Characteristics of Imported Malaria and Species of Plasmodium Involved in Shandong Province, China (2012-2014)

Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.

A Case of Plasmodium malariae Infection Imported from Guinea

Recently, the number of Korean travelers and workers to malaria-endemic regions has increased, and the number of patients with imported malaria cases has increased as well. In Korea, most cases of imported malaria infections are caused by Plasmodium falciparum and P. vivax. Only one report of imported P. malariae infection has been published thus far. Here, we describe a case of imported P. malariae infection that was confirmed by peripheral blood smear and nested PCR targeting the small subunit ribosomal RNA (SSU rRNA) gene. A 53-yr-old man, who had stayed in the Republic of Guinea in tropical West Africa for about 40 days, experienced fever and headache for 3 days before admission. The results of rapid malaria test using the SD Malaria Antigen/Antibody Kit (Standard Diagnostics, Korea) were negative, but Wright-Giemsa stained peripheral blood smear revealed Plasmodium. To identify the Plasmodium species and to examine if the patient had a mixed infection, we performed nested PCR targeting the SSU rRNA gene. P. malariae single infection was confirmed by nested PCR. Sequence analysis of the SSU rRNA gene of P. malariae showed that the isolated P. malariae was P. malariae type 2. Thus, our findings suggest that when cases of imported malaria infection are suspected, infection with P. malariae as well as P. falciparum and P. vivax should be considered. For the accurate diagnosis and treatment of imported malaria cases, we should confirm infection with Plasmodium species by PCR as well as peripheral blood smear and rapid malaria antigen test.

Malaria in pregnant women living in areas of low transmission on the southeast Brazilian Coast: molecular diagnosis and humoural immunity profile

Studies on autochthonous malaria in low-transmission areas in Brazil have acquired epidemiological relevance because they suggest continued transmission in what remains of the Atlantic Forest. In the southeastern portion of the state of São Paulo, outbreaks in the municipality of Juquitiba have been the focus of studies on the prevalence of Plasmodium, including asymptomatic cases. Data on the occurrence of the disease or the presence of antiplasmodial antibodies in pregnant women from this region have not previously been described. Although Plasmodium falciparum in pregnant women has been widely addressed in the literature, the interaction of Plasmodium vivax and Plasmodium malariae with this cohort has been poorly explored to date. We monitored the circulation of Plasmodium in pregnant women in health facilities located in Juquitiba using thick blood film and molecular protocols, as well as immunological assays, to evaluate humoural immune parameters. Through real-time and nested polymerase chain reaction, P. vivax and P. malariae were detected for the first time in pregnant women, with a positivity of 5.6%. Immunoassays revealed the presence of IgG antibodies: 44% for ELISA-Pv, 38.4% for SD-Bioline-Pv and 18.4% for indirect immunofluorescence assay-Pm. The high prevalence of antibodies showed significant exposure of this population to Plasmodium. In regions with similar profiles, testing for a malaria diagnosis might be indicated in prenatal care.

Malaria in the state of Rio de Janeiro, Brazil, an Atlantic Forest area: an assessment using the health surveillance service

The lethality of malaria in the extra-Amazonian region is more than 70 times higher than in Amazonia itself. Recently, several studies have shown that autochthonous malaria is not a rare event in the Brazilian southeastern states in the Atlantic Forest biome. Information about autochthonous malaria in the state of Rio de Janeiro (RJ) is scarce. This study aims to assess malaria cases reported to the Health Surveillance System of the State of Rio de Janeiro between 2000-2010. An average of 90 cases per year had parasitological malaria confirmation by thick smear. The number of malaria notifications due to Plasmodium falciparum increased over time. Imported cases reported during the period studied were spread among 51% of the municipalities (counties) of the state. Only 35 cases (4.3%) were autochthonous, which represents an average of 3.8 new cases per year. Eleven municipalities reported autochthonous cases; within these, six could be characterised as areas of residual or new foci of malaria from the Atlantic Forest system. The other 28 municipalities could become receptive for transmission reintroduction. Cases occurred during all periods of the year, but 62.9% of cases were in the first semester of each year. Assessing vulnerability and receptivity conditions and vector ecology is imperative to establish the real risk of malaria reintroduction in RJ.

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 Case of Imported Plasmodium malariae Malaria

Malaria, the most common vector-borne parasite infection worldwide, results from infection by Plasmodium species. Approximately 80% of malaria cases are caused by P. vivax, which is broadly distributed from tropical to temperate regions; P. falciparum is the second most common infectious species. P. malariae and P. ovale are responsible for a relatively small proportion of malaria cases. Here, we report the case of a 23-yr-old Korean woman who acquired a P. malariae infection while visiting the Republic of Ghana in West Africa for business. She was diagnosed with P. malariae malaria on the basis of peripheral blood smear (PBS) and species-specific conventional and real-time PCR assays for 18S rRNA. She was treated with hydroxychloroquine, and the resulting PBS examination on day 2 suggested that negative conversion occurred. At her 1-month follow-up, however, both the PBS examination and molecular test for malaria demonstrated recurrent parasitemia. We started rescue therapy with mefloquine, and the patient recovered successfully. This is an important finding suggesting possible late recrudescence of a chloroquine-resistant P. malariae strain identified not only by its morphological features, but also by molecular tests.

Mapa de riesgo de transmisión de malaria en la cuenca del río Caura, Venezuela / Risk map of malaria transmission in the Caura river basin, Venezuela

Los mapas de riesgo de malaria se han usado para apoyar la optimización de recursos humanos, materiales y financieros disponibles para la prevención y control de la enfermedad. En Venezuela, estos mapas se basan en el Índice Parasitario Anual donde se clasifican municipios en diferentes intervalos de riesgo. Los mismos tienen poca resolución espacial, usan intervalos de riesgo muy amplios y no consideran múltiples factores de riesgo tales como comportamiento biológico de parásitos y vectores, condiciones favorables al contacto hombre-vector y para la prevención y control de la enfermedad. El objetivo del trabajo es identificar áreas de riesgo de malaria en la cuenca del río Caura, estado Bolívar, Guayana venezolana, basado en una evaluación multicriterio de variables ambientales y antrópicas favorables para la transmisión de la malaria. Los criterios de riesgo se expresaron en capas de imágenes raster usando reglas de decisión y se normalizaron usando lógica difusa. La combinación de los criterios produjo un mapa síntesis de valores continuos de riesgo de transmisión de malaria basado en índices de: a) conveniencia climática para la viabilidad de Anopheles darlingi y Plasmodium spp.; b) conveniencia geomorfológica y de vegetación para la formación de criaderos; c) preferencias de ocupación humana y, d) vulnerabilidad de las comunidades. El mapa se reclasificó en niveles de riesgo y se evaluó superponiendo sobre éste el número de casos de malaria acumulados por nivel de riesgo entre 2000 y 2010, y se discute su importancia para la vigilancia epidemiológica en la región.

Malaria risk maps have been used to support the optimization of the use of human, material and financial resources for the prevention and control of the disease. In Venezuela, these maps are based on annual parasite index, where municipalities are classified using different risk intervals. These maps have low spatial resolution, use risk intervals too broad and do not consider multiple risk factors and their different spatial and temporal scales (eg. biological behavior of parasites and vectors, conditions conducive to man-vector contact and potentially favorable conditions to the prevention and control of the disease). The aim of this study was to identify risk areas of malaria in the Caura River Basin (Venezuelan Guayana), based in a multi-criteria evaluation of climatic, geographical and anthropogenic variables and their suitability for malaria transmission. The risk criteria were expressed spatially as raster image layers using decision rules and normalized using fuzzy logic. The combination of different criteria produced a synthesis map of continuous values of risk of malaria transmission based on the following indexes: a) climatic suitability for the viability of Anopheles darlingi and Plasmodium spp., b) geomorphologic and vegetation suitability for vector hatcheries; c) human occupation preferences and d) vulnerability of communities. The resultant map was reclassified in levels of risk and it was evaluated overlaying the number of cases accumulated per level of risk between 2000 and 2010, and its epidemiological surveillance importance is discussed for the region.

Malaria diagnosis from pooled blood samples: comparative analysis of real-time PCR, nested PCR and immunoassay as a platform for the molecular and serological diagnosis of malaria on a large-scale

Malaria diagnoses has traditionally been made using thick blood smears, but more sensitive and faster techniques are required to process large numbers of samples in clinical and epidemiological studies and in blood donor screening. Here, we evaluated molecular and serological tools to build a screening platform for pooled samples aimed at reducing both the time and the cost of these diagnoses. Positive and negative samples were analysed in individual and pooled experiments using real-time polymerase chain reaction (PCR), nested PCR and an immunochromatographic test. For the individual tests, 46/49 samples were positive by real-time PCR, 46/49 were positive by nested PCR and 32/46 were positive by immunochromatographic test. For the assays performed using pooled samples, 13/15 samples were positive by real-time PCR and nested PCR and 11/15 were positive by immunochromatographic test. These molecular methods demonstrated sensitivity and specificity for both the individual and pooled samples. Due to the advantages of the real-time PCR, such as the fast processing and the closed system, this method should be indicated as the first choice for use in large-scale diagnosis and the nested PCR should be used for species differentiation. However, additional field isolates should be tested to confirm the results achieved using cultured parasites and the serological test should only be adopted as a complementary method for malaria diagnosis.

Transfusion-transmitted malaria: case report of asymptomatic donor harboring Plasmodium malariae / Malária transfusional: relato de caso de doador assintomático infectado por Plasmodium malariae

Malaria in Brazil is endemic in the Amazon region, but autochthonous cases with low parasitaemia occur in the Atlantic Forest area of the country. According to Brazilian legislation no test is mandatory for blood donors from non-endemic areas. However if they have traveled to malaria transmission regions they are deferred for six months before they can donate. This report describes a transfusion-transmitted malaria case in Sao Paulo, Brazil, where one recipient received infected blood and developed the disease. He lived in Sao Paulo and had no previous transfusion or trips to endemic areas, including those of low endemicity, such as Atlantic Forest. Thick blood smears confirmed Plasmodiummalariae. All donors lived in Sao Paulo and one of them (Donor 045-0) showed positive hemoscopy and PCR. This asymptomatic donor had traveled to Juquia, in the Atlantic Forest area of S ao Paulo State, where sporadic cases of autochthonous malaria are described. DNA assay revealed P. malariae in the donor's (Donor 045-0) blood. Serum archives of the recipient and of all blood donors were analyzed by ELISA using both P. vivax and P. falciparum antigens, and IFAT with P. malariae. Donor 045-0's serum was P. malariae IFAT positive and the P. vivax ELISA was reactive. In addition, two out of 44 donors' archive sera were also P. vivax ELISA reactive. All sera were P. falciparum ELISA negative. This case suggests the need of reviewing donor selection criteria and deferral strategies to prevent possible cases of transfusion-transmitted malaria.

No Brasil a malária é endêmica na Amazônia, porém casos autóctones com baixas parasitemias ocorrem na área costeira de Mata Atlântica. De acordo com a legislação brasileira, não são obrigatórios testes para detecção de malária em doadores de sangue de áreas não-endêmicas; entretanto são excluídos por seis meses aqueles com relato de deslocamento para áreas de transmissão. Este trabalho descreve um caso de malária transfusional ocorrido em São Paulo, Brasil, em que um paciente recebeu sangue infectado, desenvolvendo a doença. Ele residia em São Paulo e não apresentava histórico de transfusão anterior ou deslocamentos para áreas endêmicas, incluindo as de baixa endemicidade, como a Mata Atlântica. A gota espessa revelou Plasmodium malariae. Os doadores eram residentes em São Paulo e um deles (045-0) apresentou hemoscopia e PCR positivos. Este era assintomático com PCR positiva para P. malariae e viagem para Juquiá, Mata Atlântica de São Paulo, onde são descritos casos esporádicos de malária autóctone. Amostras de soro do receptor e de todos os doadores foram ensaiadas por ELISA com antígenos de P. vivax e P. falciparum e RIFI com P. malariae. O doador 045-0 apresentou RIFI positiva para P. malariae. ELISA-P. vivax foi reagente no doador infectado (045-0) e em dois dos 44 doadores. Todos os soros foram negativos com antígeno de P. falciparum. Este caso aponta a necessidade de revisão dos critérios de triagem clínico-epidemiológica para evitar casos transfusionais e também adequar as estratégias de exclusão de doadores de sangue.

Platelet count in Malaria patients

Malaria is a major health problem in the tropics with high morbidity and mortality. This study is conducted to analyse the effects of malaria on platelets. This prospective study was conducted on 200 diagnosed cases of malaria in Department of Medicine, LUMHS, Jamshoro/Hyderabad from February to December 2010. The diagnosis of malaria was carried out by thin and thick blood films. Platelet count was performed using an automated counter. Thrombocytopenia was classified as mild [50-150x10[3] cells/microl], moderate [20-50x10[3] cells/microl] and severe [<20x10[3] cell/microl]. The age of patients ranged from 16 to 80 [28 +/- 10.5] years, median age was 30 years. Among the study population, males were 124 [62%] and females were 76 [38%]. Out of them 105 [52.5%] were cases of Plasmodium falciparum, 93 [46.5%] were of P. vivax, and 2 [1%] were of P. malaria. The data showed that 171 [85.5%] patients were having low platelet count; 141 [70.5%] had mild, 21 [10.5%] moderate, and 9 [4.5%] had severe thrombocytopenia. Twenty-nine [14.5%] patients had normal platelet count. Malaria is associated with different degrees of low platelet count with rarely increased bleeding tendency

Prevalence of malaria infection in Sarbaz, Sistan and Bluchistan province

<p><b>OBJECTIVE</b>To survey malaria prevalence in Sarbaz from April 2009 to October 2010.</p><p><b>METHODS</b>Epidemiological data of 1 464 confirmed malarial patients were analyzed according to demographic status, sex, age, nationality, isolated species and residence place.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSIONS</b>Therefore, 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.</p>

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).

Intermittent preventive treatment for malaria in infants: a decision-support tool for sub-saharan Africa

Objective To develop a decision-support tool to help policy-makers in sub-Saharan Africa assess whether intermittent preventive treatment in infants (IPTi) would be effective for local malaria control. Methods An algorithm for predicting the effect of IPTi was developed using two approaches. First; study data on the age patterns of clinical cases of Plasmodium falciparum malaria; hospital admissions for infection with malaria parasites and malaria-associated death for different levels of malaria transmission intensity and seasonality were used to estimate the percentage of cases of these outcomes that would occur in children aged 10 years targeted by IPTi. Second; a previously developed stochastic mathematical model of IPTi was used to predict the number of cases likely to be averted by implementing IPTi under different epidemiological conditions. The decision-support tool uses the data from these two approaches that are most relevant to the context specified by the user. Findings Findings from the two approaches indicated that the percentage of cases targeted by IPTi increases with the severity of the malaria outcome and with transmission intensity. The decision-support tool; available on the Internet; provides estimates of the percentage of malaria-associated deaths; hospitalizations and clinical cases that will be targeted by IPTi in a specified context and of the number of these outcomes that could be averted. Conclusion The effectiveness of IPTi varies with malaria transmission intensity and seasonality. Deciding where to implement IPTi must take into account the local epidemiology of malaria. The Internet-based decision-support tool described here predicts the likely effectiveness of IPTi under a wide range of epidemiological conditions

Epidemiología de malaria por Plasmodium malariae en Venezuela, 1999 - 2008 / Epidemiology of Plasmodium malariae in Venezuela (1999 – 2008)

El paludismo es un problema mundial grave que afecta de forma inaceptable la salud y el bienestar económico de las comunidades más pobres del mundo. En Venezuela, durante el decenio 1999 - 2008, fueron diagnosticados 341.200 casos de malaria, con una incidencia de 0,1% a Plasmodium malariae. Históricamente se conocía que la incidencia a este Plasmodium era exclusiva del estado Amazonas y así lo demuestran los registros del programa nacional antimalárico. Ahora la mayoría de los diagnósticos (61,4%) son realizados en el estado Bolívar, en sesenta y nueve (69) de sus localidades, pudiendo ser consideradas algunas, como focos de P. malariae durante los últimos tres años, especialmente la localidad de Matupo I, en el municipio Sifontes. Aunque el laboratorio Central o de referencia nacional para el diagnóstico de malaria de la Dirección de Salud Ambiental, ubicado en la ciudad de Maracay, no ha podido corroborar los diagnósticos realizados en el país sobre la especie, es conocido el aumento de interés por el mismo, de un grupo de investigadores y la Dirección Regional de Saneamiento Ambiental del estado Bolívar, lo cual podría ser la causa del aumento de su incidencia en el área

Malaria remains a major global problem, affecting in an unacceptable way the health and economic welfare of the world’s poorest communities. In Venezuela, during the decade 1999 - 2008, 341,200 cases of malaria were diagnosed, with an incidence of 0.1% for Plasmodium malariae. Historically it has been known that the incidence of this Plasmodium was unique to the Amazon state as shown by the national malaria program records. Now most of the diagnoses (61.4%) are made in Bolivar state in sixty-nine (69) localities, some may be considered as foci of P. malariae in the last three years, especially the town of Matupo I in the municipality Sifontes. Although the central or national reference laboratory for malaria diagnosis of the Directorate of Environmental Health, located in the city of Maracay, was unable to corroborate the diagnoses on this species, it has an increased interest in it, including a group of researchers and the Regional Bureau of Environmental Sanitation in Bolívar state, who think this could be the cause of increased incidence in the area

Epidemiological characteristics of imported and locally-acquired malaria in Singapore

<p><b>INTRODUCTION</b>The objective of the study was to determine the trend of malaria, the epidemiological characteristics, the frequency of local transmission and the preventive and control measures taken.</p><p><b>MATERIALS AND METHODS</b>We analysed the epidemiological records of all reported malaria cases maintained by the Communicable Diseases Division, Ministry of Health, from 1983 to 2007 and the Anopheles vector surveillance data collected by the National Environment Agency during the same period.</p><p><b>RESULTS</b>The annual incidence of reported malaria ranged from 2.9 to 11.1 per 100,000 population, with a sharp decline observed after 1997. There were 38 deaths, 92.1% due to falciparum malaria and 7.9% due to vivax malaria. Of the reported cases, 91.4% to 98.3% were imported, with about 90% originating from Southeast Asia and the Indian subcontinent. Among the various population groups with imported malaria, the proportion of cases involving work permit/employment pass holders had increased, while that of local residents had decreased. Between 74.8% and 95.1% of the local residents with imported malaria did not take personal chemoprophylaxis when they travelled overseas. Despite the extremely low Anopheles vector population, a total of 29 local outbreaks involving 196 cases occurred. Most of the larger outbreaks could be traced to foreign workers with imported relapsing vivax malaria and who did not seek medical treatment early. One of the outbreaks of 3 cases in 2007 was caused by Plasmodium knowlesi, a newly recognised simian malaria which was probably acquired in a forested area where long-tail macaques had been sighted.</p><p><b>CONCLUSIONS</b>Singapore remains both vulnerable and receptive to the reintroduction of malaria and a high level of vigilance should be maintained indefinitely to prevent the re-establishment of endemicity. Medical practitioners should highlight the risk of malaria to travellers visiting endemic areas and also consider the possibility of simian malaria in a patient who has no recent travel history and presenting with daily fever spikes and with malaria parasite morphologically similar to that of P. malariae.</p>

Anopheles darlingi bionomics and transmission of Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in Amerindian villages of the Upper-Maroni Amazonian forest, French Guiana

French Guiana is one of the areas in South America most affected by malaria and where the disease has become a serious public health problem. In spite of this situation, little recent entomological data are available from the main localities where the disease occurs, even though they are crucial for development of an effective vector control strategy. A longitudinal entomological survey was carried out from March 2000-February 2002 in three Amerindian villages, namely Twenké, Taluène and Cayodé, located in the Amazonian forest of the Upper-Maroni area, to assess anopheline mosquitoes and malaria transmission dynamics. Anopheles darlingi (Diptera: Culicidae) was the most abundant mosquito species caught during the study. This efficient American malaria vector was active the entire year, but showed an evident peak of abundance during the main rainfall season, from April-June, with an average human biting rate of 255.5 bites per person per night. Parity rates were homogeneous all year, indicating no significant seasonal variability in female survival rates. Estimated vectorial capacity indices were higher during the rainy season, even though the risk of transmission was present throughout the year (VCI > 1). A total of 14 An. darlingi were found infected with Plasmodium falciparum, Plasmodium vivax or Plasmodium malariae. The annual circumsporozoite indices were 0.15, 0.14 and 0.05, and the entomological inoculation rates were 22.8, 27.4 and 14.4 infected bites per person per year in Twenké, Taluène and Cayodé, respectively. An. darlingiwas endo-exophagic and rather exophilic in these localities. The species was collected throughout the night but was more aggressive between 21:30-03:30 h and after 05:30 h. Parity rates were homogeneous during the entire night. Impregnated hammock and/or bed nets, coupled with the use of mosquito repellents, as well as the early treatment of malarial cases, appear to be the most suitable tools for fighting...

Diagnóstico molecular da malária em uma unidade de atenção terciária na Amazônia Brasileira / Molecular diagnosing of malaria in a tertiary care center in the Brazilian Amazon region

O exame de rotina para o diagnóstico da malária continua sendo a gota espessa, apesar da comprovada diminuição da sensibilidade e especificidade em situações de densidade parasitária baixa e infecções mistas. A reação em cadeia da polimerase vem sendo cada vez mais utilizada para a detecção molecular e identificação das espécies de plasmódio, por apresentar maior sensibilidade e especificidade. Foi realizada a nested-PCR em amostras de sangue total de 344 pacientes com síndrome febril aguda que se apresentaram para o diagnóstico de malária, em uma unidade terciária de saúde, em Manaus (Amazonas). Nenhum caso de malária por Plasmodium malariae foi diagnosticado à gota espessa ou PCR. Observou-se co-positividade de 96,7 por cento, co-negatividade de 62,2 por cento e coeficiente kappa de 0,44 entre PCR e gota espessa para Plasmodium falciparum. Para Plasmodium vivax, co-positividade de 100 por cento, co-negatividade de 78,1 por cento e coeficiente kappa de 0,56. Na detecção da malária mista, co-positividade de 100 por cento, co-negatividade de 84,9 por cento e coeficiente kappa de 0,26. A reação em cadeia da polimerase detectou alto número de infecções mistas nas amostras analisadas, mas seu uso rotineiro no diagnóstico da malária merece ainda ampla discussão.

The routine test for diagnosing malaria is still the thick blood smear, despite its known decreased sensitivity and specificity in situations of low parasite density and mixed infections. The polymerase chain reaction is increasingly being used for molecular detection and identification of Plasmodium species, due to its higher sensitivity and specificity. Nested PCR was performed on whole-blood samples from 344 patients with acute febrile syndrome who came to a tertiary healthcare center in Manaus (State of Amazonas) for diagnostic confirmation of malaria. No malaria cases caused by Plasmodium malariae were detected through the blood smear or PCR. Co-positivity of 96.7 percent, co-negativity of 62.2 percent and kappa coefficient of 0.44 were observed between PCR and thick blood smear for Plasmodium falciparum. For Plasmodium vivax, co-positivity of 100 percent, co-negativity of 78.1 percent and kappa coefficient of 0.56 were observed. For mixed infection, co-positivity of 100 percent, co-negativity of 84.9 percent and kappa coefficient of 0.26 were observed. Polymerase chain reaction detected a high number of mixed infections in the samples analyzed, but its routine use for diagnosing malaria still deserves further discussion.

Detection & molecular confirmation of a focus of Plasmodium malariae in Arunachal Pradesh, India.

BACKGROUND & OBJECTIVE: During a malaria epidemiological study in Arunachal Pradesh, Plasmodium malariae like human malaria parasites were seen in blood smears from fever cases. The study was undertaken to detect the presence of P. malariae and to confirm its identity through DNA based polymerase chain reaction approach. METHODS: Fever survey was carried out in 22 villages in Indo-Myanmar bordering district of Lohit, Arunachal Pradesh in 2005. Morphologically suspected P. malariae cases were confirmed using nested PCR based on 18S small subunit ribosomal DNA gene sequence. RESULTS: Screening of 1,995 fever cases resulted in 9 probable cases of P. malariae based on morphological identification in Chakma tribe people residing in 2 villages. Nested PCR confirmed the identity of all probable cases of P. malariae by producing diagnostic band of 144 bp. PCR method was able to detect mixed infection of P. malariae with P. vivax and with P. falciparum. INTERPRETATION & CONCLUSION: P. malariae may have been present in Arunachal Pradesh but most probably is being misdiagnosed due to its close resemblance with P. vivax, especially in ring forms. Estimation of actual case load of P. malariae in north-east India is, therefore, important with accurate species identification using molecular methods.

A case of imported malaria: the first report of a Plasmodium malariae infection in Sri Lanka after 37 years.

We report a case of Plasmodium falciparum and P. malariae mixed infection in a patient who had been living in Malawi. This is the first case of P. malariae reported in Sri Lanka in 4 decades. The presence of both parasites was confirmed by microscopy and polymerase chain reaction (PCR). The history strongly indicated that the infection had been acquired from Malawi. The patient had liver dysfunction and a transient glomerulonephritis, both of which subsided with antimalarial treatment.