In malaria, splenic rupture is a serious complication potentially leading to death. Subcapsular hemorrhage of spleen is thought to be an impending sign of splenic rupture; however, the characteristics of subcapsular hemorrhage are not well known. We report 3 cases of subcapsular hemorrhage of the spleen in vivax malaria, with varying degrees of severity. Case 1 showed subcapsular hemorrhage without splenic rupture, was treated by antimalarial drug without any procedure. The healing process of the patient's spleen was monitored through 6 computed tomography follow-up examinations, over 118 days. Case 2 presented subcapsular hemorrhage with splenic rupture, treated only with an antimalarial drug. Case 3 showed subcapsular hemorrhage with splenic rupture and hypotension, treated using splenic artery embolization. They all recovered from subcapsular hemorrhage without any other complications. These 3 cases reveal the process of subcapsular hemorrhage leading to rupture and a potentially fatal outcome. The treatment plan of subcapsular hemorrhage should be determined carefully considering the vital signs, changes in hemoglobin, and bleeding tendency.
Fatal Outcome ; Follow-Up Studies ; Hemorrhage ; Hypotension ; Malaria ; Malaria, Vivax ; Plasmodium vivax ; Rupture ; Spleen ; Splenic Artery ; Splenic Rupture ; Vital Signs

Plasmodium vivax is usually considered morbidity in endemic areas of Asia, Central and South America, and some part of Africa. In Thailand, previous studies indicated the genetic diversity of P. vivax in malaria-endemic regions such as the western part of Thailand bordering with Myanmar. The objective of the study is to investigate the genetic diversity of P. vivax circulating in Southern Thailand by using 3 antigenic markers and 8 microsatellite markers. Dried blood spots were collected from Chumphon, Phang Nga, Ranong and, Surat Thani provinces of Thailand. By PCR, 3 distinct sizes of PvMSP3α, 2 sizes of PvMSP3β and 2 sizes of PvMSP1 F2 were detected based on the length of PCR products, respectively. PCR/RFLP analyses of these antigen genes revealed high levels of genetic diversity. The genotyping of 8 microsatellite loci showed high genetic diversity as indicated by high alleles per locus and high expected heterozygosity (H(E)). The genotyping markers also showed multiple-clones of infection. Mixed genotypes were detected in 4.8% of PvMSP3α, 29.1% in PvMSP3β and 55.3% of microsatellite markers. These results showed that there was high genetic diversity of P. vivax isolated from Southern Thailand, indicating that the genetic diversity of P. vivax in this region was comparable to those observed other areas of Thailand.
Africa ; Alleles ; Asia, Central ; Genetic Variation ; Genotype ; Malaria ; Microsatellite Repeats ; Myanmar ; Plasmodium vivax ; Plasmodium ; Polymerase Chain Reaction ; South America ; Thailand

BACKGROUND: Vivax malaria reemerged in the Korean peninsula in 1990s beginning from the western border area and spread across both Koreas rapidly with its peak incidences reported on the early 2000s. There have been few reports on the malaria incidence in the Democratic People's Republic of Korea (North Korea) that provides detailed epidemiological features. The purpose of this study was to describe the time trends and spatial distribution of malaria in North Korea with comparison to those in South Korean regions across the border. METHODS: The incidence of malaria in each province of North Korea from 2004 to 2016 was estimated based on data from domestic and international health authorities. Consistency of the data was evaluated by calculating the ratio of malaria cases in each province to the total cases each year. We also compared the changes in malaria incidence over time in South and North Korea adjacent to the demilitarized zone. RESULTS: In North Korea, the incidence of malaria in the three provinces adjacent to the demilitarized zone was the highest (52.1−315.3 per 100,000), followed by Pyeonganbuk-do (14.7−113.5 per 100,000), where railways and road networks were connected to northern China. The incidence of malaria in each province of North Korea reported after 2011 was more consistent than when compared with previous annual data, and there was also a positive correlation between changes in incidence over time when compared with malaria incidence in South Korea (r = 0.855, r = 0.596). CONCLUSION: The malaria report of North Korea was relatively consistent in its spatiotemporal tendency since 2011, suggesting improvement of the quality of the surveillance data. The strong correlation between North and South Korean malaria incidence at regional level suggests that collaboration between both sides are essential for the successful elimination of malaria in the Korean peninsula.
China ; Cooperative Behavior ; Democratic People's Republic of Korea ; Incidence ; Korea ; Malaria ; Malaria, Vivax

Molecular techniques have been introduced for malaria diagnosis because they offer greater sensitivity and specificity than microscopic examinations. Therefore, DNA isolation methods have been developed for easy preparation and cost effectiveness. The present study described a simple protocol for Plasmodium DNA isolation from EDTA-whole blood. This study demonstrated that after heating infected blood samples with Tris–EDTA buffer and proteinase K solution, without isolation and purification steps, the supernatant can be used as a DNA template for amplification by PCR. The sensitivity of the extracted DNA of Plasmodium falciparum and Plasmodium vivax was separately analyzed by both PCR and semi-nested PCR (Sn-PCR). The results revealed that for PCR the limit of detection was 40 parasites/μl for P. falciparum and 35.2 parasites/μl for P. vivax, whereas for Sn-PCR the limit of detection was 1.6 parasites/μl for P. falciparum and 1.4 parasites/μl for P. vivax. This new method was then verified by DNA extraction of whole blood from 11 asymptomatic Myanmar migrant workers and analyzed by Sn-PCR. The results revealed that DNA can be extracted from all samples, and there were 2 positive samples for Plasmodium (P. falciparum and P. vivax). Therefore, the protocol can be an alternative method for DNA extraction in laboratories with limited resources and a lack of trained technicians for malaria diagnosis. In addition, this protocol can be applied for subclinical cases, and this will be helpful for epidemiology and control.
Cost-Benefit Analysis ; Diagnosis ; DNA ; Edetic Acid ; Endopeptidase K ; Epidemiology ; Heating ; Hot Temperature ; Humans ; Limit of Detection ; Malaria ; Methods ; Myanmar ; Plasmodium falciparum ; Plasmodium vivax ; Plasmodium ; Polymerase Chain Reaction ; Sensitivity and Specificity ; Transients and Migrants

Malaria is one of the most important public health problems in tropical areas on the globe. Several factors are associated with susceptibility to malaria and disease severity, including innate immunity such as blood group, hemoglobinopathy, and heme oxygenase-1 (HO-1) polymorphisms. This study was carried out to investigate association among ABO blood group, thalassemia types and HO-1 polymorphisms in malaria. The malarial blood samples were collected from patients along the Thai-Myanmar border. Determination of ABO blood group, thalassemia variants, and HO-1 polymorphisms were performed using agglutination test, low pressure liquid chromatography and polymerase chain reaction, respectively. Plasmodium vivax was the major infected malaria species in the study samples. Distribution of ABO blood type in the malaria-infected samples was similar to that in healthy subjects, of which blood type O being most prevalent. Association between blood group A and decreased risk of severe malaria was significant. Six thalassemia types (30%) were detected, i.e., hemoglobin E (HbE), β-thalassemia, α-thalassemia 1, α-thalassemia 2, HbE with α-thalassemia 2, and β-thalassemia with α-thalassemia 2. Malaria infected samples without thalassemia showed significantly higher risk to severe malaria. The prevalence of HO-1 polymorphisms, S/S, S/L and L/L were 25, 62, and 13%, respectively. Further study with larger sample size is required to confirm the impact of these 3 host genetic factors in malaria patients.
Agglutination Tests ; Blood Group Antigens ; Chromatography, Liquid ; Healthy Volunteers ; Heme Oxygenase (Decyclizing) ; Heme Oxygenase-1 ; Heme ; Hemoglobin E ; Hemoglobinopathies ; Hemoglobins ; Humans ; Immunity, Innate ; Malaria ; Plasmodium vivax ; Polymerase Chain Reaction ; Prevalence ; Public Health ; Sample Size ; Thalassemia

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.
Asymptomatic Infections ; Diagnosis ; Epidemiology ; Genetic Variation ; Human Migration ; Incidence ; Korea ; Malaria ; Malaria, Vivax ; Parasites ; Plasmodium vivax ; Plasmodium ; Population Characteristics ; Republic of Korea

Historically, Plasmodium vivax malaria has been one of the most highly endemic parasitic diseases in the Korean Peninsula. Until the 1970s, vivax malaria was rarely directly lethal and was controlled through the Korean Government Program administered by the National Malaria Eradication Service in association with the World Health Organization's Global Malaria Eradication Program. Vivax malaria has re-emerged in 1993 near the Demilitarized Zone between South and North Korea and has since become an endemic infectious disease that now poses a serious public health threat through local transmission in the Republic of Korea. This review presents major lessons learned from past and current malaria research, including epidemiological and biological characteristics of the re-emergent disease, and considers some interesting patterns of diversity. Among other features, this review highlights temporal changes in the genetic makeup of the parasitic population, patient demographic features, and spatial distribution of cases, which all provide insight into the factors contributing to local transmission. The data indicate that vivax malaria in Korea is not expanding exponentially. However, continued surveillance is needed to prevent future resurgence.
Communicable Diseases ; Culicidae ; Democratic People's Republic of Korea ; Global Health ; Government Programs ; Humans ; Korea ; Malaria ; Malaria, Vivax ; Parasitic Diseases ; Plasmodium vivax ; Population Characteristics ; Public Health ; Republic of Korea

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.
Adolescent ; Blackwater Fever* ; Child* ; Delivery of Health Care ; Female ; Fever ; Hemolysis ; Humans ; Korea ; Malaria* ; Malaria, Falciparum ; Plasmodium vivax ; Quinine

Vivax malaria reemerged in Korea in 1993 and the outbreak has been continued with fluctuating numbers of annual indigenous cases. Understanding the nature of the genetic population of Plasmodium vivax circulating in Korea is beneficial for the knowledge of the nationwide parasite heterogeneity and in the implementation of malaria control programs in the country. Previously, we analyzed polymorphic nature of merozoite surface protein-1 (MSP-1) and MSP-3α in Korean P. vivax population and identified the Korean P. vivax population has been diversifying rapidly, with the appearance of parasites with new genetic subtypes, despite the recent reduction of the disease incidence. In the present study, we developed simple PCR-RFLP methods for rapid subtyping of MSP-1 and MSP-3α of Korean P. vivax isolates. These PCR-RFLP methods were able to easily distinguish each subtype of Korean P. vivax MSP-1 and MSP-3α with high accuracy. The PCR-RFLP subtyping methods developed here would be easily applied to massive epidemiological studies for molecular surveillance to understand genetic population of P. vivax and to supervise the genetic variation of the parasite circulating in Korea.
Epidemiologic Studies ; Genetic Variation ; Incidence ; Korea ; Malaria ; Malaria, Vivax ; Merozoite Surface Protein 1 ; Parasites ; Plasmodium vivax* ; Plasmodium* ; Population Characteristics

Plasmodium vivax merozoite surface protein-1 (PvMSP1) gene codes for a major malaria vaccine candidate antigen. However, its polymorphic nature represents an obstacle to the design of a protective vaccine. In this study, we analyzed the genetic polymorphism and natural selection of the C-terminal 42 kDa fragment within PvMSP1 gene (Pv MSP142) from 77 P. vivax isolates, collected from imported cases of China-Myanmar border (CMB) areas in Yunnan province and the inland cases from Anhui, Yunnan, and Zhejiang province in China during 2009–2012. Totally, 41 haplotypes were identified and 30 of them were new haplotypes. The differences between the rates of non-synonymous and synonymous mutations suggest that PvMSP142 has evolved under natural selection, and a high selective pressure preferentially acted on regions identified of PvMSP133. Our results also demonstrated that PvMSP142 of P. vivax isolates collected on China-Myanmar border areas display higher genetic polymorphisms than those collected from inland of China. Such results have significant implications for understanding the dynamic of the P. vivax population and may be useful information towards China malaria elimination campaign strategies.
China ; Genetic Variation* ; Haplotypes ; Malaria ; Merozoite Surface Protein 1* ; Merozoites* ; Myanmar ; Plasmodium vivax* ; Plasmodium* ; Polymorphism, Genetic ; Selection, Genetic* ; Silent Mutation