Endemic Severe Fever with Thrombocytopenia Syndrome, Vietnam

Tran, Xuan Chuong; Yun, Yeo-Jun; An, Lê Văn; Kim, Sohee; Thảo, Nguyễn Thị Phương; Man, Phan Kim C.; Yoo, Jeong Rae; Heo, Sang Taek; Cho, Nam Hyuk; Lee, Keun Hwa

doi:10.3201/eid2505.181463

Cited by 346 publications

(229 citation statements)

References 10 publications

Supporting

Mentioning

227

Contrasting

Order By: Relevance

“…Subsequently, the virus was isolated from sick patients in Japan and South Korea, indicating that SFTSV was endemic not only to China, but also to South Korea and Japan (Kim et al, 2013;Takahashi et al, 2014). In addition, recent studies have reported SFTS as endemic to Vietnam (Tran et al, 2019) and Xinjiang, China (Zhu et al, 2019), indicating that the distribution of SFTSV in Southeast Asia might be much more extensive than expected. Humans become infected mainly via tick-bites, but through close contact with animals such as cats, and dogs and human-to-human transmission has also been reported (Gai et al, 2012;Niu et al, 2013;Kida et al, 2019).…”

Section: Introductionmentioning

confidence: 97%

Antiviral Drugs Against Severe Fever With Thrombocytopenia Syndrome Virus Infection

Takayama-Ito

Saijo

2020

Front. Microbiol.

View full text Add to dashboard Cite

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by SFTS virus (SFTSV), which is a novel bunyavirus. SFTSV was first isolated from patients who presented with fever, thrombocytopenia, leukocytopenia, and multiorgan dysfunction in China. Subsequently, it was found to be widely distributed in Southeast Asia (Korea, Japan, and Vietnam). SFTSV can be transmitted not only from ticks but also from domestic animals, companion animals, and humans. Because the case fatality rate of SFTS is high (6-30%), development of specific and effective treatment for SFTS is required. Studies of potential antiviral drugs for SFTS-specific therapy have been conducted on existing or newly discovered agents in vitro and in vivo, with ribavirin and favipiravir being the most promising candidates. While animal experiments and retrospective studies have demonstrated the limited efficacy of ribavirin, it was also speculated that ribavirin would be effective in patients with a viral load <1 × 10 6 copies/mL. Favipiravir showed higher efficacy than ribavirin against SFTSV in in vitro assays and greater efficacy in animal models, even administrated 3 days after the virus inoculation. Although clinical trials evaluating the efficacy of favipiravir in SFTS patients in Japan are underway, this has yet to be confirmed. Other drugs, including hexachlorophene, calcium channel blockers, 2 ′ -fluoro-2 ′ -deoxycytidine, caffeic acid, amodiaquine, and interferons, have also been evaluated for their inhibitory efficacy against SFTSV. Among them, calcium channel blockers are promising because in addition to their efficacy in vitro and in vivo, retrospective clinical data have indicated that nifedipine, one of the calcium channel blockers, reduced the case fatality rate by >5-fold. Although further research is necessary to develop SFTS-specific therapy, considerable progress has been achieved in this area. Here we summarize and discuss recent advances in antiviral drugs against SFTSV.Keywords: severe fever with thrombocytopenia syndrome, severe fever with thrombocytopenia syndrome virus, antiviral, ribavirin, favipiravir Frontiers in Microbiology | www.frontiersin.org

show abstract

Section: Introductionmentioning

confidence: 97%

Antiviral Drugs Against Severe Fever With Thrombocytopenia Syndrome Virus Infection

Takayama-Ito

Saijo

2020

Front. Microbiol.

View full text Add to dashboard Cite

show abstract

“…Disease mortality of SFTS patients have been estimated to be 52 0% [3]. Even though the majority of SFTS cases has been reported from China [3], Korea [4], and Japan [5], SFTSV infections in southern Asia, including Vietnam, have been recently reported in a retrospective survey [6]. Currently, no specific viral therapy nor vaccine is available.…”

Section: Introductionmentioning

confidence: 99%

Vaccination with single plasmid DNA encoding IL-12 and antigens of severe fever with thrombocytopenia syndrome virus elicits complete protection in IFNAR knockout mice

et al. 2020

Self Cite

View full text Add to dashboard Cite

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by SFTS virus (SFTSV) infection. Despite a gradual increase of SFTS cases and high mortality in endemic regions, no specific viral therapy nor vaccine is available. Here, we developed a single recombinant plasmid DNA encoding SFTSV genes, Gn and Gc together with NP-NS fusion antigen, as a vaccine candidate. The viral antigens were fused with Fmslike tyrosine kinase-3 ligand (Flt3L) and IL-12 gene was incorporated into the plasmid to enhance cell-mediated immunity. Vaccination with the DNA provides complete protection of IFNAR KO mice upon lethal SFTSV challenge, whereas immunization with a plasmid without IL-12 gene resulted in partial protection. Since we failed to detect antibodies against surface glycoproteins, Gn and Gc, in the immunized mice, antigen-specific cellular immunity, as confirmed by enhanced antigen-specific T cell responses, might play major role in protection. Finally, we evaluated the degree of protective immunity provided by protein immunization of the individual glycoprotein, Gn or Gc. Although both protein antigens induced a significant level of neutralizing activity against SFTSV, Gn vaccination resulted in relatively higher neutralizing activity and better protection than Gc vaccination. However, both antigens failed to provide complete protection. Given that DNA vaccines have failed to induce sufficient immunogenicity in human trials when compared to protein vaccines, optimal combinations of DNA and protein elements, proper selection of target antigens, and incorporation of efficient adjuvant, need to be further investigated for SFTSV vaccine development.

show abstract

“…A new pathogenic TBPV, severe fever with thrombocytopenia syndrome virus (SFTSV), transmitted by Haemaphysalis longicornis, was first found in China, Japan, Korea and Vietman in patients with severe fever, thrombocytopenia and leukocytopenia accompanied by gastrointestinal symptoms, chills, joint pain and myalgia (7)(8)(9)(10)(11). In the western hemisphere, Heartland virus (HRTV) was first isolated in 2009 from two patients in the state of Missouri, USA, who showed symptoms similar to those of SFTSV.…”

Section: In Recent Years New Tbpvs Capable Of Inducing Serious Diseamentioning

confidence: 99%

First report of Lihan Tick virus (Phlebovirus, Phenuiviridae) in ticks, Colombia

López¹,

Miranda²,

Mattar³

et al. 2020

Preprint

View full text Add to dashboard Cite

Background: Tick-borne Phleboviruses (TBPVs) comprise human and animal viruses that can cause a variety of clinical syndromes ranging from self-limiting febrile illness to fatal haemorrhagic fevers.Objective: Detect Phlebovirus in ticks collected from domestic animals in Córdoba, Colombia. Methods: We collected 2,365 ticks from domestic animals in three municipalities of the Department of Cordoba, Colombia in 2016. Ticks were identified and pooled by species for RNA extraction. A nested real-time PCR with specific primers for Phlebovirus and a probe for Heartland virus (HRTV) were performed. Also, a conventional nested PCR, with the same specific primers was used to detect other Phleboviruses, with positive reactions indicated by an amplified cDNA fragment of approximately 244 bp determined by gel electrophoresis. These bands were gel-purified and sequenced by the Sanger method. Results: Using real-time RT-PCR, no positive results for HRTV were found. However, using conventional nested PCR 2.2% (5/229 pools) yielded a product of 244 bp. One positive sample was detected in a pool of Dermacentor nitens ticks collected from a horse, and the four remaining positive pools were from Rhipicephalus microplus collected from cattle. The five positive nucleotide sequences were identical to each other, with identities of 93% to 96% compared to a section of the L-segment of Lihan Tick virus, a Phlebovirus originally detected in R. microplus ticks in China. The strongest identity (96%-99%) was with Lihan Tick virus detected in R. microplus ticks from Brazil.Conclusions: This is the first report of viral detection in ticks in Colombia. We detected a Colombian strain of Lihan Tick virus. We recommend investigating possible disease associations with this tickborne virus in Colombia.

show abstract

Endemic Severe Fever with Thrombocytopenia Syndrome, Vietnam

Cited by 346 publications

References 10 publications

Antiviral Drugs Against Severe Fever With Thrombocytopenia Syndrome Virus Infection

Antiviral Drugs Against Severe Fever With Thrombocytopenia Syndrome Virus Infection

Vaccination with single plasmid DNA encoding IL-12 and antigens of severe fever with thrombocytopenia syndrome virus elicits complete protection in IFNAR knockout mice

First report of Lihan Tick virus (Phlebovirus, Phenuiviridae) in ticks, Colombia

Contact Info

Product

Resources

About