Bacterial Vaginosis

Bacterial vaginosis is the most common type of vaginal infection, although you may not have heard as much about it as you have heard about yeast infections.

What causes bacterial vaginosis?

Bacterial vaginosis is caused by an overgrowth in your vagina of anaerobic bacteria (meaning that they don't need any oxygen to survive or grow) and an organism called Gardnerella vaginalis. Small amounts of these anaerobic bacteria and Gardnerella can normally be found in your vagina. Bacterial vaginosis occurs when the balance of organisms in your vagina is upset and the anaerobic bacteria overgrow. The good, protective bacteria Lactobacilli are then outnumbered and not able to do their normal job, which is to produce a natural disinfectant (like hydrogen peroxide) which helps keep organisms at the normal, healthy balance in your vagina. An infection then occurs.

 
The exact reasons that bacteria overgrow are not known. Bacterial vaginosis (often called BV) is more common in women with multiple sexual partners and may develop after sexual intercourse with a new partner. Lesbian women also get bacterial vaginosis, and even women who are not sexually active can develop BV.

What are the signs/symptoms of bacterial vaginosis?

The outward signs of bacterial vaginosis may include a foul or fishy vaginal odor and a clear, milky-white, or gray vaginal discharge. The discharge may be light or heavy. The odor may get worse around the time of menstruation or after unprotected sexual intercourse. When semen (male sperm) mixes with vaginal secretions, the odor becomes stronger. The vagina may also be itchy and/or may burn.

However, many women have bacterial vaginosis but don't have any outward symptoms. The health care provider may notice vaginal discharge or odor during a physical examination and do a test of the vaginal fluid and then recommend treatment.

How can a health care provider definitely tell if I have bacterial vaginosis?

A health care provider will use a cotton swab to take a sample of your vaginal discharge. He/she can then measure the acidity of the discharge with pH paper. If your vagina is less acidic than it should be (pH of more than 4.5), this may be a sign that you may have bacterial vaginosis. Your health care provider can look at the sample under a microscope. If the normal bacteria (lactobacilli) are not there and numerous "clue" cells (cells from the vaginal lining that are coated with bacteria) are present, then you have bacterial vaginosis.

How is bacterial vaginosis treated?

If you have bacterial vaginosis, your health care provider will either give you a prescription for pills that you take by mouth, or a prescription for a cream or gel that you insert into your vagina with an applicator. (You should let your health care provider know about any other medications that you are taking.) If you use a cream, then you should not use tampons during the treatment since it will absorb the medication and make it less effective. The antibiotics work against the overgrowth of the anaerobic bacteria and Gardnerella. The medication works pretty quickly to cure bacterial vaginosis, but you need to make sure that you take all of the medication for it to be the most effective.

You should not use douches or deodorant spray that cover up your vaginal odor to treat bacterial vaginosis. Although they may help mask the odor, they will not cure the infection, and they might make your infection worse.

Even though bacterial vaginosis is more common in young women who have sexual intercourse, treatment of a male partner does not prevent the abnormal imbalance of bacteria from happening again. However, condoms are helpful in giving time for the vagina to return to normal.

Can I get bacterial vaginosis again?

Unfortunately, bacterial vaginosis often comes back, even if you take all of your medication and follow all advice. If your symptoms come back, see your health care provider and get treated again, often for a longer time.

What serious health problems can bacterial vaginosis cause?

Bacterial vaginosis can increase your chance of getting a serious pelvic infection called pelvic inflammatory disease (PID), or an infection after a vaginal or uterus operation. It can also increase your chance of having problems with pregnancy such as low-birth weight babies or premature delivery (delivery before the normal 9 months). Treatment is important in pregnant women who have had premature babies in the past.

If bacterial vaginosis is caught early and treated, the risks of getting any of these health problems are low.

Written by the CYWH Staff at Children's Hospital Boston

Updated: 11/24/2009

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