Can Gardnerella bacteria increase HIV risk?

The vagina is not a body part that many people feel comfortable talking about. But, as with many medical issues, the more we educate ourselves, the better equipped we are to stay healthy.

In the case of bacterial vaginosis, for instance, it’s important to understand that there’s a link between this common, but not life-altering, condition and the transmission of more serious infections – most critically HIV.

New studies have found that the microflora of a woman’s vagina has a direct effect upon how susceptible she is to the human immunodeficiency virus. To understand this connection, it’s important to elaborate a little on what we mean by vaginal microflora.

The first thing to know is that a healthy vagina is slightly acidic, as this keeps unwanted bacteria from multiplying. The second thing to know is that this acidity level is, strangely enough, maintained by a type of (good) bacteria called Lactobacillus.

In women who have lower levels of Lactobacillus, the acidity of the vagina can become compromised, and unwanted bacteria can begin to develop. One common type of bacteria that develops under these circumstances is Gardnerella vaginalis. Its presence can lead to bacterial vaginosis, which causes unusual, unpleasant-smelling vaginal discharge.

The question is: what does this all have to do with HIV?

Well, as described here, HIV transmission is more likely when there is inflammation in the vagina. In turn, vaginal inflammation is closely associated with low levels of Lactobacillus. When researchers examined which types of bacteria were linked to decreasing levels of Lactobacillus and inflammation, one in particular was singled out: Prevotella bivia. Shockingly, women whose vaginal microflora contained more than 1% P. bivia showed the highest levels of inflammation; these women were 13 times more likely to contract HIV.

Gardnerella was also found to play a role in HIV transmission when it comes to pre-exposure prophylaxis (where medication is taken to prevent infection). In one study looking at tenofovir, an anti-HIV drug applied to the vagina in the form of a gel, it was found that the efficacy of the medication dropped by half when Gardnerella was introduced to the vagina.

This research could lead to much progress being made in the HIV/AIDS crisis, particularly in African countries. If bacterial infections in the vagina can be effectively treated with antibiotics, and if greater awareness can be spread about the importance of vaginal health, then we could start to see a decrease in HIV diagnoses.

Maintaining a Healthy Vagina

The first thing to know about vaginal health is that vaginal discharge is a completely natural feature of a healthy vagina. It is produced by the cervix to keep the vagina moist and free from infection. Normal vaginal discharge is clear or white, and thick and sticky for the majority of your menstrual cycle (it may become wetter around ovulation). Normal vaginal discharge should not smell strong or unpleasant.

Unusual vaginal discharge is characterised by any significant change in colour, consistency or smell. If it smells fishy, becomes lumpy, or turns green, yellow, or grey and watery, this is typically a sign of a sexually transmitted infection or a condition such as bacterial vaginosis.

Bearing this information in mind, it’s advised that you follow these guidelines to keep your vagina healthy:

• Keep the vagina, anus and perineum clean, particularly during your period

• Wash your hands before and after changing your sanitary towel, tampon or menstrual cup

• Avoid using vaginal douches, as these can disrupt your vaginal microflora

• Avoid using perfumed or antiseptic products on your vagina as these can also disrupt the microflora

• Use condoms and dental dams during sex when you aren’t sure that your partner is free from STIs

• Get tested for STIs if you might be at risk, even if you are not experiencing symptoms

• Get checked out if you experience any significant change in your discharge, or experience irregular bleeding or pelvic pain

• Attend a cervical screening every three years

The STI Clinic can supply safe home sampling kits for all kinds of STIs, including HIV and chlamydia. We can also supply a test for bacterial vaginosis. Click here to visit our clinic and find out more.