Severe fever with thrombocytopenia syndrome, Shandong Province, China, 2011.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease in China. The incidence and clinical and laboratory characteristics of SFTS are not clearly defined. During May 22-October 2, 2011, a total of 24 patients with fever, thrombocytopenia, and leukopenia were clinically diagnosed as having SFTS in Yiyuan County, Shandong Province, China. We conducted laboratory tests for these SFTS patients. SFTS virus (SFTSV) infection was confirmed in 22 patients by using reverse transcription PCR and ELISA by acute-phase and convalescent-phase serum samples. Clinical and laboratory manifestations included fever (100%), gastrointestinal symptoms (91%), myalgia (55%), chills (41%), thrombocytopenia (100%), and leukopenia (95%).