Infection caused by bacterial overgrowth in the vagina. Most affected women are asymptomatic. When symptoms occur, they include foul-smelling vaginal discharge, vaginal itching, and burning. Risk factors include sexual activity with multiple partners and the use of vaginal douches and intrauterine devices. Up to a third of cases resolve without treatment. Antibiotic treatment is recommended when symptoms are present and for women that are pregnant at the time of infection. The disease is bacterial vaginosis (Monarch Disease Ontology identifier MONDO_0005316).