Clinical Characteristics and Risk Factors for Severe Japanese Spotted Fever: A Retrospective Multicenter Study in Nagasaki Prefecture, Western Japan.

Japanese spotted fever (JSF) is a tick-borne rickettsial disease prevalent in western Japan, with an increasing incidence and geographical distribution. This retrospective study aimed to describe the clinical features of JSF and identify factors associated with its severe form. We included adult patients with laboratory confirmed JSF in Nagasaki prefecture from 2010 to 2021.