• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.625-632
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• 2018

Malaria remains one of the leading health burdens in the developing world, especially in several sub-Saharan Africa countries; and Uganda has some of the highest recorded measures of malaria transmission intensity in the world. It is evident that the prevalence of malaria infection, the incidence of disease, and mortality from severe malaria remain very high in Uganda. Although the recent stable political and economic situation in the last few decades in Uganda supported for a fairly good appreciation of malaria control, the declines in infection, morbidity, and mortality are not sufficient to interrupt transmission and this country is among the top 4 countries with cases of malaria, especially among children under 5 years of age. In fact, Uganda, which is endemic in over 95% of the country, is a representative of challenges facing malaria control in Africa. In this study, we evaluated an active case detection program in 6 randomly selected villages, Uganda. This program covered a potential target population of 5,017 individuals. Our team screened 12,257 samples of malaria by active case detection, every 4 months, from February 2015 to January 2017 in the 6 villages (a total of 6 times). This study assessed the perceptions and practices on malaria control in Kiyuni Parish of Kyankwanzi district, Uganda. Our study presents that the incidence of malaria is sustained high despite efforts to scale-up and improve the use of LLINs and access to ACDs, based on the average incidence confirmed by RDTs.

• Parasites, Hosts and Diseases
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• 제30권3호
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• pp.177-182
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• 1992

Saimiri 원숭이 21마리와 Aotus 원숭이 12마리에게 Plasmedium falciparum Indochina CDC-1충주(원숭이 순응 충주)를 접종시킨 후 3주간 혈소판과 혈액치를 경시적으로 관찰하였던 바, 이들 원숭이 (Saimiri sciureus boliviensis와 Aotus nancymai karyotype-1)는 접종 14일 후에 최고의 기생률, 호중구감소증, 임파구증가증 그리고 심한 혈색소혈증과 섬유소원의 퇴행성 산물(FDP's)치의 증가를 수반한 섬한 혈소판 감소성 빈혈증이 관찰되었다. Aotus에 있어서는 평균혈색소량(MCH)과 평균혈구용적(MCV)치의 감소와 기생률의 증가를 가져왔으나, Saimiri에 있어서는 기생률이 상승함에 따라서 이들 혈액치는 유의적 차이로 상승하는 결과를 가져왔다. 일반적으로 이들 두 원숭이에 있어서 혈소판의 감소 증세와 최고 기생률을 14잎 째 나타낸 후 곧 정상 혈액치로 회복되는 소견이 관찰된다. 특히 혈소판의 변화에 있어서 Aotus 원숭이는 다른 혈액치의 변화 그리고 기생률과 깊 은 상관관계를 갖고 있었으나, Saimiri에 있어서는 상관관계를 유지하지 못하였다. 결론적으로 말라리아 연구시 Aotus 원숭이가 Saimiri 원숭이 보다 우수한 품종임과 말라리아 진단과정에 있어서 혈소판의 회복률과 재생은 말라리아의 감염시기 판정에 유용한 자료로서 활용될 수 있음을 관찰하였으며, 말라리아 병원성 판정에 대한 실험에 있어서 이들 두 종류 원숭이의 혈액치 변화 특이성을 보고하는 바이다.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.545-552
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• 2018

Plasmodium vivax is more challenging to control and eliminate than P. falciparum due to its more asymptomatic infections with low parasite densities making diagnosis more difficult, in addition to its unique biological characteristics. The potential re-introduction of incidence cases, either through borders or via human migrations, is another major hurdle to sustained control and elimination. The Republic of Korea has experienced re-emergence of vivax malaria in 1993 but is one of the 32 malaria-eliminating countries to-date. Despite achieving successful nationwide control and elimination of vivax malaria, the evolutionary characteristics of vivax malaria isolates in the Republic of Korea have not been fully understood. In this review, we present an overview of the genetic variability of such isolates to increase understanding of the epidemiology, diversity, and dynamics of vivax populations in the Republic of Korea.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.431-436
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• 2011

The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors as well as by individual host responses to these determinants. In both humans and mice, liver injury follows parasite entry, persisting to the erythrocytic stage in the case of infection with the fatal strain of Plasmodium falciparum. Hepatic nuclear factor (HNF)-$1{\alpha}$ is a master regulator of not only the liver damage and adaptive responses but also diverse metabolic functions. In this study, we analyzed the expression of host HNF-$1{\alpha}$ in relation to malaria infection and evaluated its interaction with the 5'-untranslated region of subtilisin-like protease 2 (subtilase, Sub2). Recombinant human HNF-$1{\alpha}$ expressed by a lentiviral vector (LV HNF-$1{\alpha}$) was introduced into mice. Interestingly, differences in the activity of the 5'-untranslated region of the Pf-Sub2 promoter were detected in 293T cells, and LV HNF-$1{\alpha}$ was observed to influence promoter activity, suggesting that host HNF-$1{\alpha}$ interacts with the Sub2 gene.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.571-574
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• 2015

In order to determine the status of malaria among schoolchildren on Kome Island (Lake Victoria), near Mwanza, Tanzania, a total of 244 schoolchildren in 10 primary schools were subjected to a blood survey using the fingerprick method. The subjected schoolchildren were 123 boys and 121 girls who were 6-8 years of age. Only 1 blood smear was prepared for each child. The overall prevalence of malaria was 38.1% (93 positives), and sex difference was not remarkable. However, the positive rate was the highest in Izindabo Primary School (51.4%) followed by Isenyi Primary School (48.3%) and Bugoro Primary School (46.7%). The lowest prevalence was found in Muungano Primary School (16.7%) and Nyamiswi Primary School (16.7%). These differences were highly correlated with the location of the school on the Island; those located in the peripheral area revealed higher prevalences while those located in the central area showed lower prevalences. Plasmodium falciparum was the predominant species (38.1%; 93/244), with a small proportion of them mixed-infected with Plasmodium vivax (1.6%; 4/244). The results revealed that malaria is highly prevalent among primary schoolchildren on Kome Island, Tanzania, and there is an urgent need to control malaria in this area.

• Parasites, Hosts and Diseases
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• 제40권4호
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• pp.165-172
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• 2002

Collaborative studies have identified some genetic factors contributing to the development of severe forms of malaria and schistosomiasis. In Thailand, the $TNF-{\alpha}{\;}5'-flanking$ region shows biallelic polymorphic sites at nucleotides -238, -308, -857, -863, and -1031, and seven alleles have been identified in patients from Myanmar. We found that the TNF promoter (TNFP)-D allele was significantly associated with cerebral malaria in populations from Karen (P < 0.0001. OR ＝ 124.86) and ethnic Burma (P < 0.0001, OR = 34.50) . In China, we have identified two major genes related to the severity of liver fibrosis, one an HLA class II gene, and the other the IL-13 gene. The frequency of the HLA- DRB5*0101 allele and that of the IL-13 promoter A/A (IL- l3P- A/A) genotype were elevated in fibrotic patients, although the two genes are located on different chromosomes, chromosomes 6p and 5q, respectively Subjects with both genotypes had odds ratios (OR = 24.5) much higher than the sum of the ratios for each individual genotype (OR ＝ 5.1,95% Confidence Interval 1.3-24.7 for HLA-DRB5*0101, OR ＝ 3.1 95% CI 1.5 - 6.5 for IL-l3P-A/A). That the effects of the two susceptibility markers are synergistic rather than additive, strongly suggests that the pathogenic Th2 response directly influences the prognosis of post-schistosomal liver fibrosis.

• Laboratory Medicine Online
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• 제1권2호
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• pp.100-104
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• 2011

배경: 말라리아는 국내에서 여전히 유행하고 있는 감염질환이다. 현재까지 말라리아의 진단에는 혈액도말검사의 검경법이 표준방법으로 되어 있으나 혈중 원충 농도가 낮을 경우에 예민도가 떨어지고 판독하기까지 많은 시간이 소요된다. 본 연구자들은 최근 개발된 LG Advansure^TM Malaria P.f./P.v. real-time QPCR (LG 생명과학)의 수행능력을 평가하고자 한다. 방법: 고려대학교 안산병원에 내원한 173명의 검체를 사용하였다. 고전적인 검경법으로 말라리아로 진단받았던 73명의 환자와 100명의 건강인을 대상으로 하여 LG Advansure^TM Malaria P.f./P.v. real-time QPCR를 시행하였고 그 결과를 비교하였다. 또한 말라리아 양성 혈액을 정상 혈액으로 10배로 배수 희석하여 검출 한계를 설정하였다. 결과: 총 73명의 환자 중 혈액도말 검사상 70명이 삼일열 말라리아로 진단받았으며 중합효소연쇄반응검사상 69명(98.6%)이 양성률을 보였다. 또한 혈액도말 검사상 열대열 원충이 발견되었던 3명(100%)의 경우 중합효소연쇄반응 검사상 모두 양성 결과였다. 본 중합효소연쇄반응 키트의 경우 μL당 0.1개의 원충까지 검출할 수 있는 높은 예민도를 보였다. 결론: LG Advansure^TM Malaria P.f./P.v. real-time QPCR 검사는 민감도와 특이도가 높았으며 원충의 농도가 매우 낮을 경우에도 검출할 수 있어 말라리아 감염의 진단에 유용할 것으로 생각한다.

• Parasites, Hosts and Diseases
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• 제61권1호
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• pp.24-32
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• 2023

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), encoded by the polymorphic var multigene family, is a highly polymorphic antigen that plays a crucial role in the pathology of malaria. The contribution of the genetic diversity of var toward the immune escape of P. falciparum has not yet been fully elucidated. This study aimed to characterize the diversity of var repertoires by screening P. falciparum Duffy-binding-like α domain (PfDBLα) among field isolates from central Myanmar. Genetic analysis revealed that the D-H segments of var in Myanmar populations have an extensive polymorphic repertoire, with high numbers of unique sequence types in each individual. However, var genes from the global population, including Myanmar, shared close genetic lineages regardless of their geographic origins, indicating that they have not undergone rapid evolutionary changes.

• Parasites, Hosts and Diseases
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• 제62권3호
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• pp.302-312
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• 2024

Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is a major candidate for the blood-stage malaria vaccine. Genetic polymorphisms of global pfama-1suggest that the genetic diversity of the gene can disturb effective vaccine development targeting this antigen. This study was conducted to explore the genetic diversity and gene structure of pfama-1 among P. falciparum isolates collected in the Khyber Pakhtunkhwa (KP) province of Pakistan. A total of 19 full-length pfama-1 sequences were obtained from KP-Pakistan P. falciparum isolates, and genetic polymorphism and natural selection were investigated. KP-Pakistan pfama-1 exhibited genetic diversity, wherein 58 amino acid changes were identified, most of which were located in ectodomains, and domains I, II, and III. The amino acid changes commonly found in the ectodomain of global pfama-1 were also detected in KP-Pakistan pfama-1. Interestingly, 13 novel amino acid changes not reported in the global population were identified in KP-Pakistan pfama-1. KP-Pakistan pfama-1 shared similar levels of genetic diversity with global pfama-1. Evidence of natural selection and recombination events were also detected in KP-Pakistan pfama-1.

• Parasites, Hosts and Diseases
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• 제34권3호
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• pp.211-213
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• 1996

Malaysian, Ajricn and Thai PZQsmodiumJnkipamm isolates were cultured in uiko by the Tracer and Jensen method (1976, 1977) and were later cloned by the limiting dilution method (Rosario, 1981), Forty-eight clones were obtained and were characterized by electrophoretic variations of GDH (NADP-dependent glutamate dehydrogenase)(EC. 1.4.1.4). It was found that they were pure clones because they possessed either GDH-1 or GDH-2 unlike their parent isolates which exhibited both GDH-1 and GDH-2.