This test, called the whiff test, is performed by adding a small amount of potassium hydroxide to a microscope slide containing the vaginal discharge. A characteristic fishy odor is considered a positive whiff test and is suggestive of bacterial vaginosis. Loss of acidity. To control bacterial growth, the vagina is normally slightly acidic with a pH of 3.8–4.2. A swab of the discharge is put onto litmus paper to check its acidity. A pH greater than 4.5 is considered alkaline and is suggestive of bacterial vaginosis. The presence of clue cells on wet mount. Similar to the whiff test, the test for clue cells is performed by placing a drop of sodium chloride solution on a slide containing vaginal discharge. If present, clue cells can be visualized under a microscope. They are so-named because they give a clue to the reason behind the discharge. These are epithelial cells that are coated with bacteria.Differential diagnosis for bacterial vaginosis includes the following:
Normal vaginal discharge. Candidiasis (thrush, or a yeast infection). Trichomoniasis, an infection caused by Trichomonas vaginalis. Aerobic vaginitisThe Center for Disease Control (CDC) defines STIs as "a variety of clinical syndromes and infections caused by pathogens that can be acquired and transmitted through sexual activity." But the CDC does not specifically identify BV as sexually transmitted infection.
Bacterial vaginosis (BV) is a disease of the vagina caused by excessive growth of bacteria. Common symptoms include increased vaginal discharge that often smells like fish. The discharge is usually white or gray in color. Burning with urination may occur. Itching is uncommon. Occasionally, there may be no symptoms. Having BV approximately doubles the risk of infection by a number of sexually transmitted infections, including HIV/AIDS. It also increases the risk of early delivery among pregnant women.BV is caused by an imbalance of the naturally occurring bacteria in the vagina. There is a change in the most common type of bacteria and a hundred to thousand fold increase in total numbers of bacteria present. Typically, bacteria other than Lactobacilli become more common. Risk factors include douching, new or multiple sex partners, antibiotics, and using an intrauterine device, among others. However, it is not considered a sexually transmitted infection and, unlike gonorrhoea and chlamydia, sexual partners are not treated. Diagnosis is suspected based on the symptoms, and may be verified by testing the vaginal discharge and finding a higher than normal vaginal pH, and large numbers of bacteria. BV is often confused with a vaginal yeast infection or infection with Trichomonas.Usually treatment is with an antibiotic, such as clindamycin or metronidazole. These medications may also be used in the second or third trimesters of pregnancy. However, the condition often recurs following treatment. Probiotics may help prevent re-occurrence.