Objective To retrospectively analyze the clinical characteristics,prognosis and risk factors of novel bunyavirus infection.Methods The clinical data of 68 patients with novel bunyavirus infection confirmed by laboratory diagnosis at Wendeng Central Hospital of Weihai were retrospectively collected.Epidemiological characteristics,clinical manifestations,physical signs and laboratory results were analyzed.Results Twenty two patients (32.4 ％) had intimate contact with ermine (breeding ermine or ermine biting) ; 4 patients (5.9％) had been bitten by tick within 2 weeks,6 patients (7.4％) had intimate contact with patients with severe fever with thrombocytopenia syndrome (SFTS) ; and 25 patients (36.8 ％) had a history of fieldwork before the onset of the disease.Thirty-four patients (50.0 ％) were over 60 years old and 27 cases (39.7％) had underlying diseases.Initial symptoms in all patients were fever accompanied by loss of appetite,fatigue and other toxemic symptoms,followed by multi organ damage.Other clinical manifestations included nervous system damage (27 cases,39.7％),hemorrhage (4 cases,5.9％),rapid atrial fibrillation (10 cases,14.7％) and pneumonia (18 cases,26.5％).White blood cell count of 55 cases (80.9％) was less than or equal to 2.0 × 109/L,platelet count of 18 cases (26.5％) was less than or equal to 30 × 109/L.Abnormal hepatic function was found in 62 cases (91.2％); elevated myocardial enzymes was found in 68 cases (100.0％),prolonged activated partial thromboplastin time in 44 cases (64.7％),hyponatremia in 23 cases (33.8％),hypokalemia in 29 cases (42.6％),hypocalcemia in 36 cases (82.4％),hyperglycemia in 49 cases (72.1％).Serum nucleic acid quantitation of novel bunyavirus varied from 1.10 × 102 to 5.78 × 107 tissue culture infective dose (TCID)/ mL.Fifty five cases were cured,accounting for 80.9 ％,while 13 (19.1％) died eventually.Conclusions High risk factors of novel bunyavirus infection included intimate contact with ermine and infected patients,tick biting and fieldwork.Patients with elder age,underlying diseases,nervous system symptoms,hemorrhage,pneumonia,low platelet,high viral load and elevated myocardial enzymes may have poor progonsis.

Objective To explore the severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) existence time in the body,and the correlation between viral load and the severity and prognosis of disease.Methods The clinical data of 125 SFTS patients from May 2015 to October 2016 in Weihai Central Hospital in Shandong province were analyzed retrospectively.Patients were divided into low viral load group and high viral load group according to the SFTSV RNA levels.Neurological symptoms,bleeding tendency,the incidence of myocardial damage and severe pneumonia,laboratory biochemical index and prognosis of two groups were compared.SFTSV RNA of 46 cases were detected dynamically.Data with homogeneity of variance were tested by t test,and data with heterogeneity of variance was tested by rank sum test.Results Among the 125 cases,64 were male and 61 were female.The mean age was (59.0±3.6) years old.One hundred and one cases were cured,and 24 died.SFTSV RNA loads in low viral load group(81 cases) were (3.08± 1.01) copies/mL,and those in high viral load group (44 cases) were (5.69 ± 0.99) copies/mL,with statically significant difference (t =11.78,P＜0.05).By the dynamic detection of SFTSV RNA load in 46 patients,viral loads in most patients were gradually declined after 1 week of onset,and cleared after 23 days.The incidence of neurological symptoms,bleeding tendency,severe myocardial damage and pneumonia of two groups showed significant difference (x2 =92.987,38.711,75.889 and 54.680,respectively,all P＜0.05).The viral loads of patients who died varied from 1.06× 104 copies/mL to 5.78 × 107 copies/mL.White blood counts of two groups showed no significant difference (t =0.181,P＞ 0.05).The platelet counts of two groups had significant difference (t =2.869,P＜0.05).AST and γ-GT of two groups also had significant difference (P＜0.01 and 0.05,respectively).creatine kinase,creatine kinase isoenzyme,lactic dehydrogenase and hydroxybutyrate dehydrogenase of two groups all had significant difference (P＜0.01 or 0.05).Serum sodium,blood calcium and glucose of the two groups had significant difference (P＜0.01 or 0.05).activated partial thromboplastin time of the two groups showed significant difference as well (t=5.623,P＜0.01).Conclusions After the onset of SFTSV infection,the virus existence in the body may less than 4 weeks.Viral loads are closely associated with disease severity and prognosis.The higher the viral loads are,the heavier organ dysfunction could be and the higher mortality is.

Objective:To analyze the clinical characteristics and prognostic factors of severe fever with thrombocytopenia syndrome patients with high novel Bunya viral load.Methods:The clinical data of 141 patients with severe fever with thrombocytopenia syndrome whose viral load higher than 1×10 4 copies/mL were retrospectively collected from May 20, 2013 to October 30, 2019 in Weihai Central Hospital. All patients were diagnosed by laboratory tests. According to the prognosis, the cases were divided into survival group and death group. The clinical manifestations, laboratory test results and the influence of viral load on the conditions and the risk factors of prognosis were compared and analyzed. Chi-square test, rank sum test and logistic regression analysis were used for statistical analysis. Results:There were 76 patients in survival group, with a median age of 64 years. There were 65 patients in death group, with a median age of 71 years. There were significant differences in neurological injury, coma, hemorrhage, atrial fibrillation with rapid ventricular rate, and renal injury between the survival group and the death group ( χ2=16.45, 64.06, 11.25, 6.98 and 33.80, respectively, all P<0.01). There were significant differences in activated partial thromboplastin time (APTT), aspartate aminotransferase (AST), creatine kinase (CK), creatine kinase isoenzymes (CK-MB), lactic acid dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), creatinine, and platelet count between the survival group and the death group ( Z=6.33, 4.51, 2.93, 4.65, 5.00, 4.93, 5.36 and -4.34, respectively, all P<0.01). The RNA quantification of viral load in 138 cases ranged from 1.06×10 4 to 6.53×10 7 copies/mL, and the remaining three cases were higher than 1.00×10 8 copies/mL. The viral load of the two groups were 4.63(4.32, 5.22) and 5.29(4.92, 6.17) lg copies/mL, respectively ( Z=4.91, P<0.01). The mortalities of patients with viral loads of 1.00×10 4-<1.00×10 5 copies/mL, 1.00×10 5-<1.00×10 6 copies/mL and 1.00×10 6-<1.00×10 7 copies/mL were 29.33%(22/75), 51.28%(20/39), 80.95% (17/21), respectively. Six cases with viral loads higher than 1.00×10 7 copies/mL were dead. Logistic regression analysis showed that when age ≥60 years old, viral load >1.00×10 6 copies/mL, platelet count <30.00×10 9/L, LDH ≥5 000.00 U/L, APTT ≥84.00 s, the risk of death increased significantly. Conclusions:The occurrences of coma, hemorrhage, atrial fibrillation with rapid ventricular rate, renal injury suggest that the patients′ conditions are more serious and the risk of death is higher. Age, viral load, platelet count, LDH and APTT can be used as indicators to assess the risk of death.