Four Year Surveillance of the Vector Hard Ticks for SFTS, Ganghwa-do, Republic of Korea

The seasonal abundance of hard ticks that transmit severe fever with thrombocytopenia syndrome virus was monitored with a collection trap method every April to November during 2015–2018 and with a flagging method every July and August during 2015–2018 in Ganghwa-do (island) of Incheon Metropolitan City, Republic of Korea. This monitoring was performed in a copse, a short grass field, coniferous forest and broad-leaved forest. A total of 17,457 ticks (8,277 larvae, 4,137 nymphs, 3,389 females, and 1,654 males) of the ixodid ticks comprising 3 species (Haemaphysalis longicornis, H. flava, and Ixodes nipponensis) were collected with collection traps. Of the identified ticks, H. longicornis was the most frequently collected ticks (except larval ticks) (94.26%, 8,653/9,180 ticks (nymphs and adults)), followed by H. flava (5.71%, 524/9,180) and Ix. nipponensis (less than 0.04%, 3/9,180). The ticks collected with collecting traps were pooled and assayed for the presence of SFTS virus with negative results. In addition, for monitoring the prevalence of hard ticks, a total of 7,461 ticks (5,529 larvae, 1,272 nymphs, 469 females, and 191 males) of the ixodid ticks comprising 3 species (H. longicornis, H. flava, and Ix. nipponensis) were collected with flagging method. H. longicornis was the highest collected ticks (except larval ticks) (99.53%, 1,908/1,917 ticks (nymphs and adults)), followed by H. flava (1.15%, 22/1,917).

Construction of the recombinant plasmids encoding nonstructural proteins of SFTS virus and immunogenicity study / 中华实验和临床病毒学杂志

Objective@#To study the construction and humoral immunogenicity of the recombinant plasmids encoding nonstructural proteins(NSs) of severe fever with thrombocytopenia syndrome(SFTS) virus(SFTSV).@*Methods@#Recombinant plasmids encoding NSs gene and optimized NSs gene of SFTSV were constructed by polymerase chain reaction(PCR) and cloned into eukaryotic expression vector pJW4303, which were named pJW4303-NSs and pJW4303-NSs-opt, respectively. Then, the plasmid pJW4303-NSs was tagged with Flag, named pJW4303-NSs-Flag. Meanwhile, Nhe I restrict site and tissue plasminogen activator(tPA) signal sequence were inserted to construct bi-optimized recombinant plasmid named pJW4303-tPA-NSs-opt. All plasmids were identified by sequencing. The transient expression of NSs was confirmed by Western blotting in human embryonic kidney 293T cells. The NSs-specific IgG antibodies in BALB/c mice which were immunized by intramuscular injection with electroporation were examined by enzyme-linked immunosorbent assay(ELISA).@*Results@#The recombinant plasmids pJW4303-NSs, pJW4303-NSs-opt, pJW4303-tPA-NSs-opt and pJW4303-NSs-Flag were successfully constructed. The expression of NSs was confirmed in lysates and supernatants of 293T cells. The NSs-specific IgG responses of all three recombinant plasmids were detected by ELISA in BALB/c mice. It was found that optimized recombinant plasmid pJW4303-NSs-opt elicited higher levels of the NSs-specific IgG than that of pJW4303-NSs in week 6, 8 which induced stronger immune response.@*Conclusions@#The recombinant plasmids encoding SFTSV NSs possess the satisfied immunogenicity. In addition, the plasmid pJW4303-NSs-opt could induce the strongest humoral immune response.

Investigation of animals infected with novel bunyavirus in Xinyang City,Henan Province,China / 中国人兽共患病学报

To investigate the animals infection situation of novel bunyavirus in Xinyang City ,Henan Province ,China , animal serum samples such as cattle ,dog ,swine ,mice were collected in Shangcheng County and Guangshan County in Xinyang City .All the serum samples were detected by novel bunyavirus ELISA and real time RT-PCR method .A total of 292 animal serum samples were collected including 5 kinds of animals .The result of all the animal serum samples were negative by using real time RT-PCR ,and the positive rate was 45 .19% (141/312) by ELISA method .Of the 5 animal serum samples including mice ,cattle ,goats ,swine and dogs ,the positive rate were detected to be 1 .06% ,100 .00% ,76 .27% ,3 .57% ,and 75 .00%respectively .There was significant difference in results among 5 kind of animal serum antibodies .Animals such as cattle and dog may be the host of novel bunyavirus which were detected novel bunyavirus antibodies in cattle and dog in Xinyang City , Henan Province ,China .

Experience of Therapeutic Plasma Exchange in Patients with Severe Fever with Thrombocytopenia Syndrome / 대한수혈학회지

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease recently issued in northeast Asia and China. The disease is caused by a new phlebovirus in the family Bunyaviridae, severe fever with thrombocytopenia syndrome virus (SFTSV); the transmission vector is believed to be a tick. The number of infections and resulting deaths has been increasing, but there is no effective treatment. METHODS: Clinical and laboratory features of SFTSV-positive patients during the period from May 2013 to October 2014 were reviewed retrospectively using medical records. In cases of patients who underwent therapeutic plasma exchange (TPE), the performance records were also investigated. RESULTS: During the study period, 14 patients were SFTSV-positive. The patients, who ranged in age from 47 to 82, had mostly outdoor activities before admission. The major symptoms included high fever, myalgia, and gastrointestinal symptoms. Laboratory findings showed decreased white blood cell (WBC), neutrophils and platelets and elevated activated partial thromboplastin time (aPTT), aspartate aminotransferase (AST), lactate dehydrogenase (LD), and creatine phosphokinase (CK). Two patients died during the study period, however, nine patients who received TPE showed improvement. CONCLUSION: We suppose that TPE can be used for treatment of serious SFTS and gives the effect of reducing the fatality rate.