• Title/Summary/Keyword: Disease vectors

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Environmental survey on the vectors and hosts of Tsutsugamushi disease in Jeonnam province, Korea (전남지방에서 쯔쯔가무시병 숙주와 매개체의 서식환경 조사)

  • Song, Hyeon-Je
    • Korean Journal of Veterinary Service
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    • v.35 no.3
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    • pp.183-189
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    • 2012
  • Tsutsugamushi disease or scrub typhus cause by Orientia tsutsugamushi is an endemic disease in Korea. Chigger mites and field rodents play roles in transmission of the disease by the vector and host of the agent. The purpose of this study is to investigate the density of the chigger mites and field rodents due to environmental factors such as temperature, relative humidity, soil thickness and the various vegetations to the 9 field rodent collection sites. The total 62 field rodents was captured by the Sherman collapsible traps from April to October 2009 at the Jangseong of Jeonnam Province, Korea. The trapping rate of the field rodents by the different collecting sites was dominant at subside storage water (24%), bush near by dam (22%), bank around field (20%), followed by 18% of grassy field and surround cattle shed. The distribution of chigger mites by the different collecting sites was the highest at Bush near by dam (28.7%). And the sites of subside storage water, bank around field and surround cattle shed were 20.4%, 18.8%, 16.4%, respectively. On the other hand the collecting sites of stream bank and ridges between rice paddies were not collected. The temperature to the collecting sites was showed $24.1^{\circ}C$ in June and $24.2^{\circ}C$ in October which was higher than April ($10.6^{\circ}C$), whereas lower than May ($25.3^{\circ}C$) and September ($26.8^{\circ}C$). The highest number of mites was collected at $24.2^{\circ}C$ and 46.6% relative humidity in October. The chigger mites and field rodents were highly collected between 18 and 24% at the sites where are loosely in the superficial layers of the soil from 8.0 cm to 10.2 cm. Total 25 species of vegetation were distributed at the collecting sites. In the present study, strong evidence was found that bank around field and grassy field were provided for the prevalence sites of tsutsugamushi disease.

Disease Occurrence and Overwintering of Rice Dwarf Virus (벼오갈병의 발생 및 병원바이러스의 월동에 대하여)

  • Lee Key Woon
    • Korean Journal Plant Pathology
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    • v.2 no.1
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    • pp.17-21
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    • 1986
  • The viruliferous vectors of the rice dwarf virus, nymphs of Nephotettix cincticeps did not overwinter in Uljin, although the disease occurred in fields. When considered the relationship between seasonal changes of vector and disease occurrence, there were 5 and 3 peaks in a year in occurrence of vector and disease, respectively. The over­wintered adults and the nymphs of the 2nd and 3rd generation served as the major transmittor of the. virus. In a field where the disease has been a problem for years, the ratoon hills rice cultivar Milyang No. 30 was infected $22.4\~26.8\%$ with the rice dwarf virus. When nonviruliferous nymphs were fed on the infected ratoon hills for 11 to 30 days, viruliferous nymphs overwintered, increased to $13.0\~18.2\%$. The winter barley infected with rice dwarf virus did not survive in winter, suggesting that infected barley may not serve as a inoculum source.

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Natural Spread Pattern of Damaged Area by Pine Wilt Disease Using Geostatistical Analysis (공간통계학적 방법에 의한 소나무 재선충 피해의 자연적 확산유형분석)

  • Son, Min-Ho;Lee, Woo-Kyun;Lee, Seung-Ho;Cho, Hyun-Kook;Lee, Jun-Hak
    • Journal of Korean Society of Forest Science
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    • v.95 no.3
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    • pp.240-249
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    • 2006
  • Recently, dispersion of damaged forest by pine wilt disease has been regarded as a serious social issue. Damages by pine wilt disease have been spreaded by natural area expansion of the vectors in the damaged area, while the national wide damage spread has induced by human-involved carrying infected trees out of damaged area. In this study, damaged trees were detected and located on the digital map by aerial photograph and terrestrial surveys. The spatial distribution pattern of damaged trees, and the relationship of spatial distribution of damaged trees and some geomorphological factors were geostatistically analysed. Finally, we maked natural spread pattern map of pine wilt disease using geostatistical CART(Classification and Regression Trees) model. This study verified that geostatistical analysis and CART model are useful tools for understanding spatial distribution and natural spread pattern of pine wilt diseases.

Efficiency Evaluation of Nozawa-Style Black Light Trap for Control of Anopheline Mosquitoes

  • Lee, Hee-Il;Seo, Bo-Youl;Shin, E-Hyun;Burkett, Douglas A.;Lee, Jong-Koo;Shin, Young-Hack
    • Parasites, Hosts and Diseases
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    • v.47 no.2
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    • pp.159-165
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    • 2009
  • House-residual spraying and insecticide-treated bed nets have achieved some success in controlling anthropophilic and endophagic vectors. However, these methods have relatively low efficacy in Korea because Anopheles sinensis, the primary malaria vector, is highly zoophilic and exophilic. So, we focused our vector control efforts within livestock enclosures using ultraviolet black light traps as a mechanical control measure. We found that black light traps captured significantly more mosquitoes at 2 and 2.5 m above the ground (P<0.05). We also evaluated the effectiveness of trap spacing within the livestock enclosure. In general, traps spaced between 4 and 7m apart captured mosquitoes more efficiently than those spaced closer together (P>0.05). Based on these findings, we concluded that each black light trap in the livestock enclosures killed 7,586 female mosquitoes per trap per night during the peak mosquito season (July-August). In May-August 2003, additional concurrent field trials were conducted in Ganghwa county. We got 74.9% reduction (P<0.05) of An. sinensis in human dwellings and 61.5% reduction (P>0.05) in the livestock enclosures. The black light trap operation in the livestock enclosures proved to be an effective control method and should be incorporated into existing control strategies in developed countries.

Self Disease Diagnosis System Using Enhanced ART2 Algorithm (개선된 ART2 알고리즘을 이용한 자가 질병 진단 시스템)

  • Kim, Kwang-Baek;Woo, Young-Woon;Kim, Ju-Sung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.11
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    • pp.2150-2157
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    • 2007
  • In this paper, we have proposed a self disease diagnosis system for ordinary persons to help the decision of access methods to a specialized medical management, and for medical specialities to discover new diseases and their symptoms easily, using verification of an individual#s health status by a series of processes performed by oneself. In the proposed self disease diagnosis system, illness is decided by 60 kinds of diseases selected using the report called #Diseases that Koreans take seriously# published by Ministry of Health & Welfare and medical contents called #Engel Pharm#, and also using 161 representative symptoms for the 60 kinds of diseases. An individual#s health information is extracted by diagnosis of one#s health status by a clustering of the 60 kinds of diseases using enhanced ART2 algorithm and input vectors from the results of questions for symptoms of each disease.

Disease Incidences in Radish and Chinese Cabbage. I. Major Diseases in Radish and Chinese Cabbage grown in Alpine Areas in Jeonbug Province (고냉지단경기채소(무우. 배추) 및 평야지 추작채소단지에 발생하는 주요병해조사 I. 전북고냉지단경기 무우, 배추 주요병해)

  • So I.Y.;Lee S.H.;Kim H.M.;Lee W.H.
    • Korean journal of applied entomology
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    • v.20 no.3 s.48
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    • pp.135-145
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    • 1981
  • Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.

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Epidemiological Aspects of Cutaneous Leishmaniasis during 2009-2016 in Kashan City, Central Iran

  • Moein, Doroodgar;Masoud, Doroodgar;Saeed, Mahboobi;Abbas, Doroodgar
    • Parasites, Hosts and Diseases
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    • v.56 no.1
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    • pp.21-24
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    • 2018
  • Cutaneous leishmaniasis (CL) can be seen in 2 forms, zoonotic and anthroponotic, in Iran. In this study, epidemiological aspects of CL were studied during an 8-year period (2009-2016) in city of Kashan, central Iran. The demographic and epidemiological data, including age, sex, occupation, number and site of the lesions, treatment regimen, past history of CL, and season of all patients were gathered from the health centers. Descriptive statistics were used to describe features of the study data. Total 2,676 people with CL were identified. The highest annual incidence was estimated to be 182 per 100,000 population in 2009 and the least was in 2016 (47 per 100,000 population). The highest frequency affected age groups were observed in 20-29 year-old patients (20.9%). More than 51% of the patients were under 30 years old. The maximum frequency of the disease, 1,134 (43.3%), was seen in autumn. The most common location of lesions was hands (61.4%). Most of the patients (81.6%) were treated by systemic glucantime regimen. In the city of Kashan, the incidence rate of the CL disease is significantly higher than many other regions of Iran. To reduce the risk of disease, control of reservoir hosts and vectors of disease, and education of individual protection are strongly recommended.

Survey and Phylogenetic Analysis of Rodents and Important Rodent-Borne Zoonotic Pathogens in Gedu, Bhutan

  • Phuentshok, Yoenten;Dorji, Kezang;Zangpo, Tandin;Davidson, Silas A.;Takhampunya, Ratree;Tenzinla, Tenzinla;Dorjee, Chencho;Morris, Roger S.;Jolly, Peter D.;Dorjee, Sithar;McKenzie, Joanna S.
    • Parasites, Hosts and Diseases
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    • v.56 no.5
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    • pp.521-525
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    • 2018
  • Rodents are well-known reservoirs and vectors of many emerging and re-emerging infectious diseases, but little is known about their role in zoonotic disease transmission in Bhutan. In this study, a cross-sectional investigation of zoonotic disease pathogens in rodents was performed in Chukha district, Bhutan, where a high incidence of scrub typhus and cases of acute undifferentiated febrile illness had been reported in people during the preceding 4-6 months. Twelve rodents were trapped alive using wire-mesh traps. Following euthanasia, liver and kidney tissues were removed and tested using PCR for Orientia tsutsugamushi and other bacterial and rickettsial pathogens causing bartonellosis, borreliosis, human monocytic ehrlichiosis, human granulocytic anaplasmosis, leptospirosis, and rickettsiosis. A phylogenetic analysis was performed on all rodent species captured and pathogens detected. Four out of the 12 rodents (33.3%) tested positive by PCR for zoonotic pathogens. Anaplasma phagocytophilum, Bartonella grahamii, and B. queenslandensis were identified for the first time in Bhutan. Leptospira interrogans was also detected for the first time from rodents in Bhutan. The findings demonstrate the presence of these zoonotic pathogens in rodents in Bhutan, which may pose a risk of disease transmission to humans.

Seroepidemiological Survey of Zoonotic Diseases in Small Mammals with PCR Detection of Orientia tsutsugamushi in Chiggers, Gwangju, Korea

  • Park, Jung Wook;Chung, Jae Keun;Kim, Sun Hee;Cho, Sun Ju;Ha, Yi Deun;Jung, So Hyang;Park, Hye Jung;Song, Hyun Jae;Lee, Jung Yoon;Kim, Dong Min;Pyus, Jah;Ha, Dong Ryong;Kim, Eun Sun;Lee, Jae Il
    • Parasites, Hosts and Diseases
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    • v.54 no.3
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    • pp.307-313
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    • 2016
  • Serosurveillance for zoonotic diseases in small mammals and detection of chiggers, the vector of Orientia tsutsugamushi, were conducted from September 2014 to August 2015 in Gwangju Metropolitan Area. Apodemus agrarius was the most commonly collected small mammals (158; 91.8%), followed by Myodes regulus (8; 4.6%), and Crocidura lasiura (6; 3.5%). The highest seroprevalence of small mammals for O. tsutsugamushi (41; 26.3%) was followed by hantaviruses (24; 15.4%), Rickettsia spp. (22; 14.1%), and Leptospira (2; 1.3%). A total of 3,194 chiggers were collected from small mammals, and 1,236 of 3,194 chiggers were identified with 7 species of 3 genera: Leptotrombidium scutellare was the most commonly collected species (585; 47.3%), followed by L. orientale (422; 34.1%), Euchoengastia koreaensis (99; 8.0%), L. palpale (58; 4.7%), L. pallidum (36; 2.9%), Neotrombicula gardellai (28; 2.3%), and L. zetum (8; 0.6%). L. scutellare was the predominant species. Three of 1,236 chigger mites were positive for O. tsutsugamushi by PCR. As a result of phylogenetic analysis, the O. tsutsugamushi strain of chigger mites had sequence homology of 90.1-98.2% with Boryong. This study provides baseline data on the distribution of zoonotic diseases and potential vectors for the development of prevention strategies of vector borne diseases in Gwangju metropolitan area.

Analysis of the Biological Function of ELDF15 Using an Antisense Recombinant Expression Vector

  • Liu, Yan;Wang, Long;Wang, Zi-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9131-9136
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    • 2014
  • ELDF15, homologous with AT2 receptor-interaction protein 1 (ATIP1), may play an important role in cell differentiation, proliferation, and carcinogenesis. We aimed to understand the biological function of ELDF15 via construction and transfection of a recombinant expression vector containing antisense ELDF15. Recombinant expression vectors were successfully constructed and transfected into K562 cells. A stable transfectant, known as pXJ41-asELDF15, stably produced antisense ELDF15. Compared with K562 and K562-zeo cells, K562-pXJ41-asELDF15 cells showed inhibition of cell proliferation. RT-PCR analysis showed that the expression and protein level of ELDF15 decreased significantly in K562 cells transfected with pXJ41-asELDF15. Expression of hemoglobin increased in K562 cells transfected with pXJ41-asELDF15 by benzidine staining. increases NBT reduction activity in K562 cells transfected with pXJ41-asELDF15.Colony forming efficiency in two-layer soft agar was clearly inhibited as assessed by electron microscopy. These results suggest that ELDF15 plays a potential role in cell differentiation, proliferation and carcinogenesis.