• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.377-381
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• 2014

Microscopy is considered as the gold standard for malaria diagnosis although its wide application is limited by the requirement of highly experienced microscopists. PCR and serological tests provide efficient diagnostic performance and have been applied for malaria diagnosis and research. The aim of this study was to investigate the diagnostic performance of nested PCR and a recently developed an ELISA-based new rapid diagnosis test (RDT), NovaLisa test kit, for diagnosis of malaria infection, using microscopic method as the gold standard. The performance of nested-PCR as a malaria diagnostic tool is excellent with respect to its high accuracy, sensitivity, specificity, and ability to discriminate Plasmodium species. The sensitivity and specificity of nested-PCR compared with the microscopic method for detection of Plasmodium falciparum, Plasmodium vivax, and P. falciparum/P. vivax mixed infection were 71.4 vs 100%, 100 vs 98.7%, and 100 vs 95.0%, respectively. The sensitivity and specificity of the ELISA-based NovaLisa test kit compared with the microscopic method for detection of Plasmodium genus were 89.0 vs 91.6%, respectively. NovaLisa test kit provided comparable diagnostic performance. Its relatively low cost, simplicity, and rapidity enables large scale field application.

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.99-103
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• 2010

Malaria is endemic in the Cukurova region while it is sporadic in other regions of Turkey. Therefore, the laboratory and clinical diagnosis of malaria is important for the treatment of malaria. In this study, 92 blood samples that were taken from the suspected malaria patients for routine diagnosis in a period of 10 years between 1999 and 2009 were analyzed. All of these blood samples were examined by microscopic examinations using Giemsa-stained thick blood films, nested PCR, and real-time PCR. The sensitivity-specificity and positive-negative predictive values for these diagnostic tests were then calculated. It was found that the positive predictive values of microscopic examination of thick blood films, nested PCR, and real-time PCR were 47.8%, 56.5%, and 60.9% for malaria, respectively. The real-time PCR was found to have a specificity of 75% and sensitivity of 100%, while specificity and sensitivity of nested PCR was found 81.2% and 97.7% according to the microscopic examination of thick blood films, respectively.

• Journal of Microbiology
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• v.37 no.4
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• pp.234-242
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• 1999

To obtain the recombinant circumsporozoite (CS) protein for the diagnosis of patients and seroepidemiology of Plasmodium vivax malaria which have been prevalent in northern part of Kyonggido, the CS protein gene was amplified by the polymerase chain reaction (PCR) from genomic DNA of the Korean vivax malaria patient. The gene consists of 1,123 nucleotides except signal peptide sequences and had an uninterrupted reading frame encoding a protein of 374 amino acids with a central region of 20 tandem repeats of the nonapeptide. The CS protein gene was expressed in Escherichia coli and purified, the molecular weight of recombinant CS protein was about 44 kDa (monomer) under denaturing purification and about 65 kDa (dimer) under native purification by SDS-PAGE. The purified recombinant CS protein which has antigenicity to malaria patients in Western blot analysis and Enzyme-linked immunosorbent assay, reacted only with the serum of P. vivax (PV210) infected malaria patients with no cross reaction to the P. falciparum malaria patient. The recombinant CS protein purified in this study will serve as a useful antigen to support the diagnosis of malaria patients and seroepidemiology.

• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.171-176
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• 2001

Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), meroxoite surface protein (MSP-1), apical merozoite antigen (AMA- 1), serine repeat antigen (SERA), and exported antigen (EXP- 1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using S antigens (91.9%) rather than using each antigen solely (55.6 - 80%), a combination of 2 (76.3 - 87.5%), 3 (85.6 - 90.6%), or 4 antigens (89.4 - 91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

• Parasites, Hosts and Diseases
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• v.39 no.4
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• pp.301-306
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• 2001

A total of 827 malaria cases were reported in the Gangwon-do in the year 2000. There were 18.2 cases per 100,000 inhabitants. There were 283 cases among civilians and 544 cases among the military. 90.6% of cases were reported in Cheorwon-(531), Hwacheon- (152), and Goseong- (66) gun (county), which bordered the demilitarized zone (DMZ). A distinct feature pertaining to the malaria cases in Gangwon-do is that the number of cases has increased about two times over the last year. The mean time from the beginning of symptoms to malaria diagnosis was five days. Control systems for malaria by public health organizations and military organizations are well maintained , but were not able to reduce the malaria prevalence rate. The cause for the increase in pattern of the malaria cases in Gangwon-do may be caused by the spreading of prevalent areas of malaria to the east. Continuous endeavor such as early detection of cases, early treatment, education on clinical symptoms and prevention of mosquito bites with repellent and mosquito nets will help to reduce the infection rate of malaria in Gangwon-do.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.288-292
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• 1997

Malaria is a febrile disease caused by protozoan parasites, genus Plasmodium. In Korea., indigenous malaria has been believed to be eradicated by 1984, and, thereafter, all of the reported cases were imported malaria. But since the first case report of re-emerging indigenous malaria in 1993, increasing number of cases were reported reaching more than 350 cases in 1996. However, indigenous malaria in children has not been reported yet. We experienced two cases of indigenous malaria in sisters who were 7 and 5 years old, respectively. Elder sister was presented with periodic fever, splenomegaly and mild headache. She had been to Guam before 4 months of the onset of symptoms. Younger sister was suffered from fever and splenomegaly and has not been abroad. They were diagnosed by examination of peripheral blood smear to be infected with Plasmodium vivax and were treated with hydroxychloroquine and primaquine successfully. These cases are believed to be first re-emerging cases of indigenous malaria in children, and malaria should be included in the differential diagnosis of unexplained febrile children.

• Journal of agricultural medicine and community health
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• v.31 no.2
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• pp.157-164
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• 2006

Objectives: Early diagnosis and treatment is the most important strategy to control malaria effectively. Microscopic examination of blood films is a traditional and standard method for diagnosing malaria, which takes a long time and needs expertise, Therefore, the alternative method, rapid diagnostic kit has been used for quick diagnosis in some counties, a highly infectious region by P. vivax. The purpose of this study was to evaluate the utility of malaria rapid diagnostic kit in Ganghwa county. Methods: The utility was evaluated by mean diagnosis time and sensitivity and specificity. For monitoring mean diagnosis time, 942 cases which were diagnosed for P. vivax were collected between 1998 and 2005, And for calculating sensitivity and specificity, 434 whole bloods in EDTA which were presented for P. vivax by microscopy and rapid diagnostic kit were collected between 2004 and 2005. Results: After malaria rapid diagnostic kit was used in 2003, mean diagnosis time has decreased to 3.36-3.14 day. The sensitivity and specificity of the rapid diagnostic kit was 98.2% and 98,5% and comparable to that of microscopic examination. Conclusions: The malaria rapid diagnostic kit is useful tool in a highly infectious region like Ganghwa county.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.609-617
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• 2020

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.

• Parasites, Hosts and Diseases
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• v.58 no.1
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• pp.61-65
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• 2020

Majority of the imported malaria cases in Korea is attributed to Plasmodium falciparum and P. vivax infections, whereas P. malariae and P. ovale infections are very rare. Falciparum and ovale malaria are mostly imported from Africa, while most of the vivax malaria cases are imported from Southeast Asia. Here, we report 6 Korean imported ovale malaria cases (4 males and 2 females) who had visited in Africa during 2013-2016. These subjects were diagnosed with P. ovale based on microscopic findings, Plasmodium species-specific nested-PCR, and phylogenetic clade using 18S rRNA gene sequences. We identified 2 P. ovale subtypes, 1 P. ovale curtisi (classic type) and 5 P. ovale wallikeri (variant type). All patients were treated with chloroquine and primaquine, and no relapse or recrudescence was reported for 1 year after treatment. With increase of travelers to the countries where existing Plasmodium species, the risk of Plasmodium infection is also increasing. Molecular monitoring for imported malaria parasites should be rigorously and continuously performed to enable diagnosis and certification of Plasmodium spp.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.447-452
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• 2018

Prompt diagnosis of malaria cases with rapid diagnostic tests (RDTs) has been widely adopted as an effective malaria diagnostic tool in many malaria endemic countries, primarily due to their easy operation, fast result output, and straightforward interpretation. However, there has been controversy about the diagnostic accuracy of RDTs. This study was conducted to evaluate the diagnostic performances of the 2 commercially available malaria RDT kits, RapiGEN Malaria Ag Pf/Pv (pLDH/pLDH) and Asan $EasyTest^{TM}$ Malaria Ag Pf/Pv (HRP-2/pLDH) for their abilities to detect Plasmodium species in blood samples collected from Ugandan patients with malaria. To evaluate the diagnostic performances of these 2 RDT kits, 229 blood samples were tested for malaria infection by microscopic examination and a species-specific nested polymerase chain reaction. The detection sensitivities for P. falciparum of Malaria Ag Pf/Pv (pLDH/pLDH) and Asan $EasyTest^{TM}$ Malaria Ag Pf/Pv (HRP-2/pLDH) were 87.83% and 89.57%, respectively. The specificities of the 2 RDTs were 100% for P. falciparum and mixed P. falciparum/P. vivax infections. These results suggest that the 2 RDT kits showed reasonable levels of diagnostic performances for detection of the malaria parasites from Ugandan patients. However, neither kit could effectively detect P. falciparum infections with low parasitaemia (<$500parasites/{\mu}l$).