• Parasites, Hosts and Diseases
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• v.54 no.2
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• pp.215-219
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• 2016

Clonorchis sinensis is currently the most important parasite affecting public health problems in the Republic of Korea. We investigated the prevalence of C. sinensis infection among residents living along 5 major rivers in Korea. A total of 42,562 individual stool samples were collected from 37 localities and examined using the formalin-ether sedimentation technique. Helminth eggs were detected in 4,052 (9.5%) residents and 3,586 (8.4%) were infected with C. sinensis. The egg positive rate of C. sinensis in Nakdong, Seomjin, Geum, Yeongsan, and Han River was 11.7%, 9.9%, 6.5%, 3.1%, and 1.0%, respectively. The overall prevalence of clonorchiasis by sex was 11.2% in males and 6.2% in females. The age-prevalence was the highest in the 50-59 years band. It has been reconfirmed that the endemicity of clonorchiasis is higher in southern areas of Korea, especially along Nakdong and Seomjin Rivers. A combination of continuous control programs with health education initiatives is urgently required in these highly endemic areas of clonorchiasis in Korea.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.227-233
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• 2009

Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less incomparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.285-294
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• 2006

Changing patterns of the reemerging Plasmodium vivax malaria in the Republic of Korea (South Korea) during the period 1993 to 2005 are briefly analyzed with emphasis on the control measures used and the effects of meteorological and entomological factors. Data were obtained from the Communicable Diseases Monthly Reports published by the Korea Center for Disease Control and Prevention, and webpages of World Health Organization and United Nations. Meteorological data of Kangwon-do (Province) were obtained from local weather stations. After its first reemergence in 1993, the prevalence of malaria increased exponentially, peaking in 2000, and then decreased. In total, 21,419 cases were reported between 1993 and 2005 in South Korea. In North Korea, a total of 916,225 cases were reported between 1999 and 2004. The occurrence of malaria in high risk areas of South Korea was significantly (P < 0.05) correlated with the mosquito population but not with temperature and rainfall, Control programs, including early case detection and treatment, mass chemoprophylaxis of soldiers, and international financial aids to North Korea for malaria control have been instituted. The situation of the reemerging vivax malaria in the Republic of Korea is remarkably improving during the recent years, at least in part, due to the control activities undertaken in South and North Korea.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.65-70
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• 2008

Artemisinin-based combination therapy (ACT) is currently promoted as a strategy for treating both uncomplicated and severe falciparum malaria, targeting asexual blood-stage Plasmodium falciparum parasites. However, the effect of ACT on sexual-stage parasites remains controversial. To determine the clearance of sexual-stage P. falciparum parasites from 342 uncomplicated, and 217 severe, adult malaria cases, we reviewed and followed peripheral blood sexualstage parasites for 4 wk after starting ACT. All patients presented with both asexual and sexual stage parasites on admission, and were treated with artesunate-mefloquine as the standard regimen. The results showed that all patients were asymptomatic and negative for asexual forms before discharge from hospital. The percentages of uncomplicated malaria patients positive for gametocytes on days 3, 7, 14, 21, and 28 were 41.5, 13.1, 3.8, 2.0, and 2.0%, while the percentages of gametocyte positive severe malaria patients on days 3, 7, 14, 21, and 28 were 33.6, 8.2, 2.7, 0.9, and 0.9%, respectively. Although all patients were negative for asexual parasites by day 7 after completion of the artesunate-mefloquine course, gametocytemia persisted in some patients. Thus, a gametocytocidal drug, e.g., primaquine, may be useful in combination with an artesunate-mefloquine regimen to clear gametocytes, so blocking transmission more effectively than artesunate alone, in malaria transmission areas.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.375-377
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• 2012

Malaria is still a leading cause of morbidity and mortality. The increase in lipid peroxidation reported in malaria infection and antioxidant status may be a useful marker of oxidative stress during malaria infection. The aim of this study was to investigate the role of antioxidant enzymes against toxic reactive oxygen species in patients infected with Plasmodium vivax and healthy controls. Malondialdehyde levels, superoxide dismutase, and glutathione peroxidase activities were determined in 91 P. vivax patients and compared with 52 controls. Malondialdehyde levels, superoxide dismutase, and glutathione peroxidase activities were $8.07{\pm}2.29$ nM/ml, $2.69{\pm}0.33$ U/ml, and $49.6{\pm}3.2$ U/g Hb in the patient group and $2.72{\pm}0.50$ nM/ml, $3.71{\pm}0.47$ U/ml, and $62.3{\pm}4.3$ U/g Hb in the control group, respectively. Malondialdehyde levels were found statistically significant in patients with vivax malaria higher than in healthy controls (P<0.001). On the other hand, superoxide dismutase and glutathione peroxidase activities were found to be significantly lower in vivax malaria patients than in controls (P<0.05). There was an increase in oxidative stress in vivax malaria. The results suggested that antioxidant defense mechanisms may play an important role in the pathogenesis of P. vivax.

• Journal of the Korean association of regional geographers
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• v.20 no.3
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• pp.334-343
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• 2014

The number of malaria cases has been undulating for the past 10 years in Korea since the reemergence of malaria in early 1990's. Considering the spatial variations of malaria incidence across the northmost border areas near the demilitarized zone (DMZ), the occurrence of the disease seems to be influenced by the natural and human environment in the region. Malaria is an infectious disease that is transmitted to humans by the bites of vector-mosquitoes that carry malaria parasites, and its incidence rate depends on specific climatic and sociodemographic factors. This study found that the spatial characteristics of malaria incidence have varied depending on relative proportions of mosquito habitats, distance between mosquito habitats and human residence, the physical and sociodemographic environments of the city by urbanization, and local topography.

• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.111-114
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• 2007

Chloroquine remains the drug of choice for the treatment of vivax malaria in Thailand. Mixed infections of falciparum and vivax malaria are also common in South-East Asia. Laboratory confirmation of malaria species is not generally available. This study aimed to find alternative regimens for treating both malaria species by using falciparum antimalarial drugs. From June 2004 to May 2005, 98 patients with Plasmodium vivax were randomly treated with either artemether-lumefantrine (n = 47) or chloroquine (n = 51). Both treatments were followed by 15 mg of primaquine over 14 days. Adverse events and clinical and parasitological outcomes were recorded and revealed similar in both groups. The cure rate was 97.4% for the artemether-lumefantrine treated group and 100% for the chloroquine treated group. We concluded that the combination of artemether-lumefantrine and primaquine was well tolerated, as effective as chloroquine and primaquine, and can be an alternative regimen for treatment of vivax malaria especially in the event that a mixed infection of falciparum and vivax malaria could not be ruled out.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.293-297
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• 1997

Malaria, caused by any of four species of protozoan parasites of the genus Plasmodium, is charaterized by high fever, anemia and splenomegaly. Although malaria is a cause of significant morbidity and mortality worldwide, in Korea indigenous malaria has been believed to be eradicated by 1984. However, since the case report of native malaria in 1993, reported cases have been increased annually, reaching more than 300 cases in 1996. We experienced a 2 years-old male with fever, severe anemia and splenomegaly who resided in Inchon city. He had the history of travelling to the area (Yunchon) near western Demilitarized Zone for 1 month this summer. After more than 2 weeks without special attention, he was presented with pallor, anemia and splenomegaly. He was diagnosed to have malaria by Plasmodium vivax with the help of peripheral blood smears which showed various forms of malaria, i.e., ring form, trophozoites, shizonts and gametocytes. He was treated successfully with hydroxychloroquine and primaquine. We report this case with brief review of related literature.

• Pediatric Infection and Vaccine
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• v.24 no.2
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• pp.117-122
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• 2017

Blackwater fever is a serious clinical syndrome manifested by acute intravascular hemolysis, fever, and the passage of black or red urine, which is classically associated with falciparum malaria and irregular administration of quinine. In Korea, Plasmodium vivax is the only endemic malaria circulating; a number of imported cases of falciparum malaria have been reported in patients following return from international travel to a malaria endemic area. Therefore, it is important for health care professionals including pediatricians to be aware of the falciparum malaria and its clinical courses. Herein, we report a case of a 14-year-old girl with severe falciparum malaria that was complicated by blackwater fever.

• Laboratory Medicine Online
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• v.1 no.2
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• pp.100-104
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• 2011

Background: Malaria is a problematic disease in Korea, and microscopic examination of Giemsa-stained blood smear has been used as the gold standard for its diagnosis. However, this technique is time-consuming and has low sensitivity in samples with low numbers of malarial parasites (<20 parasites/μL). Here, we evaluated the performance characteristics of the LG Advansure^TM Malaria P.f./P.v. real-time QPCR (LG life sciences, Korea). Methods: Blood samples from 173 persons who visited Korea University Ansan Hospital were evaluated. QPCR was performed in 73 malaria patients and 100 healthy subjects by using the LG Advansure Malaria P.f./P.v. real-time QPCR^R kit, and the results were compared with those of microscopy. The detection limit of this kit was determined by serial dilution of Plasmodium-infected blood with normal blood (blood not infected with Plasmodium). Results: Among the 73 patients that were microscopically confirmed to have malaria (Plasmodium vivax infection, N=70, P. falciparum infection, N=3), 69 patients were diagnosed with P. vivax infection and 3 were diagnosed with P. falciparum infection by LG Advansure^TM Malaria P.f./P.v. realtime QPCR. Both the tests indicated absence of infection in the 100 healthy subjects. The detection limit of LG Advansure^TM Malaria P.f./P.v. real-time QPCR was 0.1 parasite/μL. Conclusions: LG Advansure^TM Malaria P.f./P.v. real-time QPCRis a very sensitive and specific technique and can be used as a confirmatory test for malaria.