• Parasites, Hosts and Diseases
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• 제52권4호
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• pp.443-447
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• 2014

Babesiosis is an emerging tick-borne disease in humans worldwide; however, little is known about the frequency of infection or prevalence of this disease in other parts of the world, excluding North America. In this study, we aimed to investigate Babesia microti infection frequency in a human population in Mongolia. One hundred blood samples were collected from stock farmers living in Khutul city of Selenge province, Mongolia. The sera and DNA from blood samples were evaluated for the presence of B. microti infection by using indirect fluorescent antibody (IFA) tests and PCR. The positive detection rates obtained using the IFA tests and PCR assays were 7% and 3%, respectively. This study is the first to detect of B. microti infections based on antibody seroprevalence or PCR assays for the presence of B. microti DNA in a Mongolian population.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.559-565
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• 2018

The identification and characterization of pathogenic and zoonotic tick-borne diseases like granulocytic anaplasmosis are essential for developing effective control programs. The differential diagnosis of pathogenic Anaplasma phagocytophilum and non-pathogenic A. phagocytophilum-like Anaplasma spp. is important for implementing effective treatment from control programs. The objective of the present study was to investigate the prevalence of Anaplasma spp. in horses in Korea by nucleotide sequencing and restriction enzyme fragment length polymorphism assay. Of the 627 horses included in the study, only 1 (0.2%) was infected with A. phagocytophilum. Co-infection with A. phagocytophilumlike Anaplasma spp. was not detected in the study. The 16S rRNA sequence of A. phagocytophilum was similar (99.5-100%) to A. phagocytophilum 16S rRNA isolated from horses in other countries. PCR adapted to amplify A. phagocytophilum groEL and msp2 genes failed to generate amplicons, suggesting genetic diversity in these genes. This study is the first molecular detection of A. phagocytophilum in horses in Korea. Human granulocytic anaplasmosis and animal infection of A. phagocytophilum have been reported in Korea recently. Because of vector tick distribution, global warming, and the increase of the horse industry, horses should be considered as a potential reservoir for A. phagocytophilum, and cross infectivity should be evaluated even though a low prevalence of infection was detected in this study. Furthermore, continuous surveillance and effective control measures for A. phagocytophilum should be established to prevent disease distribution and possible transmission to humans.

• 대한바이러스학회지
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• 제27권2호
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• pp.209-216
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• 1997

Three dimensional structures of envelope protein from Korean isolates and Nakayama-NIH strain of Japanese encephalitis virus (JEV) were deduced by a computer program (HyperChem 4.0 Chemplus 1.0) based on the data of the three dimentional structure of Tick-borne encephalitis virus. In the three dimensional structure of envelope protein, neutralizing epitope and T-helper cell recognition site of C-terminal region of Korean isolates were structually similar to those of Nakayama-NIH but the N-terminal region was not. Korean JE isolates were compared with Nakayama-NIH strain by using cross-neutralization antibody test. Neutralizing activities of Korean isolates derived from guinea pigs were higher than those of Nakayama-NIH strain against Korean isolates, although the polyclonal antibody titers of Nakayama-NlH showed 1:160 to 1:640 against Korean isolates. According to the results from three dimentional structures and cross-neutralization analyses, the antigenic difference between Korean JE isolates and Nakayama-NIH strain may be dependent on structural difference of envelope protein.

• Journal of Preventive Medicine and Public Health
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• 제52권3호
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• pp.195-199
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• 2019

Objectives: Jeju Province is well known as the region showing the highest incidence of severe fever with thrombocytopenia syndrome (SFTS) in South Korea. The aim of this study was to evaluate the epidemiological and clinical characteristics of SFTS patients in Jeju Province. Methods: The primary data for this study were obtained from the Integrated Diseases and Health Control System of the Korea Centers for Disease Control and Prevention (KCDCIS). The selection criteria were confirmed cases of SFTS with a residence listed in Jeju Province at the time of diagnosis, reported to the KCDCIS between July 16, 2014 and November 30, 2018. Results: Of 55 confirmed cases of SFTS, the case fatality rate was 10.9% (95% confidence interval [CI], 4.1 to 22.2). The most common presenting symptoms at diagnosis of severe fever, myalgia, and diarrhea had incidences of 83.6% (95% Cl, 71.2 to 92.2), 45.5% (95% Cl, 32.0 to 59.5), and 40.0% (95% CI, 27.0 to 54.1), respectively. Conclusions: Compared to SFTS patients nationwide in 2013-2015, the subjects of this study exhibited a lower case fatality rate and had a lower incidence of severe fever, myalgia, and confusion.

• Parasites, Hosts and Diseases
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• 제60권1호
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• pp.65-71
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• 2022

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a zoonotic, tick-borne RNA virus of the genus Bandavirus (Family Phenuiviridae), mainly reported in China, Japan, and the Republic of Korea (Korea). For the purpose of this study, a total of 3,898 adult and nymphal ticks of species Haemaphysalis longicornis (94.2%), Haemaphysalis flava (5.0%), Ixodes nipponensis (0.8%), and 1 specimen of Ixodes ovatus, were collected from the Deogyusan National Park, Korea, between April 2016 and June 2018. A single-step reverse transcriptase-nested PCR was performed, targeting the S segment of the SFTSV RNA. Total infection rate (IR) of SFTSV in individual ticks was found to be 6.0%. Based on developmental stages, IR was 5.3% in adults and 6.0% in nymphs. The S segment sequences obtained from PCR were divided into 17 haplotypes. All haplotypes were phylogenetically clustered into clades B-2 and B-3, with 92.7% sequences in B-2 and 7.3% in B-3. These observations indicate that the Korean SFTSV strains were closer to the Japanese than the Chinese strains. Further epidemiological studies are necessary to better understand the characteristics of the Korean SFTSV and its transmission cycle in the ecosystem.

• 대한임상검사과학회지
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• 제47권3호
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• pp.147-152
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• 2015

참진드기 3종류의 발육단계별 즉 유충, 자충, 성충에 대한 계절적 발생 유형을 2014년 4월에서 10월까지 조사하였다. 천끌기와 천젓기 방법으로 포천 영중면 금주리에서 작은소피참진드기 610개체, 개피참진드기 296개체 그리고 일본참진드기 15개체가 채집되었으며 같은 방법으로 철원 서면 자등리에서는 작은소피참진드기 254개체, 개피참진드기 345개체, 일본참진드기 15개체가 채집되었다. 작은소피참진드기의 성충은 6월에 가장 높은 채집 비율을 보였으며 자충은 4월에서 6월사이에 주로 채집되었다. 반대로 작은소피참진드기의 유충은 9월과 10월에만 채집되었다. 개피참진드기의 성충은 4월, 9월, 10월에 채집된 반면 자충은 4월부터 10월까지 채집되었다. 개피참진드기의 자충은 포천에서는 4월에 그리고 철원에서는 5월에 가장 많이 채집되었다. 개피참진드기의 유충은 작은소피참진드기의 유충과 같이 9월과 10월에만 채집되었다. 일본 참진드기의 성충과 자충은 주로 4월에 채집되었으나 유충은 채집되지 않았다. 천끌기과 천젓기 방법으로 채집된 특정한 진드기종의 발육단계별 밀도를 조사한 결과는 진드기의 계절별 밀도 평가와 진드기 매개 질병 위험 분석에 활용할 수 있다.

• 한국응용곤충학회지
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• 제59권3호
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• pp.233-241
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• 2020

Ixodidae에 속하는 일부 참진드기들은 중증열성혈소판감소증후군(severe fever with thrombocytopenia syndrome; SFTS)을 비롯한 질병을 매개하는 공중보건학적으로 중요한 해충이다. 우리나라에서는 2013년 이후로 SFTS 환자 발생수가 지속적으로 증가하는 경향을 보이며, 경상북도는 전국적으로 2번째로 많은 SFTS 환자가 발생하는 지역이다. 본 연구에서는 2019년 경북 상주 지역의 진드기 분포를 조사하기 위해 시민의 생활 반경 주변을 도심 녹지지역, 관리 취약지역 및 농촌지역으로 구별하여 flagging 방법을 통해 진드기를 채집하였고, 채집 진드기내 SFTS 바이러스 보균 여부를 조사하였다. 채집된 진드기 수를 Collection Index (CI = tick number / 1h / 2 people)로 산출한 결과, 상주시 내 총 26개 지점에서 작은소피참진드기와 개피참진드기, 일본참진드기를 포함하는 총 CI 143의 진드기가 채집되었고, 그 중 작은소피참진드기가 96.5%(CI 138)로 우점종으로 확인되었다. 채집된 진드기의 약 92%(131 CI)는 인적이 드물고 시청이나 관계 당국의 관리가 이루어지지 않는 관리 취약지역에서 채집되었으나, 도심의 녹지지역와 농촌 지역에서는 8.4%(CI 12)의 진드기만 관찰되었다. 총 CI 143의 진드기를 26개 pooling 한 후 SFTS 바이러스 존재 여부를 조사하였으나, 모두 음성으로 확인되었다. 본 연구의 결과는 지역주민들로 하여금 진드기 매개 질병으로부터 안전한 생활을 하기 위한 권고 자료로 활용할 수 있을 것으로 기대된다.

• Parasites, Hosts and Diseases
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• 제56권3호
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• pp.287-290
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• 2018

Anaplasmosis is a tick-borne, non-contagious, zoonotic disease caused by Anaplasma spp., which include Anaplasma marginale, A. centrale, A. phagocytophilum, A. platys, A. ovis, and A. bovis. Recently, in Korea, the prevalence of Anaplasma spp. has been investigated in some animals, such as dogs, horses, goats, cats, and Korean water deer. In cattle, A. marginale is the most virulent species and regarded as the typical type of species. However, data on the seroprevalence of Anaplasma spp. in cattle in Korea during the last decade is limited. This study was designed to investigate the seroprevalence of bovine anaplasmosis in Korea. From 2010 to 2013, blood samples were collected from 568 cattle. Forty animals (7.0%) tested seropositive for Anaplasma spp. by cELISA. Despite that current bovine anaplasmosis seropositivity rate in the Gyeongsangbuk-do is lower than those in tropical countries, anaplasmosis needs to be regarded as a concerning disease. The identification of the specific Anaplasma species infecting cattle in this province requires additional molecular studies. Moreover, further monitoring and control programs for bovine anaplasmosis is required, and the information from this study will be beneficial to develop these programs.

• 대한수의학회지
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• 제35권1호
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• pp.137-142
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• 1995

Anaplasmosis is a tick-borne disease of large and small ruminants, causing losses through mortality, abortion, weight loss and reduced milk production. In one dairy farm, for example, 250 of a total of 800 imported goats were diagnosed with a mysterious type of anemia during the summer and autumn of 1992. The etiologic agent was identified as Anaplasma spp by acridine orange and ultrastructure by electron microscopy. In order to monitor variations in blood biochemical and hematological parameters associated with the disease, blood samples were collected by jugular venipuncture from 50 goats at 3 month intervals between the period of February and October, 1993. The levels of RBCs, HB and HCT decreased from $18.48{\pm}1.96$ to $13.47{\pm}2.48X10^6/mm^3$, $12.25{\pm}1.41$ to $9.54{\pm}1.77g/dl$, and $43.09{\pm}4.75$ to $30.93{\pm}5.78%$, respectively. The values of MCH(Mean corpuscular hemoglobin), MCHC(Mean corpuscular hemoglobin concentration) and PLT(Platelet) were elevated from $6.58{\pm}0.30$ to $7.05{\pm}0.47pg$, $28.40{\pm}1.20$ to $30.82{\pm}1.85g/dl$ and $1688.34{\pm}750$ to $2046.82{\pm}783X10^3/mm^3$, respectively. Percent parasitized erythrocytes(PPE) increased from $0.61{\pm}0.5$ to $2.22{\pm}1.9%$, clinical biochemical parameters aspartate aminotransferase and alanine aminotransferase were $66.64{\pm}23.1K.U$ and $14.90{\pm}6.59K.U$, respectively and persisted at high levels throughout the observation period. The level of albumin(2.46)0.52 g/dl) was decreased corresponding to an elevated globulin and a reduced albumin/globulin ratio in October as compared with the values in February. It is concluded that caprine anaplasmosis may be an important cause of anemia and hepatic malfunction in goats.

• Parasites, Hosts and Diseases
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• 제62권1호
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• pp.64-74
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• 2024

This pilot study aimed to investigate the effects of regional and seasonal variations on the prevalence of Theileria orientalis and the hematological profile of non-grazed dairy cows in Korea. A total of 365 clinically healthy lactating Holstein Friesian cows from 26 dairy farms in 7 provinces that were categorized into northern, central, and southern regions were sampled during the warm period from July to August and the cold period from October to December. The detection of T. orientalis major piroplasm surface protein gene and the hematology non-grazed dairy cows were analyzed using peripheral blood samples. The T. orientalis prevalence was 20.0% (73/365). The prevalence in the southern region was 35.9%, which was significantly higher than that in the central (21.6%) and northern (12.9%) regions (P<0.05). The prevalence during warm period was higher (43.0%) than that during the cold season (13.5%). The infected cows showed significantly lower erythrocyte counts in the southern region (5.8±0.6 M/㎕) and during the warm period (5.8±0.7 M/㎕) compared with those in the central and northern regions and during the cold season, which affected the extended RBC parameters, including hematocrit and hemoglobin concentrations. Our findings revealed the prevalence of T. orientalis in Korea, highlighting its high occurrence during warm periods and in certain geographical regions. Climatic factors could contribute to the health and productivity of cattle, as evidenced by the prevalence of T. orientalis and its negative impact on animals.