Page 411 - TBE_Book_V2_2019

Chapter 12b

TBE in South Korea

Song Joon Young

History and Current Situation

Although no human case of tick-borne examined ticks] × 100) was particularly high in
encephalitis (TBE) has been documented in Yangpyeong (5.9–20.0%), Dongducheon (1.3–
5
South Korea to date, surveillance studies 6.7%), Pyeongchang (0.8–1.3%), and
have been conducted to evaluate the Jeongseon (0.4–8.3%) with variation by tick
prevalence of tick-borne encephalitis virus species. As usual, 1–30 ticks were included in
1-5
(TBEV) in wild ticks. Four studies collected each pool. Phylogenetic analysis revealed that
ticks by dragging or flagging in grassland and the TBEV in South Korea belonged to the
forest, while 1 study tested wild mammals Western subtype, contrary to neighboring
(boars and rodents) by removing ticks from countries including Japan, China, and
them. In the wild of South Korea, northeastern Russia, where the Far-Eastern
Haemaphysalis spp. were the predominant subtype was only isolated (Table 1).
species found by tick dragging, while Ixodes
nipponensis became predominant when In the second study by the same research
harvested from small mammals. 6 team, TBEV was also isolated from wild
rodents (Apodemus agrarius) captured in
2
According to the results, TBEV was detected in Hapcheon, Gyeongsangnam-do. These TBEV
numerous regions (Figure 1): isolates (KrM216, KrM219) caused symptoms
- Gyeonggi-do (Yangpyeong and of encephalitis in suckling mice and were able
Dongducheon), to grow from brain preparations in cell
- Gangwon-do (Pyeongchang, Jeongseon, culture. In 2007, the third TBEV surveillance
Sokcho, and Chuncheon), was conducted in the southern provinces of
- Jeonllabuk-do (Gunsan and Gurye), South Korea, including Jeju Special Self-
- Gyeongsangbuk-do (Hapcheon, Dongu, Governing Province (Jeju Island), Jeollanam-
Andong, and Uiseong), do, Gyeongsangbuk-do, and Gyeongsangnam-
3
- Gyeongsangnam-do (Yangsan), and do. Among the 6,788 ticks collected, 4,077
- Jeju-do (Jeju). 1-5 were pooled (649 pools) by collection site. In

Jeju Island, the minimum field detection rate
The first study was conducted in 12 regions of was 0.17% in H. longicornis and 0.14% in H.
5 provinces of South Korea in 2005–2006. 1 flava. In accordance with the previous study,
the Jeju strains were identified as Western
TBEV was detected from Haemaphysalis subtype TBEV by phylogenetic analysis.
longicornis (minimum field detection rate,
0.2%), Haemaphysalis flava (0.8%), Haema- Later during 2011–2012, the fourth larger-
physalis japonica (0.9%), and I. nipponensis scale surveillance study was carried out in 25
4
(1.6%), as depicted in Table 1. localities of 10 provinces of South Korea. A
total of 13,053 ticks were collected with H.
The minimum field detection rate ([number of longicornis as the most abundant species
detection positive pools/ total number of (90.8%, 11,856/13,053), followed by H. flava

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