Human Infection with Novel Spotted Fever Group Rickettsia Genotype, China, 2015.

Only 4 species of spotted fever group rickettsiae have been detected in humans in China. However, phylogenetic analysis of samples from 5 ill patients in China indicated infection with a novel spotted fever group Rickettsia, designated Rickettsia sp. XY99. Clinical signs resembled those of severe fever with thrombocytopenia syndrome.

Effect of tocilizumab plus corticosteroid on clinical outcome in patients hospitalized with severe fever with thrombocytopenia syndrome: A randomized clinical trial.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral hemorrhagic fever with high fatality rates. The blockade of pro-inflammatory cytokines presents a promising therapeutic strategy. METHODS: We conducted a randomized clinical trial at the 154th hospital, Xinyang, Henan Province. Eligible patients with severe SFTS disease were randomly assigned in a 1:2 ratio to receive either a single intravenous infusion of tocilizumab plus usual care; or usual care only. The primary outcome was the clinical status of death/survival at day 14, while secondary outcomes included improvement from baseline in liver and kidney damage and time required for hospital discharge. The efficacy of tocilizumab plus corticosteroid was compared to those receiving corticosteroid alone. The trial is registered with the Chinese Clinical Trial Registry website (ChiCTR2300076317). RESULTS: 63 eligible patients were assigned to the tocilizumab group and 126 to the control group. The addition of tocilizumab to usual care was associated with a reduced death rate (9.5%) compared to those received only usual care (23.0%), with an adjusted hazard ratio (aHR) of 0.37 (95% confidence interval [CI], 0.15 to 0.91, P = 0.029). Combination therapy of tocilizumab and corticosteroids was associated with a significantly reduced fatality (aHR, 0.21; 95% CI, 0.08 to 0.56; P = 0.002) compared to those receiving corticosteroids alone. CONCLUSIONS: A significant benefit of reducing fatality in severe SFTS patients was observed by using tocilizumab. A combined therapy of tocilizumab plus corticosteroids was recommended for the therapy of severe SFTS.

Case-fatality ratio and effectiveness of ribavirin therapy among hospitalized patients in china who had severe fever with thrombocytopenia syndrome.

BACKGROUND: The wide distribution and high case-fatality ratio of severe fever with thrombocytopenia syndrome (SFTS) have made it a significant public health problem. This study was designed to identify the predictors of fatal outcomes and to evaluate the effectiveness of antiviral therapy in treating SFTS virus (SFTSV)-infected patients. METHODS: A cross-sectional study was performed in a general hospital located in Xinyang city, whereas the largest number of patients with SFTS in China were treated during 2011-2012. The primary outcome for the treatment effect analysis was death. Other outcomes included sequential platelet levels and viral loads observed throughout the hospitalization and the interval between the initiation of ribavirin therapy and the return of the platelet count to a normal level. RESULTS: A total of 311 SFTSV-infected patients were included in the study. The most frequent clinical presentations were fever, weakness, myalgia, and gastrointestinal symptoms. Each patient had thrombocytopenia, leukopenia, or both. The case-fatality ratio (CFR) was 17.4% (95% confidence interval [CI], 13.1%-21.6%). Older age (odds ratio [OR], 1.061; 95% CI, 1.023-1.099; P = .001), decreased level of consciousness (OR, 5.397; 95% CI, 2.660-10.948; P < .001), and elevated levels of lactate dehydrogenase (>1200 U/L; OR, 2.620; 95% CI, 1.073-6.399; P = .035) and creatine kinase (>800 U/L; OR, 2.328; 95% CI, 1.129-4.800; P = .022) were significantly associated with fatal outcome. The CFRs were similar between patients who received ribavirin and those who did not. Ribavirin treatment showed no significant effect on either platelet counts or viral loads during hospitalization of patients with fatal or nonfatal cases. CONCLUSIONS: These findings can improve knowledge about the characteristics of patients with fatal outcomes and the use of antiviral drug for SFTS.

[The clinical characteristics of 169 cases of severe fever with thrombocytopenia syndrome].

OBJECTIVE: To analyze the clinical characteristics of severe fever with thrombocytopenia syndrome (SFTS) so as to improve the recognition of the emerging infectious disease. METHODS: A retrospective analysis was performed upon clinical manifestations, laboratory test results and prognostic features of 169 patients with SFTS admitted to the 154 Hospital, Chinese People's Liberation Army from October 2010 to May 2011. The patients were divided into moderate disease group and severe disease group according to the prognosis. The differences between two groups were compared to explore the prognostic indicator of severe type. RESULTS: All patients with SFTS inhabited in hilly ground with history of field work. The main clinical symptoms were severe fever (98.8%, 167/169), headache (52.1%, 88/169), muscle soreness (95.9%, 162/169), nausea (73.4%, 124/169), vomiting (67.5%, 114/169), coughing (61.5%, 104/169), etc. Superficial lymph node enlargement with haphalgesia was observed in 45.0% (76/169) patients. Petechia or ecchymosis was observed in 36.7% (62/169) patients. Critical patients were mainly aged > 60 years, associated with nerve and circulatory system syndrome, prominent hemoptysis, dyspnea, and nearly 73.3% (22/30) of severe thrombocytopenia. Serum levels of aspartate aminotransferase, creatinine and urea nitrogen were significantly higher in severe disease group than those in moderate disease group [235 (47 - 1750) U/L vs 88 (14 - 2000) U/L, 997(281 - 2601) U/L vs 399 (26 - 2633) U/L, 101 (62 - 291) µmol/L vs 70 (26 - 205) µmol/L, 7.0 (2.2 - 20.0) mmol/L vs 4.8 (1.4 - 18.5) mmol/L, all P values < 0.001]. CONCLUSION: Nerves system syndrome, transaminase and urea nitrogen are risk factors of prognosis of severe SFTS to whom deserves paying attention.

Human-to-human transmission of severe fever with thrombocytopenia syndrome virus through potential ocular exposure to infectious blood.

Severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease with high mortality, was first reported in 2009 in China and subsequently endemic to South Korea, Japan, Vietnam, and Myanmar. This disease is transmitted predominantly by tick bites and potentially human-to-human. Personal protective equipments (PPEs) have been recommended to prevent SFTS human-to-human transmission, whereas the specific use of PPEs and the effect on viral transmission have rarely been reported. This report identified a family cluster of six patients with SFTS virus (SFTSV) infection. All five secondary patients had been wearing gloves and masks when exposed to the blood of the index patient, but none of them wore goggles or face shields for eye protection. Ocular route was suggested as a highly possible mode for SFTSV transmission through epidemiological, serological, and phylogenetic analysis. Eye protection should be stressed for clinicians when exposed to blood or bloody secretions.

Clinical effect and antiviral mechanism of T-705 in treating severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne virus with high fatality and an expanding endemic. Currently, effective anti-SFTSV intervention remains unavailable. Favipiravir (T-705) was recently reported to show in vitro and in animal model antiviral efficacy against SFTSV. Here, we conducted a single-blind, randomized controlled trial to assess the efficacy and safety of T-705 in treating SFTS (Chinese Clinical Trial Registry website, number ChiCTR1900023350). From May to August 2018, laboratory-confirmed SFTS patients were recruited from a designated hospital and randomly assigned to receive oral T-705 in combination with supportive care or supportive care only. Fatal outcome occurred in 9.5% (7/74) of T-705 treated patients and 18.3% (13/71) of controls (odds ratio, 0.466, 95% CI, 0.174-1.247). Cox regression showed a significant reduction in case fatality rate (CFR) with an adjusted hazard ratio of 0.366 (95% CI, 0.142-0.944). Among the low-viral load subgroup (RT-PCR cycle threshold ≥26), T-705 treatment significantly reduced CFR from 11.5 to 1.6% (P = 0.029), while no between-arm difference was observed in the high-viral load subgroup (RT-PCR cycle threshold <26). The T-705-treated group showed shorter viral clearance, lower incidence of hemorrhagic signs, and faster recovery of laboratory abnormities compared with the controls. The in vitro and animal experiments demonstrated that the antiviral efficacies of T-705 were proportionally induced by SFTSV mutation rates, particularly from two transition mutation types. The mutation analyses on T-705-treated serum samples disclosed a partially consistent mutagenesis pattern as those of the in vitro or animal experiments in reducing the SFTSV viral loads, further supporting the anti-SFTSV effect of T-705, especially for the low-viral loads.

Clinical progression and predictors of death in patients with severe fever with thrombocytopenia syndrome in China.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease of which the clinical progression and factors related to death are still unclear. OBJECTIVE: To identify the clinical progression of SFTS and explore predictors of fatal outcome throughout the disease progress. STUDY DESIGN: A prospective study was performed in a general hospital located in Xinyang city during 2011-2013. Confirmed SFTS patients were recruited and laboratory parameters that were commonly evaluated in clinical practice were collected. The clinical progression was determined based on analysis of dynamic profiles and Friedman's test. At each clinical stage, the laboratory features that could be used to predict fatal outcome of SFTS patients were identified by stepwise discriminant analysis. RESULTS: Totally 257 survivors and 54 deceased SFTS patients were recruited and the data of 11 clinical and laboratory parameters along their entire disease course were consecutively collected. Three clinical stages (day 1-5 post onset, day 6-11 post onset and day 12 to hospital discharge) were determined based on distinct clinical parameters evaluations. Multivariate discriminant analysis at each clinical stage disclosed the indicators of the fatal outcome as decreased platelet counts at early stage, older age and increased AST level at middle stage, and decreased lymphocyte percentage and increased LDH level at late stage. CONCLUSIONS: The significant indicators at three clinical stages could be used to assist identifying the patients with high risk of death. This knowledge might help to perform supportive treatment and avoid fatality.