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The STI Files: Bacterial Vaginosis

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Stat: Bacterial vaginosis (BV) is the most common cause of vaginitis symptoms among women of childbearing age (15-45). However, half the women who meet clinical criteria for BV have no symptoms.

What is it exactly? Bacterial vaginosis reflects a change in the vaginal environment. A healthy vagina contains several different kinds of bacteria in balance with each other so that no one type outnumbers all the others. BV results when an imbalance, including pH changes, occurs in the vagina because the amount of one or two types of bacteria has increased and outnumbered the rest. There's no one type of bacteria which are always responsible: any number of different bacteria can cause BV.

Douching can increase the risk of acquiring BV, but the root cause of this disruption in the balance of the vaginal flora is not fully understood, and it is not clear exactly what role sexual activity may have as BV can occur in women who are not sexually active. However, women who are sexually active do run a high risk of developing the condition, as do those with multiple partners or who have changed partners recently. BV is also one of the more common infections among lesbian women.

About how many people have it? Statistics are elusive, but it is estimated that over 2 million women in America have BV at any given time.

How is it spread? BV can result any time something causes a change in the vaginal environment, making it easier for an overgrowth of one particular bacteria to occur, or from activities which introduce new bacteria into the vagina. This can be achieved through vaginal or anal intercourse, manual sex, shared sex toys, vaginal intercourse wearing a condom that was also used for anal intercourse or through nonsexual activities such as wiping improperly after a bowel movement or the use of antibiotics.

What are its symptoms? The main symptom of BV is often a thin, creamy greyish-white, odorous vaginal discharge. A sudden increase in discharge that does not seem to pass within a handful of days or which isn't related to the appropriate fertility phase can often be a sign of BV. A fish-like odor is sometimes noticeable especially after intercourse or exercise. Some women with BV may have mild itching or burning with urination. Nearly half of the women with clinical signs of BV, however, report no symptoms.

How is it diagnosed? By an examination of a sample of vaginal fluid under a microscope, either stained or in special lighting, to detect the presence of the organisms associated with BV. Diagnosis is 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 odour, and/or decreased acidity or change in pH of vaginal fluid.

Is it treatable? Yes. Women can be treated with antibiotics such as metronidazole or clindamycin. Generally, male sex partners are not treated.

Is it curable? Yes, but you can contract it again.

Can it affect fertility? BV is associated with premature delivery, low birth weight, and pelvic inflammatory disease, and may increase a woman's risk of contracting STIs such as chlamydia and gonorrhea which can also impact fertility .

Can it cause death? Not by itself, no. But bacterial vaginosis can increase the risk for HIV infection for which there is no cure and which can lead to AIDS and other fatal illnesses. Pregnant women with BV run higher risks of miscarriage, especially in the first trimester.

How can we protect against it? Avoid activities which could lead to the introduction of the bacteria to the vagina or change the vaginal environment (unprotected vaginal or anal intercourse, unprotected manual sex, vaginal intercourse wearing a condom that was also used for anal intercourse - read how to use a condom) and practice proper hygiene (wipe from front to back after urinating or bowel movements, do not douche). Do not share sex toys, particularly those that cannot be boiled before use or which have not been or cannot be covered with a condom. Limit your number of sexual partners.

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written 29 Apr 2007 . updated 27 Nov 2012

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