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Objective@#To construct a model for clinical identification of spotted fever (SF) and severe fever with thrombocytopenia syndrome (SFTS), so as to provide insights into early identification of SF and SFTS.@*Methods@#The clinical data of laboratory-confirmed SF and SFTS patients in secondary and tertiary hospitals in Lu'an City, Anhui Province from May 2017 to May 2021 were retrieved from Chinese Disease Prevention and Control Information System. Factors affecting SF were identified using a logistic regression model, and the model for early identification of SF and SFTS was created. The model fitting effect was evaluated using Hosmer-Lemeshow test, and the value of the model for identification of SF and SFTS was evaluated using the area under the receiver operating characteristic curve (AUC).@*Results@#Data of 62 SF cases and 115 SFTS cases were included. Multivariable logistic regression analysis showed that rash (β=5.994), C-reactive protein (β=4.409), white blood cell (β=-3.176) and platelet (β=-3.234) were included in the model, which were scored 6, 4, -3 and -3, with a total score ranging from -5 to 10. Hosmer-Lemeshow test revealed a high model fitting effect (χ2=3.245, P=0.662). The AUC of the model was 0.992, and the sensitivity and specificity were 0.935 and 0.991 if the cutoff was 1.@*Conclusion@#A model for early identification of SF and SFTS that includes four variables of rash, C-reactive protein, white blood cell and platelet has been created, which has a high accuracy.
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@#Abstract: Objective This article aims to present a rare case of severe fever with thrombocytopenia syndrome (SFTS) complicated by with bacteraemia caused by Campylobacter jejuni, and to discuss the pathogenic characteristics, culture methods, clinical features and treatment points of Campylobacter jejuni and the patient's outcome, with a view to raising clinical awareness of blood culture and providing experience for the treatment of this disease. Methods The clinical data of a case with SFTS complicated by bacteremia caused by Campylobacter jejuni admitted to Weihai Municipal Hospital were collected and the diagnostic process of the pathogenic bacteria as well as the treatment plan were retrospectively analysed. Results The patient was a female who had been bitten by a tick bite half a month ago and presented to the hospital on 30th August with a fever, vague pain in the peribulbar abdomen and diarrhea for 5 days. Laboratory tests showed leukopenia and thrombocytopenia, and nucleic acid detection for SFTS was positive, resulting in a diagnosis of SFTS. After a week of antiviral treatment with ribavirin and symptomatic treatment, the patient suddenly experienced high fever at night, with a temperature reaching 39.5 °C. Blood cultures were immediately taken from both sides of the double bottle. Bilateral anaerobic bottles were tested for positive after 53.06 hours, and Gram-negative Campylobacter was cultured anaerobically in a transfer blood plate and further identified as Campylobacter jejuni using mass spectrometry MALDI-TOF MS. Vancomycin was stopped clinically on the basis of bacterial pathogenesis and meropenem was used for anti-infection and symptomatic treatment. During the treatment, blood culture and nucleic acid detection for SFTS turned negative, and the patient's symptoms improved. After normal results were achieved in the follow-up testing, the patient was discharged. Conclusions This case serves as a reminder that Campylobacter jejuni not only causes intestinal infections, but can also lead to extra-intestinal infections in immunocompromised individuals. Clinical and laboratory personnel should increase their recognition of Campylobacter jejuni, prioritize blood culture methods, and utilize a multidisciplinary approach in diagnosis and treatment.
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@#Abstract: Objective To investigate the differences in epidemiological and clinical characteristics of patients with spotted fever (SF) and severe fever with thrombocytopenia syndrome (SFTS). Methods A total of 86 patients with SF and 113 patients with SFTS who were laboratory-confirmed in the second-level and above hospitals in Lu'an City from January 2017 to January 2022 were selected. The basic data, epidemiological history, clinical data and laboratory test results of the two diseases were retrospectively analyzed for comparison. Results The proportion of male in SF group was 32.56% (28/86), and the proportion of male in SFTS group was 53.98% (61/113), the difference was statistically significant (χ2=9.067, P<0.01). The proportions of abdominal pain and diarrhea in the SF group were (3.49%, 3/83) and (21.24%, 24/113), which were significantly lower than corresponding (6.98%, 6/86) and (46.90%, 53/113) in the SFTS group (χ2=13.121, 37.322, P<0.01). The incidences of rash and eschar in SF group were 95.35% (82/86) and 20.93% (18/86), which were significantly higher than corresponding 1.77% (2/113) and 0.88% (1/113) in SFTS group (χ2=175.311, 22.721, P<0.01). The levels of leukocytes, platelets and C-reactive protein in the SF group were significantly higher than those in the SFTS group, and the levels of transaminase, lactate dehydrogenase and D-dimer were significantly lower than those in the SFTS group, and the differences were statistically significant (all P<0.05). Conclusions The rash and inflammatory reaction are more obvious in SF patients, while the liver function, myocardial function and coagulation function are significantly impaired in SFTS patients.
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@#Abstract: Objective To investigate the composition and diversity of midgut microbial community of Haemaphysalis longicornis infected with severe fever with thrombocytopenia syndrome virus (SFTSV)． Methods The midgut DNA of three group Haemaphysalis longicornis infected with SFTSV was extracted, and the 16S rDNA gene of the sample was sequenced by HiSeq platform. The composition and diversity of endosymbiotic microbial community were clarified by OTU cluster analysis and alpha diversity analysis. Results The midgut microbial clusters of the three groups infected with SFTSV were 143, 113, 163 OTUs respectively; the sparsity curve and abundance grade curve showed that the data had sufficient sequencing depth, and the midgut of Haemaphysalis longicornis infected with SFTSV was rich in microbial composition, but the species distribution was uneven. The analysis of microbial community composition showed that Proteobacteria, Firmicutes and Actinobacteria were the main dominant bacteria at the phyla level. At the class level, Gammaproteobacteria, Bacilli, Betaproteobacteria and Actinomycetia were the main dominant bacteria. At the order level, Legionellales, Bacillales, Burkholderiales and Actinomycetales were the main dominant orders. At the family level, Coxiellaceae, Bacillaceae, Moraxellaceae and Rhodococcaceae were the main dominant families. At the genus level, the relative abundance of Coxiella was the highest, followed by Aeribaillus and Azonexus. Alpha diversity analysis showed that the average Shannon index was 139.67, the average Simpson index was 0.48, the average Chao index was 145.06, and the average ACE index was 147.11. Conclusions The species diversity of intestinal microorganisms in Haemaphysalis longicornis infected with SFTSV is rich. The results provide a basis for further exploring the interaction between intestinal microbes of Haemaphysalis longicornis and SFTSV and developing new ideas for the prevention and control of ticks and tick-borne diseases.
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Objective:To report the first case of sever fever with thrombocytopenia syndrome caused by severe fever with thrombocytopenia syndrome virus (SFTSV) in Puyang city, and to study the epidemiological and molecular characteristics of S, M, L fragments of the SFTSV isolate.Methods:The epidemiological characteristics of this case was analyzed with epidemiological methods. SFTSV was isolated from the patient′s serum sample. Nucleic acid of SFTSV was extracted and detected by fluorescent RT-PCR. A multiplex PCR method was constructed to amplify the nucleic acid sequence of the virus. whole-genome sequencing was performed on the next-generation sequencing platform. MEGA11 and DNAStar was used for homology analysis and a phylogenetic tree was constructed.Results:Epidemiological investigation showed that the patient and his close contacts had no history of travel or tick bite within 14 d, but had a history of fieldwork. The patient′s serum sample was positive for SFTSV nucleic acid. Genetic analysis showed that the S, M, L gene fragments of the first SFTSV isolate in Puyang belonged to genotype E. This isolate shared 94.8%-99.6%, 94.0%-99.8% and 95.7%-99.7% nucleotide sequence homology with the representative strains acquired from GeneBank in S, M, L gene fragments, respectively.Conclusions:This case was the first case of SFTSV-caused severe fever with thrombocytopenia syndrome in Puyang. The SFTSV isolate shared a close homology with domestic isolates, but its genotype was significantly different from the SFTSV strains isolated in Henan in recent years, indicating that it might an imported case from other places in Henan Province or Hubei Province. Disease monitoring and professional training for medical personnel should be strengthened and more attention should be paid to the evolution and mutation of SFTSV.
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ABSTRACT Introduction: Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly emerged virus that poses a great threat to human health because of high fatality rate. Methods: To develop sensitive and specific sero-diagnostic systems for SFTSV infections, monoclonal antibodies (MAbs) against recombinant SFTSV nucleocapsid (rSFTSV-N) protein were developed by immunizing BALB/C mice with rSFTSV-N protein and fusing the spleen cells with SP2/0 myeloma cells. Three hybridoma cell lines secreting MAbs against rSFTSV-N were obtained. MAb based IgG sandwich enzyme linked immunosorbent assay (ELISA) and IgM capture ELISA systems were established by using the newly developed MAbs. One hundred fifteen clinical suspected SFTS patients serum samples were used to evaluate the newly established systems by comparing with the total antibody detecting sandwich ELISA system and indirect ELISA systems. Results: The MAbs based sandwich IgG ELISA was perfectly matched with that of the total antibody sandwich ELISA and the indirect IgG ELISA. IgM capture ELISA results perfectly matched with that of the total antibody sandwich ELISA while detecting eight additional positive samples missed by the indirect IgM ELISA. Conclusions: The MAbs against rSFTSV-N protein offer new tools for SFTSV studies and our newly developed MAb-based IgG and IgM capture ELISA systems would offer safe and useful tools for diagnosis of SFTS virus infections and epidemiological investigations.
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ObjectiveTo understand the epidemiological characteristics of severe fever with thrombocytopenia syndrome （SFTS）， and the association with seasonal fluctuation in tick density， so as to provide scientific evidence for better control and prevention measures. MethodsDescriptive epidemiological methods were used to analyze the SFTS epidemic situation in Chongyang County from 2013 to 2021. The cloth flag method was used to investigate the seasonal fluctuation in tick density and determine the association with the SFTS. ResultsA total of 71 SFTS cases were reported in Chongyang County from 2013 to 2021 including 8 deaths， with the annual morbidity rate of 1.88/10-5. The majority were mainly from June to August， accounting for 61.97% of the total reported cases. The cases were geographically distributed in 41 administrative villages and 4 urban areas in 11 towns. The highest incidence was in Lukou town （n=26） and Baini town （n=12）， which accounted for 53.52% of the total reported cases. Furthermore， the cases were mainly 50‒69 years old， accounting for 57.75% of the total reported cases. The ratio of male to female was 1.84∶1， and most were farmers. Blood samples during acute phase in 41 cases were collected for examination of SFTS virus， of which 25 cases tested positive （60.98%）. There was a positive association between tick density and the number of reported SFTS cases （r=0.78， P=0.003）. ConclusionSeasonal density of free adult ticks and nymphs is associated with the number of reported SFTS cases in Chongyang County.
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Objective:To establish a sequencing method for the genome of severe fever with thrombocytopenia syndrome virus (SFTSV) based on next-generation sequencing (NGS).Methods:SFTSV RNA was extracted from serum samples of patients with severe fever with thrombocytopenia syndrome. SFTSV-specific primers were designed using Primer 5.0 software. A multiplex PCR method was constructed and used to amplify the nucleotide sequence of SFTSV. Whole-genome sequencing was performed on the NGS platform.Results:The whole genes of SFTSV isolates in 28 serum samples were amplified by the multiplex PCR with a coverage over 94%. Sequencing and phylogenetic analysis of those strains revealed that the predominant strains ( n=20) belonged to genotype A, followed by genotypes B ( n=4) and E ( n=3). Conclusions:A high-throughput sequencing method for SFTSV based on multiplex PCR was established in this study. This method was characterized by high specificity and good quality and could improve the sequencing efficiency.
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Since 2010, the incidence of severe fever with thrombocytopenia syndrome (SFTS) has been increased. Owing the progress in diagnosis and treatment, the overall mortality of SFTS in China has decreased, while the mortality in critical SFTS patients is still high. In order to provide guidance and working procedures for clinicians to diagnose and treat critical SFTS, the National Medical Center for Major Public Health Events invited experts to discuss and formulate this consensus based on their experience and up-to-date knowledge on SFTS.
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ObjectiveTo understand the epidemiological characteristics of severe fever with thrombocytopenia syndrome （SFTS） in Yiyuan County， and provide scientific evidence for prevention and control strategies. MethodsDescriptive epidemiological methods were used to analyze the incidence of SFTS in Yiyuan County during 2014—2019. ResultsA total of 130 SFTS cases were documented in Yiyuan County during 2014—2019， of which four were death cases. The annual incidence was determined to be 3.79/105 and the mortality was 3.08%， showing an upward trend in the incidence （ χ T r e n d 2 =9.06， P=0.003）. Majority of the cases occurred between May and August （88.46%）， were more than 50 years old （81.54%）， and farmers （94.62%）. The median duration of time from onset to diagnosis was five days. ConclusionSFTS was widely distributed in Yiyuan County with seasonal pattern. Middle aged and elderly farmers were mainly susceptible. It warrants strengthening prevention and control of SFTS and health education in elderly.
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ObjectiveTo understand the epidemiological characteristics of severe fever with thrombocytopenia syndrome （SFTS） in Yiyuan County， and provide scientific evidence for prevention and control strategies. MethodsDescriptive epidemiological methods were used to analyze the incidence of SFTS in Yiyuan County during 2014—2019. ResultsA total of 130 SFTS cases were documented in Yiyuan County during 2014—2019， of which four were death cases. The annual incidence was determined to be 3.79/105 and the mortality was 3.08%， showing an upward trend in the incidence （ χ T r e n d 2 =9.06， P=0.003）. Majority of the cases occurred between May and August （88.46%）， were more than 50 years old （81.54%）， and farmers （94.62%）. The median duration of time from onset to diagnosis was five days. ConclusionSFTS was widely distributed in Yiyuan County with seasonal pattern. Middle aged and elderly farmers were mainly susceptible. It warrants strengthening prevention and control of SFTS and health education in elderly.
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BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality in East Asia. This study aimed to develop, for primary care providers, a prediction score using initial symptoms and basic laboratory blood tests to differentiate between SFTS and other endemic zoonoses in Korea.METHODS: Patients aged ≥ 18 years diagnosed with endemic zoonoses during a 3-year period (between January 2015 and December 2017) were retrospectively enrolled from 4 tertiary university hospitals. A prediction score was built based on multivariate logistic regression analyses.RESULTS: Of 84 patients, 35 with SFTS and 49 with other endemic zoonoses were enrolled. In multivariate logistic regression analysis, independent predictors of SFTS included neurologic symptoms (odds ratio [OR], 12.915; 95% confidence interval [CI], 2.173–76.747), diarrhea (OR, 10.306; 95% CI, 1.588–66.895), leukopenia (< 4,000/mm3) (OR, 19.400; 95% CI, 3.290–114.408), and normal C-reactive protein (< 0.5 mg/dL) (OR, 24.739; 95% CI, 1.812–337.742). We set up a prediction score by assigning one point to each of these four predictors. A score of ≥ 2 had 82.9% sensitivity (95% CI, 71.7%–87.5%) and 95.9% specificity (95% CI, 88.0%–99.2%). The area under the curve of the clinical prediction score was 0.950 (95% CI, 0.903–0.997).CONCLUSION: This study finding suggests a simple and useful scoring system to predict SFTS in patients with endemic zoonoses. We expect this strategic approach to facilitate early differentiation of SFTS from other endemic zoonoses, especially by primary care providers, and to improve the clinical outcomes.
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Objective To study the severe fever with thrombocytopenia syndrome bunyavirus (SFTSV)-related vector biological monitoring in Daishan County, Zhoushan Island of Zhejiang Province, and to explore the prevention and control strategies. Methods The monitoring was conducted as follows:squirrel-cage method was used for rodents from 2012 to 2014;the Buqi method for free tick density in villages and towns with confirmed cases in Daishan County from 2015 to 2018;and body surface comb method for parasitic ticks.RT-PCR method was used to detect SFTSV in ticks and rat specimens.Epidemiological survey followed by extensive health education was conducted from 2011 to 2015.Comprehensive health prevention and control measures, such as precision health education and chemical elimination of vectors were taken from 2016 to 2018. Results A total of 327 rodents were captured, including 172 stinking shrews, accounting for 52.60%, and 92 yellow mice, accounting for 28.13%.The main species of ticks was Haematopsus longicortus, accounting for 94.20%.Among them, there were 135 parasitic ticks in three species:Haematopsus longicorum, S.scallopus, and T.nigra. There were 382 free ticks in 6 species, including Haematopsichum longicorum, Sickle fan tick, Hemophilus fannicus, Ixodes ovaliformis, Ixodes granulata, and Ixodes sinensis.From May to October in 2015, the density of field ticks was ≥50 per cloth flag.From May 2016 to 2018, after the elimination application of chemical agents for elimination, the density of ticks was ≤50 per cloth flag.All ticks and rodent specimens tested by RT-PCR were negative for SFTSV.Since precision education in 2016, the awareness rate of SFTS in rural areas has increased from 32.05% to 83.33%.Approximately 70 early warning notices for the epidemic situation were issued in advance.Since 2017, the number of SFTS has been declining year by year, and only 8 cases occurred in 2018. Conclusion In the field environment, chlorothalonil is the dominant mouse species and long horn blood ticks are the dominant ticks.The government leadership, cooperation among departments, technical service provided by professional organization, health education, reduction of tick density in residential environment, timely risk early warning notice, and other comprehensive prevention and control hand strategy all contribute to the achieved result of prevention and control.
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Objective@#To analyze three events of severe fever with thrombocytopenia syndrome （SFTS） among family members by exposure risk matrix, so as to provide reference for SFTS prevention and control.@*Methods @#The field investigation and clinical data of seven confirmed cases with SFTS reported in Linhai from 2014 to 2016 were collected. Exposure risk matrix was used to list the risk of exposure two weeks before the onset, such as the environment, duration of activity and protection, and evaluate the possible routes of transmission. @*Results@#The first event involved three sisters. Two of them had plucked tea together on a hill, and the possibility of infection through tick bites were 60% and 75%, respectively. Another sister was more likely to be infected by ticks in her residence after visiting her sister （no physical contact with the sick sister）, with a possibility of 74%. The second event involved two cases （mother and son）. They were more likely to be infected by ticks in the current residential area, and the possibility were 100% and 80%, respectively. The third event involved two cases （husband and wife）. The wife had 60% possibility of being infected by the ticks on the hill she picked arbutus, and 40% by the ticks in her residence. The husband was most likely to be infected through contacting with body fluids or blood of his wife （44%）, then through the ticks on the hill he picked arbutus （33%）. @*Conclusion@#Among seven cases with SFTS reported in Linhai from 2014 to 2016, six cases have more than 50% possibility of being infected by tick bites; one case has higher possibility of being infected by contacting with body fluids or blood of a patient, but tick bites could not be ruled out.
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Objective@#To study the epidemiology and the etiology characteristics of first imported severe fever with thrombocytopenia syndrome (SFTS) case reported in Shenzhen city in 2017.@*Methods@#Data on descriptive epidemiology was collected to study the characteristics to the epidemic. The serum sample collected from the suspect SFTS case was detected for IgM, IgG by ELISA and severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) nucleic acid by real-time RT-PCR. The samples were further inoculated in Vero cell for virus isolation. The partial fragements of L and S gene were amplified by RT-PCR and sequenced to construct homology comparison and phylogenetic tree with the strains isolated from other areas.@*Results@#The case was laboratory confirmed imported SFTS case in Shenzhen on May 2017. IgM antibody and RNA of SFTSV were detected in the serum sample. SFTSV named GDSZ01/2017/China was successfully isolated from the serum sample. The high nucleotide homology of L and S genome segments were found at 95.3%-98.2% and 93.8%-98.8% with other representative strains from the popular provinces, respectively. The phylogenetic tree indicated that GDSZ01 was most close to SDTA_3 strain, next to strains in Hubei procince. The isolated SFTSV belonged to genotype C3 with HB29, HB154.@*Conclusions@#The virological, serological and molecular features showed that the imported case of SFTS in 2017 was caused by SFTSV C3 genotype.
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Objective@#To analyze the prevalence of severe fever with thrombocytopenia syndrome virus(SFTSV)infection in Zhoushan island of Zhejiang province and the duration of serum positive IgG antibody in patients infected with SFTSV.@*Methods@#One thousand one hundred and twenty-two healthy people from Zhoushan island of Zhejiang province were recruited for cross-sectional study in August 2019, including 641 from non-epidemic areas and 481 from epidemic areas. The serum SFTSV-IgG antibody was detected by enzyme-linked immunosorbent assay (ELISA), and the positive rates of SFTSV-IgG antibody were compared between people from the epidemic areas and non epidemic areas. Meanwhile, the antibody titer of SFTSV-IgG in 19 patients confirmed between July 2011 and June 2018 was detected by indirect ELISA. SPSS 17.0 software was used to analyze data.@*Results@#The positive rate of SFTSV-IgG antibody was 1.5% (7/481) in the epidemic area, which was higher than that in the non-epidemic area (0/641) (χ2=7.187, P<0.01). The positive rates of SFTSV-IgG antibody in 2019 were lower than those in the epidemic area (11.7%) and non-epidemic area (2.5%) in 2013 (χ2=22.556 and 10.352, both P<0.01). The serum SFTSV-IgG antibody of 18 patients with previous infection was still positive, and the longest one lasted for 8 years.@*Conclusions@#There is a SFTSV latent infection in population from epidemic area of Zhoushan island. The SFTSV-IgG antibody can last for a long time in patients with SFTS and it may have certain protective effect.
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Objective@#To investigate the clinical value of blood routine tests (RT) and coagulation function in differential diagnosis of mild and severe patients infected with bunyamwera virus.@*Methods@#Twenty-five mild patients and 25 severe patients infected with bunyamwera virus were selected and their blood RT and coagulation function tests were performed.@*Results@#The earliest prothrombin time (PT-early) and activated partial thromboplastin time(APTT-early) were significantly lower than those of severe patients(t=-2.43, P<0.05; t=-2.53, P<0.05). The lowest values of white blood cells (WBC-low) of mild patients were significantly higher than those of severe patients (t=5.66, P<0.01). The highest value of D-dimer (DD-high) of mild patients were significantly lower than that of severe patients (z=1.35, P<0.05). When mild patients values were set as outcome variable, AUC of APTT-early was the highest (AUC=0.713, P<0.05). When values of severe patients were set as outcome variable, AUC of DD-high was the highest (AUC=0.874, P<0.01).@*Conclusions@#APTT-early and DD-high are suitable for differential diagnosis of mild and severe patients infected with bunyamwera virus.
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Objective@#The objective of this study was to establish a next generation sequencing (NGS) method for severe fever with thrombocytopenia syndrome virus(SFTS).@*Methods@#SFTS virus RNA was extracted from the patient serum inoculated and isolated by Vero cells. Two methods of random primer sequencing and oligo(dT) beads selection sequencing were used for library construction. The libraries were built based on the best amplification and purification conditions. Whole genome sequencing was performed on NGS platform.@*Results@#There were significant differences in data of 3 virus between the two methods.The sample was sequenced by random primer sequencing showed low coverage and depth. However, three samples were sequenced by oligo(dT) beads selection showed coverage was over 99% and depth was over 900.The alignment rate of database from NCBI was more than 90%. The initial detection quality of this method was 300ng RNA.@*Conclusions@#In this study, we used the method of oligo(dT) beads selection to build libraries, and established a SFTS virus genome detection based on next generation sequencing.
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Objective The secretion level of inflammatory factors is closely related to the severity of severe fever with thrombocytopenia syndrome (SFTS). This paper mainly discussed the effect of SFTSV infection on the expression of Toll-like receptor 2（TLR2） and inflammatory factors in macrophages in mice. Methods The expression of TLR2 andTNF-α, IFN-β, IL-6, IL-10 and other inflammatory factors were observed at 0, 6, 12, 24, 36, 48, 72 hours after SFTSV infected mice macrophages by qPCR, Western blot and ELISA. Results QPCR results showed that the mRNA levels of TNF-α at 0, 6, 12, 24, 36, 48, 72 h were 0.85±0.14, 15.23±2.45, 28.67±1.59, 94.52±7.05, 55.86±1.82, 23.55±6.15, 9.76±2.03, and the mRNA levels of IFN-β were 0.93±0.21, 1.55±0.33, 14.51±1.98, 55.16±3.64, 26.57±1.49, 9.22±0.51, 5.18±1.06. QPCR results showed that the mRNA levels of TNF-α and IFN-β produced by abdominal macrophages in the infected mice showed a trend of first increasing (the highest at the 24 hour) and then decreasing, and the difference of TNF-α and IFN-β mRNA levels at other time points was statistically significant compared with that at the 0 hour (P<0.05). However, IL-6 and IL-10 mRNA levels continued to increase, and the difference at other time points was statistically significant (P<0.05). ELISA results showed that the expression of four inflammatory factors showed a trend of gradual increase: TNF-α 0 and 72 h were (38.31±4.25, 140.41±23.45) pg/mL; IFN-β 0th and 72th were (17.56±0.66, 1084.93±111.42) pg/mL; IL-6 protein 0 and 72 h were (113.30±0.07, 2302.32±134.09) pg/mL; IL-10 protein 0 and 72 h were (515.00±21.21, 2590.40±226.19) pg/mL, respectively, with significant increases at the 24, 36, 48 and 72 hours compared with that at the 0 hour (P<0.05). The expression of TLR2 mRNA generated by mouse peritoneal macrophages showed a trend of first increasing and then decreasing, and increased to the highest level at 24 h, and the difference between each time point and 0 h was statistically significant (P<0.01). The expression of TLR2 gradually increased after infection with time extension. Conclusion SFTSV infection can up-regulate the expression of TLR2 in macrophages, thereby leading to the increased secretion of the cytokines.
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Objective To analyze the differences of clinical manifestations and organ damage between patients with severe fever with thrombocytopenia syndrome(SFTS)and patients with tsutsugamushi disease,and to investigate the prognostic factors of SFTS.Methods The research was performed on 49 patients with SFTS and 16 patients with tsutsugamushi disease who visited the First Affiliated Hospital of Anhui Medical University from October 2014 to June 2017.The general information of patients including region,age,gender and clinical manifestations were evaluated.Blood routine,liver and kidney function,myocardial enzyme levels,lipase,amylase,electrolytes,C-reactive protein,procalcitonin,prothrombin time(PT)and activated partial thromboplastin time(APTT)were continuously monitored during the course of disease.T test was used for continuous variables of normal distribution,and non-parametric test was used for variables of non-normal distribution.Chi-square test was used for categorical variables.Results The mean age of SFTS patients was 62.1±15.5(ranging from 17 to 87 years)and the mean age of tsutsugamushi patients was 56.1±9.2(ranging from 47 to 73 years).There was no significant difference between the two groups(t=1.47,P=0.147).There were 25 males(51%)in SFTS patients and 8 males(50%)in tsutsugamushi disease patients.There was no significant difference between the two groups(x2=0.005,P=0.943).The incidences of headache,vomiting,superficial lymphadenectasis,disturbance of consciousness,proteinuria,hematuria,pulmonary infection,multiple organ dysfunction and acute pancreatitis in SFTS patients were all significantly higher than those in tsutsugamushi disease patients(x2=8.82,4.38,8.71,11.17,7.88,5.56,4.35,9.43,and 8.13,respectively,P <0.05 or 0.01).The counts of leukocytes(Z=2.73),neutrophils(Z=2.46),lymphocytes(Z=3.15),platelets(Z=4.25),albumin(Z=2.65)and sodium ion(t=2.10)in SFTS patients were all significantly lower than those in patients with tsutsugamushi disease(P <0.05 or 0.01).The levels of aspartate aminotransferase(Z=2.94),lactate dehydrogenase(Z=3.42),creatine kinase(CK)(Z=2.88),amylase(Z=2.11),lipase(Z=2.82),creatinine(Z=2.07)and urea nitrogen(Z=2.50)in fatal SFTS patients were all significantly higher than those in patients with tsutsugamushi disease(P <0.05 or 0.01).Among 49 SFTS patients,16 patients died and 33 patients recovered finally.The age(t=3.33),platelet count(Z=2.55),alanine aminotransferase(ALT)(Z=2.10),aspartate aminotransferase(AST)(Z=2.22),lactate dehydrogenase(Z=2.26),CK(Z=3.50),CK-MB(Z=3.10),creatinine(Z=2.17),urea nitrogen(Z=2.36),and sodium(t=2.65)between the two subgroups had significant differences(P <0.05 or 0.01).Conclusions SFTS is more severe and has high mortality,while tsutsugamushi disease has a better prognosis.Early differential diagnosis and early rational treatment are important to reduce the mortality of patients with SFTS.