Prevalence of tick-borne encephalitis virus in ticks from southern Korea

Abstract

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.

Phylogenetic Analysis of Severe Fever with Thrombocytopenia Syndrome Virus in South Korea and Migratory Bird Routes Between China, South Korea, and Japan

“…15 These migratory birds are known to breed and migrate between China, South Korea, and Japan (Figures 1 and 3). 8,10,12,14,15 Another previous study detected tick-borne encephalitis virus (TBEV) in the H. longicornis collected from various habitats on Jeju Island (including wetland habitats for migratory birds) before SFTSV was first reported in Korea in 2013. 14 …”

“…There is strong evidence that SFTSV is transmitted, at least in part, by the H. longicornis tick and moved over long distances through migratory birds, and we support this hypothesis through a meta-analysis of the literature. 8,10,12,14,15 H. longicornis is a vector of SFTSV, and regular hosts of H. longicornis include mammals such as goats, cattle, sheep, yak, donkeys, pigs, deer, cats, rats, mice, hedgehogs, weasels, brushtail possums, chickens, and humans, along with some birds. This tick is widely distributed in the Asia-Pacific region, including China, Korea, Japan, Australia, the Pacific Islands, and New Zealand.…”

“…A total of 17 SFTS cases were laboratory confirmed in this study ( Table 1) 14 were farmers living in wooded, hilly areas and three made visits to similarly wooded, hilly, or mountainous areas before the onset of symptoms. This study was approved by institutional review board of Jeju National University Hospital and all subjects signed an informed consent form.…”

“…In addition, the tick distribution matches the bird migration flyways between China, South Korea, and Japan. 1,4,[10][11][12][13][14][15][16] This also coincides with the occurrence of SFTS, suggesting that migratory birds may play a role in the dissemination of SFTSV bearing H. longicornis.…”

Tick-Borne Encephalitis Virus: A General Overview

“…Simultaneously, the virus was also revealed in Northern China and Japan (Ando et al, 1952). Recently, a successful detection of TBE virus in South Korea was reported (Kim et al, 2009;Ko et al, 2010). The clinical course of the disease, its pathology and epidemiology, as well as the properties of the virus, its ecology, and ecology of the vectors have been studied in detail.…”