• 제목/요약/키워드: Transmission of infection

검색결과 536건 처리시간 0.024초

Detection and genotyping of Giardia intestinalis isolates using intergenic spacer (IGS)-based PCR

  • Lee, Jong-Ho;Lee, Jong-Weon;Park, Soon-Jung;Yong, Tai-Soon;Hwang, Ui-Wook
    • Parasites, Hosts and Diseases
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    • 제44권4호
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    • pp.343-353
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    • 2006
  • Giardia intestinalis infections arise primarily from contaminated food or water Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was peformed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.

1차 확산기 이후 코로나바이러스감염증-2019의 전파가 부모와 아동의 심리에 미치는 영향 (The Effect of the Transmission of Coronavirus Disease-2019 on the Mentality of Parents and Children After the First Wave of Infections)

  • 김정연;이고은;남옥형;이효설;최성철;김광철;김미선
    • 대한소아치과학회지
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    • 제48권3호
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    • pp.269-279
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    • 2021
  • 이 연구의 목적은 코로나바이러스감염증-2019의 전파가 학령기 아동과 부모의 심리에 미친 영향을 수면장애와 우울증의 측면에서 평가하는 것이었다. 2020년 4월 2일부터 2020년 4월 25일까지 강동 경희대학교 치과병원 소아치과를 방문한 123명의 부모와 108명의 학령기 아동을 대상으로 직접 기입 방식의 설문조사를 실시하였다. 참가자들은 Pittsburgh Sleep Quality Index, Generalized Anxiety Disorder (GAD) - 7, Center for Epidemiology Scale for Depression 로 평가되었다. 로지스틱 회기 분석은 유의 수준 5%로 시행되었다. 부모의 GAD, 우울증, 낮은 수면의 질은 각각 34.1%, 17.1%, 44.7%에서 나타났다. 아동의 GAD 유병률은 20.4%였다. 로지스틱 회기분석 결과 코로나바이러스 관련 안전재난문자로 인한 스트레스가 부모의 불안장애, 우울증과 관련이 있었다. 아동의 경우, 코로나바이러스감염증 발생 이후의 감정 변화 정도가 GAD와 연관성이 있었다. 이 연구를 통해 코로나바이러스감염증-2019의 유행으로 인한 어린이와 보호자들의 심리적 상태 변화가 있음을 확인하였고, 치과진료 시 이들의 심리상태를 고려해야 하겠다.

2001년 경상북도에서 발생한 콜레라 유행에 관한 역학조사 (Epidemiologic Investigation on an Outbreak of Cholera in Gyeongsangbuk-do, Korea, 2001)

  • 이준호;이관;김준철;이상원;고운영;양병국;이종구;김문식;임현술
    • Journal of Preventive Medicine and Public Health
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    • 제35권4호
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    • pp.295-304
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    • 2002
  • Objectives : This study was carried out to investigate the cause, magnitude and transmission route of the cholera outbreak in 2001 Methods : The study population were those persons who ingested foods at the restaurant, were confirmed as cholera patients, had symptoms of diarrhea and sewed as workers at the restaurant. A questionnaire survey and microbiological examinations on the microbes isolated from rectal swabs were conducted. Of the cases, 316 food histories were surveyed by an analysis of the restaurant menu. Results : There were 139 confirmed cases of cholera reported in Korea in 2001. Of these, 104 were related to the restaurant. By region, Gyeongsangbuk-do had the highest incidence with 91 cases. Of these 91 cases, 74 had ingested foods at the restaurant, 2 were employees and 3 were secondary infection cases within the families. The results of the odds ratio analysis of the 316 persons having ingested foods at the restaurant were as follows: sandwiches 5.07 (95% CI, 1.85-14.59), soybean curd 2.45 (95% CI, 1.09-5.56), noodles 2.34 (95% CI, 1.24-4.42), steamed squid 2.01 (95% CI, 1.17-3.47) and vinegared rice 1.82 (95%, CI, 1.08-3.09). It was certain the restaurant in question was the cause of the 2001 outbreak. Conclusions : We suspected that more than one restaurant employee contaminated foods served at the restaurant. In addition, eating raw fishes purchased at the Pohang Fisheries infected the employees of the restaurant. There is a possibility that these raw fishes were themselves contaminated by cholera bacilli in the sea.

Severe Fever with Thrombocytopenia Syndrome Virus in Ticks in the Republic of Korea

  • Kang, Jun-Gu;Cho, Yoon-Kyoung;Jo, Young-Sun;Han, Sun-Woo;Chae, Jeong-Byoung;Park, Jung-Eun;Jeong, Hyesung;Jheong, Weon-Hwa;Chae, Joon-Seok
    • 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.

코로나19 팬데믹 기간의 서울의 사회적 거리두기 단계 변화와 The Suomi National Polar-Orbiting Partnership (S-NPP) 위성 영상을 이용한 Nighttime Light (NTL) 간의 상관관계 (Correlation Between Social Distancing Levels and Nighttime Light (NTL) during COVID-19 Pandemic in Seoul, South Korea Based on The Day-Night Band (DNB) Onboard The Suomi National Polar-Orbiting Partnership (S-NPP) Satellite)

  • ;이슬기;;한주
    • 대한원격탐사학회지
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    • 제37권6_1호
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    • pp.1647-1656
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    • 2021
  • 한국은 코로나19로 인한 감염전파를 줄이기 위해 4단계의 사회적 거리두기 기준을 설정하고 확진자 발생 비율을 기준으로 단계를 전환하여 시행하고 있다. 이러한 사회적 거리두기는 사람들의 이동 및 모임 등 사회적 접촉을 제한함으로써 시민들의 활동량에 변화를 가져왔다. 이를 직관적으로 확인할 수 있는 데이터 중 하나가 Night Time Light (NTL)이다. NTL은 인공위성에 포착된 불빛을 활용해 측정한 국가경제규모를 측정할 수 있는 변수로, 야간동안 사람의 사회 활동을 파악하는데 활용할 수 있다. NTL 자료는 수오미 위성(Suomi National Polar-orbiting Partnership, S-NPP)에 탑재된 센서인 Visible Infrared Imaging Radiometer Suite (VIIRS)에 포함된 Day-Night Band (DNB)를 통해 얻을 수 있다. 본 연구는 2019년 1월 5일부터 2021년 10월 26일까지 1023개의 Suomi 자료를 수집하고, 서울의 NTL 변화를 시계열로 생성하여 사회적 거리두기 단계와의 상관관계를 분석하였다. 그 결과 사회적 거리두기의 단계가 높아질수록 NTL의 공간적, 시간적 변화가 모두 감소된 것으로 나타났다. 이는 더 높은 단계의 사회적 거리두기 정책이 실행됨에 따라 야간 시간대의 상업 활동 및 모임 인원제한 등과 같은 사회적 활동의 제한이 실제로 서울의 NTL 감소에 영향을 준 것으로 해석할 수 있다. 본 연구는 향후 코로나19 관련 정부의 정책을 평가하고 개선하기 위한 참고자료로 활용할 수 있을 것이다.

3D8 scFv 형질전환 돼지 개발 및 PRRS 저항성 평가 (Production of a transgenic pig expressing 3D8 single chain variable fragment (scFv) and its evaluation of PRRS resistant)

  • 이휘철;이건섭;김지윤;양현;이보람;박미령;황인설;이풍연;변승준;김원일;오건봉
    • 한국동물위생학회지
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    • 제43권4호
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    • pp.227-236
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    • 2020
  • In this study, we have developed 3D8 scFv transgenic pig (TG) by microinjection of fertilized one-cell pig zygotes (2.17%). The effect of 3D8 scFv TG on porcine reproductive and respiratory syndrome virus (PRRSV) resistance were evaluated through PRRSV VR2332 (1×103 TCID50/mL) challenge and transmission experiments. As a result, the average daily weight gain (ADWG) of TG increased compared to the wild type pigs (WT) in PRRSV challenge groups and the serum viremia levels of the TG was significantly lower than of WT on the 7 day and 21 day after infection, meaning that the viral shedding was suppressed by 3D8 scFv expression. These results suggest that the expression of 3D8 scFv in pig could suppress spreading of infected virus to pigs sharing a room.

Bovine mastitis-associated Escherichia coli

  • Hong Qui Le;Se Kye Kim;Jang Won Yoon
    • 한국식품위생안전성학회지
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    • 제39권3호
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    • pp.181-190
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    • 2024
  • 소 유방염 관련 대장균(BMEC)은 생산되는 우유의 양과 품질을 변화시키고 도태율을 높임으로써 전 세계 낙농 산업에 심각한 재정적 손실을 초래할 수 있는 주요 원인 물질로 간주된다. 연구자, 수의사, 농부가 가장 효과적인 치료법과 진단 기술을 이해하고 결정하는 것은 젖소 유방염을 극복하는데 중요하다. 특히 무증상 혹은 준임상형 유방염의 경우, 소는 뚜렷한 증상을 보이지 않고, 장기간에 걸쳐 겉보기에 정상적인 우유를 계속 분비하여 원인 병원체인 대장균이 무리 내에서 감염을 퍼뜨릴 수 있다. 유방염 예방을 위해서는, 병원균의 유방 내 침입, 감염 확립, 유방의 염증의 3단계 병인 과정에 대한 이해가 필수적이다. 지금까지 대장균 유방염의 임상적 중증도에 기여하는 독성 인자와 병원성 사이에 명확한 상관관계가 발견되지 않았다. 다제내성 대장균과 새로운 내성 기전의 진화는 유방염 치료에 항생제를 광범위하게 사용하고 있기 때문에 문제시 되고 있는 실정이다. 따라서 BMEC 치료의 효능을 향상시키기 위해서는 대체제 발굴이 중요하다. 지난 30년 동안 소 유방염의 역학 조사를 위해 다양한 유전자형 분석 기술이 사용되었다. 이러한 연구는 BMEC 계통 간의 진화 관련성 뿐 아니라 기원, 전염 경로, 개체군 구조에 대한 이해를 크게 향상시켰다. 따라서 본 리뷰에서는 BMEC의 전반적 개요를 제공하여 병인, 유전적 관계, 발병 기전, 관리 및 질병 통제를 위한 새로운 치료 옵션에 대한 통찰력을 제공하고자 한다.

닭 티푸스의 발생상황과 Salmonella gallinarum의 항균제 감수성 (Prevalent Characteristics of Fowl Typhoid and Antibiotic Susceptibility of Salmonella gallinarum)

  • 박노찬;도재철;조광현;장성준;권헌일;박덕상
    • 한국동물위생학회지
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    • 제18권2호
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    • pp.113-123
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    • 1995
  • The present study was conducted to investigate the prevalent characteristics of Fowl Typhoid and antibiotic susceptibility of Salmonella gallinarum isolated from 56 infective or dead chickens of 20 egg laying farms in Kyung Buk province during the period from August to December 1994. 1. Among 416, 000 chickens of 92 flocks in 20 egg laying farms, 17, 360 chickens of 31 flocks were died of Fowl Typhoid. 2. Salmonella gallinarum was isolated from 56 chickens in liver and spleen, and then blood of infective chickens was positive to Pullorum antigen. 3, In the survey of gross lesion of 56 chickens, 43 chickens(76.8%) were swelled at liver, 39(69.6%) were swelled at spleen, 12(21.4%) were changed with bronze, 3(5.4% ) were hemorrhagic in peritoneal cavity. 4. In transmission pattern, 4 farms were outbreaked the entrance of chicken house at first, but the others were outbreaked at various place. They were transmitted at right and left directions in flock. 5. 2 farms confirmed at the early stage of infection were eradicated by removing infective chickens and administrating antibiotics, but 18 farms at chronic stage were not. 6. The biochemical properties of 112 Salmonella gallinarum from chickens were generally identical to those of the referance, but H$_2$S was not productive, cellobiose was fermentive. 7 Minimum inhibitory concentration(MIC) of 20 isolates was performed by using 21 antibiotics, MICs of Amikacin(Ak), Gentamicin(Gm), Kanamycin(Km), and Tetracycline (Tc) were below 1.6 ug/ml, Ampicillin(Am), Furazolidone(Fu) and Neomycin(Nm) were below 3.1 ug/ml, Cephalothin(Ce), Cefazoline(Cf) and Chloramphenicol(Cm) were below 6.3 ug/ml, Nalidixic acid(Na), Polymyxin(Po) and Rifampicin(Rf) were below 12.5 ug/ml, Penicillin (Pm) was below 25 ug/ml, Colistin(Co) and Streptomycin(Sm) were below 50 ug/ml, Sulfamerazine(Sr) and Sulfamethazine (St) were below 200 ug/ml, Lincomycin(Lm) and Spiramycin(Sp) were below 400 ug/ml, Bacitracin(Ba) was below 800 ug/ml. 8. Among the 20 isolates, all(100%) of those were sensitive to Ak, Am, Ce, Cf, Cm, Fu, Gm, Km, Na, Nm, Po, Rf, Sr, St and Tc, but 6 isolates(30%) were resistent to Co, 20(100% ) to Ba, Lm, Pm, Sm, and Sp. The drug resistance patterns were simple which 6 strains were BaCoLmPmSmSp type, and 14 were BaLmPmSmSp type.

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Integrating market chain assessments with zoonoses risk analysis in two cross-border pig value chains in Lao PDR

  • Okello, Anna L;Tiemann, Tassilo T;Inthavong, Phouth;Khamlome, Boualam;Phengvilaysouk, Ammaly;Keonouchanh, Soukanh;Keokhamphet, Chattouphone;Somoulay, Virasack;Blaszak, Kate;Blacksell, Stuart D;Okello, Walter O;Allen, John
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권11호
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    • pp.1651-1659
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    • 2017
  • Objective: Lao PDR's recent accession to the World Trade Organization necessitates a greater understanding of the patterns and risk of livestock production in order to better align national policy with the Agreement on the Application of Sanitary and Phytosanitary Measures. This eco-health study was conducted to improve understanding of the interrelations between market chains and zoonotic infection risks at two strategic cross border points between Lao PDR, Thailand and Viet Nam. Methods: Information gained from smallholder farmer/trader interviews was integrated with serological surveys for pig-associated zoonoses-including hepatitis E virus (HEV), Taenia solium (T. solium) and trichinella-to identify potential linkages between disease risk and pig production and slaughter in low input systems common across the country. Results: Trichinella and HEV exposure was high in both humans and pigs in both study areas, significantly associated with pig slaughter and the subsequent consumption and handling of raw pork products. T. solium demonstrated a strong geographical and ethnic association with the northern study area bordering Vietnam. With the right knowledge and accessible, affordable inputs, the majority of smallholder farmers indicated a willingness to invest more in pig production, which could simultaneously improve livelihoods and decrease exposure to HEV, Trichinella, and T. solium through increased access to formal markets and an improved slaughter processes. Conclusion: The linkages identified when assessing disease risk in the context of potential economic and cultural drivers of transmission highlight the importance of a systems-based approach for the detection and control of zoonotic disease, and contributes to an improved understanding of the Lao PDR livestock sector.

코로나-19 보호용 페이스 마스크에서의 액적 고속 충돌 거동 (Microdroplet Impact Dynamics at Very High Velocity on Face Masks for COVID-19 Protection)

  • 최재원;이동호;어지수;이동근;강전웅;지인서;김태영;홍지우
    • Korean Chemical Engineering Research
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    • 제60권2호
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    • pp.282-288
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    • 2022
  • 코로나 팬데믹 시대에서 비말(respiratory droplet)을 통한 감염 및 확산을 막기 위해 마스크는 없어서는 안 될 생활 필수품이 되었다. 본 연구에서는 두 가지 다른 타입의 마스크(KF-94 마스크와 덴탈 마스크)가 비말 차단에 얼마나 효과적인지를 파악하기 위하여, i) 각각의 마스크를 구성하고 있는 필터의 젖음성(wettability) 특성을 분석하고, ii) 필터 표면에 빠른 속도로 충돌하는 미소 액적의 동적 거동 특성을 실험적으로 관찰하였다. 각 필터의 구성 재료에 따라 상반된 젖음성 특성, 소수성(hydrophobicity) 또는 친수성(hydrophilicity)을 보임을 확인하였다. 또한, 일정 체적을 갖는 미소 액적을 안정적으로 토출하는 공압 조건을 탐색하고 액적의 충돌 속도 변화에 따른 액적 충돌 거동 변화를 분석하였다. 마스크를 구성하고 있는 필터의 종류와 액적 충돌 속도에 따라 i) 필터를 통과하지 못하거나(no penetration), ii) 필터에 포획(capture)되거나, iii) 필터를 통과(penetration)하는 등의 다른 충돌 후 거동을 보임을 확인하였다. 이러한 결과들은 비말 차단용 마스크 디자인에 있어 매우 기본적이고 유용한 정보를 제공할 뿐만 아니라, 다양한 다공성 표면에서의 액적 거동에 대한 학문적 연구에도 도움이 될 것으로 판단된다.