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Background: Severe fever with thrombocytopenia syndrome virus (SFTSV), an emerging human pathogen naturally transmitted by ticks, has spread widely since it was first detected in 2010. Although SFTSV-specific antibodies have been detected in wild birds, these natural reservoir and amplifying hosts for the virus have not been well studied. Methodology/Principle findings: Here we report an experimental infection of spotted doves (Streptopelia chinensis) with two strains of SFTSV, JS2010-14, a Chinese lineage strain, and JS2014-16, a Japanese lineage strain, which represent the main viral genotypes currently circulating in East Asia. In these studies, we have determined that spotted doves are susceptible to SFTSV and the severity of the viremia is dose-dependent. When challenged with 107 and 105 PFU, all doves developed viremia which peaked 3–5 days post infection (dpi). Only a subset (25–62.5%) of the birds developed viremia when challenged at 103 PFU. Virulence of SFTSV in spotted doves was strain dependent. Infection with 107 PFU of strain JS2014-16 resulted in 12.5% mortality over 6.8 days and mean peak viremia titers of 106.9 PFU/mL in experimentally inoculated birds. All doves inoculated with 107 PFU of the JS2010-14 strain survived infection with relatively lower mean viremia titers (105.6 PFU/mL at peak) over 6.1 days. Conclusions/Significance: Our results suggest that spotted doves, one of the most abundant bird species in China, could be a competent amplifying host for SFTSV and play an important role in its ecology. Between the two SFTSV strains, the strain of the Japanese lineage caused mortality, higher viremia titers in infected birds over a longer time period than did the Chinese strain. Our observations shed light on the ecology of SFTSV, which could benefit the implementation of surveillance and control programs. [ABSTRACT FROM AUTHOR]

Background: A cluster of eleven patients, including eight family members and three healthcare workers with fever and thrombocytopenia occurred in Yixing County, Jiangsu Province, China, from October to November 1996. However, the initial investigation failed to identify its etiology. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS bunyavirus (SFTSV), which was first discovered in 2009. The discovery of novel SFTSV resulted in our consideration to test SFTSV on the remaining samples of this cluster in September 2010. Methodology/Principal findings: We retrospectively analyzed the epidemiological and clinical data of this cluster. The first case, one 55-year-old man with fulminant hemorrhagic diseases, died on October 14, 1996. His younger brother (the second case) developed similar hemorrhagic diseases after nursing him and then died on November 3. From November 4 to November 15, nine other patients, including six family members and three medical staffs, developed fever and thrombocytopenia after exposure to the second case. The sera of six patients were collected on November 24, 1996. IgM antibodies against SFTSV were detected in all of the six patients’ sera using enzyme-linked immunosorbent assay (ELISA), while IgG antibodies were detected in one patient’s serum using an indirect immunofluorescence assay (IFA). We also found that IgG antibodies against SFTSV were still detected in four surviving patients’ sera 14 years after illness onset. Conclusions and significance: The mysterious pathogen of the cluster in 1996 was proved to be SFTSV on the basis of its epidemiological data, clinical data and serological results. It suggests that SFTSV has been circulating in China for more than 10 years before being identified in 2009, and SFTSV IgG antibodies can persist for up to 14 years. [ABSTRACT FROM AUTHOR]