Cervical cancer is almost always caused by the human papillomavirus (HPV). This link has been well known and well documented since it was first discovered in the 1980s.

It’s been less clear why HPV clears up quickly in some people but leads to cancer in others.

Recent research suggests the answer might involve vaginal bacteria and the acidity of the vaginal environment. These findings show that certain “good” bacteria might prevent HPV from becoming cancerous, while certain “bad” bacteria might allow HPV to turn cancerous.

Keep reading to learn more about the link between bacterial infections and cervical cancer.

The link between cervical cancer and HPV is well documented. HPV causes almost all cervical cancer and is the number one risk factor for cervical cancer.

But HPV is also a very common sexually transmitted infection (STI). In fact, the U.S. Centers for Disease Control and Prevention (CDC) reports that nearly all sexually active people catch HPV at some point during their lives.

In contrast, only 0.7 percent of women will be diagnosed with cervical cancer during their lifetime, based on data from 2017 to 2019. That’s because the body’s immune system is almost always able to fight off an HPV infection.

So why does HPV become cancer in a small percentage of people? That’s a question teams of researchers around the globe have been trying to answer.

Recent breakthroughs have led researchers to believe the answer might involve vaginal bacteria. There appears to be a difference in the vaginal bacteria of people who develop cervical cancer and in those who don’t.

Bad bacteria may contribute to cervical cancer risk

Research shows that people with “good” bacteria in their vagina have a healthy cervical environment, while people with “bad” bacteria have an unhealthy environment that can increase cancer risk.

Specifically, research has found that people who have a good bacteria called Lactobacillus as the dominant bacteria in their vaginal environment are more likely to fight off an HPV infection.

People who have more of a bad bacteria called Sneathia were more likely to have HPV, which led to precancer and cervical cancer.

The Sneathia bacteria is also linked to vaginal infections, miscarriages, and earlier labor.

Healthy bacteria linked to higher levels of acidity in your vagina

Additionally, a higher level of healthy bacteria is linked to a higher level of acidity in your vaginal environment. Generally, healthy vaginal environments have a pH of less than 4.5. This acidity level destroys bad bacteria and allows good bacteria to thrive.

Higher pH levels in your vagina allow bad bacteria to grow and can lead to cervical cancer.

A bacterial infection in your vagina doesn’t always cause symptoms. It’s possible to have an infection and not know. When an infection does cause symptoms, they can include:

  • vaginal discharge that’s off-white, gray, or greenish
  • vaginal discharge that has an odor (this smell is often described as “fishy”)
  • an odor that gets stronger after sex or during menstruation if you menstruate
  • itchiness
  • soreness

Sometimes, bacterial infections in your vagina go away on their own without treatment. But if you have symptoms, it’s best to see a healthcare professional.

Over-the-counter treatments aren’t effective for bacterial infections in your vagina. These types of infections are always treated with antibiotics.

A doctor or healthcare professional might prescribe oral antibiotics like the type you’d take for strep throat or an ear infection. You might also receive an antibiotic gel or cream to insert directly into your vagina.

HPV is the biggest risk factor for cervical cancer, but it’s not the only one. There are other risk factors that make developing cervical cancer more likely. These include:

Socioeconomic factors also play a role in your risk of cervical cancer. People who live in low-income areas or who are from low-income backgrounds have less access to cervical cancer screening, HPV vaccinations, and other important healthcare.

In the United States, these socioeconomic factors disproportionately affect Black, Hispanic, and Indigenous people, thus increasing the risk of cervical cancer among people from these ethnic backgrounds.

The most important step you can take to lower your risk of cervical cancer is getting the HPV vaccine.

Get an HPV vaccine

Children can get the HPV starting as young as 9 years old, but the vaccine is recommended for kids between 11 and 12 years old. Everyone under 26 years who hasn’t been vaccinated is also highly encouraged to get the vaccine.

If you’re between 27 and 45 years old and you’ve never received the HPV vaccine, talk with a healthcare professional. The vaccine provides less benefit to people in this age range, but it might still be a good choice for many people.

Get regular screenings for cervical cancer

It’s important to continue getting cervical cancer screenings, even if you’ve had the HPV vaccine. There are two important screening tests that can help lower your risk of cervical cancer:

  • Pap smear. A pap smear looks for precancers that can lead to cervical cancer.
  • HPV test. An HPV test looks for HPV.

Make these lifestyle changes

Additional steps you can take to lower your risk of cervical cancer include:

Free and low-cost cervical cancer screenings are available

Free and low-cost screenings are available from several sources. For example, the CDC offers free screening through the National Breast and Cervical Cancer Detection Program to people who meet certain income requirements.

You can also connect with your local Planned Parenthood. They offer low-cost, sliding-scale services, which means the service fees are adjusted depending on your individual income, including cervical cancer screenings.

Federally Qualified Health Centers are another great option. These health centers are located throughout the country and offer a variety of services at low or no cost.

The link between HPV and cervical cancer is well known. But not everyone with a cervix who gets HPV develops cervical cancer. Recent research indicates that vaginal bacteria may play a significant role in the body’s ability to fight off an HPV infection.

Good bacteria can help your body fight off an infection. But vaginas with bad bacteria are more likely to have an HPV infection develop into precancer or cervical cancer.

More research still needs to be done about these findings. In the meantime, the best way to lower your risk of cervical cancer is to get the HPV vaccine and have regular cervical cancer screenings. Steps such as quitting smoking and having sex with a condom or other barrier method can also lower your risk.