What Is Bacterial Vaginosis? What Causes Bacterial Vaginosis?

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Main Category: Women's Health / Gynecology
Also Included In: Pregnancy / Obstetrics;  Infectious Diseases / Bacteria / Viruses;  Sexual Health / STDs
Article Date: 07 Apr 2010 - 0:00 PST

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Bacterial vaginosis (BV), also known as vaginal bacteriosis is the most common cause of vaginal infection for women of childbearing age. Although it frequently develops after sexual intercourse with a new partner, bacterial vaginosis is not considered as an STI (sexually transmitted infection). BV is more common in women with multiple partners.

Bacterial vaginosis - not to be confused with candidiasis (yeast infection) or Trichomonas vaginalis (trichomoniasis) which are not caused by bacteria - is caused by an imbalance of naturally occurring bacterial flora (the usual bacteria found in a woman's vagina). Smoking and the use of some hygiene products are linked to a higher risk of developing BV.

According to the National Health Service (NHS), UK, approximately 12% to 30% of adult women in the UK may be affected; about 20% of pregnant women in the UK are affected. The Centers for Disease Control and Prevention (CDC), USA, estimates that about 16% of US women are affected.

Bacterial vaginosis can sometimes be asymptomatic - about 50% of women with BV have no symptoms at all. Doctors say treatment is not required if the woman is found to have BV, but has no symptoms. Sometimes BV can appear and disappear for no reason.

Even though antibiotic medication is effective in up to 90% of cases, 25% of women will develop BV again within four weeks.

A pregnant woman with BV has a slightly higher risk of complications, such as giving birth before the 37^th week of pregnancy.

According to Medilexicon's medical dictionary:

Bacterial vaginosis is "infection of the human vagina that may be caused by anaerobic bacteria, especially by Mobiluncus species or by Gardnerella vaginalis. Characterized by excessive, sometimes malodorous, discharge."

What are the signs and symptoms of bacterial vaginosis?

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.

Approximately 50% of all women with BV have no symptoms (asymptomatic). If a woman does have symptoms, she does not need to get tested to find out.

The main sign is in the vaginal discharge:

• Vaginal discharge may become watery and thin
• Vaginal discharge may become grey or white
• Vaginal discharge may have a strong and unpleasant smell, often described as fishy

The following symptoms are possible, but much less common:

• Burning sensation during urination
• Itching around the outside of the vagina

What are the causes of bacterial vaginosis?

We know that bacterial vaginosis is linked to an imbalance in the bacteria that are normally found in a female's vagina - an imbalance in the vagina's naturally occurring bacterial flora. However, nobody fully understands why this imbalance occurs. The vagina usually contains mostly good bacteria and few harmful bacteria - bacterial vaginosis occurs when these harmful bacteria grow in numbers. We do not know what role these harmful bacteria play in causing BV.

A female's vagina should contain lactic acid bacteria, called lactobacilli. These bacteria produce lactic acid, making the vagina slightly acidic, preventing other bacteria from growing there. If the vagina is not as acidic as it should be, other bacteria may have the opportunity to grow. If there are fewer lactobacilli the vagina may become less acidic.

Any female can develop BV. Some behaviors or activities may upset the balance of the naturally occurring bacterial flora and increase the risk of developing BV, including:

• Douching - using water or a medicated solution to clean the vagina
• Having a bath with antiseptic liquids
• Having a new sex partner
• Having multiple sex partners
• Perfumed bubble baths and some scented soaps
• Smoking
• Using an IUD (intrauterine device), such as a contraceptive device made from plastic and copper that fits inside the uterus
• Using vaginal deodorants
• Washing underwear with strong detergents

However:

• Women who have never had sexual intercourse may be affected
• You cannot get BV from toilet seats, bedding, swimming pools, or touching objects

Diagnosing bacterial vaginosis

The National Health Service (NHS), UK, says that a woman who has any abnormal vaginal discharge should see her GP (general practitioner, primary care physician) as soon as possible so that BV can be diagnosed and other infections, such as gonorrhea or trichomonas vaginalis ruled out. In many countries the woman could visit a sexual health clinic for diagnosis (or genitor-urinary medicine clinic), instead of her GP.

The doctor may be able to diagnose BV from a description of symptoms and carrying out a physical examination, during which he/she will look out for an unpleasant smell and a thin, white/gray discharge. If the patient is sexually active and there is a chance she may have an STI (sexually transmitted infection), the doctor may order some diagnostic tests.

Swab (sample) - the doctor uses a swab or small plastic loop to collect sample cells from the vaginal wall. The alkaline/acid balance (pH) of the vagina may also be measured.

What are the treatment options for bacterial vaginosis?

Although anecdotal accounts of effective treatment with Probiotics exist, there is no scientific evidence so far to back this up.

Although bacterial vaginosis can often clear up without treatment, it is advised that all women with BV signs and symptoms be treated to avoid complications. Male partners do not usually require treatment. BV can spread between female sex partners.

BV treatment is especially important for pregnant women. Pregnant women who have had premature births or low weight babies should have a BV examination, even if there are no symptoms.

Some doctors say that all women undergoing a hysterectomy or abortion should be treated for BV before their procedure, regardless of symptoms.

BV can be treated with antibiotics. If used correctly they are 85% to 90% effective.

Metronidazole - the most common antibiotic for BV. It is available:

• In tablet form, to be taken orally (swallowed) twice daily for seven days. Seen as the most effective treatment. This is also the preferred treatment if the woman is breastfeeding or pregnant.
• In tablet form, to be taken orally, just once. The BV is more likely to return with this treatment, compared to the seven-day tablet course.
• In gel form, that is applied to the vagina once daily, for five days.

Metronidazole reacts with alcohol, making the patient feel very ill. If you are taking metronidazole you should not consume alcohol for at least 48 hours afterwards.

Clindamycin - this is an alternative BV treating antibiotic, often used if metronidazole did not work or the BV came back. It is available:

• As a cream, which is applied to the vagina once daily for seven days.
• In capsule form, which is taken orally (swallowed) twice daily for seven days. Rarely used today because of the risk of developing pseudomembranous colitis.

When taking clindamycin, barrier contraception methods, such as latex condoms, diaphragms and caps may be less effective. The woman should use addition contraception, such as condoms made from polyurethane.

Tinidazole - another antibiotic which is sometimes used to treat BV if metronidazole did not work, or the BV came back. Taken by mouth as a single dose. Alcohol must be avoided when taking this medication.

After completing the course of antibiotics - if symptoms go away the woman will not have to be tested for BV again. If the following occur, testing will need to be done again:

• Signs and symptoms of BV persist
• Signs and symptoms of BV go away, and then come back
• The patient being treated is pregnant

Additional treatment - approximately 10% to 15% of treatments are not effective. The doctor needs to check carefully that the patient followed the instructions on how to take the medication properly. If the medication did not work and the patient had done everything correctly, the doctor may prescribe a different antibiotic.

A GP (general practitioner, primary care physician) whose treatment was not effective may choose to refer the patient to a gynecologist - a doctor specialized in treating conditions of the female reproductive system. If a pregnant woman is having her pre-natal checks with a GP, she may be referred to an obstetrician (a doctor who specializes in pregnancies).

What are the possible complications of bacterial vaginosis?

In the majority of cases BV does not cause any complications. The following complications have been linked to BV:

• HIV infection susceptibility - having BV may make a woman more susceptible to HIV infection if she is exposed to the virus.
• Transmitting HIV - a woman with BV has a higher risk of passing her HIV infection to her sex partner.
• Other sexually transmitted infections (STIs) - a woman with BV is more susceptible to becoming infected with the herpes simplex virus, Chlamydia, gonorrhea, and HPV (human papilloma virus).
• Post-surgical infection - a woman with BV has an increased risk of developing an infection after surgery, such as an abortion or hysterectomy.
• Pregnancy complications - having BV increases the risk of some pregnancy complications, such as:
  
  
  • Giving birth early (preterm delivery)
  • A late miscarriage
  • The amniotic sac breaking open too early
  • Chorioamnionitis - inflammation of the membranes that surround the fetus (chorion and amnion). Significantly increases the risk of preterm labor, and if the child survives, the risk of cerebral palsy.
  • Postpartum endometritis - the lining of the uterus becomes irritated or inflamed after giving birth.
• Pelvic inflammatory disease (PID) - women with BV are more susceptible to developing PID; infection and inflammation of the upper female genital tract.
• Tubal factor infertility - caused by fallopian tube damage. The fallopian tubes connect the ovaries to the uterus.
• In-vitro fertilization - women with BV may have a lower success rate with IVF.

Written by Christian Nordqvist


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