Five cases of murine typhus presented as acute respiratory distress

Murine typhus is a flea-borne, worldwide rickettsial disease caused by Rickettsia typhi. It is typically a mild illness, which clinical features include fever, rash, and headache, but sometimes it is fatal. Recently, we experienced 5 cases of ARDS associated with a Rickettsia typhi infection. These cases were not suspicious initially, but later they were proven by high titers of serum IgG antibodies (1:512 or higher) with the IFA method. All 5 patients had no rash. Three of them live in urban areas. Murine typhus would be one of the etiologies for ARDS of unknown causes, especially in an endemic region.