Detection of SFTS Virus inIxodes nipponensisandAmblyomma testudinarium(Ixodida: Ixodidae) Collected From Reptiles in the Republic of Korea

Abstract

A survey of reptile-associated ticks and their infection status with severe fever with thrombocytopenia syndrome (SFTS) virus was conducted to determine the relative abundance and distribution among lizards, skinks, and snakes in the Republic of Korea (ROK). In total, 132 reptiles, including 49 lizards (two species), 15 skinks (one species), and 68 snakes (eight species) were collected. In total, 84 ixodid ticks belonging to two genera (Ixodes and Amblyomma) were collected from 28/132 (21.2%) lizards, skinks, and snakes. Ixodes nipponensis Kitaoka & Saito was only collected from lizards and skinks, while Amblyomma testudinarium Koch was only collected from snakes. Takydromus wolteri had the highest tick index (0.7; total number ticks/total number collected hosts) among lizards and skinks, while Rhabdophis tigrinus had the highest tick index (2.2) among the snakes. Ixodes nipponensis larvae and nymphs accounted for 11.1% and 88.9%, respectively, of all ticks collected from lizards and skinks, while only A. testudinarium nymphs were collected from snakes. Nymphs of both species of ticks were collected from lizards and skinks from April to October, while I. nipponensis larvae were collected only from September to October. Ixodes nipponensis larvae and nymphs were preferentially attached to the lateral trunk (83.3%) and the foreleg axillae (16.7%) of lizards and skinks. SFTS virus was detected in both I. nipponensis and A. testudinarium collected from lizards and snakes. Phylogenetic analysis of SFTS viruses of ticks collected from two lizards and one snake demonstrated close relationships with SFTS virus strains observed from humans and ticks in the ROK, China, and Japan. These results implicate lizards and snakes as potential hosts of SFTS virus.

Ixodes nipponensis Kitaoka and Saito and Amblyomma testudinarium Koch (Acari: Ixodida: Ixodidae) Collected from Reptiles (lizards, skinks, and snakes) in the Republic of Korea, 2016

“…This difference was due, in part, to the high numbers of I. nipponensis larvae (20 larvae) collected from Eremias argus in mid-June. However, in previous studies the number of I. nipponensis larvae increased in July, peaked in August, and then declined in September , Coburn et al 2016, Suh et al 2016 (Table 1).…”

“…(Cho et al 1995, Ryu et al 1998, Yun et al 2001, Ko et al 2002, Jeon et al 2014. During a 2015 reptile tick survey, I. nipponensis nymphs accounted for 88.9% of ticks collected from lizards and skinks, while larvae accounted for only 11.1% (Suh et al 2016), whereas during this survey, I. nipponensis larvae accounted for 46.4% of the ticks collected from lizards and skinks. This difference was due, in part, to the high numbers of I. nipponensis larvae (20 larvae) collected from Eremias argus in mid-June.…”

“…As in the 2015 reptile survey, I. nipponensis nymphs were collected only from lizards and skinks, while A. testudinarium nymphs were collected only from snakes (Suh et al 2016). Suh et al (2016) collected two genera of lizards (2 species) and skinks (1 species) and five genera of snakes (8 species). Similarly, this survey resulted in the collection of two genera of lizards (3 species) and skinks (1 species), and seven genera of snakes (10 species).…”

“…Noh (1965) first reported Ixodes granulatus Supino blood feeding on a Tsushima Ground Skink, Scincella vandenburghi (Schmidt), in the Republic of Korea (ROK), and later Ra et al (2011) reported Ixodes nipponensis Kitaoka and Saito nymphs on four lizard species collected at 22 sites in the ROK. More recently, I. nipponensis nymphs and larvae and Amblyomma testudinarium Koch nymphs were reported blood feeding on three species of lizards and three species of snakes, respectively, collected in 6 provinces and one metropolitan city of the ROK (Suh et al 2016).…”

“…and spotted fever group rickettsiae, has been investigated in some detail (Wright et al 1998, Dsouli et al 2006, Reeves et al 2006, while studies of their role as reservoir hosts of arboviruses, e.g., severe fever with thrombocytopenia syndrome virus (SFTSV), have been limited (Reisen et al 2007, Suh et al 2016. SFTSV, a tick-borne Bunyavirus, was first identified in China in 2009 and retrospectively in a patient that died in Korea in 2012.…”