Severe fever with thrombocytopenia syndrome


Severe fever with thrombocytopenia syndrome is an emerging infectious disease first reported between late March and mid-July 2009 in rural areas of Hubei and Henan provinces in Central China. SFTS has fatality rates ranging from 12% to as high as 30% in some areas. The major clinical symptoms of SFTS are fever, vomiting, diarrhea, multiple organ failure, thrombocytopenia, leucopenia, and elevated liver enzyme levels. It is caused by the Huaiyangshan banyangvirus, formerly called the SFTS virus.

Virology

is a phlebovirus in the family of Bunyaviridae. Person-to-person transmission was not noted in early reports but has since been documented.
The life cycle of the SFTSV most likely involves arthropod vectors and animal hosts. Humans appear to be largely accidental hosts. SFTSV has been detected in Haemaphysalis longicornis ticks.

Epidemiology

SFTS occurs in China's rural areas from March to November with the majority of cases from April to July. In 2013, Japan and Korea also reported several cases with deaths.
In July 2013, South Korea reported a death toll of 8 since Aug 2012.
In July 2017, Japanese doctors reported that a woman had died of SFTS after being bitten by a cat that may have itself infected by a tick. The woman had no visible tick bites, leading doctors to believe that the cat — which died as well — was the transmission vector.

Evolution

The virus originated 50–150 years ago and has undergone a recent population expansion.

History

In 2009 Xue-jie Yu and colleagues isolated the SFTS virus from SFTS patients’ blood.