BACTERIAL VAGINOSIS

Bacterial Vaginosis

Bacterial Vaginosis

Introduction

Bacterial vaginosis is thought to be caused by bacterial species that are normally found in low numbers in a healthy vagina as part of the normal vaginal flora. Among women of childbearing age, bacterial vaginosis is the most common cause of vaginitis and it is the most frequent reason that women in the United States visit their physician. The Centers for Disease Control and Prevention (CDC) estimates that as many as 16 percent of pregnant women have a bacterial vaginosis infection in the United States each year.

Causes

The most common causes of bacterial vaginosis are overgrowth by the following bacterial species: Gardnerella vaginalis, Bacteroides sp., Mycoplasma hominis, Ureaplasma urealyticum, and anaerobic bacteria such as Mobiluncus sp. and Prevotella species. The specific causes of bacterial vaginosis are not clear; however, activities or behaviors that upset the normal balance of bacterial normal flora in the vagina put women at increased risk. These risk activities and behaviors may include having a new sex partner or multiple sex partners, douching, and/or the use of an intrauterine device (IUD) for contraception (Lawrence, 2000).

Bacterial vaginosis develops when the microorganisms that normally live in the vagina and protect it from harmful bacteria are disturbed. Many investigators think that the bacteria associated with bacterial vaginosis can be sexually transmitted, though these microorganisms are also often found in the vaginas of women who have never been sexually active.

Symptoms

The bacteria that cause bacterial vaginosis break down compounds of amino acids in the body to produce chemicals called amines. These produce a thin, creamy white or grayish vaginal discharge that can smell fishy. A woman will find that the smell is especially noticeable after washing with soap or having sexual intercourse, for the amines are released into the air whenever they are mixed with alkaline substances such as semen or soap. The vulva and vaginal walls may itch, burn, or become inflamed, but some women with bacterial vaginosis have no irritation whatsoever. In some women, symptoms may fluctuate with the menstrual cycle.

Bacterial vaginosis manifests clinically as a homogeneous and thin abnormal vaginal discharge that is often white or gray with a milk-like consistency. This discharge often has a foul smell that may be described as a fish-like odor. The discharge can be associated with itching or burning in the vaginal area. Other symptoms may include burning on urination and lower abdominal pain. That being said, however, it is estimated that about half of women who are infected with bacterial vaginosis will not experience any symptoms.

Diagnosis

Bacterial vaginosis is diagnosed by analysis of a sample of the vaginal discharge. Bacterial vaginosis is confirmed if three of the following four signs are observed: (1) presence of “clue cells” (vaginal epithelial cells that are covered with numerous bacterial species, normally associated with the membrane of the vaginal epithelial cell) and an associated absence of Lactobacilli species; (2) thin and/or homogeneous abnormal discharge; (3) the pH of the discharge is greater than 4.5; (4) the presence of a fishy or amine odor (Lawrence, ...