Epidemiology, clinical characteristics, and treatment of severe fever with thrombocytopenia syndrome

SUMMARYSevere fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was caused by a novel bunyavirus, SFTSV. The study aimed to disclose the epidemiological and clinical characteristics of SFTSV infection in China so far. An integrated clinical database comprising 1920 SFTS patients was constructed by combining first-hand clinical information collected from SFTS sentinel hospitals (n = 1159) and extracted data (n = 761) from published literature. The considered variables comprised clinical manifestations, routine laboratory tests of acute infection, hospitalization duration and disease outcome. SFTSV-IgG data from 19 119 healthy subjects were extracted from the published papers. The key clinical variables, case-fatality rate (CFR) and seroprevalence were estimated by meta-analysis. The most commonly seen clinical manifestations of SFTSV infection were fever, anorexia, myalgia, chill and lymphadenopathy. The major laboratory findings were elevated lactate dehydrogenase, aminotransferase, followed by thrombocytopenia, lymphocytopenia, elevated alanine transaminase and creatine kinase. A CFR of 12·2% was estimated, significantly higher than that obtained from national reporting data, but showing no geographical difference. In our paper, the mortality rate was about 1·9 parts per million. Older age and longer delay to hospitalization were significantly associated with fatal outcome. A pooled seroprevalence of 3·0% was obtained, which increased with age, while comparable for gender. This study represents a clinical characterization on the largest group of SFTS patients up to now. A higher than expected CFR was obtained. A wider spectrum of clinical index was suggested to be used to identify SFTSV infection, while the useful predictor for fatal outcome was found to be restricted.

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Epidemiological and Clinical Characteristics of Confirmed Cases of Severe Fever With Thrombocytopenia Syndrome in Jeju Province, Korea, 2014-2018

Journal of Preventive Medicine and Public Health ◽

10.3961/jpmph.18.289 ◽

2019 ◽

Vol 52 (3) ◽

pp. 195-199 ◽

Cited By ~ 4

Author(s):

Jinhee Kim ◽

Jong-Myon Bae

Keyword(s):

Clinical Characteristics ◽

Severe Fever

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Epidemiological and clinical characteristics of severe fever with thrombocytopenia syndrome bunyavirus human-to-human transmission

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009037 ◽

2021 ◽

Vol 15 (4) ◽

pp. e0009037

Author(s):

Xinyu Fang ◽

Jianli Hu ◽

Zhihang Peng ◽

Qigang Dai ◽

Wendong Liu ◽

...

Keyword(s):

South Korea ◽

Clinical Characteristics ◽

Eastern China ◽

Transmission Risk ◽

Basic Reproductive Number ◽

World Health ◽

Reproductive Number ◽

Health Organization ◽

Associated Risk Factors ◽

Severe Fever

Background Severe fever with thrombocytopenia syndrome (SFTS) was listed as one of the most severe infectious disease by world health organization in 2017. It can mostly be transmitted by tick bite, while human-to-human transmission has occurred on multiple occasions. This study aimed to explore the epidemiological and clinical characteristics and make risk analysis of SFTS human-to-human transmission. Methods Descriptive and spatial methods were employed to illustrate the epidemiological and clinical characteristics of SFTS human-to-human transmission. The risk of SFTS human-to-human transmission was accessed through secondary attack rate (SAR) and basic reproductive number (R0). Logistic regression analysis was used to identify the associated risk factors. Results A total of 27 clusters of SFTS human-to-human transmission were reported in China and South Korea during 1996–2019. It mainly occurred among elder people in May, June and October in central and eastern China. The secondary cases developed milder clinical manifestation and better outcome than the index cases. The incubation period was 10.0 days (IQR:8.0–12.0), SAR was 1.72%-55.00%, and the average R0 to be 0.13 (95%CI:0.11–0.16). Being blood relatives of the index case, direct blood/bloody secretion contact and bloody droplet contact had more risk of infection (OR = 6.35(95%CI:3.26–12.37), 38.01 (95%CI,19.73–73.23), 2.27 (95%CI,1.01–5.19)). Conclusions SFTS human-to-human transmission in China and South Korea during 1996–2019 had obvious spatio-temporal distinction. Ongoing assessment of this transmission risk is crucial for public health authorities though it continues to be low now.

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Prognostic Factors of Severe Fever with Thrombocytopenia Syndrome in South Korea

Viruses ◽

10.3390/v13010010 ◽

2020 ◽

Vol 13 (1) ◽

pp. 10

Author(s):

Misun Kim ◽

Sang Taek Heo ◽

Hyunjoo Oh ◽

Suhyun Oh ◽

Keun Hwa Lee ◽

...

Keyword(s):

Ambient Temperature ◽

Clinical Characteristics ◽

Climatic Factors ◽

Univariate Analysis ◽

Oral Intake ◽

Positive Group ◽

Reactive Protein ◽

Creatinine Kinase Level ◽

Clinical Scoring ◽

Severe Fever

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 (2013–2019) 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 °C vs. 18.9 °C; 77.9% vs. 70.7%, all p < 0.001). In the multivariate analysis, poor oral intake (Odds ratio [OR] 5.87, 95% CI: 2.42–8.25), lymphadenopathy (OR 7.20, 95% CI: 6.24–11.76), mean ambient temperature ≥ 20 °C (OR 4.62, 95% CI: 1.46–10.28), absolute neutrophil count ≤ 2000 cells/μL (OR 8.95, 95% CI: 2.30–21.25), C-reactive protein level ≤ 1.2 mg/dL (OR 6.42, 95% CI: 4.02–24.21), and creatinine kinase level ≥ 200 IU/L (OR 5.94, 95% CI: 1.42–24.92) 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.

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Risk Factors and Clinical Characteristics of Severe Fever with Thrombocytopenia Syndrome

International Journal of General Medicine ◽

10.2147/ijgm.s292735 ◽

2020 ◽

Vol Volume 13 ◽

pp. 1661-1667

Author(s):

Fei Wang ◽

Yunjuan Wu ◽

Jie Jiao ◽

Jun Wang ◽

Zheng Ge

Keyword(s):

Risk Factors ◽

Clinical Characteristics ◽

Severe Fever

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Epidemiological and clinical characteristics of severe fever with thrombocytopenia syndrome in southern Anhui Province, 2011-2020

Japanese Journal of Infectious Diseases ◽

10.7883/yoken.jjid.2021.391 ◽

2021 ◽

Author(s):

Wenjie Wang ◽

Aiping Zhang ◽

Qiongle Wu ◽

Lingling Zhu ◽

Jinsun Yang

Keyword(s):

Clinical Characteristics ◽

Anhui Province ◽

Severe Fever

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The differential characteristics between severe fever with thrombocytopenia syndrome and hemorrhagic fever with renal syndrome in the endemic regions

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz477 ◽

2019 ◽

Author(s):

Qing-Bin Lu ◽

Hao Li ◽

Fa-Chun Jiang ◽

Ling-Ling Mao ◽

Xue-Sheng Liu ◽

...

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Confidence Interval ◽

Clinical Characteristics ◽

Area Under The Curve ◽

Hemorrhagic Fever ◽

Low Back ◽

Blood Cell Count ◽

High Area ◽

Severe Fever

Abstract The misdiagnosis between severe fever with thrombocytopenia syndrome and hemorrhagic fever with renal syndrome were identified in endemic regions for both diseases. A model based on age, mouse/tick contact in recent one month, clinical characteristics including blush, low back pain, diarrhea, enlarged lymph nodes, and white blood cell count, yielded a high area under the curve of 0.985 (95% confidence interval, 0.979-0.992), enabling an effective differentiation between two diseases.

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Application of a decision tree model in the early identification of severe patients with severe fever with thrombocytopenia syndrome

PLoS ONE ◽

10.1371/journal.pone.0255033 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0255033

Author(s):

Bohao Wang ◽

Zhiquan He ◽

Zhijie Yi ◽

Chun Yuan ◽

Wenshuai Suo ◽

...

Keyword(s):

Decision Tree ◽

Decision Trees ◽

Early Identification ◽

Clinical Characteristics ◽

Electronic Records ◽

Tree Model ◽

Laboratory Parameters ◽

Support Force ◽

Severe Fever ◽

Youden’S Index

Background Severe fever with thrombocytopenia syndrome (SFTS) is a serious infectious disease with a fatality of up to 30%. To identify the severity of SFTS precisely and quickly is important in clinical practice. Methods From June to July 2020, 71 patients admitted to the Infectious Department of Joint Logistics Support Force No. 990 Hospital were enrolled in this study. The most frequently observed symptoms and laboratory parameters on admission were collected by investigating patients’ electronic records. Decision trees were built to identify the severity of SFTS. Accuracy and Youden’s index were calculated to evaluate the identification capacity of the models. Results Clinical characteristics, including body temperature (p = 0.011), the size of the lymphadenectasis (p = 0.021), and cough (p = 0.017), and neurologic symptoms, including lassitude (p<0.001), limb tremor (p<0.001), hypersomnia (p = 0.009), coma (p = 0.018) and dysphoria (p = 0.008), were significantly different between the mild and severe groups. As for laboratory parameters, PLT (p = 0.006), AST (p<0.001), LDH (p<0.001), and CK (p = 0.003) were significantly different between the mild and severe groups of SFTS patients. A decision tree based on laboratory parameters and one based on demographic and clinical characteristics were built. Comparing with the decision tree based on demographic and clinical characteristics, the decision tree based on laboratory parameters had a stronger prediction capacity because of its higher accuracy and Youden’s index. Conclusion Decision trees can be applied to predict the severity of SFTS.

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2308. Comparison of Clinical Characteristics Between Laboratory-Confirmed Positive and Negative Patients with Severe Fever with Thrombocytopenia Syndrome

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1986 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S791-S791

Author(s):

Suhyun Oh ◽

Jeong Rae You ◽

Sang Taek Heo ◽

Sujin Jo

Keyword(s):

South Korea ◽

Clinical Characteristics ◽

Close Contact ◽

Case Fatality ◽

Oral Intake ◽

Outdoor Temperature ◽

Rt Pcr ◽

Laboratory Findings ◽

Cell Counts ◽

Severe Fever

Abstract Background Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne emerging infectious disease caused by SFTS virus (SFTSV). Mortality of SFTS estimated to be 21.8% in South Korea, and this disease is difficult differential diagnosis. Here, we analyzed clinical characteristics between SFTS positive group (SPG) and negative group (SNG) in a primary clinical setting. Methods In this prospective observational study, data were collected on patients with SFTS test performed at the single teaching hospital, in South Korea, between April 2013 and December 2018. The association between each demographic, climatic, clinical, and laboratory variable was assessed. All SFTS was confirmed at the KCDC by detecting the M segment gene of SFTSV RNA using reverse transcription-polymerase chain reaction (RT–PCR), and were confirmed at our laboratory by S segment gene of SFTSV RNA using RT–PCR about patient’s family member and those with close contact. Results Of the 199 patients in the study periods, 61 (31%) were SPG and 138 (69%) were SNG. Mean age was 55.1 ± 20.3 years, and 103 (52%) patients were male. In SPG, the comorbidity score and history of tick bite were significantly higher compared with SNG. SPG and SNG were prevalent in summer and autumn, respectively (60.7% vs. 45.7%, P < 0.05). SPG was associated with mean outdoor temperature, humidity and rainfall compared with SNG (22.9°Cvs. 18.9 ℃; 78.8% vs. 70.6%; 12.6 mm vs. 8.5 mm, all P < 0.01). Dizziness, poor oral intake, nausea, and diarrhea were common in SPG. In laboratory findings, white blood cell counts, absolute neutrophil count, and C-reactive protein were significantly lower in SPG. Lymphocyte fraction, activated partial thromboplastin time, and creatinine phosphokinase were significantly higher in SPG. Case fatality of the SPG and SNG were 9.8% and 1.0%, respectively. In multivariate analysis, mean outdoor temperature, humidity, dizziness, and low CRP were predictive factors in SPG. Conclusion Early prediction of SFTS diagnosis is important because this emerging zoonotic disease was a high fatality in endemic areas. When a physician wants to do SFTS test, they would consider according to this predictive variable for differentiating SFTS in primary care settings. Disclosures All authors: No reported disclosures.

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