Bacterial Vaginosis (BV) is a common condition resulting from a disruption in the delicate balance of the naturally occurring bacteria within the vagina. This shift involves a decrease in the protective Lactobacillus species and an overgrowth of other organisms, most notably anaerobic bacteria. A standard urine test is not used to diagnose BV because the infection is localized to the vaginal environment. Healthcare providers must collect a specific vaginal sample to accurately identify this microbial imbalance.
Bacterial Vaginosis vs. Urinary Tract Infections
Confusion often arises because symptoms of Bacterial Vaginosis, such as a burning sensation during urination, can overlap with those of a Urinary Tract Infection (UTI). However, these conditions affect two distinct parts of the body. BV is an infection of the vagina itself, while a UTI is an infection within the urinary tract, which includes the bladder, urethra, and kidneys.
A standard urine test, or urinalysis, is designed to detect markers of an infection in the urinary system. It screens for elevated levels of white blood cells, the presence of nitrites, or specific bacteria like Escherichia coli (E. coli), which are common causes of UTIs. These tests are not calibrated to look for the specific anaerobic bacteria, such as Gardnerella vaginalis, that are associated with BV.
Clinical Diagnostic Procedures for BV
To diagnose Bacterial Vaginosis, a healthcare provider performs a pelvic examination and collects a vaginal fluid sample. The diagnosis relies on a combination of clinical findings, sometimes referred to as the Amsel criteria. One step is testing the vaginal pH, which typically rises above the normal acidic range of 3.8 to 4.5 when BV is present.
The collected vaginal fluid is then examined under a microscope in what is called a wet mount preparation. A specific indicator of BV is the presence of “clue cells,” which are vaginal epithelial cells heavily coated with bacteria. The provider may also perform a whiff test by adding a potassium hydroxide solution to the sample; a strong, fishy odor upon addition of the solution is a positive sign of BV. The Nugent score uses a Gram stain of the vaginal sample to quantify the different types of bacteria present.
Treatment and Managing Recurrence
Once a diagnosis of Bacterial Vaginosis is confirmed, the condition is treated with prescription antibiotics to restore the normal microbial balance. The most common treatments are metronidazole or clindamycin, which can be prescribed as an oral pill or as a topical gel or cream inserted directly into the vagina. It is important to complete the entire course of medication as prescribed, even if symptoms begin to clear up earlier.
BV has a high rate of recurrence, with studies indicating that up to 50% of women may experience a return of symptoms within a year of treatment. For those who experience multiple recurrences, an extended course of treatment or a suppressive regimen may be recommended. Following up with a healthcare professional after treatment is important to ensure the infection has fully cleared and to discuss strategies for managing future episodes.