Gardnerella

Women colonized with G. vaginalis are typically asymptomatic unless they have bacterial vaginosis.[8] Most women with BV present with a complaint of malodorous vaginal discharge, which often becomes more pronounced after sexual intercourse. A diagnosis of BV is suggested by a higher than normal vaginal pH (greater than 4.5), the presence of clue cells on a wet-mount slide, and a positive whiff test.[8] A drop of sodium chloride solution is placed on the wet-mount slide containing some of the swab specimens, and the slide is examined under the microscope for visualization of the characteristic clue cells.[9] The whiff test is performed by adding a small amount of potassium hydroxide (KOH) to the microscopic slide containing the vaginal discharge and is considered to be positive if a characteristic fishy-scent is revealed.[9] Typically, two of these positive tests, as well as the presence of the characteristic discharge, is enough to confirm the diagnosis of BV.[8] If no discharge is present, then all of these criteria are needed to make the diagnosis.[8]

Before the identification of the rapid identification method, the only way to isolate Gardnerella was by growing cultures on selective agar medium.[10] With the advent of the rapid identification method in 1982 (a micro-method based on starch and raffinose fermentation and hippurate hydrolysis), 91.4% of the strains of Gardnerella were able to be isolated without the need for culture and Gram stain.[10]

Occasionally a Gram stain of the vaginal fluid is still done to examine the predominant strain of bacteria to make a microbiological diagnosis of BV. This technique, referred to as Nugent criteria, has a sensitivity and specificity of 89% and 83%, respectively.[10]

Asymptomatic Gardnerella colonization does not need to be treated. It has even been reported that up to 30% of cases of BV may even resolve on its own without treatment.[1] However, if a patient is bothered by the symptoms of BV, or is pregnant, it should be treated with either oral or vaginal clindamycin or metronidazole.[1][11]Unfortunately, it has been shown that recurrence may occur in up to 80% of women after treatment.[1][12] If a patient presents with recurrent symptoms, a second course of antibiotics is typically prescribed.[1] A 2009 Cochrane review found tentative but insufficient evidence to support the use of probiotics as treatment or prevention of BV.[13]

A proper pelvic exam can help to narrow down the differntial diagnosis and exclude other similarly presenting diseases such as herpes simplex virus.[1] Speculum exam can look for cervicitis and a wet mount of the vaginal discharge can determine if there is candidiasis or trichomoniasis.[1] Additional cervical swab cultures can be sent for chlamydia and gonorrhea.[14] 

Most uncomplicated cases of bacterial vaginosis resolve with treatment. However, recurrences are not uncommon. Over time, BV is a risk factor for acquiring HIV. Over the past decade, there have been multiple reports of resistant strains that do not resolve with conventional treatment.

BV can lead to the following:

• Increased risk for endometritis and salpingitis
• Increased risk of post-surgery infections
• Adverse outcomes in pregnancy including premature labor, premature rupture of membranes and postpartum endometritis.
• Pelvic inflammatory disease
• Neonatal meningitis

Untreated BV can lead to increased risk of pregnancy complications and STIs, including HIV.[14] Data also suggest an association between BV and both tubal factor infertility and pelvic inflammatory disease.[15] During pregnancy, BV has been associated with an increased risk of premature birth and miscarriage.[15] It also has been shown to increase the risk of chorioamnionitis, premature rupture of membranes and postpartum endometritis.[15]

Gardnerella is a common genital infection that is often encountered by the emergency department physician, nurse practitioner, internist, and the gynecologist.  Asymptomatic Gardnerella colonization does not need to be treated as nearly 30% of cases resolve spontaneously. All symptomatic patients need treatment but despite treatment, recurrences are common. 

Untreated BV can lead to increased risk of pregnancy complications and STIs, including HIV.[14] Data also suggest an association between BV and both tubal factor infertility and pelvic inflammatory disease.[15]

These patients need to be followed by the nurse practitioner until all symptoms have disappeared.

Even though BV is not a sexually transmitted infection, the nurse practitioner should educate the patient on the importance of safe sex measures, avoidance of multiple sex partners and use of barrier protection.