Study on the relationship between viral load of severe fever with thrombocytopenia syndrome bunyavirus and patient's condition / 中华传染病杂志

ABSTRACT

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.