Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease recently discovered in northeast and central China. SFTS cause high fatality rate of 12% and as high as 30% in some areas. The major clinical symptoms of SFTS are fever, vomiting, diarrhea, multiple organ failure, thrombocytopenia

Thrombocytopenia

Thrombocytopenia is a relative decrease of platelets in blood.A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease...

 (low platelet count), leucopenia (low white blood cell count), and elevated liver enzyme level.

SFTS occurs in rural areas from March to November, and a majority of cases are from April to July. In 2009 Xue-jie Yu and colleagues isolated the SFTS virus (SFTSV) from SFTS patients’ blood. SFTSV is a Phlebovirus in the family of Bunyaviridae

Bunyaviridae

Bunyaviridae is a family of negative-stranded RNA viruses. Though generally found in arthropods or rodents, certain viruses in this family occasionally infect humans. Some of them also infect plants....

. The life cycle of the SFTSV most likely involves arthropod

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

vectors and animal hosts. Humans are accidental hosts and play no role in the life cycle of the SFTSV. SFTSV has been detected from Haemaphysalis longicornis ticks. The transmission routine of SFTSV is unknown, but person-to-person transmission either plays no role or at least is not an important routine of transmission of SFTSV.