Evaluación de la calidad del diagnóstico de malaria en la red local de laboratorios y en los laboratorios intermedios en el contexto de la eliminación de la enfermedad en Ecuador / Quality evaluation of malaria diagnosis in the local laboratories network and in intermediate laboratories in a setting towards the disease elimination in Ecuador

Resumen Introducción. El cumplimiento de la meta de eliminación de la malaria en Ecuador en el 2020 exige contar con la capacidad requerida para el diagnóstico microscópico ajustado a los estándares de calidad de la Organización Mundial de la Salud (OMS) y de la Organización Panamericana de la Salud (OPS) y proveer el tratamiento adecuado a los pacientes. Objetivo. Conocer la idoneidad o competencia de los microscopistas de la red pública local para el diagnóstico parasitológico de la malaria y el desempeño de los laboratorios intermedios de referencia. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal a partir de la información obtenida en los talleres de evaluación de idoneidad en el diagnóstico microscópico de la red de laboratorios en las coordinaciones zonales de salud utilizando un panel de láminas para evaluar la concordancia del diagnóstico. Además, se calificó el desempeño de los laboratorios intermedios en el diagnóstico en el marco del programa de evaluación externa del desempeño. Los resultados se compararon con los obtenidos por el laboratorio supranacional de Perú. Resultados. En los 11 talleres realizados, se evaluó la idoneidad de 191 microscopistas, de los cuales 153 (80,1 %) aprobaron las pruebas. Las medianas de los indicadores fueron las siguientes: concordancia entre la detección y el resultado, 100 % (Q1- Q3: 96-100); concordancia en la especie, 100 % (Q1- Q3: 93-100); concordancia en el estadio, 93,0 % (Q1- Q3: 86-95) y concordancia en el recuento, 77 % (Q1- Q3: 71-82). En el programa de evaluación externa de desempeño, los tres laboratorios intermedios obtuvieron una concordancia del 100 % en el resultado y una del 96 % en la especie. Conclusiones. Los indicadores de competencia de la red local y de desempeño de los laboratorios intermedios alcanzaron altos estándares de calidad acordes con el proceso de entrenamiento implementado en el país.

Abstract Introduction: To reach the goal of malaria elimination in Ecuador for the year 2020, it is necessary to have a laboratory network with the capacity to perform microscopic diagnosis according to the WHO/PAHO quality standards and to provide the adequate treatment of cases. Objective: To determine the level of competence for parasitological diagnosis of the microscopists from the local public network and the performance of intermediate reference laboratories. Materials and methods: We conducted a cross-sectional study based on the information collected in workshops carried out to appraise the competence for microscopic diagnosis of the local laboratory network (zonal health coordinating offices 1 to 8) using a slide panel to evaluate diagnosis agreement, as well as the diagnostic performance of the intermediate laboratories using an external quality assessment program. The results were compared against the reference standards of the supranational laboratory in Perú. Results: We evaluated the competencies of 191 microscopists in 11 workshops and 153 (80.1%) of them were approved. The medians of the indicators were the following: concordance for parasite detection, 100% (Q1- Q3: 96-100), concordance for species identification, 100% (Q1- Q3: 93-100), and concordances for stage identification, 93.0% (Q1- Q3: 86-95) and parasite counting, 77.0% (Q1- Q3: 71-82). In the external quality assessment, the three intermediate laboratories obtained 100% in parasite detection concordance and 96% for species detection concordance. Conclusions: The results for the primary network and the performance indicators for the intermediate laboratories showed the high-quality standards of the training program implemented in the country.

Whole-genome sequencing of a Plasmodium vivax isolate from the China-Myanmar border area

Currently, there is a trend of an increasing number of Plasmodium vivaxmalaria cases in China that are imported across its Southeast Asia border, especially in the China-Myanmar border area (CMB). To date, little is known about the genetic diversity of P. vivaxin this region. In this paper, we report the first genome sequencing of a P. vivaxisolate (CMB-1) from a vivax malaria patient in CMB. The sequencing data were aligned onto 96.43% of the P. vivaxSalvador I reference strain (Sal I) genome with 7.84-fold coverage as well as onto 98.32% of 14 Sal I chromosomes. Using the de novoassembly approach, we generated 8,541 scaffolds and assembled a total of 27.1 Mb of sequence into CMB-1 scaffolds. Furthermore, we identified all 295 known virgenes, which is the largest subtelomeric multigene family in malaria parasites. These results provide an important foundation for further research onP. vivaxpopulation genetics.

A sensitive, specific and reproducible real-time polymerase chain reaction method for detection of Plasmodium vivax and Plasmodium falciparum infection in field-collected anophelines

We describe a simple method for detection of Plasmodium vivax and Plasmodium falciparum infection in anophelines using a triplex TaqMan real-time polymerase chain reaction (PCR) assay (18S rRNA). We tested the assay on Anopheles darlingi and Anopheles stephensi colony mosquitoes fed with Plasmodium-infected blood meals and in duplicate on field collected An. darlingi. We compared the real-time PCR results of colony-infected and field collected An. darlingi, separately, to a conventional PCR method. We determined that a cytochrome b-PCR method was only 3.33% as sensitive and 93.38% as specific as our real-time PCR assay with field-collected samples. We demonstrate that this assay is sensitive, specific and reproducible.

High Malaria Prevalence among Schoolchildren on Kome Island, Tanzania

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.

Alterations in cytokines and haematological parameters during the acute and convalescent phases of Plasmodium falciparum and Plasmodium vivax infections

Haematological and cytokine alterations in malaria are a broad and controversial subject in the literature. However, few studies have simultaneously evaluated various cytokines in a single patient group during the acute and convalescent phases of infection. The aim of this study was to sequentially characterise alterations in haematological patters and circulating plasma cytokine and chemokine levels in patients infected with Plasmodium vivax or Plasmodium falciparum from a Brazilian endemic area during the acute and convalescent phases of infection. During the acute phase, thrombocytopaenia, eosinopaenia, lymphopaenia and an increased number of band cells were observed in the majority of the patients. During the convalescent phase, the haematologic parameters returned to normal. During the acute phase, P. vivax and P. falciparum patients had significantly higher interleukin (IL)-6, IL-8, IL-17, interferon-γ, tumour necrosis factor (TNF)-α, macrophage inflammatory protein-1β and granulocyte-colony stimulating factor levels than controls and maintained high levels during the convalescent phase. IL-10 was detected at high concentrations during the acute phase, but returned to normal levels during the convalescent phase. Plasma IL-10 concentration was positively correlated with parasitaemia in P. vivax and P. falciparum-infected patients. The same was true for the TNF-α concentration in P. falciparum-infected patients. Finally, the haematological and cytokine profiles were similar between uncomplicated P. falciparum and P. vivax infections.

Comparison of Two Rapid Immunochromatographic Assays (ICT Malaria P.f. /P.v. Test and OptiMAL Test) with Microscopy for Detection of Malaria Parasites.

This study was done to compare the ability of newly developed immunochromatographic assays (ICT), i.e., ICT malaria P.f. / P.v. test and optiMAL test with standard microscopy for the diagnosis of malaria. ICT P.f. / P.v. test detects Plasmodium falciparum specific histidine rich protein-2 (HRP2) antigen and a pan-malarial common specific antigen, where as optiMAL test detects P. falciparum specific parasite Lactate Dehydrogenase (pLDH) enzyme and a common specific pLDH enzyme. Material and Methods: Blood samples were obtained from 150 patients clinically diagnosed as malaria between July 2011 to December 2011.The venous blood were tested for malaria by microscopy and simultaneously ICT P.f./P.v.and optiMAL tests. Results: From total 150 samples, 59 (39.3%) were positive by blood films while 64 (42.7%) were positive by ICT p.f. / p.v. and 52 (34.7%) by optiMAL tests. The blood film indicated that 32.2% (19 of 59) of patients were positive for P. vivax and 67.8% (40 of 59) were infected with P. falciparum. ICT P.f./P.v. test showed 23.4% (15 of 64) were positive for P. vivax and 76.6% (49 of 64) were infected with P. falciparum. Similarly, optiMAL test detected 30.8% (16 of 52) were positive for P. vivax and 69.2% (36 of 52) were infected with P. falciparum. ICT P.f./P.v. test had sensitivities 78.9%, 87.5% and specificities 100%, 87.3% for P. vivax and P. falciparum respectively. optiMAL test showed sensitivities 84.2%, 80% and specificities 100%, 96.4% for P. vivax and P. falciparum respectively. Conclusion: These rapid immunoassays (ICT P.f./P.v. and optiMAL) tests can be used as supplementary to traditional light microscopy for the diagnosis of malarial parasites.

Evaluation of three different DNA extraction methods from blood samples collected in dried filter paper in Plasmodium subpatent infections from the Amazon region in Brazil / Avaliação de três métodos de extração de DNA obtidos de amostras de sangue coletadas em papel de filtro em infecções subpatentes de Plasmodium da região Amazônica no Brasil

Asymptomatic Plasmodium infection is a new challenge for public health in the American region. The polymerase chain reaction (PCR) is the best method for diagnosing subpatent parasitemias. In endemic areas, blood collection is hampered by geographical distances and deficient transport and storage conditions of the samples. Because DNA extraction from blood collected on filter paper is an efficient method for molecular studies in high parasitemic individuals, we investigated whether the technique could be an alternative for Plasmodium diagnosis among asymptomatic and pauciparasitemic subjects. In this report we compared three different methods (Chelex®-saponin, methanol and TRIS-EDTA) of DNA extraction from blood collected on filter paper from asymptomatic Plasmodium-infected individuals. Polymerase chain reaction assays for detection of Plasmodium species showed the best results when the Chelex®-saponin method was used. Even though the sensitivity of detection was approximately 66% and 31% for P. falciparum and P. vivax, respectively, this method did not show the effectiveness in DNA extraction required for molecular diagnosis of Plasmodium. The development of better methods for extracting DNA from blood collected on filter paper is important for the diagnosis of subpatent malarial infections in remote areas and would contribute to establishing the epidemiology of this form of infection.

Infecção assintomática por Plasmodium é um novo desafio para a saúde pública no Brasil. A reação em cadeia da polimerase (PCR) é o melhor método para detectar baixas parasitemias presentes em pacientes com infecção assintomática. Nas áreas endêmicas, a coleta de sangue total é dificultada pela distancia geográfica, transporte e adequada armazenagem das amostras. A coleta de sangue em papel de filtro pode ser uma alternativa nessas áreas de difícil acesso. Neste estudo foram comparados três diferentes métodos de extração de ADN a partir de papel de filtro usando como controle extração a partir de sangue total. O protocolo Chelex®-Saponina foi o que obteve o melhor resultado quando comparado com os outros três protocolos. No entanto a sensibilidade foi de 66,7% para o P. falciparum e 31,6% para o P. vivax. Conclui-se que em caso de infecção assintomática o papel de filtro não é ainda uma boa alternativa para coleta de amostras.

Especies de Anopheles presentes en el departamento del Putumayo y su infección natural con Plasmodium / Anopheles species present in the department of Putumayo and their natural infectivity with Plasmodium

Introducción. El departamento del Putumayo es una región endémica para malaria, o paludismo, causada principalmente por Plasmodium vivax . Los vectores en esta región incluyen Anopheles darlingi , el cual se ha encontrado solamente en el municipio de Puerto Leguízamo, y recientemente se incriminaron como vectores en Puerto Asís a las especies An. rangeli y An. oswaldoi . Objetivo. El propósito del trabajo fue determinar el papel de An. benarrochi B en la transmisión de malaria en este departamento, ya que se reporta como la especie más abundante que pica a los humanos. Materiales y métodos. Se recolectaron larvas y adultos de Anopheles spp. entre el 2006 y el 2008 en los municipios Puerto Leguízamo y Puerto Asís, y se obtuvieron secuencias del gen ITS-2 y del gen mitocondrial COI para confirmar las determinaciones taxonómicas por morfología. Se practicó la prueba ELISA para establecer la infección por P. vivax y P. falciparum. Resultados. Se identificaron 6.238 individuos correspondientes a 11 especies: An. albitarsis s.l. (1,83 %), An. benarrochi B (72,35 %), An. braziliensis (0,05 %), An. costai (0,06 %), An. darlingi (19,37 %), An. mattogrossensis (0,08 %), An. neomaculipalpus (0,13 %), An. oswaldoi s.l. (0,64 %), An. punctimacula (0,03 %), An. rangeli (5,12 %) y An. triannulatus s.l. (0,34 %). Se evaluaron 5.038 adultos por ELISA y 5 se encontraron positivos para P. vivax 210 y VK 247, todos pertenecientes a la especie An. benarrochi B. Conclusión. Los resultados sugieren que An. benarrochi B juega un papel en la transmisión de P. vivax en el departamento de Putumayo, dada su alta atracción por los humanos y su infección natural con Plasmodium spp.

Introduction: Putumayo is considered an endemic region for malaria transmission, mainly due to Plasmodium vivax. The vectors in this region are Anopheles darlingi , which has been found only in the municipality of Puerto Leguízamo, and An. rangeli and An. oswaldoi s.l. , which were recently incriminated as vectors in Puerto Asís. Objective: The purpose of this study was to determine the role of An. benarrochi B in malaria transmission in Putumayo, given that it is the most abundant species biting humans. Materials and methods: Collections of immature and adult stages of Anopheles spp. were made between 2006 and 2008 in the municipalities of Puerto Leguízamo and Puerto Asís in Putumayo, and sequences of internal transcribed spacer 2 ( ITS-2 ) of ribosomal DNA and the mitochondrial gene COI were obtained to confirm the morphological determinations. ELISA was carried out for P. vivax and P. falciparum infectivity. Results: A total of 6,238 specimens were identified, distributed in 11 species: An. albitarsis s.l. (1.83%), An. benarrochi B (72.35%), An. braziliensis (0.05%), An. costai (0.06%), An. darlingi (19.37%), An. mattogrossensis (0.08%), An. neomaculipalpus (0.13%), An. oswaldoi s.l. (0.64%), An. punctimacula (0.03%), An. rangeli (5.12%), and An. triannulatus s.l. (0.34%). A total of 5,038 adults were assessed by ELISA and 5 were found positive for P. vivax 210 and VK 247, all belonging to An. benarrochi B. Conclusion: The results suggest that An. benarrochi B plays a role in the transmission of P. vivax in Putumayo due to its high human contact and natural infection with Plasmodium sp.

A Case of Vivax Malaria Complicated by Adult Respiratory Distress Syndrome and Successful Management with Extracorporeal Membrane Oxygenation

Complicated malaria is mainly caused by Plasmodium falciparum, but, increasingly, Plasmodium vivax is also being reported as a cause. Since the reemergence of indigenous vivax malaria in 1993, cases of severe malaria have been steadily reported in Korea. Herein, we report a case of vivax malaria complicated by adult respiratory distress syndrome (ARDS) that was successfully managed with extracorporeal membrane oxygenation (ECMO). A 59-year-old man presented at our hospital with fever and abdominal pain, which had persisted for 10 days. On admission, the patient had impaired consciousness, shock, hypoxia and haziness in both lungs, jaundice, thrombocytopenia and disseminated intravascular coagulation, metabolic acidosis, and acute kidney injury. A peripheral blood smear and a rapid diagnostic test verified P. vivax mono-infection. Ten hours after admission, hypoxia became more severe, despite providing maximal ventilatory support. The administration of antimalarial agents, ECMO, and continuous venovenous hemofiltration resulted in an improvement of his vital signs and laboratory findings. He was discharged from the hospital 7 weeks later, without any sequelae.

Caracterización de la transmisión de la malaria por Plasmodium vivax en la región fronteriza de Panamá con Costa Rica en el municipio de Barú, Panamá / Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa Rica

Introducción. Pocos estudios describen los factores asociados con la dinámica de transmisión de la malaria, o paludismo, por Plasmodium vivax en las regiones endémicas de Panamá. Objetivo. Caracterizar la dinámica de transmisión de la malaria producida por P. vivax en la región fronteriza de Panamá con Costa Rica. Materiales y métodos. Se llevó a cabo un estudio observacional, descriptivo y transversal. Se evaluaron la incidencia parasitaria anual, el índice de láminas positivas y el índice anual de exámenes de sangre. Se identificaron los anofelinos vectores, y se caracterizaron sus criaderos preferenciales, densidad larvaria e índice de picada/hombre/noche. Se hizo búsqueda pasiva y activa de casos sospechosos mediante examen de gota gruesa. Resultados. De 10.401 muestras de gota gruesa, 83 resultaron positivas para P. vivax. El 84 % de los casos provenía de zonas rurales, el 79 % constituía una población económicamente activa, la mediana de edad fue de 36 años y, la media, de 30 años. El 58,5 % de los casos fueron de sexo masculino. La incidencia parasitaria anual fue de 4,1 por 1.000 habitantes; el índice de láminas positivas fue de 0,8 % y el índice anual de exámenes de sangre fue de 51,9 %. El 65,0 % de los casos diagnosticados registró entre 100 y 2.000 parásitos/μl de sangre. Se identificaron los mosquitos vectores Anopheles albimanus y An. punctimacula. Conclusión. Es necesario el seguimiento de estudios entomológicos, el fortalecimiento de la vigilancia epidemiológica, la consideración de los factores de riesgo y la realización de un trabajo en coordinación con las autoridades de salud de Costa Rica, para controlar la malaria en esta región.

Introduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/μl. The majority of the cases were observed in May and June. Two mosquito vector species were identified-- Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation of work performance in the border region. This will require coordination with health authorities of both countries to control malaria in this region.

Incrimination of Anopheles (Anopheles) intermedius Peryassú, An. (Nyssorhynchus) nuneztovari Gabaldón, An. (Nys.) oswaldoi Peryassú as natural vectors of Plasmodium falciparum in French Guiana

Anopheles darlingi Root is the major vector of human malaria in the Neotropics and has been considered to be the sole malaria vector in French Guiana. The presence of other potential vectors suggests that malaria may be transmitted by other species under certain conditions. From 2006-2011, all anopheline specimens collected from 11 localities were assayed to determine if the Plasmodium circumsporozoite protein was present. In addition to An. darlingi, we found Anopheles oswaldoi, Anopheles intermedius and Anopheles nuneztovari specimens that were infected with Plasmodium sp. Further investigations on the behaviour and ecology of An. oswaldoi, An. intermedius and An. nuneztovari are necessary to determine their role in malaria transmission in French Guiana.

A Recombinant Plasmodium vivax Apical Membrane Antigen-1 to Detect Human Infection in Iran

In Iran, Plasmodium vivax is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant P. vivax apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant His-tagged protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-P. vivax antibodies in the field was compared to light microscopy on 84 confirmed P. vivax patients and compared to 84 non-P. vivax infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with P. vivax infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.

A History of Malaria in Modern Korea 1876-1945 / 의사학

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).

Parasitemia Characteristics of Plasmodium vivax Malaria Patients in the Republic of Korea

Parasitemia characteristics of Plasmodium vivax malaria in temperate regions may differ from those in tropical zones. However, most parasitological and clinical features of P. vivax malaria have been investigated in the latter. In this study, we investigated 383 malaria patients to clarify the parasitemia characteristics of a P. vivax strain in the Republic of Korea (ROK). The mean parasitemia (8,396/microL) was less than half of tropical P. vivax malaria, and multiple invasions of erythrocytes were not rare (53.5% of the patients, 2.4% of the total investigated RBCs), but less than the observations in tropical zones. The intervals between the first symptom onset and diagnosis were significantly longer in gametocyte (+) patients than in gametocyte (-) patients. Only half of the total patients had both genders of gametocytes (191 of 353), and the male gametocyte density (169/microL) was lower than that of P. vivax strains of a previous study. Multiple invasions of erythrocytes and gametocytemia were coincident factors of the degree of anemia in P. vivax malaria. The present findings demonstrate the P. vivax strain in ROK reveals relatively low parasitemia and low male to female gametocyte ratio. The low ratio may be related with low transmission efficacy.

Parasitemia Characteristics of Plasmodium vivax Malaria Patients in the Republic of Korea

Parasitemia characteristics of Plasmodium vivax malaria in temperate regions may differ from those in tropical zones. However, most parasitological and clinical features of P. vivax malaria have been investigated in the latter. In this study, we investigated 383 malaria patients to clarify the parasitemia characteristics of a P. vivax strain in the Republic of Korea (ROK). The mean parasitemia (8,396/microL) was less than half of tropical P. vivax malaria, and multiple invasions of erythrocytes were not rare (53.5% of the patients, 2.4% of the total investigated RBCs), but less than the observations in tropical zones. The intervals between the first symptom onset and diagnosis were significantly longer in gametocyte (+) patients than in gametocyte (-) patients. Only half of the total patients had both genders of gametocytes (191 of 353), and the male gametocyte density (169/microL) was lower than that of P. vivax strains of a previous study. Multiple invasions of erythrocytes and gametocytemia were coincident factors of the degree of anemia in P. vivax malaria. The present findings demonstrate the P. vivax strain in ROK reveals relatively low parasitemia and low male to female gametocyte ratio. The low ratio may be related with low transmission efficacy.

Unusual presentations of malaria in children: an experience from a tertiary care centre in north east India.

Objective. To identify cases of malaria with unusual presentations. Methods. The medical record of all the cases of malaria admitted to PICU and pediatric general ward from Oct 2006 to Sep 2009, were reviewed and cases with unusual presentations were identified. The study design was retrospective descriptive study. Results. Sixteen (10%) out of 162 malaria cases had unusual presentations - three had hemiplegia, two each with viral hepatitis-like presentation, acute abdomen, gastrointestinal bleed, generalized edema and hyperglycemia and one each with ptosis, severe headache and subacute intestinal obstruction-like presentation. Eleven cases had mixed parasitemia and two each with P. vivax and P. falciparum. One case was diagnosed on clinical grounds. Conclusions. Malaria is a common disease, but both typical and atypical presentations deserve attention for early diagnosis and management.

Malária vivax com tempo de incubação prolongado, detectada no Distrito Federal: relato de três casos / Vivax malaria with long incubation period, detected in the Federal District: three case reports

Foram detectados três casos de malária vivax em Brasília, Distrito Federal, área considerada indene, procedentes da Amazônia, seis meses após estarem residindo em Brasília. Período de incubação prolongado tem sido descrito apenas para infecções por cepas de Plasmodium vivax de clima temperado. Não foi possível genotipar os parasitos.

Three cases of vivax malaria originating from the Amazon region were detected after living in Brasilia, Federal District (considered to be a non-endemic area), for six months. Long incubation periods have been described only for infections due to strains of Plasmodium vivax in temperate climates. It was not possible to genotype the parasites.

Acute necrotizing encephalopathy.

Acute necrotizing encephalopathy (ANEC) is a rare disease well recognized in Japan but has not yet been reported from Indian subcontinent. We describe here a case of ANEC with the neuroimaging findings. P. vivax infection was detected as an associated finding and the treatment given.