Abstract
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.