A 7-day in vivo test system was applied to assess the parasitological response to chloroquine treatment in patients with falciparum malaria in the Central Province and National Capital District of Papua New Guinea. 30 patients were investigated but only 23 took a full course of chloroquine and were completely followed up. Of the 23 patients, 13 (57%) were negative for malaria parasites on day 2, 4 (17%) had significantly reduced parasitaemia by day 2 and cleared parasites by day 7, and 1 (4%) showed a partial response (R2). In 5 (22%) of the patients resistance at the R3 level was observed. The indication from this study is that chloroquine should continue to be the first-line drug for the treatment of uncomplicated falciparum malaria. However, judicious use of chloroquine in uncomplicated falciparum malaria is required to halt the spread of chloroquine-resistant strains of Plasmodium falciparum.
Antimalarials - therapeutic use ; Chloroquine - therapeutic use ; Drug Resistance ; Malaria, Falciparum - drug therapy ; Malaria, Falciparum - parasitology

A case of congenital malaria infection has been studied in a 46-day old female Korean infant. Her mother suffered from malaria infection during pregnancy in Uppervolta, Africa, and returned to Korea at the 9th month of gestation for delivery. At 39 days of age, the clinical features characterized by fever, irritability, pallor, jaundice and hepatosplenomegaly were developed. The laboratory data revealed a hemolytic anemia with thrombocytopenia, hyperbilirubinemia and increased hepatic enzyme values. A peripheral blood smear demonstrated intraerythrocytic malarial parasites snd gametocytes of Plasmodium falcifarum. She was successfully treated with quinine sulfate (25 mg/kg/day in three doses for 5 days) and trimethoprim/sulfamethoxazole (8 mg/kg/day in two doses for 5 days) orally, and repeated blood smear had been negative for malaria. This report also signifies the frst description of congenital malaria in Korea imported from Uppervolta in Africa. A brief review of related literature was made.
parasitology-protozoa ; malaria-congenital ; Plasmodium falciparum ; quinine ; trimethoprim-sulfamethoxazole

Toll-like receptors (TLRs) have emerged as major receptor components of pattern-recognition receptors (PRRs), which are responsible for the recognition of pathogen-associated molecular patterns (PAMPs)-derived pathogenic parasites. This recognition triggers the secretion of a large amount of type I interferons (IFNs), inflammatory cytokines, and chemokines and maturation of immune cells, for effective host defense by eradicating infectious parasites. Both the myeloid differentiation factor 88 (MyD88) and the TIR domain containing the adaptor molecule (TRIF) are involved in these signaling pathways. Here, we review the latest findings on the recognition of the pathogenic parasites and activation of corresponding signaling pathways through TLRs, with special emphasis on the recognition of pathogenic protozoan and helminthes. By highlighting recent progress in these areas, we hope to provide references in future studies not only for the complexity of host-parasite interactions but also for the prevention of the pathogenic parasite infections.
Animals ; Host-Parasite Interactions ; immunology ; Humans ; Immunity, Innate ; immunology ; Malaria, Falciparum ; parasitology ; Plasmodium falciparum ; immunology ; Signal Transduction ; Toll-Like Receptors ; immunology ; Trypanosoma ; immunology ; Trypanosomiasis ; parasitology

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles coexisted, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.
Antigens, Protozoan/*genetics ; *Gene Frequency ; *Genetic Variation ; Genotype ; Humans ; Malaria, Falciparum/epidemiology/*parasitology ; Plasmodium falciparum/classification/*genetics/isolation & purification ; Polymorphism, Genetic ; Protozoan Proteins/*genetics ; Thailand/epidemiology

Mitochondrial genome sequence of malaria parasites has served as a potential marker for inferring evolutionary history of the Plasmodium genus. In Plasmodium falciparum, the mitochondrial genome sequences from around the globe have provided important evolutionary understanding, but no Indian sequence has yet been utilized. We have sequenced the whole mitochondrial genome of a single P. falciparum field isolate from India using novel primers and compared with the 3D7 reference sequence and 1 previously reported Indian sequence. While the 2 Indian sequences were highly divergent from each other, the presently sequenced isolate was highly similar to the reference 3D7 strain.
DNA, Mitochondrial/*chemistry/*genetics ; Genetic Variation ; *Genome, Mitochondrial ; Humans ; India ; Malaria, Falciparum/parasitology ; Molecular Sequence Data ; Plasmodium falciparum/*genetics/isolation & purification ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and alpha-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and alpha-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients.
Female ; Hemoglobins/genetics/metabolism ; Humans ; Malaria, Falciparum/blood/complications/*genetics/parasitology ; Malaria, Vivax/blood/complications/*genetics/parasitology ; Male ; Middle Aged ; Plasmodium falciparum/physiology ; Plasmodium vivax/physiology ; Thailand/epidemiology ; Thalassemia/blood/complications/epidemiology/*genetics

We retrospectively examined the charts of travelers admitted to the Hospital for Tropical Diseases, Bangkok, Thailand, with malaria during the years 2000-2005. Twenty-one cases of malaria were identified, of which 12 (57%) were Plasmodium vivax infections and 9 (43%) were P. falciparum infections. There was one mixed case with vivax and falciparum infection. Only 1 P. falciparum case had complications. All cases were successfully treated with standard antimalarial drugs. Only 3 of the 21 cases were thought to be acquired in Thailand, the rest were regarded to be imported.
*Travel ; Thailand/epidemiology ; Retrospective Studies ; *Plasmodium vivax ; *Plasmodium falciparum ; Middle Aged ; Male ; Malaria/*epidemiology/*parasitology ; Humans ; Animals ; Adult

The usefulness of malaria diagnosis by Plasmodium falciparum-GDH (NADP+), obtained by affinity chromatography, is demonstrated in ELISA assays, testing IgG antibodies against GDH (NADP+) from patients with acute malaria, who have had two or more episodes of malaria, or from sera of hyperimmune patients. GDH (NADP+) thermal stability was demonstrated in a high heat resistance assay. The immunofluorescence assay demonstrated that anti-culture (P. falciparum) supernatant serum and anti-GDH (NADP+) of Proteus spp, recognized epitopes in Venezuelan isolates, and Colombian and Brasilian malarial strains. The antigen is soluble, with high specificity, is a potent immunogen and is thermoresistant.
parasitology-protozoa ; antigen ; enzymes ; glutamate dehydrogenase ; malaria ; diagnosis ; Plasmodium berghei ; Plasmodium cathemerium ; Plasmodium falciparum ; Plasmodium vivax ; enzyme-linked immunosorbent assay

A parasitological study was performed with 452 malaria patients evacuated from South Vietnam by examinations of their peripheral blood. Results were as follows: The peripheral blood examinations revealed that 52.0% of the examined have parasitemia, of which 95.3% was P. falciparum, one case of P. vivax and the other 10 patients were mixed infected. Neither P. malaria nor P. ovale were found. A total of 1,500 thick and thin blood films was prepared and 707 slides of them (47.1%) showed positive. In P. falciparum, ring forms were found most frequently and the next was gametocytes. Eighty slides (50%) showed mixed together with both ring form and gametocytes. All of the erythrocytic stages were seen in three slides of P. vivax. Weekly periodical examinations showed 233.8 parasite density every 1,000 W.B.C count in average, while occasional at fever attacks 531.7.Size of gametocytes in P. falciparum was 9.31(+/-0.89) by 2.16(+/-0.53) in macrogametocyte and 6.61(+/-0.82) by 2.51(+/-0.35) in microgametocyte. Their sex ratio was 100 : 92. Repeated blood examinations showed increased detection rates. The positive rate of parasitemia was 52.0% in single examination, increasing in succession with repetitions.
parasitology-protozoology-malaria ; Plasmodium falciparum ; Plasmodium vivax ; Plasmodium ovale ; Plasmodium malariae ; ring form gametocyte ; epidemiologyk Vietnam ; parasitemia

After invasion of red blood cells, malaria matures within the cell by degrading hemoglobin avidly. For enormous protein breakdown in trophozoite stage, many efficient and ordered proteolysis networks have been postulated and exploited. In this study, a potential interaction of a 60-kDa Plasmodium falciparum (Pf)-heat shock protein (Hsp60) and Pf-calpain, a cysteine protease, was explored. Pf-infected RBC was isolated and the endogenous Pf-Hsp60 and Pf-calpain were determined by western blot analysis and similar antigenicity of GroEL and Pf-Hsp60 was determined with anti-Pf-Hsp60. Potential interaction of Pf-calpain and Pf-Hsp60 was determined by immunoprecipitation and immunofluorescence assay. Mizoribine, a well-known inhibitor of Hsp60, attenuated both Pf-calpain enzyme activity as well as P. falciparum growth. The presented data suggest that the Pf-Hsp60 may function on Pf-calpain in a part of networks during malaria growth.
Amino Acid Sequence ; Calpain/genetics/*metabolism ; Chaperonin 60/chemistry/genetics/*metabolism ; Erythrocytes/parasitology ; Humans ; Malaria, Falciparum/parasitology ; Molecular Sequence Data ; Plasmodium falciparum/chemistry/enzymology/genetics/*metabolism ; Protein Binding ; Protozoan Proteins/chemistry/genetics/*metabolism ; Sequence Alignment