• Parasites, Hosts and Diseases
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• 제52권1호
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• pp.99-103
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• 2014

Mitochondrial genome sequence of malaria parasites has served as a potential marker for inferring evolutionary history of the Plasmodium genus. In Plasmodium falciparum, the mitochondrial genome sequences from around the globe have provided important evolutionary understanding, but no Indian sequence has yet been utilized. We have sequenced the whole mitochondrial genome of a single P. falciparum field isolate from India using novel primers and compared with the 3D7 reference sequence and 1 previously reported Indian sequence. While the 2 Indian sequences were highly divergent from each other, the presently sequenced isolate was highly similar to the reference 3D7 strain.

• Parasites, Hosts and Diseases
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• 제39권2호
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• pp.185-192
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• 2001

To evaluate the factors that determine the transmission level of vivax malaria using vectorial capacity, entomological surveys were conducted from .lune to August, 2000. From 6 nights of human-bait collection in Paju, the human biting rate (ma) was counted as 87.5 bites/man/night. The parity of Anopheles sinensis from human baiting collections fluctuated from 41% to 71% (average 48.8%) of which the rate gradually increased as time passed on: 35.2% in Jun. ; 55.0% in July; 66.2% in Aug. From this proportion of parous, we could estimate the probability of daily survival rate of An. sinensis to be 0.79 assumed with 3 days gonotrophic cycle and the expectancy of infective life through 11 days could be defined as 0.073. Blood meal analysis was performed using ELISA to determine the blood meal source. Only 0.8% of blood meals were from human hosts. We could conclude that An. sinensis is highly zoophilic (cow 61.8%) Malaria is highly unstable (stability index < 0.5) in this area. From these data, vectorial capacity VC) was determined to be 0.081. In spite of a high human biting rate (ma), malaria transmission potential is very low due to a low human blood index. Therefore, we could conclude that malaria transmission by An. sinensis is resulted by high population density, not by high transmission potential. For this reason, we need more effort to decrease vector population and vector-human contact to eradicate malaria in Korea.

• Parasites, Hosts and Diseases
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• 제48권1호
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• pp.9-13
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• 2010

Pentatrichomonas hominis is considered a commensal protozoan in the large intestine of a number of mammalian hosts, such as cats, dogs, and non-human primates. The resulting infections, which can induce diarrhea, have been attributed to opportunistic overgrowth of P. hominis. This study was performed to confirm the P. hominis infection and its molecular characterization from the feces of puppies with diarrhea. Fecal samples were obtained from 14 German shepherd puppies with diarrhea over 1 week (7 females and 7 males, 2-9 months of age) residing on a dog farm in August 2007. Species-specific PCR assay identified P. hominis 18S rRNA genes in 3 of the 14 puppies (1 female and 2 males; 1 aged 2 months and 2 aged 9 months). This phylogenetic analysis established that P. hominis belonged to the 1st clade, which is comprised of Bos taurus and Felines.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.551-555
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• 2013

Complicated malaria is mainly caused by Plasmodium falciparum, but, increasingly, Plasmodium vivax is also being reported as a cause. Since the reemergence of indigenous vivax malaria in 1993, cases of severe malaria have been steadily reported in Korea. Herein, we report a case of vivax malaria complicated by adult respiratory distress syndrome (ARDS) that was successfully managed with extracorporeal membrane oxygenation (ECMO). A 59-year-old man presented at our hospital with fever and abdominal pain, which had persisted for 10 days. On admission, the patient had impaired consciousness, shock, hypoxia and haziness in both lungs, jaundice, thrombocytopenia and disseminated intravascular coagulation, metabolic acidosis, and acute kidney injury. A peripheral blood smear and a rapid diagnostic test verified P. vivax mono-infection. Ten hours after admission, hypoxia became more severe, despite providing maximal ventilatory support. The administration of antimalarial agents, ECMO, and continuous venovenous hemofiltration resulted in an improvement of his vital signs and laboratory findings. He was discharged from the hospital 7 weeks later, without any sequelae.

• Parasites, Hosts and Diseases
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• 제35권4호
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• pp.291-294
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• 1997

1997년 7월과 8월에 경기도 김포군 통진중학교 축구부 부원인 15세 남자 환자 두 명이 각각 발열을 주소로 강남 성모병원에 입원하여 말초혈액 박층 도말검사강 삼일열 말라리아로 진단받고 chloroquine과 primaquine으로 치료받았다. 이들은 외국여행이나 마약사용 경험이 없었으며. 학교 내 축구부 숙소에서 합숙생활을 하고 있었다. 환자들은 합숙하는 친구 중에 발열환자가 더 있 다고 주장하였으므로 말라리아가 집단으로 발생하였을 가능성이 있다고 생각하고. 축구부원에 대한 역학 조사를 실시하였다. 합숙소에서 생활하는 학생들은 총 57명이었다. 문진 결과상 1주일 이상 지속되는 발열 과거력을 가진 사람은 없었다. 진찰 결과 이번에 환자이었던 1명에서만 비장 종대가 관찰되었고. 환자로 입원했던 2명에서 IFAT 항체가는 각각 1: 256 및 1: 2,048이었다 (양성 기준 항체가 1: 32). 말라리아 병력이 없었던 사람 중에는 IFAT 항체가가 1: 64이었던 1명을 제외하고 모두 음성을 나타냈다. 말초혈액 박층도말 검사도 모두 음성이었다. 경기도 김포군에 위치한 통진중학교 축구부 학생 두 명에서 거의 동시에 발생한 삼일열 말라리아는 이 지역에서 전파되어 감염된 것은 아니라고 생각된다.

• Parasites, Hosts and Diseases
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• 제36권2호
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• pp.143-146
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• 1998

최근 primaquine으로 완치 (radicalcure)된 후에도 재발하는 삼일열 말라리아 보고가 많아지면 서 primaquine에 대한 내성 가능성이 언급되고 있다. 저자들은 해외여행 중에 감염된 삼일열 말라리아를 hydroxychloroquine과 primaquine으로 치료한 후 재발한 예를 경험하였기에 문헌고찰과 함께 보고한다. 35세 남자 환자가 내원 34일 전부터 15일간 인도 뭄바이와 중국 쉬천에 출장 다녀왔고 귀국 3일 후부터 고열이 발생하여 발열 17일째 본원에 입원하였다. 말초혈액 도말검사에 서 분열체 내의 분열소체의 수가 14개 이상 되고 세포질 형태가 불규칙적인 영양형이 보여 삼일열 말라리아로 진단한 후 hydrouychloroquine를 투여하고 열이 떨어진 후 primaquine (15 mg/일, 14일간)을 투여하였다. 치료 후 55일째까지 말라리아 재발의 증상이 없었고 말초혈액 도말에서도 말라리아 원충이 없음을 확인하였다. 6개월 후 다시 발열이 생기고 말초혈액 도말검사에서 분열소 체와 영양형이 보여 재발로 진단하였다 처음 입원 때와 같은 방법으로 치료하였고 현재까지 10개월간 경과 관찰 중이며 증상의 재발은 없었다.

• Parasites, Hosts and Diseases
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• 제53권4호
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• pp.421-430
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• 2015

The parasite Plasmodium falciparum causes severe malaria and is the most dangerous to humans. However, it exhibits resistance to their drugs. Farnesyltransferase has been identified in pathogenic protozoa of the genera Plasmodium and the target of farnesyltransferase includes Ras family. Therefore, the inhibition of farnesyltransferase has been suggested as a new strategy for the treatment of malaria. However, the exact functional mechanism of this agent is still unknown. In addition, the effect of farnesyltransferase inhibitor (FTIs) on mitochondrial level of malaria parasites is not fully understood. In this study, therefore, the effect of a FTI R115777 on the function of mitochondria of P. falciparum was investigated experimentally. As a result, FTI R115777 was found to suppress the infection rate of malaria parasites under in vitro condition. It also reduces the copy number of mtDNA-encoded cytochrome c oxidase III. In addition, the mitochondrial membrane potential (${\Delta}{\Psi}m$) and the green fluorescence intensity of MitoTracker were decreased by FTI R115777. Chloroquine and atovaquone were measured by the mtDNA copy number as mitochondrial non-specific or specific inhibitor, respectively. Chloroquine did not affect the copy number of mtDNA-encoded cytochrome c oxidase III, while atovaquone induced to change the mtDNA copy number. These results suggest that FTI R115777 has strong influence on the mitochondrial function of P. falciparum. It may have therapeutic potential for malaria by targeting the mitochondria of parasites.

• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.169-175
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• 2015

The relationship between anti-Plasmodium vivax circumsporozoite protein (CSP) antibody levels and the prevalence of malaria in epidemic areas of South Korea was evaluated. Blood samples were collected from inhabitants of Gimpo-si (city), Paju-si, and Yeoncheon-gun (county) in Gyeonggi-do (province), as well as Cheorwon-gun in Gangwon-do from November to December 2004. Microscopic examinations were used to identify malaria parasites. ELISA was used to quantitate anti-circumsporozoite protein (CSP) antibodies against P. vivax. A total of 1,774 blood samples were collected. The overall CSP-ELISA-positive rate was 7.7% (n=139). The annual parasite incidences (APIs) in these areas gradually decreased from 2004 to 2005 (1.09 and 0.80, respectively). The positive rate in Gimpo (10.4%, 44/425) was the highest identified by CSP-ELISA. The highest API was found in Yeoncheon, followed by Cheorwon, Paju, and Gimpo in both years. The positive rates of CSP-ELISA were closely related to the APIs in the study areas. These results suggest that seroepidemiological studies based on CSP may be helpful in estimating the malaria prevalence in certain areas. In addition, this assay can be used to establish and evaluate malaria control and eradication programs in affected areas.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.133-137
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• 2008

This study was performed to investigate prevalence of clonorchiasis among the inhabitants living in villages along the 4 major rivers, Nakdong-gang (= river), Seomjin-gang, Youngsan-gang, and Guem-gang in southern Korea. From January to December 2006, a total of 24,075 stool samples (1 sample per an inhabitant) were collected in 23 localities and examined by the formalin-ether sedimentation technique. Of the inhabitants examined, 3,441 (14.3%) were found to harbor various types of intestinal parasite eggs, cysts or larvae. Numbers of infected people were 2,661 (11.1%) for Clonorchis sinensis, 431 (1.8%) for heterophyids, 226 (0.9%) for Entamoeba spp., 57 (0.2%) for Giardia lamblia, 30 (0.1%) for Trichuris trichiura, and 18 (0.07%) for echinostomes. Prevalence rates of clonorchiasis according to the river basin were 17.1% in Nakdong-gang, 11.2% in Seomjin-gang, 5.5% in Youngsan-gang and 4.6% in Guem-gang. Of the 2,661 C. sinensis egg-positive cases, 57.7% was male. The present findings suggest that clonorchiasis is still highly prevalent among inhabitants in the riverside areas of southern Korea, and it is necessary to implement a systematic control program in the endemic areas.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.195-198
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• 2008

Plasmodium falciparum liver stage antigen-1 (PfLSA-1) is one of the few antigens expressed exclusively in liver stage parasites. In this study, we evaluated the antibody responses against recombinant PfLSA-1 in naturally infected individuals in Myanmar. High levels of antibody responses (70.7%) were detected in 82 serum samples from 116 infected individuals, and IgG responses to PfLSA-1 principally composed of responses of IgG1 and IgG3 subclasses. These results show that PfLSA-1 elicits effective antibody responses in individuals infected with P. falciparum, and thus it could be not only an attractive candidate protein for vaccine development, but also a useful antigen for serodiagnosis of the infection.