Epidemiological Characteristics Of Severe Fever With Thrombocytopenia Syndrome In Zibo

Objective:Study:1.Severe fever with thrombocytopenia syndrome in Zibo,the relationship between sample collection time and virus detection;2.The difference between the results of real-time fluorescence PCR and enzyme linked immunosorbent assay for severe fever with thrombocytopenia syndrome;3.Analysis of the epidemiological features of severe fever with thrombocytopenia syndrome,so as to provide a basis for clinical diagnosis.Methods:Collect Zibo city in 2013-2017 severe fever with thrombocytopenia syndrome serum samples of 186 cases,to record the onset time and sampling time,using real-time fluorescent quantitative method to detect serum SFTS fever with thrombocytopenia syndrome,RNA virus nucleic acid detection rate and patients’serum respectively the relationship between the acquisition times.Randomly choose 85 cases of serum samples,using real-time fluorescent quantitative method to detect serum SFTS fever with thrombocytopenia syndrome virus RNA,enzyme linked immunosorbent method is used respectively to detect the serum IgM and IgG antibody,and the total using kappa value calculation,chi-square test,compare the effect of several detection methods.Collected in Zibo city severe fever with thrombocytopenia syndrome cases of epidemiological data(epidemiology,time distribution,region distribution,population distribution,time window,the main clinical manifestation,diagnosis and treatment,etc.),using descriptive epidemiological methods to analyze the distribution characteristics.Results:Were collected in 2013-2017,Zibo suspected case SFTS serum samples of 186 cases,all the real-time fluorescence quantitative method to detect the positive specimens of 71cases,with a positive rate of 38.17%,based on the number of days the patient is sick and SFTSV nucleic acid testing the statistics and analysis of positive relations,in patients with severe fever with thrombocytopenia syndrome incidence 0-19 days,all can be detected in serum SFTSV positive nucleic acids,in the 3 to 8 days in pursuance of the detection positive rate is higher,7 days is highest,64.53%.The positive rate of serum samples was gradually decreased in 8 days.In this study,85 cases of SFTS were randomly selected,and SFTSV RNA was detected by real-time fluorescence quantitative PCR method,at the same time,the antibody of SFTSV was detected by ELISA method.The Kappa value between PCR results and IgM results was 0.3435,indicating that the consistency of the two methods was satisfactory.The Kappa value between the total antibody and IgM results indicates that the two test methods were moderately consistent.A total of 186 cases of fever and thrombocytopenia syndrome were recorded in Zibo city from 2013 to 2017,and 71 cases were confirmed.Gender distribution:in 2013-2017,Zibo city reported 107 males and 79 females in SFTS.The gender ratio is about 1.35:1.The incidence rate of men and women was 2.28/100,000 and 1.68/100,000 respectively,and the difference were not statistically significant(c~2=0.10,P>0.05).Ethnic distribution:among all patients,184 were Han and 2 were Hui.Age distribution:age range from 13 to 83,with an average age of 60.125 years.Time distribution:36 cases in 2013,26 cases in 2014,33 cases in 2015,49 cases in 2016,and 42 cases in 2017.With the passage of time between 2013 and2017,the area of case discovery is expanding.Zibo SFTS were more obvious seasonal,1-3month report with low incidence,began to rise in April,May to August-achieving peak case report,and then gradually reduced.Occupational distribution:Zibo city reported SFTS cases(mainly farmers,accounting for 85.8%of the total reported cases,followed by workers,retired persons and students,accounting for 4.0%,2.3%and 1.7%respectively).Distribution:calculation of Zibo cumulative incidence from 2013 to 2017 the number of cases,Zibo have SFTS report cities gradually increase in 5 years,cases are mainly in the interpretation of the yiyuan area,boshan ship and linzi area also more cases.The main pathogenic sites of SFTS in the yiyuan area are Lu village,Nanlu Mountain and south hemp.Onset of hospitalization time window:all patients were treated within 48 hours of onset of disease.Among them,91cases were outpatient,86 were hospitalized,and 9 cases were treated with ICU.Patients were admitted with a temperature ranging from 37.7 to 42 degrees,with an average temperature of 39.02 degrees Celsius.Causes:the number of ticks in the residential area was 52.15%in one month,and29.03%were bitten by ticks.The history of outdoor activities accounted for 73.18%in the first two weeks.75.81 percent of the animals were raised in the home.Fever is the first symptom for 92.04%,all cases have fever,the highest temperature is 42 degrees Celsius,the lowest temperature is 37.5 degrees Celsius,and the average temperature is 39.02 degrees Celsius.Most of the cases have fatigue,chills,body aches nonspecific symptoms,such as loss of appetite,nausea,swollen lymph nodes,the signs and symptoms such as headache,diarrhea,vomiting occurrence rate is relatively high.The number of platelet counts in the laboratory was reduced by 81.69%,and the number of white blood cells in the peripheral blood was decreased by 77.46%,The PLT value was low in the initial stage of the disease.In this study,the cure rate was 20%,the hospital discharge was 61.22%,the hospital was not discharged as 10%,the family members asked the hospital to transfer about 5%,and the death rate was about 3.98%.Conclusion:Blood was collected from the patient on the 3rd to 8th day of onset,and the positive rate was high by real-time fluorescence quantitative PCR,indicating that serum samples collected during this period could improve the diagnosis rate of the disease.The early diagnosis of SFTS preferred real-time fluorescent PCR method,ELISA-IgM method can be used as an auxiliary means;Zibo area living in the hilly region of middle-aged and old farmers SFTS of high-risk groups,seasonal distribution is very significant,and the areas of different also show some differences in the disease.Ticks are closely related to the occurrence of diseases,attention should be paid to protection,thereby cutting the path of virus and disease.