What is Gardnerella Vaginalis?
Gardnerella vaginalis is a type of bacteria that is typically found in the vagina. It was named after Hermann L. Gardner, the scientist who discovered it in 1955. Normally, the vagina is home to many helpful bacteria, predominantly a type called Lactobacillus. However, if other bacteria like Gardnerella become more numerous, it can upset the balance and lead to a condition called bacterial vaginosis (BV).
BV can cause unusual vaginal discharge and happens when there’s an overgrowth of certain bacteria in the vagina. It can lead to a number of health problems including infertility, early delivery if you’re pregnant, infection after childbirth, pelvic inflammatory disease (an infection of the female reproductive organs) and a higher chance of catching HIV and other diseases passed on through sexual contact.
What Causes Gardnerella Vaginalis?
We don’t fully understand why bacterial vaginosis (BV) occurs, but we believe it has something to do with the growth of a bacteria called Gardnerella. Although this bacteria isn’t typically contagious, we’re still not sure exactly how it can be spread. It’s possible that it can be transmitted through sexual intercourse, which may upset the natural balance of bacteria within the vagina, possibly leading to BV.
In most cases, BV happens when there are fewer of the normal Lactobacillus bacteria which produce lactic acid and hydrogen peroxide. This reduction allows for the excessive growth of other bacteria, like Gardnerella.
In the past, people referred to BV as Gardnerella vaginitis, thinking that this bacterium was the sole cause. But now we use the term bacterial vaginosis to underscore that several different bacteria naturally found in the vagina can grow too much and cause BV.
Research has found Gardnerella in the vaginas of about 50% of women who show no symptoms. This led researchers to believe that this bacterium might be part of the normal vaginal flora, or the mix of bacteria typically found in the vagina.
Several lifestyle factors could contribute to BV. These include frequent baths, douching, smoking, having multiple sexual partners, using over-the-counter vaginal hygiene products, stress, and having sex often. It might also be more common in women who don’t change their underwear often.
Risk Factors and Frequency for Gardnerella Vaginalis
Bacterial vaginosis (BV) is the most common vaginal infection among women of childbearing age. The number of women who have this infection can vary dramatically, with anywhere from 5% to 70% of women experiencing it. The frequency of BV also changes between different countries, ranging from 20% to 60%. However, in the United States, about 30% of women experience BV. The rates of BV are lowest in Australia, New Zealand, and Western Europe.
- The condition is notably more common among black women than white women.
- Women with multiple sexual partners also seem to have higher rates of BV.
- The bacteria known as Gardnerella is often identified in cases of BV, indicating that this pathogen is common among affected individuals.
Signs and Symptoms of Gardnerella Vaginalis
Women who carry the bacteria Gardnerella vaginalis usually do not exhibit any symptoms unless there’s an imbalance between the amounts of Gardnerella and another bacteria, Lactobacillus. About half of the women who have bacterial vaginosis, a condition that results from this imbalance, will have noticeable symptoms. Common issues include a smelly vaginal discharge that becomes more noticeable after sex and occasional itching.
Testing for Gardnerella Vaginalis
Bacterial Vaginosis (BV), a common vaginal infection, is typically diagnosed using either the Amsel criteria or the Nugent score. In a medical setting, the Amsel criteria is often used and it requires at least 3 out of 4 specific signs to be present.
The Amsel criteria includes the following signs:
- A homogeneous, thin, grayish-white vaginal discharge that evenly coats the inside of the vagina.
- Discovery of 20% or more clue cells upon examination of a wet mount.
- A vaginal pH of 4.5 or higher.
- A positive whiff test.
Clue cells are a type of cell from inside the vagina that are coated with rod-shaped bacteria. Using a drop of sodium chloride solution on a microscopic slide containing the vaginal specimen reveals these distinctive clue cells. The whiff test involves adding a small amount of potassium hydroxide to the slide containing the vaginal discharge. If a fishy odor is detected, the whiff test is positive.
The Nugent scoring system, typically used in research, relies on microscopic and gram-stain techniques to measure the presence of vaginal bacteria and assigns a numerical score from 0 to 10. A higher score suggests a higher concentration of bacteria associated with BV.
Most often, point-of-care tests, which are quick diagnostic tests at or near the place of patient care, are not commonly used in clinical settings because of their high cost. Rather, medical professionals usually use commercial molecular diagnostic tests. These tests are able to quantify, or count, bacteria and show a sensitivity ranging from 90.5% to 96.7% and a specificity of 85.8% to 95%. Since the development of a rapid identification method in 1982, it has been possible to isolate 91.4% of Gardnerella strains, a type of bacteria, using a process involving starch, raffinose fermentation, and hippurate hydrolysis.
Treatment Options for Gardnerella Vaginalis
If you’ve tested positive for Gardnerella but are not experiencing any symptoms, treatment isn’t always necessary. Studies show that about 30% of these cases can clear up on their own. However, if you are feeling uncomfortable due to symptoms, treatment will likely be suggested and it typically involves either oral medication or a medication that is inserted into the vagina.
In 2017, the United States Food and Drug Administration approved a medication named secnidazole to treat Gardnerella. This medication, which is part of a broader group of drugs known as 5-nitroimidazoles, has been used for years to treat various infections but only recently received approval for treating Gardnerella.
Initial treatments for Gardnerella are usually quite effective, with roughly 80% to 90% of patients seeing improvement within a month. That being said, recurrence is common within the first 9 months after treatment, occurring in approximately 80% of women. If the symptoms come back, a second round of antibiotics is typically prescribed. Research on the effectiveness of probiotics (healthy bacteria) in treating and preventing reoccurrence is ongoing and results are still inconclusive. It’s important to note that recurrent Gardnerella does not have a universally accepted definition.
When it comes to treating Gardnerella, the medication metronidazole is often used, either taken orally or in the form of an intravaginal gel. There’s also a medication called clindamycin, which is used as an intravaginal cream.
Alternatively, other forms of clindamycin can be used – either as oral tablets or as intravaginal ovules. Additionally, tinidazole, which is a drug taken orally, and secnidazole oral granules are other options. Your healthcare provider will decide on the best treatment option for your specific situation.
What else can Gardnerella Vaginalis be?
When a doctor is trying to diagnose bacterial vaginosis, they also need to consider that it could be due to other conditions. These conditions can potentially include:
- Atrophic vaginitis (thin, drying, and inflammation of the vaginal walls due to a decrease in estrogen)
- Candidiasis (yeast infection in the vagina)
- Cervicitis (inflammation of the cervix)
- Chlamydia (sexually transmitted disease that affects the genital areas)
- Desquamative inflammatory vaginitis (a condition characterized by yellowish, genital discharge and inflammation)
- Gonorrhea (sexually transmitted infection that affects the genital areas)
- Herpes simplex (genital herpes caused by a viral infection)
- Trichomoniasis (sexually transmitted disease that affects the genital areas)
The physician will perform an extensive pelvic examination to confirm or dismiss any possible conditions. This examination can involve using a speculum to identify any signs of cervicitis and analyzing the vaginal discharge to detect any presence of candidiasis or trichomoniasis. Additionally, cervical swab cultures might be taken to test for chlamydia and gonorrhea.
What to expect with Gardnerella Vaginalis
Most straightforward cases of Bacterial Vaginosis (BV) generally get better with treatment. However, it’s not rare for the condition to return because antibiotic treatment often fails to restore the vagina to its normal state, which is dominated by ‘good’ bacteria called Lactobacillus. Specially, a type of bacteria called Gardnerella forms biofilms — a kind of protective layer — that make it hard for the antibiotic metronidazole to penetrate.
In fact, within three months of treatment, about 80% of women may experience a relapse of BV. Furthermore, there have been more and more reports in the last ten years of BV strains that don’t respond to traditional treatments.
In a recent study, a powder containing a natural strain of Lactobacillus, called Lactobacillus crispatus CTV-05, was used. After being treated with metronidazole, women used the powder locally in the vagina to reduce the chances of BV returning. They started by using the powder four times daily during the first week, then reduced it to twice weekly for the next 10 weeks. This approach, which is not yet approved by the FDA, managed to significantly lower BV recurrence up to 24 weeks post-treatment. There are currently alternative vaginal products being tested to improve the results regarding BV recurrence.
BV has been linked to a higher risk of contracting Sexually Transmitted Infections (STIs), such as gonorrhea, chlamydia, trichomonas, herpes, human papillomavirus (HPV), and HIV. This is because Gardnerella damages the lining of the vagina, which in turn raises the risk of HPV infection. BV may also contribute to difficulties in getting pregnant naturally and through assisted reproductive techniques, although it’s not yet certain whether BV is the cause. The idea of treating male partners with antibiotics to prevent recurrent BV is currently being explored, but it is not recommended as a standard strategy yet.
Another alternative for dealing with recurrent BV is the use of boric acid administered in the vagina. Although this approach has not been approved by the FDA, existing evidence suggests that it’s safe for non-pregnant women. It’s usually recommended at a dosage of 600 mg, given locally in the vagina, twice weekly as a preventive measure against BV. Boric acid should not be used during pregnancy and should never be taken orally.
According to the Centers for Disease Control and Prevention (CDC), multiple recurrences of BV can be managed using various treatment strategies. These include either a gel or vaginal suppository form of metronidazole administered twice weekly over 3 months, or an oral course of metronidazole or tinidazole, followed by locally administered boric acid and ongoing treatment with metronidazole gel. Another regimen involves oral metronidazole taken simultaneously with oral fluconazole once monthly.
Possible Complications When Diagnosed with Gardnerella Vaginalis
The complications linked with Bacterial Vaginosis (BV) include:
- Higher chances of endometritis (inflammation of the lining of your uterus) and salpingitis (inflammation of the fallopian tubes).
- Increased likelihood of infections after surgery.
- Negative effects on pregnancy, such as premature labor (baby born too early), premature rupture of membranes (waters breaking too early), and postpartum endometritis (inflammation of the uterine lining after childbirth).
- The development of pelvic inflammatory disease, a condition that affects the female reproductive organs.
- Possible risk of neonatal meningitis, a serious infection that causes inflammation in the surrounding areas of a newborn’s brain.
Preventing Gardnerella Vaginalis
Education about Gardnerella, a common bacteria that can lead to a condition called bacterial vaginosis (BV), is crucial for identifying early symptoms and seeking treatment. Despite not knowing the exact reason why certain conditions may lead to an overgrowth of this bacteria and increased pH levels in the vagina (creating an environment that favors BV), there are some steps women can take to reduce the chances of getting BV.
Health professionals should thoroughly explain the factors that can heighten the risk of getting BV. These factors include having multiple sexual partners, douching (cleansing the inside of the vagina with water or other mixtures of fluids), not using condoms regularly, smoking, and having female sexual partners. By understanding and managing these risks, women may be able to lower their likelihood of both getting BV and other sexually transmitted infections (STIs) that could stem from an overgrowth of Gardnerella.
