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Severe fever with thrombocytopenia syndrome (SFTS) is caused by infection with Dabie bandavirus [formerly SFTS virus (SFTSV)] and is an emerging zoonotic disease. Dogs can be infected with SFTSV, but its pathogenicity and transmissibility have not been fully elucidated. In experiment 1, immunocompetent dogs were intramuscularly inoculated with SFTSV. In experiment 2, immunosuppressed dogs (immunosuppressed group; oral azathioprine 5 mg/kg/day for 30 days) were intramuscularly inoculated with SFTSV. Both immunosuppressed and immunocompetent contact dogs were co-housed with the SFTSV-inoculated dogs that had been immunosuppressed. Immunocompetent SFTSV-infected dogs did not show any clinical symptom. However, immunosuppressed SFTSV-infected dogs showed high fever and weight loss without lethality. In all SFTSV-infected dogs, viral RNA could be measured in the serum only after 3 days post infection (DPI) and neutralizing antibodies were detected in the serum beginning 9 DPI. SFTSV shedding in the urine and faeces of some infected dogs occurred between 4 and 6 DPI. The immunocompromised SFTSV-infected dogs showed thrombocytopenia beginning 3 DPI to the end of the experiment (24 DPI). We confirmed SFTSV transmission to one of three immunocompetent co-housed dogs. This dog showed a high fever, weight loss, and shed viral RNA by urine. Viral RNA and neutralizing antibodies were also detected in the serum. These results demonstrated that intramuscular inoculation with SFTSV induced minor clinical symptoms in dogs, and intraspecies SFTSV transmission in dogs can occur by contact.

Severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV) is an emerging tick-borne infectious disease. Few studies have assessed the clinical usefulness of nested reverse-transcription polymerase chain reaction (RT-PCR) for diagnosing SFTS. We performed conventional RT-PCR targeting the M segment, nested RT-PCR targeting M and S segments, and real-time RT-PCR targeting the S segment of SFTSV for four patients with suspected SFTS. Although conventional RT-PCR results for the first two patients were negative at admission, nested RT-PCR using the S or M targets was positive for the same samples. Likewise, in the other two patients, initial samples were confirmed positive in all three tests, but follow-up testing demonstrated negative conventional RT-PCR and positive nested RT-PCR results. Thus, delayed testing using conventional RT-PCR or real-time RT-PCR in symptomatic patients with SFTS may result in missed diagnoses, and compared with these methods, nested RT-PCR may increase the window for obtaining positive SFTSV PCR results. Meanwhile, the indirect immunofluorescence assay showed seroconversion to SFTSV antibodies in all four patients. Nested RT-PCR for SFTSV M and S segments could help diagnose SFTS in patients testing negative by conventional RT-PCR.

Severe fever with thrombocytopenia syndrome (SFTS) was first detected in China in 2009. The incidence of SFTS increases year by year, and there is no effective treatment. Considering that the reported prevalence of SFTSV infection varies from region to region, we aimed to quantitatively evaluate the epidemic characteristics of SFTSV infection in China from 2010 to 2020, including the distribution differences in infectious season, sex, age, occupation, and region. A meta-analysis framework was used to search for the related published data with keywords in electronic databases (CNKI, Wanfang, CBM, and PubMed). According to the PRISMA statement, the studies that included SFTS diagnosed in China were analyzed. Furthermore, we used Revman and Stata to merge statistical effects, and used I2 and P-values for heterogeneity test and quality assessment. Eleven studies containing 4,932 cases confirmed by SFTSV infection were included in this meta-analysis. The ratio of male-to-female is 1.04 to 1. Cases were concentrated between 40 and 80 years of age (MD = 92%, 95%CI: 91%–93%). Farmers are at the highest risk of SFTSV infection (MD = 84%, 95%CI: 77%–90%). The risk of infection for consecutive period of April-August was significantly higher than the sum of the remaining months (MD = 82%, 95%CI: 78%–85%). In addition, the patient has an extensive history of exposure, including living in the mountains, exposure to ticks, livestock, mouse and the patient. We came to the conclusion that SFTSV is transmitted primarily through tick bites in China, so middle-aged and older adults living in mountains regions are at the highest risk for SFTSV infection in April through August each year.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease worldwide. It can be transmitted from person to person, and the fatality rate is very high. During this study, three SFTS clusters including 12 associated cases were identified in three counties in Zhejiang Province from 2018 to 2020. The median age of the three index patients was 70 years, and that of secondary case patients was 59 years. Of note, the mortality rate of the index patients was 100%. The mortality rate of secondary case patients was 11%. The total secondary attack rate (SAR) was 30% (9/30). The SARs of cluster A, cluster B, and cluster C were 38% (3/8), 21% (3/14), and 38% (3/8), respectively. Additionally, the interval from onset to diagnosis was 4 days. The intervals from disease onset to confirmation of the index cases and secondary cases were 7 days and 4 days, respectively. All secondary case patients had a history of close contact with blood or body fluids of the index patients. These results indicate that SFTS patients should not be discharged until recovery. When SFTS patients die, the corpses should be transferred directly from the hospital to the crematorium for cremation by persons wearing proper protective equipment to prevent virus transmission.

Relevance. Severe fever with thrombocytopenia syndrome is a viral disease characterized by acute fever, accompanied by progressive thrombocytopenia, leucopenia. The mortality is up to 30%. The disease was first identified in 2009 in rural areas of central China, Hubei and Henan. The causative agent of the disease is a new Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV). The SFTSV is mainly transmitted through tick bites, especially Haemaphysalis longicornis which is the dominant tick species in East Asia.The aim of the review is to analyze relevant information about Severe Fever with Thrombocytopenia Syndrome, including the molecular genetics features of the pathogen, clinical manifestations, geographical distribution, epidemiological features, as well as the possibility of drift and spread of infection in the Russian Federation.Conclusions. SFTS is a serious health threat as it relates to new and re-emerging infections. The further spread of SFTS in China may complicate the epidemiological situation in the country. SFTSV may have a much wider global distribution in Southeast Asia than is currently known. The risk of H. longicornis ticks spreading is predicted in the north-east United States, New Zealand, parts of Australia and several Pacific islands. The presence of the H. longicornis in the Primorsky Territory on the Far East indicates a possible risk of the natural focus formation in the event of the introduction of the pathogen.

Objective To identify the correlation between the level of at-admission fasting blood glucose (FBG) with poor outcomes in hospitalized patients suffering from severe fever with thrombocytopenia syndrome (SFTS). Methods Between April 1 and December 1, 2020, the list of hospitalized patients affected with SFTS infection was provided by the Infectious Disease Department at First Affiliated Hospital of Anhui Medical University, followed by the collection of information I.e., gender, age, diabetic history and the level of FBG on admission. Results In this study, a total of 77 patients were included and were categorized into three groups (r = − 0.28, P = 0.01), however, a linear positive correlation was observed between AST, IL10, D-Dimer, and FDP levels and FBG (P-value P P P = 0.96). With the prolongation of time, the changes of FBG were different between survivor group and non-survivor group. The FBG in survival group shown a downward trend; The non-survivor group shown an upward trend. Conclusions Elevated level of FBG has been correlated with hypercoagulability, inflammation, and lower PLT in SFTS patients. The measurement of FBG level can help in evaluating the inflammatory process, hypercoagulability, and prognosis of patients suffering from SFTS. FBG can predict the prognosis of SFTS. It is necessary to pay attention to the role of FBG in the process of treatment in patients with SFTS.

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

This study aimed to characterize the seasonal abundance of hard ticks that transmit severe fever with thrombocytopenia syndrome virus from April to November 2019 and 2020 on Ganghwa-do, Incheon Metropolitan City, Korea. The ticks were collected at grassland, grave site, copse and mountain road using a collection trap method. The ixodid hard ticks comprising three species (Haemaphysalis longicornis, H. flava, and Ixodes nipponensis) collected were 6,622 in 2019 and 3,811 in 2020. H. longicornis was the most frequent (97.9% in 2019 and 96.0% in 2020), followed by H. flava (2.0% and 3.0% in 2019 and 2020, respectively) and I. nipponensis (less than 0.1%). Our study demonstrated that seasonal patterns of the tick populations examined for two years were totally unsimilar. The hard ticks tested using RT-qPCR were all negative for severe fever with thrombocytopenia syndrome virus.

An emerging infectious disease first identified in central China in 2009, severe fever with thrombocytopenia syndrome (SFTS) was found to be caused by a novel phlebovirus. Since SFTSV was first identified, epidemics have occurred in several East Asian countries. With the escalating incidence of SFTS and the rapid, worldwide spread of SFTSV vector, it is clear this virus has pandemic potential and presents an impending global public health threat. In this review, we concisely summarize the latest findings regarding SFTSV, including vector and virus transmission, genotype diversity and epidemiology, probable pathogenic mechanism, and clinical presentation of human SFTS. Ticks most likely transmit SFTSV to animals including humans; however, human-to-human transmission has been reported. The majority of arbovirus transmission cycle includes vertebrate hosts, and potential reservoirs include a variety of both domestic and wild animals. Reports of the seroprevalence of SFTSV in both wild and domestic animals raises the probability that domestic animals act as amplifying hosts for the virus. Major clinical manifestation of human SFTS infection is high fever, thrombocytopenia, leukocytopenia, gastrointestinal symptoms, and a high case-fatality rate. Several animal models were developed to further understand the pathogenesis of the virus and aid in the discovery of therapeutics and preventive measures., Virology: An emerging tick-borne disease Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne infectious disease caused by a novel phlebovirus, is a growing global health concern. The main symptoms are high fever, low platelet and white blood cell levels, and gastrointestinal problems. The disease was first identified in China in 2009, and several SFTS epidemics have occurred in East Asia, with mortality rates of between 6 and 27 per cent. Researchers in South Korea led by Young Ki Choi at Chungbuk National University, Cheongju, review the latest research into SFTS virus and disease, including transmission, genetic diversity, epidemiology, pathology and clinical features, and pandemic potential. Animal models are helping researchers understand the virus and disease and develop treatments and vaccines.

Knowledge of the clinical progress of severe fever with thrombocytopenia syndrome (SFTS) and the associated predictors of mortality is important for providing appropriate treatment in severe cases. A multihospital retrospective study was conducted in three SFTS-endemic cities, in 2018. Of the 208 SFTS-confirmed cases, there were 189 survivors and 19 deaths. The median age was 64 years; 104 (50.0%) patients were men, and 188 (90.4%) were farmers. Furthermore, 203 (97.6%) patients reported fever and 70 (33.7%) reported fatigue. Most fatal cases had complications including multiple-organ failure, central nervous syndrome (CNS) abnormalities, and disseminated intravascular coagulation. During the fever phase, alanine transaminase, aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine, D-dimer, glucose, hydroxybutyrate dehydrogenase, lactate dehydrogenase (LDH), procalcitonin, prothrombin time, and uric acid levels were higher in fatal than in nonfatal cases (P < 0.05). Creatine kinase (CK), CK-MB (CKMB), AST, and LDH levels were significantly lower in nonfatal than in fatal cases (P < 0.05). Central nervous syndrome abnormalities (odds ratio [OR] = 20.9, 95% CI: 4.3, 100), body temperature ≥ 38.5°C (OR = 23.2, 95% CI: 3.4, 158), BUN levels ≥ 6.4 mmol/L (OR = 9.9, 95% CI: 2.2, 44), CKMB levels ≥ 100 U/L (OR = 33.2, 95% CI: 5.8, 192), and LDH levels ≥ 1,000 U/L (OR = 8.3, 95% CI: 1.9, 37) were predictors of mortality. Our findings reveal that the presence of specific complications and laboratory parameters may serve as predictors of mortality and aid in early identification of severe SFTS cases in clinical practice.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne infectious disease caused by SFTS virus (SFTSV). We report 7 cases of spontaneous fatal SFTS in felines. Necropsies revealed characteristic lesions, including necrotizing lymphadenitis in 5 cases and necrotizing splenitis and SFTSV-positive blastic lymphocytes in all cases. We detected hemorrhagic lesions in the gastrointestinal tract in 6 cases and lungs in 3 cases, suggesting a more severe clinical course of SFTS in felids than in humans. We noted necrotic or ulcerative foci in the gastrointestinal tract in 3 cases, the lung in 2 cases, and the liver in 4 cases. We clarified that blastic lymphocytes are predominant targets of SFTSV and involved in induction of necrotic foci. We also found that thymic epithelial cells were additional targets of SFTSV. These results provide insights for diagnosing feline SFTS during pathological examination and demonstrate the similarity of feline and human SFTS cases.

SFTS virus (SFTSV) is a novel bunyavirus, which was discovered as the etiological agent of severe fever with thrombocytopenia syndrome (SFTS) in China in 2009, and was now prevalent in at least 25 provinces in China. SFTS was subsequently identified in South Korea and Japan in 2012. To explore the molecular evolution and genetic characteristics of this newly identified pathogen, we reported 72 whole genome sequences of SFTSV, and built a dataset of SFTSV genome sequences containing 292 L-segment, 302 M-segment and 502 S-segment. We clearly divided SFTSV into six genotypes, Genotype A-F. It was found that genotype F was the dominant epidemic genotype of Japan, South Korea, and Zhejiang province of China. The coalescent analysis supported that SFTSV originated in the early 18th century from Zhejiang province, and Genotype F was the most primitive one. Henan, Hubei, and Anhui provinces which are located in Dabie Mountain area were mainly epidemic of Genotype A, which emerged relatively late but distributed widely. A total of 37 recombination events were identified, making SFTSV with a high recombination frequency (L segment 5.1%, M segment 3.6%, S segment 0.8%) among negative-strand segmented RNA viruses. It was identified that 19 reassortant strains belonged to 12 reassortment forms of SFTSV genome containing 6 newly identified forms. The reassortment virus and recombination in tick were both found for the first time. We also found many of genotype-specific mutation sites, 7 of which could be considered as potential molecular marker for genotype classification. This study promoted a more comprehensive understanding of the phylogeny and origin, and the genetic diversity of SFTSV, and it could help the studies of other newly discovered tick-borne bunyavirus as reference data and research ideas.

Severe fever with thrombocytopaenia syndrome (SFTS) is a tick-borne viral haemorrhagic fever with a high case fatality rate. Clinicians, veterinarians and scientists are working together to elucidate its pathophysiology and develop effective vaccines and treatments. The work is led by Dr Masayuki Saijo from the National Institute of Infectious Diseases (NIID) and also involves researchers from Yamaguchi University, Ehime University and Yamaguchi Grand Medical Center. The team is investigating the maintenance of the SFTS virus in nature by exploring the relationship of the virus between animals and ticks and the researchers are also working to clarify the pathophysiology of the disease, which will lead to the development of diagnostics, specific treatments and additional treatments and contribute to the further development of a vaccine. The researchers believe that a 'one health' approach to tackling SFTS is crucial, which is why they are tackling human and animal treatment and prevention in parallel. Favipiravir is an antiviral agent developed by Dr Yosuke Furuta from Toyama Chemicals and is the primary candidate for treatment. The team believes that if favipiravir can be administered to patients in the early stages of SFTS, this will reduce the case fatality rate of the disease. So far, the team has developed two recombinant vaccine candidates for SFTS that have so far demonstrated no major adverse effects. The researchers plan to develop other types of vaccines that will be safe for humans and animals.

Severe fever with thrombocytopenia syndrome (SFTS) has a high fatality rate and is caused by SFTS virus (SFTSV). Currently, SFTS is endemic to some areas in western Japan, and wild animals are considered to play important roles in the circulation of SFTSV in the environment. Previous retrospective surveys using samples mainly obtained between 2006 and 2015 revealed serological evidence of SFTSV infection in wild animals; however, seroprevalence before 2006 remains unclear. In this study, we investigated the presence of anti‐SFTSV antibodies in a total of 521 serum samples from nine wild animal species collected from 11 prefectures in central and eastern Japan between 1980 and 2000. All samples yielded negative results for antibodies to SFTSV, suggesting that there had been few or no SFTSV infections before 2000 in the sampled areas., In this study, we investigated the presence of anti‐SFTSV antibodies in a total of 521 serum samples from nine wild animal species collected from 11 prefectures in central and eastern Japan between 1980 and 2000. All samples yielded negative results for antibodies to SFTSV, suggesting that there had been few or no SFTSV infections before 2000 in the sampled areas.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonosis in China, the Republic of Korea (ROK), and Japan. The presence of the SFTS virus (SFTSV) in compani...

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by the SFTS virus (SFTSV) of family Phenuiviridae. Since the virus was first identified in 2009, it has been rapidly spread in many Asian countries including Myanmar, Korea, Japan, and central China. In this study, we investigated the epidemiological characteristics of SFTS patients in Hefei from 2011 to 2018. In addition, we conducted a serological survey of SFTSV-specific antibody among healthy residents of five counties. We performed a retrospective observational study of SFTS cases reported to Hefei Center for Disease Control and Prevention (CDC) during Jan 2011 to Dec 2018. Almost every patient completed a structure questionnaire including clinical examination, course of disease, and history of epidemiology. A total of 754 serum specimens were collected and tested for IgG antibody with double-antigen sandwich ELISA method. Of 257 cases reported during that period, 33 died, with a case fatality rate of 13.0%. We found no significant difference between 30 non-survivors and 198 survivors except for age. The overall rate of seropositivity for SFTSV antibodies among healthy residents were 20.16%. We demonstrated that living in hilly areas, direct contact with domestic livestock and knowledge of tick-borne disease were significantly associated with positive serology result. SFTSV infection was prevalent among farming-related populations. Our study identified a relatively high seroprevalence of SFTSV-specific antibody in healthy residents, which provided the basis for asymptomatic SFTSV infections. More attention should be given to susceptible population and prevent SFTSV outbreak in high-endemic areas.

We report a case of an 8-year-old Korean girl diagnosed with severe fever with thrombocytopenia syndrome with Q fever coinfection after playing with a dog and being bitten by a tick in a suburb in South Korea. The clinical findings and treatment were summarized. To the best of our knowledge, this case is the youngest patient reported to have been diagnosed with severe fever with thrombocytopenia syndrome and Q fever from South Korea.

Background The growing epidemics of severe fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne disease in East Asia, and its high case fatality rate have raised serious public health concerns. Methods Surveillance data on laboratory-confirmed SFTS cases in China were collected. The spatiotemporal dynamics and epidemiological features were explored. The socioeconomic and environmental drivers were identified for SFTS diffusion using survival analysis and for SFTS persistence using a two-stage generalized boosted regression tree model. Results During 2010‒2018, a total of 7721 laboratory-confirmed SFTS cases were reported in China, with an overall case fatality rate (CFR) of 10.5%. The average annual incidence increased >20 times and endemic areas expanded from 27 to 1574 townships, whereas the CFR declined from 19% to 10% during this period. Four geographical clusters—the Changbai Mountain area, the Jiaodong Peninsula, the Taishan Mountain area, and the Huaiyangshan Mountain area—were identified. Diffusion and persistence of the disease were both driven by elevation, high coverages of woods, crops, and shrubs, and the vicinity of habitats of migratory birds but had different meteorological drivers. Residents ≥60 years old in rural areas with crop fields and tea farms were at increased risk to SFTS. Conclusions Surveillance of SFTS and intervention programs need to be targeted at areas ecologically suitability for vector ticks and in the vicinity of migratory birds to curb the growing epidemic., This retrospective study determined the spatiotemporal patterns of severe fever with thrombocytopenia syndrome (SFTS) and socioeconomic and environmental risk drivers for its diffusion and persistence, which bridges the knowledge gap in the epidemiology and ecology of the disease. The ecological model can be used to assess risks of STFS in countries where the disease or vector ticks are emerging to guide the planning of surveillance and controls.

Severe fever with thrombocytopenia syndrome was diagnosed in a febrile woman in Japan after a tick bite. However, Rickettsia japonica DNA was retrospectively detected in the eschar specimen, suggesting co-infection from the bite. Establishment of the severe fever with thrombocytopenia syndrome virus infection might have overpowered the R. japonica infection.

Severe fever with thrombocytopenia syndrome (SFTS) virus is an emerging zoonotic virus in East Asia. However, SFTS virus (SFTSV) has not been reported to cause clinical infection in companion dogs to date. We report the case of a 4‐year‐old companion dog that presented with fever, vomiting, leukocytopenia and thrombocytopenia at a veterinary hospital in the Republic of Korea. It was diagnosed with SFTS, which was confirmed using real‐time reverse transcription PCR, sequencing and an indirect immunofluorescence assay, and recovered after supportive care. Further studies are required to investigate SFTSV infection in companion animals, living in close contact with humans, as well as animal‐to‐human transmission., A 4‐year‐old companion dog presented with fever, vomiting, leukocytopenia, and thrombocytopenia at a veterinary hospital in Republic of Korea. It was diagnosed with severe fever with thrombocytopenia syndrome (SFTS) and recovered after supportive care. To our knowledge, this is the first report of SFTSV infection with clinical manifestations in a companion dog.

This study focuses on the comparative and quantitative analysis of the epidemiologic trends and aspects of severe fever with thrombocytopenia syndrome (SFTS) outbreaks between Korea and Japan from 2013 to 2017. The following factors were analyzed; cumulative incidence rate (CIR), cases-fatality rate (CFR), and the epidemic aspects, including cases related to gender, male-to-female morbidity ratio (MFMR), age, seasonal, and geographical distributions. We observed 607 SFTS cases with CIR in Korea during the period 2013 to 2017 were as 0.24 per 100,000 populations and with a 127 fatal-cases (F.C.s), corresponding to a CFR of 20.9%, respectively. During the same period in Japan, 319 SFTS cases with a CIR of 0.05 and with 60 F.C.s to a CFR of 18.8% observed. When compared, the CIR of SFTS in Korea was significantly higher than in Japan (P

Background Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with the high case-fatality rate, and lack of vaccines. We aimed to systematically analysed the epidemiological characteristics, clinical signs, routine laboratory diagnosis, risk factors, and outcomes. Methods Documents on SFTS were collected by searching the Chinese National Knowledge Infrastructure, Wan Fang Data, PubMed, Embase, and Web of Science databases from 2011 to 2018. Meta-analysis was performed by using Review Manager and Stata software. Results Twenty-five articles involving 4143 cases were included. Diarrhea (odds ratio (OR) =1.60, 95% confidence interval (CI): 1.06 to 2.42, P = 0.02), and vomiting (OR = 1.56, 95% CI: 1.01 to 2.39, P = 0.04) on admission were associated with the fatal outcomes of SFTS. Compared to patients with mild symptoms, patients with severe symptoms had significantly elevated levels of lactic acid dehydrogenase (standard mean difference (SMD) =1.27, 95% CI: 0.59 to 1.94), alanine aminotransferase (SMD = 0.55, 95% CI: 0.24 to 0.85), aspirate aminotransferase (SMD = 1.01, 95% CI: 0.69 to 1.32), and creatine kinase (SMD = 1.04, 95% CI: 0.74 to 1.33) but had reduced platelet counts (SMD = -0.87, 95% CI: − 1.16 to − 0.58) and albumin levels (SMD = -1.00, 95% CI: − 1.32 to − 0.68). The risk factors for poor prognosis included age (mean difference (MD) =6.88, 95% CI: 5.41 to 8.35) and farming (OR = 2.01, 95% CI: 1.06 to 3.80). For the risk factors of contracting SFTS, the incidence of SFTS related to tick bites was 24% [95% CI: 0.18 to 0.31]. The pooled case-fatality rate of SFTS patients was 18% [95% CI: 0.16 to 0.21]. Conclusions China is the country with the highest incidence of SFTS. May to July was the peak of the epidemic, and farmers were a high-risk group. The risk factor for SFTS included age (poor prognosis) and tick bites (contracting SFTS). Patients with severe diarrhea and vomiting symptoms on admission should be noted. Clinicians could use routine laboratory parameters and clinical symptoms as references for clinically suspected cases, classification of SFTS, and timely treatment, especially in basic hospitals.

Serologic and molecular surveillance of serum collected from 152 suspected scrub typhus patients in Myanmar revealed Orientia tsutsugamushi of genotypic heterogeneity. In addition, potential co-infection with severe fever with thrombocytopenia syndrome virus was observed in 5 (3.3%) patients. Both scrub typhus and severe fever with thrombocytopenia syndrome are endemic in Myanmar.

The recent increase in severe fever with thrombocytopenia syndrome (SFTS) cases has led to the development of the SFTS-QS kit (MiCoBioMed, Seongnam, Korea) for detecting the SFTS virus (SFTSV, now renamed Huaiyangshan banyangvirus). SFTS-QS is a qualitative real-time reverse transcription PCR assay based on lab-on-a-chip technology. We evaluated the performance of the SFTS-QS kit and compared it with that of the PowerChek SFTSV Real-time PCR kit (PowerChek; Kogene Biotech, Seoul, Korea). A total of 117 serum samples were simultaneously assayed using the SFTS-QS and PowerChek kits. Sanger sequencing targeting the S and M segments of SFTSV was performed as the reference method. The total turnaround time of the two kits was compared. The SFTS-QS results agreed with those of PowerChek with a kappa value of 0.92. The diagnostic sensitivity and specificity of the SFTS-QS kit were both 100% (14/14 and 103/103, respectively), whereas those of the PowerChek kit were 100% (14/14) and 98.1% (101/103), respectively. The results of SFTS-QS and PowerChek were comparable; however, the SFTS-QS kit required a shorter total turnaround time. The SFTS-QS kit produced accurate and fast results and thus could serve as a useful tool for detecting SFTSV.

A sporadic but autochthonous dengue fever outbreak occurred in Tokyo in 2014, although the dengue virus is not in general circulation in Japan. Another lethal infectious disease, known as severe fever with thrombocytopenia syndrome (SFTS), was discovered to be endemic to Japan in January 2013. More than 400 patients with SFTS have been reported so far. The fatality rate of SFTS is approximately 30%. Also in 2014, a large outbreak of mosquito-borne Zika virus infections occurred in the South and Central parts of the American continent. Transplacental infection of a fetus with Zika virus occurs when pregnant women are infected. We cannot escape the risk of being infected with these viruses. Thus, preparedness for these emerging and reemerging virus infections is required.

The study examined the seasonal pattern of larvae, nymph, and adult life stages for Haemaphysalis longicornis and the rate of infection with severe fever from the thrombocytopenia syndrome virus in ticks collected from 12 sections (Jichukdong), 14 sections (Uldaeri), and 18 sections (Howondong) in Bukhansan dullegil for April–October 2019. Haemaphysalis longicornis ticks have been considered the main vector for severe fever with thrombocytopenia syndrome (SFTS). Haemaphysalis flava and Ixodes nipponensis were collected using the dragging and flagging method. The ratios of Haemaphysalis longicornis of the collected ticks were 91% (Jichukdong), 94% (Uldaeri), and 98% (Howondong). Monthly distributional studies of Haemaphysalis longicornis based on the developmental stage showed that the adults peaked in September while nymphs were collected more frequently from April through June. The larvae peaked in September and October. SFTS virus detection was performed using 2 × OneStep RT-PCR and nested PCR. On the other hand, no SFTS virus-specific gene was detected in 1,158 ticks of Haemaphysalis longicornis. This result provides estimates of the population densities for the life stages of Haemaphysalis longicornis and the associated disease risk in Bukhansan dullegil, where many people have visited since opening in 2010.

Severe fever with thrombocytopenia syndrome (SFTS) caused by the SFTS virus (SFTSV), a novel Phlebovirus, is endemic to South Korea, central and northeastern China, and western Japan. SFTS poses a threat to public health because of its high mortality and secondary transmission. Ticks and domestic animals are hosts for SFTSV in endemic areas. There is no specific treatment for SFTS, and avoiding tick bites is the best way to prevent infection. Early therapeutic plasma exchange (TPE) is a rescue therapy in patients with rapidly progressive SFTS. Here, we present a patient with SFTS who was improving on TPE but died suddenly due to acute lung injury after TPE.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality (12%–30%). The mechanism by which the SFTS bunyavirus (SFTSV) causes severe illness remains unclear. To evaluate the phenotypic and functional characteristics of the NK cell subsets in SFTS patients, twenty-nine SFTS patients were sequentially sampled from admission until recovery. Phenotypic and functional characteristics of NK cell subsets in circulating blood were analysed via flow cytometry. Then, correlations between NK cell subset frequencies and the SFTS index (SFTSI) were evaluated in all SFTS patients (15 mild, 14 severe) upon admission. The frequencies of CD56dimCD16+ NK cells were greatly decreased in early SFTSV infection and were negatively correlated with disease severity. Additionally, higher Ki-67 and granzyme B expression and relatively lower NKG2A expression in CD56dimCD16+ NK cells were observed in acute infection. Moreover, the effector function of CD56dim NK cells was increased in the acute phase compared with the recovery phase in nine severe SFTS patients. Additionally, interleukin (IL)-15, interferon (IFN)-α, IL-18 and IFN-γ secretion was markedly increased during early infection. Collectively, despite depletion of CD56dimCD16+ NK cells, activation and functional enhancement of CD56dimCD16+ NK cells were still observed, suggesting their involvement in defence against early SFTSV infection.

Severe fever with thrombocytopenia syndrome (SFTS) is being reported annually in South Korea since its first detection there in 2010. The causal agent is a negative-strand RNA virus 80–100 nm in diameter. It causes fever, thrombocytopenia, leukocytopenia, gastrointestinal symptoms, and neural symptoms. The mortality rate of SFTS was 32.6% among 172 cases reported from 2012 to 2015 in South Korea. Thus, is necessary to develop an effective diagnostic method that selectively identifies the isolates circulating in South Korea. The real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay is a simple, rapid, and sensitive approach for molecular diagnosis. Here, we designed novel primers for this assay and found that the technique had very high specificity, sensitivity, and efficiency. This real-time RT-LAMP approach using the novel primers developed herein can be applied for early diagnosis of SFTSV strains in South Korea to reduce the mortality rate of SFTS.

Background To analyze and discuss the transmission route of a cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus (SFTSV). Method We performed an epidemiological investigation and a genetic analysis of patients with severe fever with thrombocytopenia syndrome (SFTS) caused by SFTSV, their close contacts and the surrounding population. Results We found that all patients had contact with the blood of the first patient. The comparison of gene sequences in the three isolated SFTSV strains showed that the strains were closely related. Six close contacts and nine individuals in the surrounding population were positive for SFTSV IgM antibody. Conclusion We suspect that the cluster outbreak was transmitted via blood and that the natural reservoir host of SFTSV exists in the patients’ environment.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease. SFTS is caused by the SFTS virus, a novel phlebovirus, and is spread by ticks. Methods: A 50-year-old man was admitted to our hospital with the chief complaint of fever and was diagnosed with confirmed SFTS. An epidemiological investigation was conducted, and immunofluorescent antibody assays (IFAs) were performed to determine the role of the patient's three dogs in the transmission. PCR assays were performed using ticks that were collected with the dragging and flagging method from the patient's dogs and home. Results: PCR results were positive, and IFA confirmed an increased antibody titer. Although the reverse transcription PCR results of the three dogs were negative for SFTS virus, one dog had an elevated SFTS IFA immunoglobulin G (IgG) titer of 1:1,024. Moreover, a number of ticks were observed in the area surrounding the dog cages. Based on the findings of the patient interview, the patient was likely to have acquired SFTS by blood splash because he removed or burst ticks from the dogs with his bare hands. Although no tick bites were reported, tick transmission could not be ruled out. Studies have shown that only one in three individuals with a diagnosis of SFTS recalls a tick bite; thus, a definite exclusion of tick transmission in this case was not possible. Conclusions: The epidemiological findings of our case suggest a possible relationship between tick infestation in domestic dogs and SFTS virus transmission to humans. However, there is no direct evidence supporting this viral transmission route. Future studies are needed to further investigate a potential route of SFTS transmission by exposure to engorged tick blood or pet dogs.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with increasing spread. Currently SFTS transmission has expanded beyond Asian countries, however, with definitive global extents and risk patterns remained obscure. Here we established an exhaustive database that included globally reported locations of human SFTS cases and the competent vector, Haemaphysalis longicornis (H. longicornis), as well as the explanatory environmental variables, based on which, the potential geographic range of H. longicornis and risk areas for SFTS were mapped by applying two machine learning methods. Ten predictors were identified contributing to global distribution for H. longicornis with relative contribution ≥1%. Outside contemporary known distribution, we predict high receptivity to H. longicornis across two continents, including northeastern USA, New Zealand, parts of Australia, and several Pacific islands. Eight key drivers of SFTS cases occurrence were identified, including elevation, predicted probability of H. longicornis presence, two temperature-related factors, two precipitation-related factors, the richness of mammals and percentage coverage of water bodies. The globally model-predicted risk map of human SFTS occurrence was created and validated effective for discriminating the actual affected and unaffected areas (median predictive probability 0.74 vs. 0.04, P

Summary Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne infectious disease with high mortality, is diagnosed by the serological testing of serum samples from patients in the acute and convalescent phases and/or by direct detection of the SFTS virus (SFTSV). Conventionally, heat and UV treatments have been used to inactivate the viruses present in serum samples before performing the serological assays. Here, we examined the inactivation conditions optimal for SFTSV-containing serum samples to ensure the safety of laboratory workers while maintaining the accuracy of serological assay results simultaneously. Heating human serum samples spiked with SFTSV to 60 °C for 30 min or exposing them to UV irradiation for 30 min, reduced the infectious virus titer below the limit of detection. SFTSV in sera from patients in the acute phase of SFTS was completely inactivated by heating to 60 °C for 30 min, followed by UV irradiation for 10 min. This inactivation procedure had minimal impact on the performance of SFTSV antibody detection tests. The data provided herein can serve as a guide for laboratory workers and researchers working with SFTS serological tests.

INTRODUCTION Severe fever with thrombocytopenia syndrome (SFTS) is an emerging zoonosis infected by virus (SFTSV) in central and eastern China, which is associated with high mortality. However, limited clinical data have been reported about this critical illness. PATIENTS AND METHODS Retrospective cohort study in intensive care unit (ICU) patients with SFTSV infection admitted in 2014 to 2019. Diagnosis was confirmed using reverse transcription polymerase chain reaction on serum samples. RESULTS One hundred sixteen patients with SFTSV infection were included (mean age 63 ± 9 years, 59 [51.3%] males). Non-survivors (43.1%) were older, and had lower Glasgow Coma Score, higher Acute Physiology and Chronic Health Evaluation II, and sequential organ failure assessment score at ICU admission. In addition, non-survivors had more severe respiratory failure (PaO2/FiO2: 208 ± 14 mm Hg vs. 297 ± 15 mm Hg), more frequent shock (25[50%] vs. 7[10.6%]), and required more frequently mechanical ventilation (78% vs. 19.7%; P

The genus Phlebovirus contains about 70 named viruses, distributed widely in Europe, Africa, Central Asia, and the Americas. These viruses are currently classified into 10 species by the International Committee on Taxonomy of Viruses (ICTV): Bujaru phlebovirus, Candiru phlebovirus, Chilibre phlebovirus, Frijoles phlebovirus, Punta Torro phlebovirus, Rift Valley fever phlebovirus, Salehabad phlebovirus, Sandfly fever Naples phlebovirus, Mukawa phlebovirus, and Uukuniemi phlebovirus. In addition, at least 32 unclassified strains are associated with this genus.1 Phleboviruses have a genome comprising three segments of negative sense, single-stranded RNA. The large segment (L) encodes the viral RNA-dependent RNA polymerase, the medium segment (M) encodes the structural glycopolyproteins, and the small segment (S) has an ambisense strategy encoding the nucleoprotein (NP) in the negative sense and the nonstructural small (NSs) protein in the positive sense.2 Phleboviruses are largely transmitted by sand flies; Phlebotomus species in the Old World or Nyssomyia (previously Lutzomyia) species in the New World.3 However, some viruses in this genus are transmitted by mosquitoes, Culicoides, and ticks. Many phleboviruses have been associated with human and animal disease. Pathogenic strains include Rift Valley fever, Toscana, Candiru, Sandfly fever Naples, Sandfly fever Sicilian, and severe fever with thrombocytopenia syndrome viruses.4 Recent discoveries of Sandfly fever Turkey,5 Heartland,6 Hunter Island Group,7 Fermo,8 and Malsoor9 viruses highlight the extent to which the diversity and public or animal health impact of phleboviruses are still unknown and likely underestimated. Despite their public health impact, some phlebovirus species remain characterized solely by serological techniques. Given the many recent discoveries, genetic characterization of historically identified phleboviruses is important for the development of diagnostic and surveillance tools, and evolutionary insights into the ever-growing breadth of recognized phleboviruses. Here, we describe the complete sequences of two phlebovirus species complexes, and three previously unclassified phleboviruses isolated in the Americas.

Two veterinary personnel in Japan were infected with severe fever with thrombocytopenia syndrome virus (SFTSV) while handling a sick cat. Whole-genome sequences of SFTSV isolated from the personnel and the cat were 100% identical. These results identified a nosocomial outbreak of SFTSV infection in an animal hospital without a tick as a vector.

Encephalitis is an infrequent manifestation in the various spectrums caused by severe fever with thrombocytopenia syndrome virus (SFTSV) infection. There are few data about the possible pathogenic mechanisms of SFTSV-associated encephalitis. Here, two SFTSV-infected patients with onset of encephalitis were enrolled. The whole genome of two SFTSV strains isolated from cerebrospinal fluid (CSF) was deeply sequenced by next-generation sequencing (NGS) and phylogenetic analysis was conducted. The specific mutations of M fragment were P98L and T665S respectively. The three-dimensional structure of glycoprotein Gn which was encoded by M fragment, an important virulence factor of SFTSV, was constructed by SWISS-MODEL. There was no significant variation in glycoprotein Gn of the two isolates comparing to other strains without encephalitis. Phylogenetic trees based on the complete sequences of M segment showed the two strains were highly identical to other local strains without encephalitis. Our study demonstrates that the virulence factors of SFTSV with encephalitis are not different from those without encephalitis. SFTSV itself is a neurotropic virus.

A 79‐year‐old woman presented with fever and general malaise. Examination revealed hepatic injury, thrombocytopenia, skin lesions, and regional lymphadenopathy; severe fever with thrombocytopenia syndrome (SFTS) was diagnosed using polymerase chain reaction. The patient developed impaired consciousness that worsened after 4 days. Magnetic resonance imaging of the head revealed a subdural hematoma in the occipital region with an uncertain onset time. As SFTS rarely causes intracranial hemorrhage, the associated risk factors are unknown. Clinicians may overlook potential intracranial hemorrhage in stuporous SFTS patients., We described a rare severe fever with thrombocytopenia (SFTS) case with subdural hematoma. As in this case, there is a possibility that a small amount of intracranial hemorrhage combined with SFTS may be overlooked.

Background Severe fever and thrombocytopenia syndrome (SFTS) is an acute illness with a high mortality (16.2–29.1%). Unfortunately, there is no specific cure or vaccine for SFTS. Methods In this open-label study, two patients with SFTS were treated with favipiravir, a new antiviral drug. Results Patients had a sustainable virologic, immunologic and symptomatic recovery. Conclusions Favipiravir may be a prosiming drug for the treatment of SFTS. Electronic supplementary material The online version of this article (10.1007/s15010-019-01364-9) contains supplementary material, which is available to authorized users.

Most prevalent infectious diseases worldwide are caused by mediators such as insects and characterized by high mortality and morbidity, thereby creating a global public health concern. Therefore, a sensitive, selective detection platform for diagnosing diseases in the early stages of infection is needed to prevent disease spread and to protect public health. Here, we developed novel DNA aptamers specific to the nucleocapsid protein (NP) of the severe fever with thrombocytopenia syndrome (SFTS) virus and synthesized ssDNA-binding protein-conjugated liposomes encapsulated with horseradish peroxidase (HRP) for application in a simple and universal platform. This platform achieved highly sensitive detection of the NP by measuring the colorimetric signal following lysis of the HRP encapsulated liposomes, mediated by a mixture of 3,3',5,5'-tetramethylbenzidine and H2O2 solution. The limit of detection was 0.009 ng·mL-1, and NP was successfully detected in diluted human serum with a high recovery rate. Moreover, this method was specific and did not exhibit cross-reactivity among NPs of other virus types. These results demonstrated the efficacy of the proposed method as a highly sensitive, specific, and universal diagnostic tool for potential application in monitoring of the early stages of infectious diseases.

Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV). We investigated the detailed kinetics of serologic response in patients with SFTS. Twenty-eight patients aged ≥18 years were enrolled between July 2015 and October 2018. SFTS was confirmed by detecting SFTSV RNA in their plasma using reverse transcription polymerase chain reaction. SFTSV-specific IgG and IgM were measured using immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA). We found that SFTSV-specific IgG was detected at days 5–9 after symptom onset, and its titer was rising during the course of disease. SFTSV-specific IgM titer peaked at around week 2–3 from symptom onset. The SFTSV-specific seropositive rates for days 5–9, 10–14, 15–19, and 20–24 from symptom onset using IFA and ELISA were 63%, 76%, 90%, and 100%, and 58%, 86%, 100%, and 100%, respectively, for IgG, whereas they were 32%, 62%, 80%, and 100%, and 53%, 62%, 70%, and 100%, respectively, for IgM. The delayed IgM response could be attributed to the low sensitivity of SFTSV-specific IgM IFA or ELISA and/or impaired immune responses. The IgM test using IFA or ELISA that we used in this study is, therefore, insufficient for the early diagnosis of SFTS.

Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne infectious disease, is difficult to differentiate from other common febrile diseases. Clinically distinctive features and climate variates associated with tick growth can be useful predictors for SFTS. This retrospective study (2013&ndash, 2019) demonstrated the role of climatic factors as predictors of SFTS and developed a clinical scoring system for SFTS using climate variables and clinical characteristics. The presence of the SFTS virus was confirmed using reverse transcription polymerase chain reaction (RT-PCR) tests. In the univariate analysis, the SFTS-positive group was significantly associated with higher mean ambient temperature and humidity compared with the SFTS-negative group (22.5 &deg, C vs. 18.9 &deg, C, 77.9% vs. 70.7%, all p &lt, 0.001). In the multivariate analysis, poor oral intake (Odds ratio [OR] 5.87, 95% CI: 2.42&ndash, 8.25), lymphadenopathy (OR 7.20, 95% CI: 6.24&ndash, 11.76), mean ambient temperature &ge, 20 &deg, C (OR 4.62, 95% CI: 1.46&ndash, 10.28), absolute neutrophil count &le, 2000 cells/&mu, L (OR 8.95, 95% CI: 2.30&ndash, 21.25), C-reactive protein level &le, 1.2 mg/dL (OR 6.42, 95% CI: 4.02&ndash, 24.21), and creatinine kinase level &ge, 200 IU/L (OR 5.94, 95% CI: 1.42&ndash, 24.92) were significantly associated with the SFTS-positive group. This study presents the risk factors, including ambient temperature and clinical characteristics, that physicians should consider when suspecting SFTS.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a recently emerged tickborne virus in east Asia with over 8,000 confirmed cases. With a high case fatality ratio, SFTSV has been designated a high priority pathogen by the WHO and the NIAID. Despite this, there are currently no approved therapies or vaccines to treat or prevent SFTS. Vesicular stomatitis virus (VSV) represents an FDA-approved vaccine platform that has been considered for numerous viruses due to its low sero-prevalence in humans, ease in genetic manipulation and promiscuity in incorporating foreign glycoproteins into its virions. In this study, we developed a recombinant VSV (rVSV) expressing the SFTSV glycoproteins Gn/Gc (rVSV-SFTSV) and assessed its safety, immunogenicity and efficacy in mice. We demonstrate that rVSV-SFTSV is safe when given to immunocompromised animals and is not neuropathogenic when injected intracranially into young immunocompetent mice. Immunization of Ifnar-/- mice with rVSV-SFTSV resulted in high levels of neutralizing antibodies and protection against lethal SFTSV challenge. Additionally, passive transfer of sera from immunized Ifnar-/- mice into naïve animals was protective when given pre- or post-exposure. Finally, we demonstrate that immunization with rVSV-SFTSV cross protects mice against challenge with the closely related Heartland virus despite low neutralizing titers to the virus. Taken together, these data suggest that rVSV-SFTSV is a promising vaccine candidate.ImportanceTick borne diseases are a growing threat to human health. Severe fever with thrombocytopenia syndrome (SFTS) and Heartland viruses are recently recognized, highly-pathogenic, tick-transmitted viruses. The fatality rates for individuals infected with SFTSV or HRTV are high and there are no therapeutics or vaccines available. The recent introduction of the tick vector for SFTSV (Haemaphysalis longicornis) to the eastern half of the United States and Austrailia raises concerns for SFTSV outbreaks outside East Asia. Here we report the development of a potential vaccine for SFTSV and HRTV based on the viral vector platform that has been successfully used for an Ebola vaccine. We demonstrate that the rVSV-SFTSV protects from lethal SFTSV or HRTV challenge when given as a single dose. We evaluated possible pathogenic effects of the vaccine and show that it is safe in immune compromised animlas and when introduced into the central nervous system.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease in China, Japan, and Korea. This study aimed to estimate the monthly SFTS occurrence and the monthly number of SFTS cases in the geographical area in Korea using epidemiological data including demographic, geographic, and meteorological factors. Important features were chosen through univariate feature selection. Two models using machine learning methods were analyzed: the classification model in machine learning (CMML) and regression model in machine learning (RMML). We developed a novel model incorporating the CMML results into RMML, defined as modified-RMML. Feature importance was computed to assess the contribution of estimating the number of SFTS cases using modified-RMML. Aspect to the accuracy of the novel model, the performance of modified-RMML was improved by reducing the MSE for the test data as 12.6–52.2%, compared to the RMML using five machine learning methods. During the period of increasing the SFTS cases from May to October, the modified-RMML could give more accurate estimation. Computing the feature importance, it is clearly observed that climate factors such as average maximum temperature, precipitation as well as mountain visitors, and the estimation of SFTS occurrence obtained from CMML had high Gini importance. The novel model incorporating CMML and RMML models improves the accuracy of the estimation of SFTS cases. Using the model, climate factors, including temperature, relative humidity, and mountain visitors play important roles in transmitting SFTS in Korea. Our findings highlighted that the guidelines for mountain visitors to prevent SFTS transmissions should be addressed. Moreover, it provides important insights for establishing control interventions that predict early identification of SFTS cases.

Severe fever with thrombocytopenia syndrome (SFTS) is a new infectious disease with a high mortality rate and increased incidence in Republic of Korea since the first case was reported in 2013. The average mortality rate varies by region and year but remains high in Asia. This study aimed to evaluate the spatial and temporal patterns of SFTS cases reported to the national Disease Control and Prevention Agency (KDCA). We analysed the spatial and temporal distribution of SFTS and observed changes in areas vulnerable to the disease. We analysed data concerning 1086 confirmed SFTS patients from 2013 to 2019 categorized according to the 247 district level administrative units. To better understand the epidemiology of SFTS, we carried out spatiotemporal analyses on a yearly basis and also calculated and mapped spatial clusters of domestic SFTS by global (regional) and local Moran’s indices. To observe the annual changes in SFTS incidence rate, scan statistics for each city and district were calculated. The incidence rate showed significant clustering in specific regions, which reoccurred annually in some regions. In Republic of Korea, SFTS clusters have been expanding into the southern regions, with annual clusters concentrated between May and October. This pattern allows prediction of SFTS occurrences through spatiotemporal analysis, which makes it possible to guide measures of disease prevention.

Significant progress has been made on the molecular biology of the severe fever with thrombopenia virus (SFTSV); however, many parts of the pathophysiological mechanisms of mortality in SFTS remain unclear. In this study, we investigated virologic and immunologic factors for fatal outcomes of patients with SFTS. We prospectively enrolled SFTS patients admitted from July 2015 to October 2020. Plasma samples were subjected to SFTSV RNA RT-PCR, multiplex microbead immunoassay for 17 cytokines, and IFA assay. A total of 44 SFTS patients were enrolled, including 37 (84.1%) survivors and 7 (15.9%) non-survivors. Non-survivors had a 2.5 times higher plasma SFTSV load than survivors at admission (p < 0.001), and the viral load in non-survivors increased progressively during hospitalization. In addition, non-survivors did not develop adequate anti-SFTSV IgG, whereas survivors exhibited anti-SFTSV IgG during hospitalization. IFN-α, IL-10, IP-10, IFN-γ, IL-6, IL-8, MCP-1, MIP-1α, and G-CSF were significantly elevated in non-survivors compared to survivors and did not revert to normal ranges during hospitalization (p < 0.05). Severe signs of inflammation such as a high plasma concentration of IFN-α, IL-10, IP-10, IFN-γ, IL-6, IL-8, MCP-1, MIP-1α, and G-CSF, poor viral control, and inadequate antibody response during the disease course were associated with mortality in SFTS patients.

Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic disease caused by the SFTS virus (SFTSV). SFTS can be considered a life-threatening notifiable infectious disease. The unavailability of specific therapeutics encourages the investigation of potential efficacy of existing drugs against this infection. Drug repurposing was done by performing virtual screening of already established drug molecules followed by 100 ns molecular dynamics simulations and molecular mechanics Poisson–Boltzmann surface area–based binding-energy calculation by targeting the SFTS L protein. On the basis of binding energy and protein–ligand interactions, top 10 promising hits were identified, showing stable binding with SFTS L protein. Further 100 ns atomistic MD simulation refined the hits from top 10 to top 4 with docking-based binding energy lesser than −8.0 kcal/mol toward the SFTS L protein and engaged in π–π interactions with pivotal amino acid residues. Various parameters and binding affinity of top 4 ligands towards L protein was computed. Ligand zaltoprofen exhibited best binding energy −220.095 kJ/mol. The present work is the first in silico study to assess bromfenac, cinchophen, elliptinium, and zaltoprofen; four promising hits against SFTS. Nonetheless, further proper biological evaluation is necessary to determine their efficacy against SFTS.

Severe fever with thrombocytopenia syndrome (SFTS), also known as fever, thrombocytopenia, and leukopenia syndrome, is an emerging tick-borne infectious disease in Asian countries. SFTS should be suspected in patients presenting with fever, thrombocytopenia, and leukopenia and have a history of tick exposure in an endemic area. Since SFTS can be accompanied by lymphadenopathy, particularly generalized lymphadenopathy, it can be confused with a primary malignancy, such as lymphoma. The study reports a case of SFTS accompanied by multiple lymphadenopathies, which mimicked malignant lymphoma on F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Severe fever with thrombocytopenia syndrome (SFTS) is a novel tick-borne infectious disease caused by a new type of SFTS virus (SFTSV). Here, a longitudinal sampling study is conducted to explore the differences in transcript levels after SFTSV infection, and to characterize the transcriptomic and epigenetic profiles of hospitalized patients. The results reveal significant changes in the mRNA expression of certain genes from onset to recovery. Moreover, m6A-seq reveals that certain genes related with immune regulation may be regulated by m6A. Besides the routine tests such as platelet counts, serum ALT and AST levels testing, distinct changes in myocardial enzymes, coagulation function, and inflammation are well correlated with the clinical data and sequencing data, suggesting that clinical practitioners should monitor the above indicators to track disease progression and guide personalized treatment. In this study, the transcript changes and RNA modification may lend a fresh perspective to our understanding of the SFTSV and play a significant role in the discovery of drugs for effective treatment of this disease., Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by tick-borne SFTS virus. Here, Wang et al. characterize transcriptomic and epigenetic changes in infected patients and correlate them with clinical parameters to improve the understanding of disease progression.