Aerobic vaginitis is an overgrowth of aerobic bacteria that causes vaginal inflammation and discomfort.
Although its name makes it sound like a spinning class or a sweaty workout, aerobic vaginitis (AV) isn’t that much fun. With AV, beneficial lactobacilli are low and are instead replaced by aerobic bacteria (that is, bacteria that need oxygen to survive and grow) and high levels of inflammatory cells [1].
Scientists don’t know exactly how AV happens. They think that a disruption of the vaginal microbiome may prompt immune cells to arrive and cause inflammation. Or it could be the other way around, meaning that an imbalance of the immune response occurs first, to which the vaginal microbiome changes as a reaction [1].
More research is needed to fully understand the dynamics of AV.
AV shares some symptoms with bacterial vaginosis
About 1.4-8% of non-pregnant women and 3-8% of pregnant women are diagnosed with AV [2]–[5].
These percentages could actually be higher, because AV is often misdiagnosed as an inflammatory form of bacterial vaginosis (BV) [2]. It wasn't until 2002 that AV was recognized as a different condition. Even so, some scientists and practitioners still debate if AV is really a distinct condition.
Common symptoms of AV include:
- An abundant, sticky yellowish vaginal discharge, with a foul or rotten smell
- Redness and swelling around the opening of the vagina
- Vaginal itching
- A burning or stinging sensation
- Pain during sex [1], [2]
While some of these symptoms may also be present in BV (which explains why AV is often confused with BV), the first two are specific for AV. In BV the vaginal discharge is thin, with a milky white or gray color and a fishy smell, and there is usually no redness and swelling, which are signs of inflammation.
However, some women can have AV and be asymptomatic [6].
A correct diagnosis of aerobic vaginitis is key
Taking only symptoms into account can lead to the wrong diagnosis and to the wrong treatment. If you’re unsure, it’s always better to ask your provider for a thorough examination or some additional tests.
AV is a highly inflammatory condition. A speculum examination will reveal a red and swollen vaginal canal that can also have small erosions and ulcerations [1], [2].
Taking a sample of your vaginal discharge and looking it under the microscope can also provide good clues for a correct diagnosis. Among other things, low numbers of lactobacilli and the presence of inflammatory cells will help distinguish AV from other conditions [7].
A pH vaginal test will show values higher than normal, between 5.0 and 8.0 [8].
In AV, the vaginal microbiome looks more “aerobic”
While this sounds like a bunch of microbes sweating their bodies to get ready for the summer, it actually means that the vaginal microbiome is low in lactobacilli and high in aerobic bacteria that require oxygen. The most common aerobic bacteria in AV are:
- Streptococcus agalactiae
- Escherichia coli
- Enterococcus faecalis
- Streptococcus aureus
But many other bacteria like Staphylococcus epidermidis, Streptococcus anginosus, and Klebsiella pneumoniae can also cause AV [2], [5], [6], [9]–[13].
Besides, new research has revealed that anaerobic bacteria, like those present in BV (e.g. Gardnerella vaginalis, Prevotella bivia, and Atopobium vaginae) can also exist at high levels in AV [8], [10].
Having AV may cause pregnancy complications
If you are pregnant and have AV, you could be at higher risk for some pregnancy complications. Although there are only a couple of studies that have looked into this, and so the evidence is not that strong, it is always better to be aware of the risks.
Compared to women with a healthy vaginal microbiome, women with AV are:
- Three times more likely to deliver preterm.
- Two to six times more likely to have premature rupture of the amniotic sac.
- Two times more likely to have a baby with a neonatal infection or admitted into the neonatal intensive care unit [11], [12].
The ideal treatment for AV doesn’t exist, but antibiotics may help
Unfortunately, as scientists are not clear on how AV starts, there is no ideal treatment for it. Standard treatment is antibiotics like topical clindamycin, kanamycin ovules, or moxifloxacin [7], [14].
In cases of severe AV with high levels of inflammation, topical steroids or estrogen creams may be used along with the antibiotics. Severe cases are more common in menopausal or post-menopausal women [1].
The problem with antibiotics is that some AV-causing bacteria may be resistant to them and this may lead to treatment failure [10]. To prevent this, clearly identifying the dominant bacteria in your vaginal microbiome and testing for resistance/sensitivity to antibiotics can help choose the most appropriate direction.
Unfortunately, there is not enough research about the role of probiotics in AV recovery. But it could be worth supplementing with some to replenish Lactobacillus levels while on antibiotics.
Things you can do to protect against AV
There are some general rules that will help you maintain a healthy vaginal microbiome. You can check our guide on lifestyle and other vaginal interventions.
Stay alert on any changes in the color, smell, and quantity of your vaginal discharge. It is normal for it to vary during the menstrual cycle (if you are not pregnant) but any major change or unpleasant smell should be taken care of.
Women with a history of vaginal infections are 2.6 times more likely to develop AV [12]. If your vaginal community is not dominated by Lactobacillus, taking a vaginal probiotic may help you restore your microbiome and avoid any further vaginal infections.
