Brief overview
- What is bacterial vaginosis? Disturbance of the balance of the natural vaginal flora through the proliferation of potentially pathogenic germs, displacing the “good” bacteria.
- Symptoms: Often none. In other cases, mainly thin, grayish-white discharge that smells unpleasant (“fishy”). Occasional signs of inflammation such as redness, burning and itching. Possibly also pain during sex or urination.
- Diagnosis: gynecological examination, smear test (including pH value determination, detection of “key cells”)
- Treatment: Necessary for symptoms and during pregnancy. Usually administration of antibiotics, which can be used locally and orally (as tablets).
- Prognosis: Sometimes bacterial vaginosis heals on its own. Treatment is usually successful, but the risk of relapse is high.
Bacterial vaginosis: Description
Bacterial vaginosis (BV) is an imbalance in the composition of the bacteria naturally living in the vagina (physiological vaginal flora) – potentially pathogenic germs have gained the upper hand and “good” bacteria have been pushed back.
However, various influences can disrupt the natural vaginal environment, causing potentially pathogenic bacteria to multiply and displace the “good” Döderlein bacteria. They are likely to form a biofilm on the vaginal wall consisting of different germs depending on the individual patient – bacterial vaginosis has developed.
Gardnerella release an increased amount of amines. These substances cause the fishy odor of vaginal discharge in affected women. This is why bacterial vaginosis is also known as amine vaginosis or amine colpitis. The term colpitis generally describes an inflammation of the vaginal mucosa.
Not a sexually transmitted disease
The vaginal infection with Gardnerella & Co. is not a classic sexually transmitted disease (STD). For some years now, however, experts have been increasingly discussing the possibility of sexual transmission. This assumption is supported by the fact that same-sex couples share a bacterial vaginosis in up to 90 percent of cases.
Bacterial vaginosis: frequency
Bacterial vaginosis is the most common form of vaginal infection. In Europe, an estimated five out of ten women of fertile age are affected. Among pregnant women, the proportion is ten to 20 percent. Among women who are treated in a clinic for a sexually transmitted disease, bacterial vaginosis can also be detected in over 30 percent.
Bacterial vaginosis: symptoms
Bacterial vaginosis is very often asymptomatic: around half of the women affected have no symptoms at all.
Typical signs of inflammation such as redness, burning or itching are usually absent. Some experts therefore insist that bacterial vaginosis is not automatically a bacterial vaginitis.
Occasionally, affected women report pain during sexual intercourse (dyspareunia) or urination (dysuria). The inguinal lymph nodes are only swollen in exceptional cases of bacterial vaginosis.
Bacterial vaginosis: causes and risk factors
The healthy vaginal flora
The term “vaginal flora” refers to all microorganisms (mainly bacteria) that colonize the vaginal mucosa in healthy women. Healthy vaginal flora consists mainly of lactobacilli (Döderlein rods). They produce lactic acid and thus ensure an acidic environment in the vagina (pH value around 3.8 to 4.4). This makes it difficult for other germs to multiply or even survive.
Function of the vaginal flora
The natural composition of the vaginal flora protects the vagina from pathogenic infections. It is assumed that pathogenic germs cannot spread due to the dense colonization with lactobacilli.
Lactobacilli also produce certain substances (biosurfactants) that prevent other germs from adhering to the vaginal mucosa. In addition, some lactic acid bacteria also produce other substances such as hydrogen peroxide or bacteriocins – these also inhibit the growth of unfavorable germs.
Development of bacterial vaginosis
Various types of bacteria multiply in bacterial vaginosis. It is therefore usually a mixed bacterial infection. Gardnerella vaginalis is almost always involved. Its discoverers Gardner and Duke named the bacterium Haemophilus vaginalis in 1955, which is why this term can still be found in some works.
However, the amount of lactobacilli decreases. In a study by the University of Washington, women were examined for hydrogen peroxide-producing lactobacilli. In healthy women, 96 percent of them were detected. In women with bacterial vaginosis, only six percent were found.
Risk factors for bacterial vaginosis
The exact processes that cause bacterial vaginosis are not yet clearly understood. However, some risk factors are suspected of promoting the decline in protective lactobacilli:
However, there are other factors that can unbalance the natural vaginal flora. For example, poor or excessive intimate hygiene (e.g. frequent vaginal douching) and the use of products that are not adapted to the vaginal environment (cosmetics, scented sprays, etc.) promote bacterial vaginosis. Pregnancy or bleeding during pregnancy can also disturb the balance of the vaginal flora. A lack of vitamin D can also contribute to the development of bacterial vaginosis, particularly in pregnant women (but also in other women).
Psychosocial stress is also considered a significant risk factor. Independent of other factors, it can significantly increase the likelihood of a bacterial vaginal infection.
Ethnic origin also has an important influence on the occurrence of bacterial vaginosis: studies from the USA, for example, have shown that African-American women suffer most frequently from bacterial vaginosis, followed by Hispanic women. White American women, on the other hand, are affected much less frequently.
These ethnic differences in the composition of the natural vaginal flora result in a significantly different normal pH value – it varies between 3.8 and 5.2 depending on ethnicity. The higher values are typically found in women of African-American and Hispanic origin, which is why they are more frequently affected by bacterial vaginosis (higher pH value = less acidic and therefore more favorable for pathogenic bacteria).
Bacterial vaginosis: diagnosis and examination
Medical history and gynecological examination
First, the doctor will take your medical history (anamnesis) by asking you various questions, for example
- Have you noticed increased vaginal discharge? If so, what does it look like?
- Have you noticed an unpleasant or even “fishy” genital odor?
- Do you feel pain, itching or burning in the genital area?
- Have you had bacterial vaginal infections in the past?
- Do you change sexual partners frequently? If so, do you pay attention to safer sex (e.g. by using condoms)?
Diagnosis based on the Amsel criteria
The doctor bases the diagnosis on the so-called Amsel criteria:
- thin, white-grayish, uniform (homogeneous) vaginal discharge
- vaginal pH value above 4.5 (in around 90 percent of bacterial vaginosis)
- At least 20 percent “clue cells” on microscopic examination of the cells on the surface of the vaginal wall (epithelial cells): These cells are so densely covered by a carpet of different bacteria (biofilm) that the cell boundaries are no longer recognizable.
At least three of the four criteria must be met for the doctor to diagnose bacterial vaginosis.
Nugent score
As an alternative or in addition to the Amsel criteria, the doctor can use the Nugent score to detect bacterial vaginosis. This involves subjecting the bacteria in the vaginal secretion sample to a specific staining method (Gram stain) in order to distinguish “good” from “bad” germs and then count them.
Gram staining
- large gram-positive rods (Lactobacillus species)
- small gram-variable rods (Gardnerella vaginalis type)
- small gram-negative rods (Bacteroides species/Prevotella type)
- sickle-shaped or curved gram-variable rods (Mobiluncus species)
In a healthy vaginal flora, the blue-colored (gram-positive) lactobacilli make up the largest proportion. Typical for bacterial vaginosis is the enormous increase in potential pathogens with their red or non-uniform coloration and a simultaneous significant decrease in blue-colored lactobacilli.
Quantitative evaluation
- Total score between 0 and 3: normal vaginal flora
- Total score between 4 and 6: unclear result
- Total score between 7 and 10: bacterial vaginosis
In some European countries, such as Germany, the Nugent score is rarely used, partly because the necessary steps (Gram staining, microbiological analysis under the microscope) are quite complex.
Cultivation of the bacteria
For this reason, cultural evidence only plays a role in special cases – for example, if very specific germs are suspected (e.g. B streptococci during pregnancy) or if the treatment of bacterial vaginosis fails, i.e. the normal vaginal flora does not return despite treatment.
Differentiation from other vaginal diseases (differential diagnosis)
The following table shows the most important differences between bacterial vaginosis, trichomonas infection and vaginal fungus:
|
bacterial vaginosis |
Trichomonas infection |
Vaginal candidiasis (yeast infection) |
|
|
annoying vaginal odor |
yes, fishy |
possible |
no |
|
Discharge |
thin, white-grey, uniform |
green-yellowish, partly foamy |
whitish, crumbly |
|
Irritation of the vulva |
sometimes, but hardly any redness |
yes |
yes |
|
Pain during sex |
possible |
yes |
yes |
|
typical cells (determined microscopically) |
key cells |
motile flagellates (flagellates) |
Pseudohyphae and shoot cells |
|
pH value |
> 4,5 |
> 4,5 |
normal (< 4.5) |
|
Lactobacilli |
diminished |
normal |
The clinical symptoms of a vaginal infection are very varied and, depending on the pathogen and the female immune or hormonal status, can be very different, similar or even completely absent. A medical examination is required to find out the exact cause.
Bacterial vaginosis: therapy
Bacterial vaginosis during pregnancy is treated even if there are no symptoms, as the risk of miscarriage is increased due to the bacterial infection. In addition, symptom-free BV should be treated if a gynecological procedure is planned (e.g. insertion of an IUD).
Treating bacterial vaginosis
Important: Only take antibiotics if and how you have discussed this with your doctor. Incorrect use can impair the success of treatment. In addition, the germs may become more resistant, making future treatments more difficult.
Occasionally, treatment of bacterial vaginosis is also attempted with other preparations, for example those containing lactic acid bacteria. It is difficult to say how effective these are – lactic acid preparations have been less well studied than antibiotics, especially as they are usually used in combination with them (and not alone).
The problem of bacterial biofilm
Bacterial vaginosis – home remedies
Some patients use various natural products to treat the symptoms of bacterial vaginosis. These include, for example, tampons soaked in milk, black tea, tea tree oil or natural yoghurt, which are inserted into the vagina. Garlic, wrapped in gauze and inserted, is also said to help against amincolpitis. Vinegar or lemon water are also popular home remedies for bacterial vaginosis that are applied locally.
Home remedies have their limits. If the symptoms persist over a longer period of time, do not improve or even get worse, you should always consult a doctor.
Bacterial vaginosis – pregnancy
Bacterial vaginosis in pregnant women is always treated, even if there are no symptoms. This is because the germs (as with other vaginal infections) can ascend via the cervix and easily increase the risk of premature labor, premature birth and miscarriage, among other things.
Medical guidelines recommend antibiotic treatment for pregnant women. Local treatment with clindamycin (e.g. as a cream) is possible at any stage of pregnancy. Metronidazole can also be applied locally from the second trimester (in exceptional cases even earlier). Systemic treatment with tablets (e.g. metronidazole, clindamycin) is also only recommended from the second trimester (or earlier if necessary).
No co-treatment of the partner
The same applies to homosexual couples: Co-treatment of the sexual partner is generally not indicated.
Bacterial vaginosis: course of the disease and prognosis
Bacterial vaginosis heals on its own in around a third of cases. However, if it causes symptoms or if the patient is pregnant, it should be treated. In the majority of cases, treatment is successful.
Bacterial vaginosis can also lead to various complications:
- Risk of further infections
- Complications during pregnancy
Bacterial vaginosis: risk of further infections
Women with bacterial vaginosis have an increased risk of further gynecological infections. The germs of BV can spread, causing the external female genitalia (vulva) or the paired vaginal vestibule gland (Bartholin’s gland) to become inflamed.
Bacterial vaginosis can therefore result in the following clinical pictures due to the spread or ascent of germs:
- Vulvitis (inflammation of the external female genitalia)
- Bartholinitis (inflammation of the Bartholin glands)
- Cervicitis (inflammation of the cervix)
- Endometritis (inflammation of the lining of the uterus)
- Salpingitis (inflammation of the fallopian tubes)
- Adnexitis (combined inflammation of the fallopian tubes and ovaries)
- Tuboovarian abscess (accumulation of pus in the area of the fallopian tubes or ovaries)
Increased risk during medical procedures
The risk of ascending infections is also increased if a medical procedure is carried out. This is because mucosal cells are damaged, which favors an infestation with germs. For example, the insertion of an IUD (intrauterine device) for contraception or an abortion can lead to bacterial vaginosis.
Risk of sexually transmitted diseases
Bacterial vaginosis not only increases the risk of further infections caused by your “own” germs – it also favors the colonization of other germs. Women with BV are therefore more susceptible to sexually transmitted diseases (STDs) such as chlamydia, trichomonas or gonorrhea.
Bacterial vaginosis & pregnancy: complications
The prostaglandins also ensure that the uterine muscles contract (important during the birth process). They also increase the number of metalloproteases (enzymes made from proteins). These proteins can, for example, cause premature rupture of the membranes.
Furthermore, the pathogens of bacterial vaginosis can infect the amniotic fluid or the egg membrane (amnion, part of the inner amniotic sac) and lead to serious infections of the mother (bacterial blood poisoning in the puerperium = puerperal sepsis) and the child.
- premature labor
- premature rupture of membranes
- premature birth or miscarriage
- Amnionitis, amniotic infection syndrome
- Infections of the newborn
- Inflammatory wound healing disorders in the mother after perineal or caesarean section (e.g. abdominal wall abscess)
Bacterial vaginosis: prevention
There is no definite tip for prevention. In principle, safer sex is recommended as a prophylaxis for all diseases that can be transmitted sexually, for example the use of condoms. This is particularly advisable with frequently changing sexual partners.
You should also avoid excessive intimate hygiene. This means, for example, no vaginal douching and no cleaning of the intimate area with other aids or substances.
The local application of lactobacillus, lactic acid or other acid preparations after professional treatment of bacterial vaginosis can help to maintain the normalization of the vaginal flora and prevent a relapse.
Special tips for pregnant women
The Erfurt and Thuringia Preterm Birth Prevention Campaign 2000 achieved promising results. The participating pregnant women measured the pH value in their vagina themselves twice a week. If the measured value was above 4.4, a medical examination for bacterial vaginosis was carried out. If the diagnosis was confirmed, antibiotic treatment was initiated. This actually reduced the premature birth rate for the duration of the study.
