obstetrics and Gynecology.
For study author Dr. Sophia Yen, the important point is that you don't have to be sexually active to develop this infection, which has been linked to serious health problems, including infertility.
"The key take-home message is that while most ob/gyns know that women who haven't been sexually active can develop BV, the average pediatrician who may be seeing more of the younger women may not realize that this is a common occurrence in non-sexually active women as well," Yen says.
BV is an infection caused by an overgrowth of bacteria found naturally in the vagina. The main symptom is a thin, watery, white discharge that can have a strong "fishy" odor. However, Yen points out that up to 50 percent of women have no symptoms at all -- and may never know they have the problem.
It's easy to treat BV -- a round of antibiotics usually obliterates the problem. But left untreated, it is associated with increased risk of miscarriage, infections following gynecologic surgery, and pelvic inflammatory disease -- a direct link to infertility. In pregnant women, BV can increase the risk of premature birth and premature rupture of membranes.
Women who are sexually active with multiple partners appear to be at higher risk for BV. But those who have no sexual experience can also develop the infection through hormonal fluctuations linked to the menstrual cycle or by introducing a foreign object into the vagina, such as during douching.
The study is also the first to note that Asian-American women have the lowest rates of BV, regardless of sexual activity. Yen believes this might indicate that subtle differences in physiology among racial groups might also act as a risk factor.
"There could be biological differences among women of different races that could account for the differences in rates of BV that we see," says Yen, an adolescent medicine specialist at UCSF's Department of Pediatrics.
BV expert Dr. Sharon Winer says the study was extremely well done and validates a lot of what doctors see in clinical practice.
"What is so good about this study is that they used a large population. And they used the Nugent score system, which makes it as objective as you are going to get, which in turn means the findings are extremely accurate," says Winer, an obstetrician/gynecologist at Cedars Sinai Medical Center in Los Angeles.
A "Nugent score system" is a highly accurate way of analyzing the bacteria on a slide -- compared to less-reliable methods often used in doctors' offices to detect an infection.
Winer says the new study "is consistent with what we see going on in practice."
The study looked at a cross-section of 1,938 women entering recruit training for the Marines from June 1999 to June 2000. Using specially prepared vaginal swabs, the women self-collected vaginal discharge samples. The fluids were first applied to a test card designed to read the vagina's pH or acid level (often a change in pH can indicate infection). The fluids were also applied to a glass slide for a "gram stain" evaluation utilizing the Nugent scoring system.
At the same time, doctors also screened the women for sexually transmitted diseases and administered Pap smears.
The result: Bacterial vaginosis was present in 27 percent of the women. And 18 percent of those cases were diagnosed in women who'd never had sex.
Conditions associated with a diagnosis of BV included vaginal odor, vaginal discharge and concurrent infection with Chlamydia trachomatis, a sexually transmitted infection.
The study also found women who used birth control pills were less likely to develop BV. Yen believes this may be due to a better control of hormonal fluctuations that, in turn, decreases the risk of infection.