Increased Prevalence of Severe Fever with Thrombocytopenia Syndrome in Eastern China Clustered with Multiple Genotypes and Reasserted Virus during 2010–2015

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is a novel tick-borne viral disease with high mortality. Since January 2010, we have conducted an epidemiological surveillance and etiological study of SFTS in Jiangsu and Anhui provinces. From January 2010 through December 2015, a total of 286 SFTS cases were confirmed in Jiangsu and Anhui provinces with a case fatality rate of 16.1%. The majority of confirmed SFTS cases were distributed in the border area of Jiangsu and Anhui provinces. Our findings suggest that the SFTS prevalence rate rose since 2010 and reached its highest in 2015. Phylogenetic analysis demonstrated that the majority of the SFTSV strains (83.6%) from Jiangsu and Anhui provinces belonged to genotypes A and D. Notably, we identified three strains of SFTSV clustered into the genotype E. This is the first report of the genotype E SFTSV strains in mainland of China. A reassortment between genotype A and D was found in the central region of the endemic areas, where three SFTSV genotypes (A, C and D) were co-circulating.

Analysis on epidemiological characteristics of 4 species natural-focal diseases in Shandong Province, China in 2009-2017: a descriptive analysis

“…The incidence of 4 species natural-focal diseases all has obvious seasonal. May to August is the epidemic peak of SFTS and HGA in Shandong Province, which was similar to other SFTS epidemic areas, such as those in Henan, Anhui, Jiangsu, and Zhejiang provinces[20-22]. Haemaphysalis longicornis is the main tick species in Shandong Province, SFTSV and AP are believed to be mainly transmitted by Haemaphysalis longicornis ticks bite in Shandong Province[7, 23].…”

Genetic and pathogenic diversity of severe fever with thrombocytopenia syndrome virus (SFTSV) in South Korea

“…The segmented nature of the Banyangvirus lends itself to genetic reassortment, which is an important molecular mechanism contributing to the genetic diversity necessary for viral evolution (31). Although there have been a few reports of genetic reassortment of SFTSV in China and Japan (21,31,32), this is the first evidence to our knowledge of large and complex reassortment events, as at least 9 different reassortant genotypes were present in South Korea ( Figure 3B). This suggests that SFTSV strains undergo evolution in nature through reassortment, resulting in the creation of novel genotypes.…”

Susceptibility of Spotted Doves (Streptopelia chinensis) to Experimental Infection with the SFTS Phlebovirus

“…The clades A, B, C and D were classified ias Chinese lineage, while clade E was classified as the Japanese lineage. SFTSV strains isolated from China fell in all 5 clades, the strains from South Korea were classified into 3 clades (A, D, and E), and all strains from Japan from only clade E [6, 19, 22-23]. At present, the SFTSV strains of clade E were the most widely disseminated in East Asia.…”

“…An active investigation including viral isolation and molecular characterization was finally implemented resulting in the isolation and confirmation of SFTSV from a farmer in Henan, China [1]. Surveillance data showed that SFTSV has spread to 23 provinces in China from 2010 to 2017 [3-6, 19]. Furthermore, SFTS cases have been reported in other Asian countries including South Korea and Japan [19-21].…”

“…Surveillance data showed that SFTSV has spread to 23 provinces in China from 2010 to 2017 [3-6, 19]. Furthermore, SFTS cases have been reported in other Asian countries including South Korea and Japan [19-21].…”