Clinical and epidemiological characteristics of laboratory confirmed cases of severe fever with thrombocytopenia syndrome infection in Shandong Province, China / 中国人兽共患病学报

ABSTRACT

We investigated the clinical and epidemiological characteristics of laboratory confirmed cases of severe fever with thrombocytopenia syndrome (SFTS) in Shandong Province,China.A descriptive epidemiological method combined with case investigation was used in this study.Cases information were collected by standard questionnaire and analyzed by Epidata3.1,SPSS 17.0 and ArcGIS10.0 software.Results showed that a total of 154 cases were analyzed and the case fatality rate was 7.1％.Epidemic peak was from May to October,the high incidence areas were located in the middle and east hilly areas of Shandong Province.The characteristic of SFTS cases were farmers (93.5％),and the age was over 40 years.Most of them were living in the hilly areas (85.7 ％),and had outdoor activities within the previous 2 weeks prior to fever onset (83.8 ％).The 16.8％ of them had tick bites history.Tick carrying rates of sheep,cattle,dogs and cats were 66.7％,40％,34.3％ and 12.5％,respectively.Directly contact with bloody secretion of SFTS death cases can be infected with the disease.Major symptoms include high fever (98.1％),anorexia (90.9 ％),fatigue (53.3％),thrombocytopenia (73.4 ％) and leukocytopenia (60.4 ％).The 35.7 ％ cases need to go through more than three referrals for treatment,the interval time between onset and diagnosis was 5 days(3-15),only hospitals above county level can make the correct diagnosis of the disease.Compared with survival patients,the death cases were elderly patients (t =2.03,P=0.044) and with bleeding performance (x2 =13.09,P＜0.01).In conclusion,SFTS is a severe disease with high mortality.Living hilly environment,doing agricultural labor,feeding animals,tick carrying rates of animals and direct contacting with bloody secretion of deaths maybe possible risk factors.To reduce morbidity and mortality of SFTS,measures should be carried out to propagandize the basic knowledge for SFTS prevention and control and to improve the medical treatment skills of doctors in the epidemic foci.