Epidemiology and etiology of severe fever with thrombocytopenia syndrome in Liaoning

Objective To understand the epidemiological and etiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) in Liaoning province in 2012 and provide evidence for the clinical diagnosis and prevention of SFTS. Methods The analysis was conducted on the distributions, clinical symptoms and etiological characteristics of laboratory confirmed SFTS cases in Liaoning during this period. Results Among 185 suspected SFTS cases reported, 38 were laboratory confirmed, the case fatality rate was 5.26%. Epidemiological findings revealed that most SFTS cases were distributed in farmers living in wooded and hilly areas and working in fields. SFTS, which had obvious seasonality, mainly occurred during June-October. Some cases had an obvious tick bite histories. The clinical manifestations included fever (100%), headache (73.68%), nausea (65.76%), thrombocytopenia (97.37%) and leukocytopenia (78.95%). The sequence homologies of segment S and M were up to 95% in 9 Bunyamwera virus strains isolated. Conclusion SFTS is endemic in Liaoning province. It is important to improve the diagnosis and treatment of SFTS and strengthen its prevention and control.