Susceptibility of Spotted Doves (Streptopelia chinensis) to Experimental Infection with the SFTS Phlebovirus

Abstract

24Background: Severe fever with thrombocytopenia syndrome virus (SFTSV), an 25 emerging human pathogen naturally transmitted by ticks, has spread widely during the 26 last few years. Although SFTSV has been detected in wild birds, the natural reservoir 27 and amplifying hosts for the virus have not been well-studied. 28 Methodology/Principle Findings: Here we report an experimental infection of 29 spotted doves (Streptopelia chinensis) with two strains of SFTSV, JS2010-14 30 (hereafter JS2010), a Chinese lineage strain and JS2014-16 (JS2014) from a Japanese 31 lineage, which represent the main viral genotypes currently circulating in East Asia. 32We determined that spotted doves were susceptible to SFTSV and the severity of the 33 viremia was dose-dependent. When challenged with 10 7 and 10 5 PFU, all doves 34 developed viremia which peaked 3-5 days post-infection (dpi). A subset (25-62.5%) 35 of the birds challenged at 10 3 PFU, developed viremia. Virulence of SFTSV in 36 spotted doves appeared to be strain-dependent. Infection with the strain of JS2014 led 37 to a death rate of 12.5% and higher viremia titers in experimentally inoculated birds. 38The doves inoculated with the JS2010 strain survived infection with relatively lower 39 virus titers in the blood. 40 Conclusions/Significance: Our results suggest that spotted doves, one of the most 41 abundant bird species in China, could be a competent amplifying host of SFTSV, the 42 strain of the Japanese lineage in particular, with higher viremia titers and play an 43 important role in the transmission of SFTSV. Our observations shed light on the 44 ecology of SFTSV which could benefit the implementation of future surveillance and 3 45 control programs. 46 47 Author Summary 48 Severe fever with thrombocytopenia syndrome virus (SFTSV), an emerging 49 human pathogen naturally transmitted by ticks. Our recent study have showed that 50 some species of migratory birds, such as swan geese and spotted doves, could be 51 parasitized by H. longicornis, and antibodies against the virus could also be 52 determined in these birds, which showed that migratory birds could be infected by 53 SFTSV naturally . Other studies have reported that migratory bird routes and the 54 distribution of H. longicornis in East Asia overlap with the geographic distribution of 55 SFTSV. Migratory birds are known to be carriers and transmitters of infectious agents, 56 like the causative agents of influenza, West Nile encephalitis, and Lyme disease. Wild 57 birds often travel long distances carrying various parasites, including ticks, which 58 may be infected with viruses and bacteria. It is therefore reasonable to hypothesize 59 that migratory birds may have played an important role in dispersing H. 60 longicornis-borne SFTSV in both scenarios, either the birds are infected directly with 61 the virus or the birds are carriers of parasitic ticks that are infected with the virus. 62 Here we report an experimental infection of spotted doves (Streptopelia chinensis) 63 with two strains of SFTS...