We report a case of vivax malaria that showed ruptured form of merozoite only in the peripheral blood. A 28-year old man was admitted to Korea University hospital because of irregular high fever, chill and abdominal pain. The peripheral blood smear, showed only small merozoites which seemed to have been recently released from schizonts and destroyed remnants form of schizonts and did not show any forms of malaria parasite such as ring forms, mature trophozoites, schizonts, and gametocytes. On acridine orange fluorochrome stain, we could not find any suspected forms of malaria. However, we detected parasite LDH which is specific to Plasmodium vivax. Malaria treatment was done to the patient, and he is now under follow up in local hospital.
Abdominal Pain ; Acridine Orange ; Adult ; Fever ; Follow-Up Studies ; Humans ; Korea ; Malaria ; Malaria, Vivax* ; Merozoites* ; Parasites ; Plasmodium vivax ; Schizonts* ; Trophozoites

The discovery and understanding of antigenic proteins are essential for development of a vaccine against malaria. In Plasmodium falciparum, Pf92 have been characterized as a merozoite surface protein, and this protein is expressed at the late schizont stage, but no study of Pv92, the orthologue of Pf92 in P. vivax, has been reported. Thus, the protein structure of Pv92 was analyzed, and the gene sequence was aligned with that of other Plasmodium spp. using bioinformatics tools. The recombinant Pv92 protein was expressed and purified using bacterial expression system and used for immunization of mice to gain the polyclonal antibody and for evaluation of antigenicity by protein array. Also, the antibody against Pv92 was used for subcellular analysis by immunofluorescence assay. The Pv92 protein has a signal peptide and a sexual stage s48/45 domain, and the cysteine residues at the N-terminal of Pv92 were completely conserved. The N-terminal of Pv92 was successfully expressed as soluble form using a bacterial expression system. The antibody raised against Pv92 recognized the parasites and completely merged with PvMSP1-19, indicating that Pv92 was localized on the merozoite surface. Evaluation of the human humoral immune response to Pv92 indicated moderate antigenicity, with 65% sensitivity and 95% specificity by protein array. Taken together, the merozoite surface localization and antigenicity of Pv92 implicate that it might be involved in attachment and invasion of a merozoite to a new host cell or immune evasion during invasion process.
Animals ; Computational Biology ; Cysteine ; Fluorescent Antibody Technique ; Humans ; Immune Evasion ; Immunity, Humoral ; Immunization ; Malaria ; Merozoites* ; Mice ; Parasites ; Plasmodium falciparum ; Plasmodium vivax* ; Plasmodium* ; Protein Array Analysis ; Protein Sorting Signals ; Schizonts ; Sensitivity and Specificity

Anemia associated with Plasmodium vivax (P.vivax) malaria occurs as a result of the lysis of red cells by schizonts, bone marrow suppression, and splenic sequestration. A 20-year-old man presented with fever and anemia. He was diagnosed with P. vivax malaria with a positive direct antiglobulin test and treated with antimalarial medication for 2 weeks. He recovered without sequelae. we suggest that autoimmune hemolytic anemia should be considered as one of cause of anemia in P. vivax malaria.
Anemia ; Anemia, Hemolytic, Autoimmune ; Bone Marrow ; Coombs Test ; Fever ; Humans ; Malaria ; Malaria, Vivax ; Plasmodium ; Plasmodium vivax ; Schizonts ; Young Adult

Anemia associated with Plasmodium vivax (P.vivax) malaria occurs as a result of the lysis of red cells by schizonts, bone marrow suppression, and splenic sequestration. A 20-year-old man presented with fever and anemia. He was diagnosed with P. vivax malaria with a positive direct antiglobulin test and treated with antimalarial medication for 2 weeks. He recovered without sequelae. we suggest that autoimmune hemolytic anemia should be considered as one of cause of anemia in P. vivax malaria.
Anemia ; Anemia, Hemolytic, Autoimmune ; Bone Marrow ; Coombs Test ; Fever ; Humans ; Malaria ; Malaria, Vivax ; Plasmodium ; Plasmodium vivax ; Schizonts ; Young Adult

Primaquine was approved for treatment of malaria in 1952 by the United States Food and Drug Administration (FDA). It has remained the only FDA-licensed drug capable of clearing the intra-hepatic schizonts and hypnozoites of Plasmodium vivax. It is associated with serious hazards and side effects, such as hemolytic anemia and methemoglobinemia. However, there is no report of primaquine causing liver injury in Korea. We describe a case of acute liver failure following primaquine overdose in a 19-year-old man.
Anemia, Hemolytic ; Drug-Induced Liver Injury ; Humans ; Korea ; Liver ; Liver Failure, Acute* ; Malaria ; Methemoglobinemia ; Plasmodium vivax ; Primaquine ; Schizonts ; United States Food and Drug Administration ; Young Adult

Plasmodium vivax malaria, which used to be endemic in the past, re-emerged in 1993 and the number of cases has increased annually. Though there has been no proven endemic drug-resistant malaria case reported, widespread use of anti-malarial chemoprophylaxis for the military personnel could cause emergence of resistance. We herein report a case of tertian malaria, which recurred three times despite the standard chloroquine-primaquine therapy. The patient is 40-year-old male, lives in Dongducheon city, Gyeonggy province, and has never been abroad. He visited hospital in September 2000, because of fever. His blood smear revealed ring forms and trophozoites of P. vivax. He took hydroxychloroquine for 3 days and primaquine for 14 days. His symptoms disappeared then. After 7 months he got fever for 2 days and his blood smear revealed schizonts of P. vivax. He took the same medicines and got well next day. Fever recurred 4 month later, and trophozoites were observed on the blood smear. Hydroxychloroquine and primaquine were prescribed in the same way and fever disappeared. Forty three days later, he had fever and positive blood smear of P. vivax trophozoite. Fever disappeared on the day drug was administered and no malaria was detected in follow up smear of 7 and 14 days. He was free of fever in follow up at 3 months later.
Adult ; Chemoprevention ; Chloroquine ; Fever ; Follow-Up Studies ; Gyeonggi-do ; Humans ; Hydroxychloroquine ; Malaria* ; Malaria, Vivax ; Male ; Military Personnel ; Plasmodium vivax ; Primaquine ; Recurrence ; Schizonts ; Trophozoites

OBJECTIVETo compare the applicability of the SYBR Green-I assay with the standard schizont maturation assay, for determination of sensitivity of Plasmodium vivax (P. vivax) to chloroquine and a new antifolate WR 99210.

METHODSThe study was conducted at Mae Tao Clinic for migrant workers, Tak Province during April 2009 to July 2010. A total of 64 blood samples (1 mL blood collected into sodium heparinized plastic tube) were collected from patients with mono-infection with P. vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P. vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-I assays.

RESULTSA total of 30 out of 64 blood samples collected from patients with P. vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays. The failure rates of the schizont maturation inhibition assay (50%) and the SYBR Green-I assay (54%) were similar (P=0.51). The median IC10s, IC50s and IC90s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P. vivax tested. Based on the cut-off of 100 nM, the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates, respectively. The strength of agreement between the two methods was very poor for both chloroquine and WR99210.

CONCLUSIONSOn the basis of this condition and its superior sensitivity, the microscopic method appears better than the SYBR Green-I Green assay for assessing in vitro sensitivity of fresh P. vivax isolates to antimalarial drugs.

Antimalarials ; pharmacology ; Chloroquine ; pharmacology ; Humans ; Inhibitory Concentration 50 ; Malaria, Vivax ; parasitology ; Organic Chemicals ; Parasitemia ; parasitology ; Parasitic Sensitivity Tests ; Plasmodium vivax ; drug effects ; isolation & purification ; Schizonts ; drug effects

BACKGROUND: Plasmodium vivax malaria was recently re-presenting infectious disease in Korea since was being controlled for about 10 years age, but has been increasing years by year in the soldiers or farmers working at the near Demilitarized Zone(DMZ). So we analyzed the Characteristics of the patients diagnosed as malaria since 1997 in Yeungnam university hospital. METHODS: From January 1997 to August 1999, the 23 patients complainted of the febrile and chilly sense were diagnosed as Plasmodium vivax malaria in Yeungnam university hospital. We analyzed the patient's records for clinical findings(i.e. clinical symptoms and signs), occupation and regions of working or visiting, laboratory findings, treatment and its results, etc. RESULTS: Male patients were 21 and female patients were 2 among the total 23 patients, the 19 of 21 male patients were soldiers discharged from military services. All patients had been visited or worked near the DMZ, as the northern part of Kyungki-do(21 cases) or Kangwon-do(2 cases). And all patients complainted of delayed onset(means 6 months) of fever and chills after working or visiting at this zones. On physical examination, liver or spleen were palpated initially at least 1 finger breadth in 9 cases(39.1%), and peripheral blood smears showed the infected RBCs(i.e. gametocyte, ring form, schizont, trophozoite) in all cases, and 21 cases(91.3%) showed thrombocytopenia. All patients were treated by the combined regimen of 2-days hydroxychloroquine and 14-days primaquine. All cases showed clinical and laboratory improvement initially, but 5 cases were recurred after 2 months and showed re-improvement. And none of 23 cases showed the significant complications and deaths after medical treatment. CONCLUSION: Plasmodium vivax malarial infection is currently re-presenting disease near the DMZ. So we should consider the active prevention and management of malaria.
Chills ; Communicable Diseases ; Female ; Fever ; Fingers ; Humans ; Hydroxychloroquine ; Korea ; Liver ; Malaria ; Malaria, Vivax* ; Male ; Military Personnel ; Occupations ; Physical Examination ; Plasmodium vivax* ; Plasmodium* ; Primaquine ; Schizonts ; Spleen ; Thrombocytopenia

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

Protozoa of the genus Cryptosporidium are small coccidian parasite known to infect the mucosal epithelium of a variety of animals including human, causing fatal course in immunodeficient patients as well as self-limited illness in healthy individuals. Various life cycle stages including trophozoite, meront, merozoite, gametocyte and oocyst in infected mucosa are a diagnostic feature. Electron microscopy (EM) provides sufficient findings for genus and species identification of this parasitic organism. The authors presented scanning and transmission EM findings of Cryptosporidium parvum infection in two children: one with acute lymphoblastic leukemia and the other without any evidence of immune compromise.
Animals ; Child ; Cryptosporidium parvum ; Cryptosporidium* ; Epithelium ; Humans* ; Intestines* ; Life Cycle Stages ; Merozoites ; Microscopy, Electron ; Mucous Membrane ; Oocysts ; Parasites ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Trophozoites