Lyme neuroborreliosis in Japan: Borrelia burgdorferi sensu lato as a cause of meningitis of previously undetermined etiology in hospitalized patients outside of the island of Hokkaido, 2010-2021.

Background And Purpose: Clinical manifestations of Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato (Bbsl), include erythema migrans, Lyme neuroborreliosis (LNB), carditis, and arthritis. LB is a notifiable disease in Japan with <30 surveillance-reported LB cases annually, predominately from Hokkaido Prefecture. However, LB, including LNB, may be under-diagnosed in Japan since diagnostic tests are not readily available.