Epidemiological and clinical characteristics of severe fever with thrombocytopenia syndrome (SFTS) in China: an integrated data analysis

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was caused by a novel bunyavirus, SFTSV. The study aimed to disclose the epidemiological and clinical characteristics of SFTSV infection in China so far. An integrated clinical database comprising 1920 SFTS patients was constructed by combining first-hand clinical information collected from SFTS sentinel hospitals (n = 1159) and extracted data (n = 761) from published literature. The considered variables comprised clinical manifestations, routine laboratory tests of acute infection, hospitalization duration and disease outcome. SFTSV-IgG data from 19 119 healthy subjects were extracted from the published papers. The key clinical variables, case-fatality rate (CFR) and seroprevalence were estimated by meta-analysis. The most commonly seen clinical manifestations of SFTSV infection were fever, anorexia, myalgia, chill and lymphadenopathy. The major laboratory findings were elevated lactate dehydrogenase, aminotransferase, followed by thrombocytopenia, lymphocytopenia, elevated alanine transaminase and creatine kinase. A CFR of 12·2% was estimated, significantly higher than that obtained from national reporting data, but showing no geographical difference. In our paper, the mortality rate was about 1·9 parts per million. Older age and longer delay to hospitalization were significantly associated with fatal outcome. A pooled seroprevalence of 3·0% was obtained, which increased with age, while comparable for gender. This study represents a clinical characterization on the largest group of SFTS patients up to now. A higher than expected CFR was obtained. A wider spectrum of clinical index was suggested to be used to identify SFTSV infection, while the useful predictor for fatal outcome was found to be restricted.

Severe Fever with Thrombocytopenia Syndrome in South Korea, 2013-2015

“…The overall CFR in our study was 32.6% which was compared with 12.2% reported recently in China [6]. Although the CFRs of consecutive three years has been decreasing, the CFRs may still be exaggerated.…”

“…The clinical manifestations of SFTS include fever, myalgia, vomiting, diarrhea, thrombocytopenia and leukopenia. In severe cases, multi-organ dysfunction may occur [5]; the case fatality ratio (CFR) has been reported to be 6.3–30% [6, 7]. …”

Score risk model for predicting severe fever with thrombocytopenia syndrome mortality

“…Though the fatality rate of SFTS in China has fallen from first reported 30% to present 12% owing to increased reporting, advances in diagnostic procedures and improved clinicians’ skills [5, 15, 16]. The risk factors for human infection with SFTSV were confirmed [15, 17] and national intervention programs were performed, including promoting public awareness, establishing sentinel hospitals and improving clinicians’ skills [2, 18–20]. Yet, the number of fatal cases increases annually in China.…”

“…The national surveillance data from 2010 to 2013 in China showed that the incidence of SFTS and its epidemic areas are growing, but the case fatality rate (CFR) has steadily declined [1]. The major clinical symptoms of SFTS include fever, thrombocytopenia, leukocytopenia, gastrointestinal symptoms and various other systemic manifestations including muscular symptoms, neurological disorders and coagulopathy [2, 3]. Neurological symptoms were strongly associated with death, even though they occurred during the first week after disease onset [4].…”

Presence of Antibodies against Severe Fever with Thrombocytopenia Syndrome Virus in Non-Endemic Areas of China

“…Since SFTSV is a leading public health issues, researches on its clinical characteristics, pathogenic mechanism, detection methods, and epidemiologic characteristics were conducted (6)(7)(8)(9)(10)(11)(12)(13). With regards to SFTSV epidemiology, seroprevalence of the healthy population in endemic areas has previously been investigated (14)(15)(16); however, in non-endemic areas, it is unclear, and more knowledge in this area is urgently needed.…”