Serial analysis of cytokine and chemokine profiles and viral load in severe fever with thrombocytopenia syndrome: Case report and review of literature

Corticosteroid Therapy for Patients With Severe Fever With Thrombocytopenia Syndrome: A Nationwide Propensity Score-Matched Study in Japan

Background

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening infectious disease for which no effective treatment strategy has been established. Although corticosteroids (CSs) are widely administered to patients with SFTS, their efficacy remains uncertain. This study aimed to assess the impact of CS therapy on the in-hospital mortality of patients with SFTS.

Methods

In this nationwide observational study using the Japanese Diagnosis Procedure Combination database, patients hospitalized for SFTS from April 2013 to March 2021 were reviewed. We compared patients who were treated with CSs to those who were treated without them after propensity score matching to adjust for their background, disease severity, and combination therapy.

Results

We included 494 patients with SFTS, and 144 pairs of them were analyzed after propensity score matching. No significant difference in the 30-day mortality (19% vs 15%, P = .272) and the number of survival days (log-rank test, P = .392) was found between the CS treatment group and the non-CS treatment group. However, in subgroup analyses, the CS treatment group tended to have better survival among patients with impaired consciousness on admission and/or shock status within 7 days after admission.

Conclusions

CS therapy does not seem effective for all patients with SFTS; however, the impact might be altered by disease severity assessed by the consciousness level and shock status. A large-scale interventional study is required to determine its efficacy, especially for critically ill patients with SFTS.

Steroid pulse therapy for severe fever with thrombocytopenia syndrome patients may not improve prognosis: Retrospective analysis with overlap weighting using a national inpatient database

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by the SFTS virus. Effective treatment for SFTS has not been established, but steroid pulse therapy is often used. This study aimed to verify whether steroid pulse therapy for SFTS improves prognosis or not.

METHODS

Data of SFTS patients were obtained from the Japanese Diagnosis Procedure Combination Database from April 2013 to March 2021. Patients treated with steroid pulse therapy were compared with untreated patients, using overlap weighting and traditional multivariable regression analysis to evaluate the impact of steroid pulse therapy on prognosis.

RESULTS

412 SFTS patients were included in this study, and 66 (16%) underwent steroid pulse therapy within 3 days of admission and were allocated to the steroid pulse therapy group. After overlap weighting, patients in the steroid pulse therapy group had a significantly higher in-hospital mortality rate than patients in the control group (31.1% vs. 20.5%; difference: +10.6%; 95% confidence interval: +2.2% to +19.0%). There were no statistically significant differences in hospitalization cost and length of hospital stay between the two groups. The results of the sensitivity analysis using traditional multivariable regression were similar to those of the main analysis.

CONCLUSION

In the analysis of SFTS patients using the Japanese Diagnosis Procedure Combination inpatient data, steroid pulse therapy did not improve patient prognosis. The evidence does not support the universal use of steroid pulse therapy in patients with severe SFTS.

Liver Function Derangement in Patients with Severe Fever and Thrombocytopenia Syndrome

BACKGROUND AND AIMS

Patients with severe fever with thrombocytopenia syndrome (SFTS) commonly show liver function impairment. This study aimed to characterize the liver function indices in SFTS patients and investigate their association with mortality.

METHODS

Clinical information and laboratory results of 459 laboratory-confirmed SFTS patients, including 78 deceased and 381 surviving patients, were retrospectively analyzed. To explore the infectivity of SFTS caused by novel Bunyavirus (SFTSV) in hepatocytes, Huh7 human hepatoma cells were infected with various concentrations of SFTSV in vitro.

RESULTS

The proportion of SFTS patients developing liver injury during hospitalization was 73.2% (336/459); the hepatocellular injury was the predominant type. The median time to occurrence of liver injury from disease onset was 8 d. Liver injury in the deceased group occurred earlier than that in the surviving group. Alanine aminotransferase (ALT) level between 2-5 times upper limit of normal (ULN) at 4-6 d and between 5-15 ULN at 7-12 d of disease course were independent predictors of mortality. Alkaline phosphatase (ALP) >2 ULN at 7-9 d and elevated ALP at 10-12 days after disease onset were risk factors for death. ALT and aspartate transaminase (AST) levels were correlated with lymphocyte count and platelet-to-lymphocyte ratio (PLR). Total bilirubin (TB), ALT, AST levels showed positive correlation with viral load. In the in vitro experiment, SFTSV infected and replicated inside Huh7 cells.

CONCLUSIONS

Liver injury is common in SFTS patients. ALT and ALP were independent predictors of SFTS-related mortality. Frequent monitoring and evaluation of liver function indices are needed for SFTS patients.

The Endless Wars: Severe Fever With Thrombocytopenia Syndrome Virus, Host Immune and Genetic Factors

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging arboviral infectious disease with a high rate of lethality in susceptible humans and caused by severe fever with thrombocytopenia syndrome bunyavirus (SFTSV). Currently, neither vaccine nor specific antiviral drugs are available. In recent years, given the fact that both the number of SFTS cases and epidemic regions are increasing year by year, SFTS has become a public health problem. SFTSV can be internalized into host cells through the interaction between SFTSV glycoproteins and cell receptors and can activate the host immune system to trigger antiviral immune response. However, SFTSV has evolved multiple strategies to manipulate host factors to create an optimal environment for itself. Not to be discounted, host genetic factors may be operative also in the never-ending winning or losing wars. Therefore, the identifications of SFTSV, host immune and genetic factors, and their interactions are critical for understanding the pathogenic mechanisms of SFTSV infection. This review summarizes the updated pathogenesis of SFTS with regard to virus, host immune response, and host genetic factors to provide some novel perspectives of the prevention, treatment, as well as drug and vaccine developments.

Severe fever with thrombocytopenia syndrome, a viral hemorrhagic fever, endemic to Japan: achievements and directions to the future in the scientific and medical research

A novel infectious disease, severe fever with thrombocytopenia syndrome (SFTS) caused by a novel bunyavirus, with high case fatality rate (CFR) was reported by Chinese scientists in 2011. The causative virus, Dabie bandavirus [former SFTS virus (SFTSV)] belonged to the Bandavirus genus (former Phlebovirus genus) of Phenuiviridae family (former Bunyaviridae family). SFTS was also reported to be endemic to South Korea and Japan in 2013. Humans are infected with SFTSV through bites by ticks such as Haemophysalis longicornis and Amblyomma testidinarium. However, it was reported that domesticated animals such as cats and dogs were also infected with SFTSV probably through tick bites in living environment and show the SFTS-like symptoms with high CFR. Furthermore, there have been the cases of SFTS patients, who were infected with SFTSV through close contacts with sick cats or dogs. The high CFR in patients with SFTS is approximately 30% in Japan. SFTSV is circulating in nature between some species of ticks and animals. There are always the risks of SFTSV infection for human populations living in the endemic areas. Therefore, development of specific therapies and vaccines is an urgent need to reduce the number of fatal SFTS patients.

The Diagnosis of Severe Fever with Thrombocytopenia Syndrome Using Metagenomic Next-Generation Sequencing: Case Report and Literature Review

Background

Severe fever with thrombocytopenia syndrome (SFTS) is an infectious disease caused by a bunyaviridae virus. Its main clinical manifestation is fever with thrombocytopenia, which may be accompanied by other clinical symptoms. Here, we report a patient diagnosed with SFTS using metagenomic next‑generation sequencing (mNGS).

Case Presentation

A 56-year-old female patient was hospitalized with intermittent diarrhea and fever. She visited a local clinic for treatment, but instead of improving, the symptoms progressed to unconsciousness.

Diagnosis

Using mNGS, we isolated the bunyaviridae virus and several other pathogens from the patient’s blood samples to confirm the diagnosis.

Interventions

The patient was treated with symptomatic and supportive therapy, including intravenous human γ-globulin (20 g/d), platelet transfusion, platelet elevation (subcutaneous injection of recombinant human thrombopoietin, 15,000 IU), white blood cell elevation (subcutaneous injection of recombinant human granulocyte colony-stimulating factor, 200 ug, qd); and antibiotic (cefoperazone sodium and tazobactam sodium, 2 g, q8h), antiviral (ganciclovir, 250 mg, q12h), and antifungal therapy (voriconazole for injection, 0.2 g, q12h). After ten days of treatment, the patient’s condition gradually improved.

Conclusion

Compared to traditional detection methods, mNGS has many advantages. It can quickly identify the pathogen when the patient’s clinical manifestations are complex and difficult to diagnose, resulting in the formulation of an effective treatment.

Residual and Late Onset Symptoms Appeared in a Patient with Severe Fever with Thrombocytopenia in a Convalescence Stage

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by Dabie bandavirus (formerly SFTS virus, SFTSV). Its manifestations during the convalescent phase have not been widely described. We report a patient presenting with hematospermia, fatigue, myalgia, alopecia, insomnia, and depression during the recovery phase of SFTS. Since these symptoms are widely observed in patients with viral hemorrhagic fevers, there might be common mechanisms between SFTS and other viral hemorrhagic fevers. Close monitoring may be required during the recovery phase of SFTS.

Invasive pulmonary aspergillosis is a frequent complication in patients with severe fever with thrombocytopenia syndrome: A retrospective study

OBJECTIVES

Invasive pulmonary aspergillosis (IPA) usually occurs in immunocompromised hosts. It has recently been reported that patients with severe fever with thrombocytopenia syndrome (SFTS) can also develop IPA. The aim of this study was to determine the incidence of IPA in SFTS patients and to investigate the relevant clinical, imaging, and laboratory characteristics.

METHODS

A retrospective review was conducted of all patients with SFTS admitted to Nanjing Drum Tower Hospital, a tertiary hospital in Nanjing City, China, between January 2016 and December 2019. The patients were divided into two groups according to whether they had IPA: the IPA group and the non-IPA group. Data on clinical manifestations, laboratory findings, imaging characteristics, treatments, and outcomes were collected and analysed.

RESULTS

A total of 91 SFTS patients were included, of whom 29 (31.9%) developed IPA. In-hospital mortality (22.0%) was higher in the IPA group than in the non-IPA group. Univariate logistic regression showed that diabetes, cough, wheezing, amylase level, vasopressor use, encephalopathy, and intensive care unit transfer were risk factors for the development of IPA. Multivariate logistic regression analysis identified wheezing as an independent predictor of IPA in SFTS patients.

CONCLUSIONS

SFTS combined with IPA is associated with high morbidity and mortality. It is necessary to strengthen screening for fungal infections after admission in SFTS patients. However, whether early antifungal prophylaxis should be administered needs further investigation.