OBJECTIVETo explore the polymorphism in circumsporozoite protein of Plasmodium vivax before malaria was eliminated in Hainan island.

METHODSPCR amplification, sequencing, and alignment methodologies were conducted and phylogenetic tree constructed.

RESULTSFrom all the cases, 19 of them belonged to two types, with 18 as VK210 type and 1 as VK247 type. VK210 type could be divided into seven kinds of subtypes but VK247 had only one type. Ratio of tropical strain with temperate stain in VK210 type was explored between the two stages:control or elimination. Phylogenetic tree was constructed by amino acid sequencing which clearly manifested that VK210 type and VK247 type belonged to different clusters.

CONCLUSIONCompared the proportion of two types in the control stage, there was no significant difference seen in the stage of elimination.

China ; epidemiology ; Genotype ; Humans ; Malaria, Vivax ; epidemiology ; prevention & control ; Plasmodium vivax ; classification ; genetics ; isolation & purification ; Polymorphism, Genetic ; Spores, Protozoan ; genetics

Vivax malaria is a significant military and civilian health threat in the north of the Republic of Korea (ROK). The island of Baengnyeong-do is the westernmost point of the ROK and is located close to the southwestern coast of the Democratic People's Republic of Korea (DPRK). Mosquitoes were collected using a black light trap on Baengnyeong-do, and Anopheles spp. were assayed by PCR, to identify the species, and screened for sporozoites of Plasmodium vivax. Of a subsample of 257 mosquitoes, Anopheles lesteri was the most frequently collected (49.8%), followed by Anopheles sinensis (22.6%), Anopheles pullus (18.7%), Anopheles kleini (7.8%), and Anopheles belenrae (1.2%). The overall sporozoite rate was 3.1%, with the highest rates observed in An. kleini (15.0%), An. sinensis (5.2%), and An. lesteri (1.6%). No sporozoite positive An. pullus or An. belenrae were observed. The results extend our knowledge of the distribution and potential role in malaria transmission of An. kleini, An. lesteri, and An. sinensis, for an area previously considered to be at a low risk for contracting vivax malaria.
Animals ; Anopheles/*classification/genetics/*parasitology ; Plasmodium vivax/genetics/*isolation & purification ; Polymerase Chain Reaction ; Prevalence ; Republic of Korea

Although it is not certain when malaria began to appear in Korea, malaria is believed to have been an endemic disease from ancient times. It was Dr. H. N. Allen (1858-1932) who made the first description and diagnosis of malaria in terms of Western medicine. In his first year report (1885) of Korean Government Hospital he mentioned malaria as the most prevalent disease. Very effective anti-malarial drug quinine was imported and it made great contribution in treating malaria. After Japan had annexed Korea in 1910, policies for public health system were fundamentally revised. Japan assumed control of Korean medical institutions and built high-quality Western hospitals for the health care of Japanese residents. The infectious diseases which were under special surveillance were cholera, typhoid fever, dysentery, typhus, scarlet fever, smallpox, and paratyphoid fever. Among chronic infectious diseases tuberculosis and leprosy were those under special control. Malaria, however, was not one of these specially controlled infectious diseases although it was widely spread throughout the peninsula. But serious studies on malaria were carried out by Japanese medical scientists. In particular, a Japanese parasitologist Kobayasi Harujiro(1884-1969) carried out extensive studies on human parasites, including malaria, in Korea. According to his study, most of the malaria in Korea turned out to be tertian fever. In spite of its high prevalence, malaria did not draw much attention from the colonial authorities and no serious measure was taken since tertian fever is a mild form of malaria caused by Plasmodium vivax and is not so much fatal as tropical malaria caused by P. falciparum. And tertian malaria was easily controlled by taking quinine. Although the majority of malaria in Korea was tertian fever, other types were not absent. Quartan fever was not rarely reported in 1930s. The attitude of colonial authorities toward malaria in Korea was contrasted with that in Taiwan. After Japan had set out to colonize Taiwan as a result of Sino-Japanese war, malaria in Taiwan was a big obstacle to the colonization process. Therefore, a lot of medical scientists were asked to engage the malaria research in order to handle health problems in colonized countries caused by malaria. Unlike the situation in Taiwan, malaria in Korea did not cause a serious health problem as in Taiwan. However, its risk was not negligible. In 1933 there were almost 130,000 malaria patients in Korea and 1,800 patients among them died of malaria. The Japanese Government General took measures to control malaria especially during the 1930s and the number of patients decreased. However, as Japan engaged in the World War II, the general hygienic state of the society worsened and the number of malarial patients increased. The worsened situation remains the same after Liberation (1945) and during the Korean war (1950-53).
Colonialism/history ; History, 19th Century ; History, 20th Century ; Humans ; Korea ; Malaria/diagnosis/drug therapy/*history ; Malaria, Vivax/diagnosis/drug therapy/history ; Microscopy, Polarization ; Plasmodium malariae/isolation & purification ; Plasmodium ovale/isolation & purification ; Plasmodium vivax/isolation & purification ; Quinine/history/therapeutic use

We investigated population densities of mosquitoes infected with sporozoites in three highly epidemic areas of Josan-ri and Jangpa-ri (Paju City) and Dongjung-ri (Yeoncheon County) in Korea. Anopheline mosquitoes were collected from both indoors and outdoors by human baiting collection method during the period of the first week of June to the second week of September 1999. Total 13,296 female mosquitoes were collected and 8,650 (65.1%) were Anophelines. Thirty seven percent (3,199) of the Anopheline mosquitoes were captured outdoors and 63.9% (5,531) indoors. Employing a sandwich enzyme-linked immunosorbent assay (ELISA), we analyzed a total of 7,820 Anopheline mosquitoes and found that 7 Anopheline mosquitoes were infected with sporozoites. The positive rate in Josan-ri was 0.14% (5/3,500) and 0.15% (2/1,370) in Jangpa-ri. The total positive rate in all three surveyed areas was 0.09% (7/7,820). The mosquitoes infected with the sporozoites were detected on June 28th (n=2), July 5th (n=1), July 19th (n=1), August 9th (n=1), September 6th (n=1), and the last one on September 13th (n=1). They were all classified as Anopheles sinensis, which showed positive reaction in ELISA test. Therefore it might be concluded that A. sinensis plays an important role in re-emerging malaria transmission in Korea.
Animals ; Culicidae/*parasitology ; Enzyme-Linked Immunosorbent Assay ; Female ; Human ; Korea/epidemiology ; Malaria, Vivax/epidemiology/parasitology/transmission ; Plasmodium vivax/*isolation & purification ; Support, Non-U.S. Gov't

Splenic infarction is a rare complication in malaria cases, and is caused primarily by Plasmodium falciparum. Recently in South Korea, only P. vivax has prevailed since 1993. Although the probability that symptomatic splenic infarction may occur in vivax malaria cases is considered relatively high, there have never been any case reports describing the occurrence of symptomatic splenic infarction in cases of vivax malaria. A 34-year-old man presented with fever that had persisted for 5 days. P. vivax infection was verified using a peripheral blood smear, and chloroquine was utilized to treat the fever successfully. Six days later, the patient developed pain in the left upper abdomen, which was diagnosed as splenic infarction by computed tomography.
Adult ; Animals ; Humans ; Malaria, Vivax/blood/*complications/drug therapy ; Male ; Plasmodium vivax/*isolation & purification ; Primaquine/therapeutic use ; Splenic Infarction/blood/*parasitology

Splenic infarction is a rare complication in malaria cases, and is caused primarily by Plasmodium falciparum. Recently in South Korea, only P. vivax has prevailed since 1993. Although the probability that symptomatic splenic infarction may occur in vivax malaria cases is considered relatively high, there have never been any case reports describing the occurrence of symptomatic splenic infarction in cases of vivax malaria. A 34-year-old man presented with fever that had persisted for 5 days. P. vivax infection was verified using a peripheral blood smear, and chloroquine was utilized to treat the fever successfully. Six days later, the patient developed pain in the left upper abdomen, which was diagnosed as splenic infarction by computed tomography.
Adult ; Animals ; Humans ; Malaria, Vivax/blood/*complications/drug therapy ; Male ; Plasmodium vivax/*isolation & purification ; Primaquine/therapeutic use ; Splenic Infarction/blood/*parasitology

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

OBJECTIVETo survey malaria prevalence in Sarbaz from April 2009 to October 2010.

METHODSEpidemiological data of 1 464 confirmed malarial patients were analyzed according to demographic status, sex, age, nationality, isolated species and residence place.

RESULTSThe majority of patients were male 950 (64.8%) but 514 (35.2%) were female. 82.5% of patients were Iranian, 14% Pakistani immigrants, and 3.5% Afghan immigrants. Data collected showed that 90% of isolated species were Plasmodium vivax, 7.8% Plasmodium falciparum, and 2.2% Plasmodium malariae and mixed species.

CONCLUSIONSTherefore, it is crystal clear that refugees should be prohibited by government and controlled by experts in health centers in order to campaign effectively with this life threating disease.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Demography ; Ethnic Groups ; Female ; Humans ; Infant ; Infant, Newborn ; Iran ; epidemiology ; Malaria ; epidemiology ; parasitology ; Male ; Middle Aged ; Plasmodium falciparum ; isolation & purification ; Plasmodium malariae ; isolation & purification ; Plasmodium vivax ; isolation & purification ; Prevalence ; Young Adult

The objectives of the present study were to (1) determine the susceptibility of Anopheles sinensis to Korean isolates of Plasmodium vivax, (2) establish a method to collect large quantities of P. vivax sporozoites for use as antigen in seroepidemiological studies, and (3) investigate the characteristics of Korean isolates of P. vivax sporozoites. Females of Anopheles sinensis were collected at non-epidemic area, Seokwha-ri, Cheongwon-gun and Chungcheongbuk-do using tent-trap methods coupled with dry ice. The females were artificially infected with gametocytes of P. vivax using blood obtained from P. vivax malaria patients. Individual mosquitoes were infected using either a parafilm-covered glass feeding apparatus or were allowed to feed on naturally infected volunteers. Mosquitoes were sacrificed between 16 and 18 days post-feeding and an enzyme-linked immunosorbent assay (ELISA) was used to detect sporozoites. Four (33.4%) of 12 mosquitoes, which were fed on naturally infected volunteers directly, were positive for sporozoites. In cases, the mosquitoes allowed to feed on whole blood which were extract from three different patients with heparin treated vacuutainers using a parafilm-covered glass apparatus. Two of 55 (3.6%) were positive which blood sample was maintained at room temperature for 8 hours, 1 of 68 (1.5%) was positive which blood was maintained at 4 degrees C for 24 hours and 1 of 47 (2.3%) was positive at 4 degrees C for 48 hours. The mean number of sporozoites was estimated about 818 (n = 8; range of 648-1,056) based on optical density values of ELISA.
Animals ; Anopheles/*parasitology ; Enzyme-Linked Immunosorbent Assay ; Human ; Korea ; Plasmodium vivax/isolation & purification/*pathogenicity ; Support, Non-U.S. Gov't

In order to determine the status of malaria among schoolchildren on Kome Island (Lake Victoria), near Mwanza, Tanzania, a total of 244 schoolchildren in 10 primary schools were subjected to a blood survey using the fingerprick method. The subjected schoolchildren were 123 boys and 121 girls who were 6-8 years of age. Only 1 blood smear was prepared for each child. The overall prevalence of malaria was 38.1% (93 positives), and sex difference was not remarkable. However, the positive rate was the highest in Izindabo Primary School (51.4%) followed by Isenyi Primary School (48.3%) and Bugoro Primary School (46.7%). The lowest prevalence was found in Muungano Primary School (16.7%) and Nyamiswi Primary School (16.7%). These differences were highly correlated with the location of the school on the Island; those located in the peripheral area revealed higher prevalences while those located in the central area showed lower prevalences. Plasmodium falciparum was the predominant species (38.1%; 93/244), with a small proportion of them mixed-infected with Plasmodium vivax (1.6%; 4/244). The results revealed that malaria is highly prevalent among primary schoolchildren on Kome Island, Tanzania, and there is an urgent need to control malaria in this area.
Blood/parasitology ; Child ; Coinfection/epidemiology/parasitology ; Cross-Sectional Studies ; Female ; Humans ; Malaria/*epidemiology/parasitology ; Male ; Microscopy ; Plasmodium falciparum/*isolation & purification ; Plasmodium vivax/*isolation & purification ; Prevalence ; Tanzania/epidemiology ; Topography, Medical