SFTS Virus in Ticks in an Endemic Area of China

In total, 3,145 ticks of the species Haemaphysalis longicornis (3,048; 96.9%), R. microplus (82; 2.6%), H. campanulata (9; 0.3%), and Dermacentor sinicus (5; 0.2%) were collected from animals and vegetation at Yantai in Shandong Province. Both adult and immature ticks were obtained, and all ticks collected from vegetation were unfed. Eggs were obtained from 22 blood-fed female ticks through maintenance at room temperature after collection. Severe fever with thrombocytopenia syndrome virus (SFTSV) viral RNA was identified in H. longicornis and R. microplus, with a prevalence of 4.75 per 100 ticks (95% confidence interval [95% CI] = 3.87-5.63) for ticks collected from animals and 2.24 per 100 ticks (95% CI = 1.27-3.21) for ticks collected from vegetation. The possibility that SFTSV transmission may occur by both the transstadial and transovarial routes was suggested by the fact that viral RNA was detected in H. longicornis at all developmental stages. Tick-derived sequences shared over 95.6% identity with human- and animal-derived isolates. This study provides evidence that implicates ticks as not only vectors but also, reservoirs of SFTSV.