Severe Fever with Thrombocytopenia Syndrome Virus among Domesticated Animals, China

Guoyu Niu¹, Jiandong Li¹, Mifang Liang, Xiaolin Jiang, Mei Jiang, Haiying Yin, Zhidian Wang, Chuan Li, Quanfu Zhang, Cong Jin, Xianjun Wang, Shujun Ding, Zheng Xing, Shiwen Wang, Zhenqiang Bi, and Dexin Li

Author affiliations: Key Laboratory for Medical Virology–Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China (G. Niu, J. Li, M. Liang, C. Li, Q. Zhang, C. Jin, S. Wang, D. Li); Shandong Province Center for Disease Control and Prevention, Jinan, China (X. Jiang, X. Wang, S. Ding, Z. Bi); Yantai City Center for Disease Control and Prevention, Yantai, China (M. Jiang); Laizhou County Center for Disease Control and Prevention, Laizhou, China (H. Yin); Penglai County Center for Disease Control and Prevention, Penglai, China (Z. Wang); Nanjing University Medical School, Nanjing, China (Z. Xing)

Abstract

To investigate the infections of severe fever with thrombocytopenia syndrome virus (SFTSV) in domesticated animals, we sampled a total of 3,039 animals in 2 counties in Shandong Province, People’s Republic of China, from April to November 2011. SFTSV-specific antibodies were detected in 328 (69.5%) of 472 sheep, 509 (60.5%) of 842 cattle, 136 (37.9%) of 359 dogs, 26 (3.1%) of 839 pigs, and 250 (47.4%) of 527 chickens. SFTSV RNA was detected in all sampled animal species, but the prevalence was low, ranging from 1.7% to 5.3%. A cohort study in 38 sheep was conducted to determine when seroconversion to SFTSV occured. SFTSVs were isolated from sheep, cattle, and dogs and shared >95% sequence homology with human isolates from the same disease-endemic regions. These findings demonstrate that natural infections of SFTSV occur in several domesticated animal hosts in disease-endemic areas and that the virus has a wide host range.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly identified pathogenic member of the Phlebovirus species in the family Bunyaviridae, which in humans causes fever with thrombocytopenia syndrome (SFTS) (1). The common signs and symptoms of SFTS include high fever, gastrointestinal symptoms, thrombocytopenia, leukocytopenia, and multiorgan dysfunction with an average case-fatality rate of 10%–16%, according to the information system for disease control and prevention, Chinese Center for Disease Control and Prevention (China CDC). In severe SFTS cases, neural symptoms, hemorrhages, disseminated intravascular coagulation, and multiorgan failure can occur and may result in death (2).
SFTS has been reported in at least 13 provinces in the central, eastern, and northeastern regions of the People’s Republic of China. Most patients are farmers living in wooded, hilly, or mountainous areas, and the epidemic season is from March through November, with the peak incidence usually in June and July (1). Although Haemophysalis longicornis ticks have been implicated as vectors of SFTSV (1,3), and high seroprevalence to SFTSV has been reported in goats (4,5), the host range of the virus has not been determined. The role of domesticated animals in the circulation and transmission of SFTSV remains unclear.
To assess the prevalence of SFTSV infections in domesticated animals, combined cross-sectional and cohort studies were conducted in Laizhou and Penglai in Shandong Province. This study area was selected on the basis of its high incidence of human SFTS cases in 2010 (Technical Appendix Figure 1

[PDF - 376 KB - 3 pages]). We report the detection of viral RNA and antibodies in sheep, cattle, dogs, pigs, and chickens. Our findings may provide valuable insights for understanding SFTSV ecology and transmission among animals and from animals to humans.