Bacterial Vaginosis (BV)

Vaginitis is an inflammation of the vagina characterized by discharge, odor, irritation, and/or itching. The cause of vaginitis may not always be determined adequately solely on the basis of symptoms or a physical examination. For a correct diagnosis, a doctor should perform laboratory tests including microscopic evaluation of vaginal fluid. A variety of effective drugs are available for treating vaginitis.

Vaginitis often is caused by infections, which cause distress and discomfort. Some infections are associated with more serious diseases. The most common vaginal infections are bacterial vaginosis, trichomoniasis, and vaginal yeast infection or candidiasis. Some vaginal infections are transmitted through sexual contact, but others such as yeast infections probably are not, depending on the cause. This article discusses bacterial vaginosis.

Bacterial Vaginosis (BV)

Bacterial vaginosis (BV) is the most common cause of vaginitis symptoms among women of childbearing age. Previously called nonspecific vaginitis or Gardnerella-associated vaginitis, BV is associated with sexual activity. BV reflects a change in the vaginal ecosystem. This imbalance, including pH changes, occurs when different types of bacteria outnumber the normal ones. Instead of Lactobacillus bacteria being the most numerous, increased numbers of organisms such as Gardnerella vaginalis, Bacteroides, Mobiluncus, and Mycoplasma hominis are found in the vaginas of women with BV. Investigators are studying the role that each of these microbes may play in causing BV, but they do not yet understand the role of sexual activity in developing BV. A change in sexual partners and douching may increase the risk of acquiring bacterial vaginosis.

Symptoms

The primary symptom of BV is an abnormal, odorous vaginal discharge. The fish-like odor is noticeable especially after intercourse. Nearly half of the women with clinical signs of BV, however, report no symptoms. A physician may observe these signs during a physical examination and may confirm the diagnosis by doing tests of vaginal fluid.

Diagnosis

A healthcare worker can examine a sample of vaginal fluid under a microscope, either stained or in special lighting, to detect the presence of the organisms associated with BV. They can make a diagnosis based on the absence of lactobacilli, the presence of numerous "clue cells" (cells from the vaginal lining that are coated with BV organisms), a fishy odor, and decreased acidity or change in pH of vaginal fluid.

Treatment

All women with BV should be informed of their diagnoses, including the possibility of sexual transmission, and offered treatment. They can be treated with antibiotics such as metronidazole or clindamycin. Generally, male sex partners are not treated. Many women with symptoms of BV do not seek medical treatment, and many asymptomatic women decline treatment.

Complications

Researchers have shown an association between BV and pelvic inflammatory disease (PID), which can cause infertility and tubal (ectopic) pregnancy. BV also can cause adverse outcomes of pregnancy such as premature delivery and low-birth-weight infants. Therefore, the U.S. Centers for Disease Control and Prevention (CDC) recommends that doctors check all pregnant women for BV who previously have delivered a premature baby, whether or not the women have symptoms. If these women have BV, they should be treated with oral metronidazole or oral clindamycin. A pregnant woman who has not delivered a premature baby should be treated if she has symptoms and laboratory evidence of BV. BV is also associated with increased risk of gonorrhea and HIV infection (HIV, human immunodeficiency virus, causes AIDS).

Other Causes of Vaginitis

Although most vaginal infections in women are due to bacterial vaginosis, trichomoniasis, or yeast, there may be other causes as well. These causes may include allergic and irritative factors or other sexually transmitted diseases (STDs). Noninfectious allergic symptoms can be caused by spermicides, vaginal hygiene products, detergents, and fabric softeners. Cervical inflammation from these products often is associated with abnormal vaginal discharge, but can be distinguished from true vaginal infections by appropriate diagnostic tests.

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.