• 제목/요약/키워드: Natural hosts

검색결과 109건 처리시간 0.03초

Strategies to prevent the new infectious diseases from an ecological perspective

  • Lee, Chang Seok
    • Journal of Ecology and Environment
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    • 제46권3호
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    • pp.172-182
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    • 2022
  • Background: The coronavirus problem is an ecological problem stemming from a sudden change in the relationship between parasites and hosts. Ecologists judge organisms that are established out of their original territory as exotic species. Unlike in their original habitat, these exotic species become very aggressive in their newly settled habitat. Coronavirus infection damage was bigger in Europe or the United States than that in the country of its origin, China, and its neighboring countries. Therefore, coronavirus infection damage resembles the damage due to the invasive species. Results: Exotic species are found in places with similar environmental conditions to those of their origin when introduced to other ecological regions. However, there are few ecological ill effects in their place of origin, while the damage is usually severe in the ecological regions in which it is introduced. According to historical records, exotic infectious diseases, such as European smallpox and measles, also showed a similar trend and caused great damage in newly established places. Therefore, it is expected that measures to manage exotic species could be used for the prevention of exotic infectious diseases such as the coronavirus. Conclusions: Prevention comes first in the management of exotic species, and in order to come up with preventive measures, it is important to collect information on the characteristics of related organisms and their preferred environment. In this respect, ecosystem management measures such as exotic species management measures could be used as a reference to prevent and suppress the spread. To put these measures into practice, it is urgently required to establish an international integrated information network for collecting and exchanging information between regions and countries. Furthermore, a systematic ecosystem-management strategy in which natural and human environments could continue sustainable lives in their respective locations may serve as a countermeasure to prevent infectious diseases.

컨벤션 관광 목적지 브랜드 슬로건 분석 - 국제 컨벤션 도시를 중심으로 - (Analysis of Convention Tourism Destination Brand Slogans: Focusing on International Convention Cities)

  • 이혜련;반서연;윤유식
    • 한국과학예술포럼
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    • 제26권
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    • pp.339-351
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    • 2016
  • 본 연구의 목적은 전 세계의 주요 국제 컨벤션 도시를 중심으로 컨벤션 관광 목적지 브랜드 슬로건을 분석하는 것이다. 자료 수집은 2013년 10개 이상의 국제회의를 개최한 190개 도시의 공식 관광 웹사이트를 통해 이루어졌다. 이중에서 확인된 106개 목적지 브랜드 슬로건의 언어적 표현과 시각적 표현에 대한 내용분석을 실시하였다. 분석 결과, 슬로건의 구조면에서 단어형과 구형이 다수로 간결성을 추구하고 있으며, 스펙트럼 유형에 있어서는 지역 특성과 혜택을 드러내지 못하는 보편형 슬로건이 절반을 차지하였으며, 핵심 용어에 있어서는 'visit, city'를 가장 많이 사용하였다. 한편, 시각적 관점에서 슬로건의 글자체는 명시성이 있는 타이포그래피가 약 70%였으며, 슬로건의 60%가 인문과 자연자원을 이미지화 대상으로 선정하여 차별적 이미지 구축을 도모하는 것으로 나타났다. 또한 본 연구결과에 대한 전문가 회의를 통해 향후 효과적인 컨벤션 관광 목적지 브랜드 슬로건 개발에 대한 시사점을 도출하였다.

Antiamoebic activities of flavonoids against pathogenic free-living amoebae, Naegleria fowleri and Acanthamoeba species

  • Huong Giang Le;Tuan Cuong Vo;Jung-Mi Kang;Thu Hang Nguyen;Buyng-Su Hwang;Young-Taek Oh;Byoung-Kuk Na
    • Parasites, Hosts and Diseases
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    • 제61권4호
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    • pp.449-454
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    • 2023
  • Free-living amoebae (FLA) rarely cause human infections but can invoke fatal infections in the central nervous system (CNS). No consensus treatment has been established for FLA infections of the CNS, emphasizing the urgent need to discover or develop safe and effective drugs. Flavonoids, natural compounds from plants and plant-derived products, are known to have antiprotozoan activities against several pathogenic protozoa parasites. The anti-FLA activity of flavonoids has also been proposed, while their antiamoebic activity for FLA needs to be emperically determined. We herein evaluated the antiamoebic activities of 18 flavonoids against Naegleria fowleri and Acanthamoeba species which included A. castellanii and A. polyphaga. These flavonoids showed different profiles of antiamoebic activity against N. fowleri and Acanthamoeba species. Demethoxycurcumin, kaempferol, resveratrol, and silybin (A+B) showed in vitro antiamoebic activity against both N. fowleri and Acanthamoeba species. Apigenin, costunolide, (-)-epicatechin, (-)-epigallocatechin, rosmarinic acid, and (-)-trans-caryophyllene showed selective antiamoebic activity for Acanthamoeba species. Luteolin was more effective for N. fowleri. However, afzelin, berberine, (±)-catechin, chelerythrine, genistein, (+)-pinostrobin, and quercetin did not exhibit antiamoebic activity against the amoeba species. They neither showed selective antiamoebic activity with significant cytotoxicity to C6 glial cells. Our results provide a basis for the anti-FLA activity of flavonoids, which can be applied to develope alternative or supplemental therapeutic agents for FLA infections of the CNS.

Morphological and molecular characteristics of Paralecithodendrium longiforme (Digenea: Lecithodendriidae) adults and cercariae from Chinese pipistrelle bats and viviparid snails in Thailand

  • Thitichai Arttra;Pheravut Wongsawad;Chalobol Wongsawad;Nattawadee Nantarat;Preeyaporn Butboonchoo;Jong-Yil Chai
    • Parasites, Hosts and Diseases
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    • 제62권1호
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    • pp.85-97
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    • 2024
  • This study aimed to describe the morphological and molecular characteristics of Paralecithodendrium longiforme (Digenea: Lecithodendriidae) adults and cercariae isolated in Thailand. Adult flukes were isolated from the Chinese pipistrelle bat (Hypsugo sp.), and cercariae were detected in the viviparid snail (Filopaludina martensi martensi) from Chiang Mai province. The morphological characteristics were observed and described using conventional methods, and the molecular characteristics with internal transcribed spacer 2 (ITS2) and 28S rDNA gene sequences. The adult flukes were fusiform, 0.84-0.98 mm in length, and 0.37-0.49 mm in width, and were distinguishable from other species by the presence of longitudinal uterine coils. The cercariae were nonvirgulate xiphidiocercariae, with the oral sucker bigger than the acetabulum, the tail without fin fold, a body size of 117.5-138.3×48.3-52.2 ㎛, and a tail size of 100.7-103.7×15.0-18.9 ㎛. Molecular studies revealed that the adults and cercariae shared 99.3% (ITS2) and 99.6% (28S rDNA) homology with each other. They were phylogenetically close to P. longiforme with an identity of 94.5% for ITS2 and 98.7% for 28S rDNA. This study provides new information on the natural definitive host and first intermediate host of P. longiforme in Thailand. The discovery of its cercarial stage in Filopaludina snails highlights the importance of monitoring the associated second intermediate host and prevention and control of this potentially zoonotic trematode.

Cowpea mild mottle virus 특이유전자 검출을 위한 검역진단시스템 개발 (Development of a Diagnostic System for the Detection of the Cowpea mild mottle virus Specific Gene in Quarantine)

  • 이시원;이진영;문보영;김창수;신용길;노재영
    • 한국미생물·생명공학회지
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    • 제43권3호
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    • pp.296-299
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    • 2015
  • Cowpea mild mottle virus (CPMMV)는 국내 미보고 바이러스로, 넓은 숙주범위를 가지며, 국내 관리급 검역바이러스로 지정되어 있다. 본 연구에서는 검역현장에서 신속하게 CPMMV를 진단할 수 있는 방법을 개발하였다. 이번 연구는 사용자를 위한 검사방법 개발을 위하여, 기존의 검역현장에서 활용하는 PCR 조성과 조건을 활용하였다. 본 연구에서는 CPMMV를 특이적으로 진단할 수 있는 2개의 RT-PCR 프라이머를 개발하였으며 각각 579와 638 bp를 증폭할 수 있다. 최종적으로 증폭되는 nested PCR 산물의 크기는 (579 → 298 bp)과 (638 → 252 bp)로 CPMMV의 특이 유전자를 진단할 수 있다. 또한, 제한효소 Xho I이 반응할 수 있는 염기 서열을 삽입하여 양성대조구 플라스미드를 개발하였다. 이것은 실험실 오염으로부터 거짓양성을 검증할 수 있게 하였다. 본 연구는 CPMMV와 관련된 수입 작물로부터 검역진단에 기여할 것이라고 사료된다.

Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea

  • Chai, Jong-Yil;Park, Jae-Hwan;Jung, Bong-Kwang;Guk, Sang-Mee;Kim, Jae-Lip;Shin, Eun-Hee;Klein, Terry A.;Kim, Heung-Chul;Chong, Sung-Tae;Baek, Luck-Ju;Song, Jin-Won
    • Parasites, Hosts and Diseases
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    • 제47권3호
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    • pp.311-314
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    • 2009
  • A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n= 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Sclerotinia sclerotiorum에 의한 시설재배 들깨 균핵병 발생특성 (Occurrence of Sclerotinia Rot on Perilla Caused by Sclerotinia sclerotiorum under Structured Cultivation Condition)

  • 신동범;송석보;문병주
    • 식물병연구
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    • 제12권3호
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    • pp.158-163
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    • 2006
  • 시설재배 되는 들깨에 발생하여 피해를 초래하는 균핵병 발생 특성에 대하여 조사연구한 결과, 들깨 균핵병균(S. sclerotiorum)의 균사생장 적온은 $20^{\circ}C$이었고, $15^{\circ}C$ 이하의 온도에서 $20^{\circ}C$ 이상의 온도에서보다 균핵의 형성수는 적었으나 보다 큰 균핵을 형성하였으며 건물중도 높았다. 토양 깊이별 균핵의 자낭반 형성은 0.5 cm에서 가장 높았고 3cm 깊이까지 자낭반을 하였으나 5cm 이상의 깊이에서는 자낭반 형성이 관찰되지 않았다. 들깨 균핵병은 전 생육기에 걸쳐 발생하였고, 특히 저온 다습기인 1월에서 2월에 발생이 높았다. 그리고 5년 이상 연작 재배시 높은 발병을 보였으며, 10년 이상 연작재배 포장은 20% 이상의 발병을 보여 많은 피해를 초래하였다. 또한 들깨 시설재배 농가 포장에서 자연 감염에 의한 균핵병이 떡쑥, 주름잎 등의 잡초에 발생하였으며, 병원성 조사결과, 화본과를 제외한 국화과 등 6개과에 속하는 11종의 잡초에 병원성을 나타내었다. 이런 결과는 윤작과 효율적인 잡초관리가 들깨 균핵병 발생을 경감할 수 있고, 벼 후작으로 시설재배 되는 들깨에 균핵병이 격발하는 원인을 설명할 수 있는 하나의 자료가 될 수 있을 것으로 생각된다.

먹이에 따른 파밤나방 발육과 DNA 메틸화 변이 (Variation in Development and DNA Methylation of Spodoptera exigua Fed with Different Diets)

  • 김태형;수닐쿠마르;김용균
    • 한국응용곤충학회지
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    • 제54권4호
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    • pp.359-367
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    • 2015
  • 곤충 생리현상의 가소성은 후생유전적 변화와 밀접하게 관련을 지을 수 있다. 이 가설을 증명하기 위해 광식성인 파밤나방(Spodoptera exigua)을 대상으로 상이한 먹이 조건에 따라 이 곤충의 발육과 DNA 메틸화에 영향을 주는 지 분석하였다. 동일한 코호트로 부터 얻은 갓 부화한 유충을 최종령에 이르기까지 세 가지 다른 먹이(대파, 배추, 인공사료)로 섭식 처리하였다. 이 결과 상이한 먹이 조건에 따라 유충발육속도, 용화율 및 우화율에서 뚜렷한 차이를 보였다. 인공사료로 사육된 유충이 가장 빠른 유충발육속도와 높은 용화율 및 우화율을 나타냈다. 반면에 두 자연 기주 가운데는 대파가 배추에 비해 파밤나방 발육에 양호하였다. 이러한 먹이에 따른 변이는 혈림프 단백질 및 혈당에서도 차이가 나타났다. 또한 발육과 연계되었을 것으로 추정되는 인슐린유사펩타이드(SeILP1) 유전자의 발현 정도도 먹이조건에 따라 상이했다. 단일항체를 이용하여 파밤나방 게놈 DNA의 시토신 메틸화를 분석한 결과 이 부위에 DNA 메틸화가 검출되었으며, 메틸화 정도는 먹이 조건에 따라 상이했다. 이 결과들은 동일 집단의 파밤나방이 상이한 먹이 조건에 따라 발육차이를 나타내고 또한 시토신 메틸화에 변이를 보여 이 곤충의 생리적 가소성에 후생유전적 인자가 작용하고 있는 것을 제시한다.

Unrecorded species of Korean invertebrates discovered through the project of 'Discovery of Korean Indigenous Species' II

  • Su-Jung Ji;Chuleui Jung;Hyun Woo Bang;Min Ok Song;Jongwoo Jung;Seong Myeong Yoon;Seunghwan Lee;Seoyoung Keum;Hee-Min Yang;Dongmin Lee;Geon Hyeok Lee;Jaeseok Oh;Kichoon Kim;Hansol Park;Heejin Moon;Omid Joharchi;Yeseul Kang;Keeseon S. Eom;Kyung Jin Lee;Ye Eun;Taeho Kim;Ivana Karanovic;Jeounghee Lee;Seongjun Choe;Gi-Sik Min
    • Journal of Species Research
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    • 제12권1호
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    • pp.68-89
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    • 2023
  • This is the second catalog listing unrecorded invertebrates discovered during the research project 'Discovery of Korean Indigenous Species'. The data to compile the catalog were primarily gathered from the final reports of the project, between 2013 and 2021. We present 38 previously undocumented species, belonging to four phyla (Platyhelminthes, Annelida, Rotifera and Arthropoda). Samples were collected from intertidal coastal waters, soil, freshwater ponds, reservoirs and hosts in South Korea. In this study, we provide brief taxonomic information, including collection site (GPS), diagnosis, specimen vouchers, figures of representative individuals and the Korean name newly assigned, for each species. All data were reviewed and updated by experts working on the respective taxonomic group. The aim of the present study is to publish species that have been previously reported through the project. Upon publication, these species will be added to the 'National Species List of Korea', curated by the National Institute of Biological Resources(NIBR).

간흡충증(肝吸虫症)의 역학(疫學) - I. 고도유행지(高度流行地) 김해지방(金海地方)에 있어서의 간흡충감염(肝吸虫感染)의 현황(現況)과 자연추이(自然推移) (Epidemiological Studies of Clonorchiasis. - I. Current Status and Natural Transition of the Endemicity of Clonorchis sinensis in Gimhae Gun and Delta, a High Endemic area in Korea)

  • 김동찬;이온영;이종수;안장수;장영미;손성창;문익상
    • 농촌의학ㆍ지역보건
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    • 제8권1호
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    • pp.44-65
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    • 1983
  • As a part of the epidemiological studies of clonorchiasis, this study was conducted to evaluate the current endemicity and the natural transition of the Clonorchis infection in Gimhae Gun and delta area a high endemic area in Korea in recent years, prior to the introduction of praziquantel which will eventually influence the status of the prevalence. The data obtained in this study in 1983 were evaluated for natural transition of the infection in comparison with those obtained 16 years ago in 1967 by the author(Kim, 1974). The areas of investigation, villages and schools surveyed, methods and techniques used in this study were the same as in 1967, except for the contents of the questionnaire for raw freshwater fish consumption by the local inhabitants. 1) The prevalence rate of clonorchiasis in the general population of the villages was 48.1% on the average out of a total of 484 persons examined. The average of those of the riverside-delta area was 65.2% and 43.0% in the inland area. Among the schoolchildren, the prevalence rate was 8.2% on the average out of a total of 1,423 examined. By area, the prevalence rate was 10.8% in the riverside delta area and 2.8% in the inland area. By sex, difference in the prevalence was seen only in the inhabitants of the inland area showing 52.4% in the male and 33.5% in the female. 2) In the natural transition of the infection, the prevalence rate among the inhabitants has decreased from 68.8% in 1967 to 48.1% in 1983, and in the schoolchildren from 56.4% in 1967 to 8.2% in 1983. The reduction rate was higher in the riverside-delta area than in the inland area. 3) In the prevalence rate by age, 11.9% was first seen in the 5-9 age group and the rate gradually increased up to 75.0% in the 50-59 age group. By sex, the rate was higher in the male than in the female in the 20-29 age group and over. 4) In the natural transition of the prevalence rate by age, the reduction rate of the infection during the past 16 years was greater in the younger age groups up to the 40-49 age group and reached the same level in the age group 50-59. Reduction was seen again in the age group over 60s. By sex, the reduction rate was greater in the female than in the male in the 20-29 age group and over. By area, the reduction rate was greater in the riverside delta area than in the inland area, particularly in the young age groups. 5) In the intensity of the infection among the cases, the mean egg out-put per mg feces per infected cases(EPmg) in the inhabitants was 6.3. EPmg of those of the river-side-delta area was 15.4 and that of the in-land was 2.8. On the other hand, in the schoolchildren, EPmg was 3.2, and no difference was seen between the two areas, the river-side-delta area and the inland area. 6) In the transition of the intensity of the infection by area, EPmg among the inhabitants inexplically increased from 7.8 in 1967 to 15.4 in 1983. This was probably caused by uneven specimen collection in the process of sampling the population. EPmg of the inhabitants in the inland area and those of the schoolchildren of both riverside delta and inland areas showed a similar decrease in the past 16 years. 7) The intensity of the infection by age showed a relatively low level in the 20-29 age group and below, and EPmg 5.1-9.5 was seen in the 30-39 age group and over. Sex, Epmg was 5.8 in the male and 4.7 the female. By in 8) In the transition of the intensity of the infection, EPmg decreased from 6.2 in 1967 to 5.4 in 1983. By age, in contrast to the figures of 1967 in which EPmg gradually increased with some fluctuation from 1.1 in the 0-4 age group to peak 10.5 in the 50-59 age group, in 1983 lower intensity of the infection was seen in the age group from 10-14 to 20-29 with the EPmg range of 0.6-2.7. 9) In the distribution of the clonorchiasis cases by the range of EPmg value, 43.2% of the cases were in 0.1 0.9 and 34.6% in 1.0-4.9. As a whole by cumulative percent, 44.6% of them were under 0.9 as light infection and 86.1% of them under 9.9 up to moderate infection. By sex, no difference was seen in Epmg. 10) In the transition of the distribution by the range of Epmg, the cases were distributed up to the range 80.0-99.9 in 1967 and to 60.0-79.9 in 1983. By cumulative percent, in the range of 0.1-0.9 and less, light infection, 34.3% of them were distributed in 1967 and 44.6% in 1983 with about 10% increase. In the range of 5.0-9.9 and less, up to moderate infection, 83.2% in 1967 and 86.1% in 1983 of the cases were seen, respectively. 11) The practice of raw freshwater fish consumption among the inhabitants seems to have decreased in recent years. Those who admitted to raw freshwater fish consumption in the last two years among the infected inhabitants were 59.3%, although 86.8% of them professed to have experience with raw freshwater fish consumption. 31.7% of those who have had experience of the raw freshwater fish consumption denied any further consumption in recent years. From an interview of 543 school-children, 24.1% of them admitted to an experience of raw freshwater fish consumption. However, those who have practised in the past two years comprized 17.9%. Those who denied raw freshwater fish consumption in recent years among those who had such experience were 26.0% out of 131 interviewed. The rate of raw freshwater fish consumption in both inhabitants and schoolchildren were higher in the male than in the female. On the contrary, the rate of those who did not practise in recent years among those who had experience of raw freshwater fish consumption was higher in the female than in the male. 12) The major reason for the reduction of raw freshwater fish consumption among the local inhabitants was the risk of the fluke infection. However, it has become apparent that such change of taste has resulted from water pollution impact which has affected throughout the areas of the freshwater systems in this locality since last several years. 13) In animal survey, Clonorchis infection was seen in 14.8% of 88 dogs examined and 3.7% of 27 house rats examined. It was noted that populations of dogs and cats have increased in the villages surveyed. Although the prevalence rate was lower in the present survey than those of 1967, the significance of the animals as the reservoir host has not changed. 14) Prevalence rate of Clonorchis infection by cercariae in the first intermediate host, Parafossarulus manchouricus, was 0.6% out of 517 snails examined. The infection rate was lower in comparison with 2.3% out of 2,124 examined in 1967. Moreover, sharp decreases in number and distribution of the intermediate host snails in many watershed areas of the huge freshwater systems in this locality seemed to reduce transmission of Clonorchis in connection with the intermediate host stage of its life cycle. 15) Clonorchis infection in the second intermediate fish hosts was relatively low. The mean number of Clonorchis metacercaria per fish in Pseudorasbora parva was 517 in 1983, whereas it was 1943 in 1968 through 1969. Environmental water pollution has also caused the decreased fish population density in these areas, and this has also apparently affected to the practice of raw freshwater fish consumption among the local inhabitants. 16) In conclusion, endemicity of Clonorchis infection in Gimhae Gum and delta area of the Nagdong River has sharply decreased during the past 16 years. The major cause of the regressive transition of the infection was the water pollution of the land water systems of this locality. The pollution has upset the ecosystems comprizing of the intermediate hosts of Clonorchis in many areas, and also affected to a significant extent to the discontinuance of the local inhabitants for raw freshwater fish consumption.

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