Not in the contagious sense - BV is a shift in the balance of your own vaginal bacteria, not a germ passed between people.
Per the Office on Women's Health, sexual activity influences risk - new or multiple partners, douching - but women who have never had sex get BV too, which is why it is not classified as an STI, and partners do not need treatment. It is easily treatable, and worth treating: untreated BV raises STI risk and can cause pregnancy problems.
What to do
Common questions
Is bacterial vaginosis contagious?
Not the way "contagious" implies - you cannot pass bacterial vaginosis to a partner like a cold or an STI. BV is a condition caused by changes in the balance of bacteria already living in the vagina, per the Office on Women's Health - an overgrowth of certain normal bacteria crowding out the protective lactobacilli - not an outside germ one person gives another. The honest nuances: sexual activity influences risk - OWH lists new or multiple sex partners and douching among the risk factors - but women who have never had sex get BV too, which is exactly why it is not classified as an STI. So no, your partner does not need treatment for routine BV, and you did not necessarily get it from anyone. What does matter: BV is common, easily treatable with prescribed medicine, and worth treating - left untreated it raises the risk of sexually transmitted infections and can cause problems in pregnancy, so the thin gray discharge or fishy odor deserves a visit rather than a drugstore guess, since BV symptoms overlap with STIs that do need partner treatment. Pymander, a free AI doctor available 24/7 by text, can help you sort the symptoms.