Scrub typhus in previously unrecognized areas of endemicity in China

Abstract

Scrub typhus, caused by Orientia tsutsugamushi, has emerged recently in areas of northern China where the disease had not been known to exist. We analyzed epidemiological, clinical, and laboratory data for 104 patients who were admitted to a hospital in Fuyang City between 26 September and 1 November 2008. We showed that the major clinical manifestations of the patients were fever (100%), headache (82%), myalgias (77%), eschar (67%), rash (52%), and unusual facial flushing (62%). Among the 104 patients, the sera of 98% contained IgM antibodies to O. tsutsugamushi detected by indirect immunofluorescence assays (IFA), and DNA of the O. tsutsugamushi 56-kDa gene was amplified by PCR from the blood of 36 patients. We conclude that 104 patients were infected with scrub typhus in Fuyang City, Anhui Province. Our study indicates that physicians need to consider the diagnosis of scrub typhus for febrile patients living in northern China, where scrub typhus had not been considered to exist in the past.

FIG. 1.

Scrub typhus study site: Fuyang City, Anhui Province, China. (Modified from a map in Wikimedia Commons.)

FIG. 2.

Temporal distribution of onsets of Fuyang scrub typhus cases.

FIG. 3.

Areas of scrub typhus endemicity in China. (Modified from a map in Wikimedia Commons.)