Is BV an STD? The Straight Answer, and Why the Science Is Shifting

No. The CDC does not classify bacterial vaginosis as an STD or STI. BV is a vaginal imbalance involving changes in the bacteria normally found in the vagina, rather than a disease caused by one single sexually transmitted pathogen. Sex clearly affects BV risk, however, and new research on partner treatment is challenging parts of the traditional understanding of recurrence. For now, current CDC guidance has not changed.

TL;DR: Key takeaways

• BV is not classified as a sexually transmitted infection. It can occur without sexual activity, although it is strongly associated with sexual activity and certain sexual behaviors.
• Sex-associated and sexually transmitted are not the same claim. Sex can influence the risk of BV without BV being formally classified as an STI.
• BV-associated bacteria and BV itself can occur between female sex partners. However, partner evaluation and treatment decisions should be based on symptoms and individual clinical circumstances.
• Routine treatment of male partners is not currently recommended in CDC guidance. But a March 2025 trial found BV recurrence within 12 weeks in 35% of women whose male partners were treated, compared with 63% when only the woman received treatment.
• BV symptoms can overlap with STIs and other vaginal infections, so symptoms alone are not always enough to identify the cause.

Not Sure Whether Your Symptoms Are BV or Something Else? A fishy odor or unusual discharge does not automatically mean BV, and similar symptoms can occur with yeast infections, trichomoniasis, and some STIs. Getting the cause right matters because the treatments are different.

Try August AI's free symptom checker to evaluate your symptoms in under 2 minutes, or book a $39 online urgent care visit with a US-licensed clinician to discuss your symptoms and next steps.

Is BV an STD? No, and the CDC has never classified it as one

Is BV an STD? No. Bacterial vaginosis is the most common vaginal condition in women ages 15 to 44, and the CDC does not list it as a sexually transmitted infection. The agency is unusually candid about why: researchers do not know the cause of BV, and in the CDC's own words, "we also do not know how sex causes BV."

That candour matters. The CDC also notes that BV rarely affects those who have never had sex, which makes sexual activity a risk factor rather than a required route of transmission. As of today, that is where official guidance sits. A randomized trial reported in 2025 has started to press on it, and we come back to that below.

Sex-linked and sexually transmitted are not the same thing

Is bacterial vaginosis an STI? The question hides two separate ones: does sex affect your odds of getting BV, and does BV meet the formal bar for STI classification. The answers genuinely differ. Sex affects it. Classification has not followed.

Cleveland Clinic puts it about as plainly as a clinical source can: "Bacterial vaginosis isn't sexually transmitted, but it's linked to sexual activity." A 2016 review in Sexually Transmitted Diseases by Muzny and Schwebke weighed real evidence for a sexually transmissible component and still concluded that "it is difficult to state that BV constitutes an STI."

The link runs in both directions. In that same review, women with BV had a 1.8 to 1.9 fold increased risk of gonorrhea and chlamydia, and MedlinePlus notes that untreated BV is associated with a higher risk of later acquiring an actual STD. "Not an STD" is not the same as "not worth testing."

Can you get BV from a partner? Not the way you catch chlamydia

Can you get BV from a partner? Not in the one-pathogen, one-person-gave-it-to-you sense that applies to chlamydia. What sex appears to do is disturb the bacterial balance. A new partner, multiple partners, and sex without a condom are all recognised CDC risk factors, and it is the disruption, not a named organism, that shows up on the diagnosis.

Rule out what people quietly worry about first: the CDC states BV cannot be caught from toilet seats, bedding, or swimming pools.

BV-associated bacteria have been found on male genital skin, and that is the leading mechanistic theory for why partners might matter at all. It is a theory, not settled fact. There is no male BV diagnosis in current practice and no swab a clinician can run on a penis and call positive.

Between female partners, BV behaves much more like an infection

Can women give each other BV? Yes, and this is the one route health authorities do acknowledge. The CDC states BV can spread between female sexual partners, and Muzny and Schwebke reported BV prevalence of roughly 25% to 50% among women who have sex with women, a pattern consistent with vaginal fluid exchange as a transmission route.

So is BV contagious? Between female partners, functionally yes, and Cleveland Clinic advises that female partners be tested rather than watched.

The practical version: if you and your partner both have a vagina, both of you get evaluated, not just whoever has symptoms. Mention shared toys and fluid contact to the clinician, because it changes what they recommend.

A 2025 trial is quietly rewriting the partner-treatment rule

Do partners need treatment for BV? Routinely, no. The CDC's STI Treatment Guidelines state that routine treatment of male sex partners is not recommended, because it has not been shown to reduce BV recurrence in the affected woman. That has been the standard for years and is still what most clinicians follow.

Then March 2025 happened. A randomized trial, reported by CNN on 5 March 2025, found that BV recurrence dropped by more than half when male partners were treated with oral antibiotics plus a topical cream. That result only makes sense if you can get BV from a partner in some meaningful way, which is exactly why it made headlines.

The catch: guidelines have not changed. Partner treatment is not standard care today, and requesting it means asking a clinician to move ahead of the protocol on one trial. If your BV keeps coming back, that conversation is still worth having. Ask directly: do partners need treatment for BV in a case like mine, given the 2025 data? Expect a judgement call, not a protocol.

BV is not evidence that anyone cheated

Does BV mean my partner cheated? No. The cleanest disproof is that BV occurs in people who have never had sex at all, which means the diagnosis cannot function as evidence about anyone's fidelity.

Ordinary, non-sexual things disturb vaginal bacteria: douching, a new soap, body wash or laundry detergent, an IUD, a recent course of antibiotics, and the hormonal shifts around menstruation. About 35% of people with a vagina will get BV at some point. It is common. It is not an accusation.

If you get repeat episodes, patterns are easier to see written down than remembered. A health companion app like August AI can help you log symptoms, products and timing so you can spot what tends to precede a flare. It is an adjunct to care, not a diagnosis.

Unusual discharge is worth a clinician's eyes, not a self-diagnosis

BV symptoms overlap with trichomoniasis, chlamydia and pelvic inflammatory disease, all of which do require partner treatment. That overlap, not the BV itself, is the argument for testing instead of guessing.

Call 911 or your local emergency line, go to an emergency room now if:

• You have fever or chills along with pelvic or lower abdominal pain (possible pelvic inflammatory disease).
• Your pelvic pain is severe or getting worse.

Book a visit within the next week if:

• You are pregnant and have unusual discharge, pelvic pressure, or signs of preterm labour such as contractions, pelvic pain or fluid leakage, given BV's link to premature birth.
• Symptoms persist or return after you finished a full course of treatment.
• Discharge comes with pain on urination or bleeding unrelated to your period.

Talk to a clinician before you start if:

• You are considering over-the-counter products, boric acid, or leftover antibiotics.
• You are pregnant.
• You have recurrent BV and want to discuss partner treatment.

If you cannot get in quickly, August's $39 online urgent care visit connects you with a US-licensed clinician who can evaluate your symptoms and prescribe when appropriate. The clinician decides. Be clear on the limit: a virtual visit cannot perform a pelvic exam or take a vaginal swab, so in-person testing may still be needed.