Mapeamento de hotspots de transmissão de malária utilizando geolocalização de pacientes / Mapping hotspots of malaria transmission using patients geolocation data

A identificação de focos de transmissão pode ser de grande utilidade no controle da malária. Por esse motivo, hospitais em regiões endêmicas buscam saber os locais que foram visitados anteriormente por pacientes. No entanto, tais informações, obtidas através de questionários fornecidos aos pacientes, são geralmente vagas e muitas vezes imprecisas. Isto torna o processo manual, lento e de pouca valia em estudos epidemiológicos de larga escala. Baseando-se no fato de que uma parcela significativa da população possui celulares com GPS, o objetivo deste projeto é melhorar a acurácia, organização e dinâmica do processo de coleta de dados de geolocalização de pacientes infectados. Um sistema (https://sipos.fcf.usp.br) foi desenvolvido para que pacientes que chegam aos hospitais possam, sob consentimento voluntário, fornecer os dados de GPS dos seus celulares. Os dados dos usuários, que são tratados de forma anônima, são automaticamente processados e armazenados de forma segura. Através do sistema SiPoS Explorer, epidemiologistas e especialistas em saúde pública podem explorar e analisar os dados de geolocalização, permitindo, desta forma, que regiões vulneráveis sejam priorizadas durante campanhas de controle

The identification of regions with high rates of infection can be of great use in the control of malaria. For this reason, hospitals in endemic regions seek to know the places previously visited by patients. However, such information, obtained through questionnaires provided to patients, is usually vague, inaccurate and not integrated into databases. This makes the process manual, slow and of little value in large-scale epidemiological studies. Based on the fact that a significant portion of the population has smartphones equipped with GPS, this project aims to improve the accuracy and organization of the process of collecting geolocation data from infected patients. The Sickness Positioning System (https://sipos.fcf.usp.br) was developed so that patients who arrive at hospitals can, with voluntary consent, provide the GPS data collected by their smartphones. User data, which is handled anonymously, is automatically processed and securely stored. Through the SiPoS Explorer system (https://sipos.fcf.usp.br/explorer), epidemiologists and public health experts can explore and analyze geolocation data, thereby allowing vulnerable regions to be prioritized during control campaigns

Association of the Single-Nucleotide Polymorphism and Haplotype of the Complement Receptor 1 Gene with Malaria

PURPOSE: Although the polymorphisms of erythrocyte complement receptor type 1 (CR1) in patients with malaria have been extensively studied, a question of whether the polymorphisms of CR1 are associated with severe malaria remains controversial. Furthermore, no study has examined the association of CR1 polymorphisms with malaria in Chinese population. Therefore, we investigated the relationship of CR1 gene polymorphism and malaria in Chinese population. MATERIALS AND METHODS: We analyzed polymorphisms of CR1 gene rs2274567 G/A, rs4844600 G/A, and rs2296160 C/T in 509 patients with malaria and 503 controls, using the Taqman genotyping assay and PCR-direct sequencing. RESULTS: There were no significant differences in the genotype, allele and haplotype frequencies of CR1 gene rs2274567 G/A, rs4844600 G/A, and rs2296160 C/T polymorphisms between patients with malaria and controls. Furthermore, there was no association of polymorphisms in the CR1 gene with the severity of malaria in Chinese population. CONCLUSION: These findings suggest that CR1 gene rs2274567 G/A, rs4844600 G/A, and rs2296160 C/T polymorphisms may not be involved in susceptibility to malaria in Chinese population.

Inmunoglobulina E anti-Plasmodium en niños de Urabá (Colombia) según la presencia de malaria / Anti-Plasmodium immunoglobulin E in children of Urabá (Colombia) according to the presence of malaria

Problema: no existen informes en Colombia sobre los niveles de IgE anti-Plasmodium en niños sin malaria y apenas hay uno en niños con malaria no complicada. Objetivo: medir la IgE anti-Plasmodium en niños sin malaria o con ella en función del sexo, el estado nutricional y la presencia de helmintos intestinales, y las relaciones con variables hematológicas. Metodología: la IgE anti-Plasmodium se midió en 335 niños sin malaria y en 125 con malaria no complicada (116 P. vivax, 9 P. falciparum). La medición se hizo con la técnica de ELISA, con antígeno de extracto crudo de P. falciparum, cepa FCB-2. Se usó el conjugado anti-anti-IgE de Sigma A3525. La IgE se midió y expresó según la densidad óptica (absorbancia). Resultados: la IgE anti-Plasmodium fue de 0,808 ± 0,508 en niños sin malaria (punto de corte usado para definir nivel alto: 0,584) y 1,968 ± 1,237 en niños con malaria (p = 0,000000). La IgE anti-Plasmodium no mostró diferencia significativa según la especie plasmodial, pero sí según el sexo y el estado nutricional de los niños. En niños sin malaria, el nivel de IgE anti-Plasmodium fue mayor en aquellos con presencia de áscaris, tricocéfalos y uncinarias, pero la diferencia fue significativa únicamente para áscaris. El nivel de IgE anti-Plasmodium mostró correlación lineal positiva y significativa con la cantidad de huevos de tricocéfalo y de áscaris por gramo de materia fecal. Conclusiones: los niños sin malaria o con ella de Urabá tienen elevados niveles de IgE anti-Plasmodium, que son más altos en mujeres y en los afectados por paludismo.

Problem: We are not aware of studies in Colombia on levels of specific IgE in children without malaria and only one is available in children with uncomplicated malaria.Objective: To measure anti-Plasmodium IgE in children with or without malaria according to sex, nutritional status, and the presence of intestinal helminthes, and the relations with hematologic variables. Methodology: anti-Plasmodium IgE was measured in 335 children without malaria and in 125 with uncomplicated malaria (P. vivax: 116; P. falciparum: 9). Measurement was done with the ELISA technique, with a crude antigen extract of P. falciparum FCB-2 strain. We used Sigma`s conjugated anti-anti-IgE A3525. IgE was measured and expressed as optical density (absorbance). Results: Anti-Plasmodium IgE in children without malaria was 0.808 ± 0.508 (cutoff point used to define high level: 0.584) and 1.968 ± 1.237 in children with malaria (p = 0.000000). Anti-Plasmodium IgE levels showed no significant difference according to plasmodial species but there was significant difference by sex and nutritional status. In children without malaria, the level of anti-Plasmodium IgE was higher in those with the presence of roundworm, whipworm and hookworm, but the difference was significant only for roundworms. The level of anti-Plasmodium IgE showed significant positive linear correlation with the number of eggs of Ascaris and whipworm per gram of stool. Conclusions: In Urabá, children with or without malaria have elevated levels of anti-Plasmodium IgE, that are higher in women and in those affected by malaria.

Orientaciones para fortalecer el programa de malaria en zonas remotas con población indígena en el Caura, Venezuela / Guidelines to strengthen the program of malaria in remote areas with indigenous population in the Caura, Venezuela

La malaria está resurgiendo en Venezuela, especialmente al sur del país a pesar de los esfuerzos de prevención y control. En el estado Bolívar representó el 71,2 % de los 42.067 casos de malaria diagnosticados en el país para el año 2007, con una incidencia parasitaria anual de 19,3 casos por cada 1.000 habitantes. Las comunidades indígenas en zonas remotas del estado Bolívar (cuenca del río Caura), consideran que la malaria representa uno de los problemas más importantes de salud pública y perciben la enfermedad como “últimamente incontrolable”, que genera costos socioeconómicos e impacta sus esfuerzos de desarrollo y conservación de sus hábitats tradicionales. En el 2005 se inicia el Proyecto Wesoichay dirigido a formular un modelo de gestión pública para controlar la malaria en la cuenca del Caura y, fortalecer las capacidades del gobierno y comunidades para instrumentarlo. Este trabajo presenta los resultados parciales de dicho proyecto. Los principales hallazgos evidencian vacíos de información pertinentes para la planificación y evaluación de la malaria; capacidad limitada de atención sanitaria y de investigación; aumento de las oportunidades de contacto hombre-vector promovido por la transformación de los ecosistemas alrededor de las comunidades y patrones de movilización de la población, dentro y fuera de su territorio tradicional y, baja participación comunitaria para identificar y adecuar respuestas a la prevención y el combate de la malaria.

Malaria is reemerging in Venezuela, especially in the south of the country despite prevention and control efforts. In 2007, the State of Bolívar represented 71.2% of the 29,940 cases of malaria diagnosed in the country, with an Annual Parasitic Index of 19.3 cases per 1,000 inhabitants. For indigenous communities that inhabit remote areas in the State of Bolívar (Caura river basin), malaria represents one of the most important problems of public health and they perceive the illness as “ultimately uncontrollable”, generating socioeconomic costs and affecting their development and conservation efforts of their traditional habitat. The Wesoichay Project started in 2005 to formulate a public management model for the control the malaria in the Caura river basin and to strengthen the capacity of the government and local communities to implement it. The main findings show information gaps pertinent for the planning and evaluation of malaria; limited health provision and research capacity; increase in human-vector contact opportunities due to the transformation of ecosystems around communities and population migration patterns inside and out of their traditional territory, and; low community participation to identify and adapt answers for malaria prevention and control.

Fluctuaciones estacionales y temporales de la densidad larvaria de Anopheles darlingi Root (Diptera: Culicidae) y familias de insectos asociados al hábitat en El Granzón, Parroquia San Isidro, municipio Sifontes del estado Bolívar, Venezuela / Seasonal and temporal fluctuations of larval densites of Anopheles darlingi Root (Diptera: Culicidae) and insects associated to the habitat in San Isidro Parish, Sifontes municipality, Bolívar state, Venezuela

Anopheles darlingi Root ha sido considerado en condiciones naturales como el principal vector de la malaria humana en América del sur y también en Venezuela, principalmente en los estados Bolívar y Amazonas, donde se produce el 90% de la malaria del país. Durante un mes (Junio de 1999) se realizaron muestreos en criaderos de mosquitos en siete localidades del área minera de San Isidro municipio Sifontes, estado Bolívar. Los sitios de muestreo fueron clasificados a priori en cuatro tipos de hábitat larvario: quebradas, lagunas, ríos, pantanos (herbáceo o arbóreo). En cada criadero se tomaron 30 muestras con un cucharón para colectar larvas de Anopheles. Simultáneamente al muestreo de larvas se midieron cuatro variables físico-químicas del criadero: pH, oxígeno disuelto, temperatura y profundidad del criadero. Asimismo, en un criadero de An. darlingi (quebrada con sombra), ubicado en la localidad de El Granzón, se llevó a cabo un estudio longitudinal, durante un año entre Julio de 1999 y Junio del 2000. En dicho criadero, se colectaron mensualmente larvas de An. darlingi e insectos acuáticos asociados. Las correlaciones entre la precipitación acumulada, la abundancia de estos insectos y la abundancia de larvas de An. darlingi, se establecieron mediante el análisis no paramétrico de correlación de Spearman (Spearman rank correlation). En el hábitat seleccionado, los resultados del análisis revelaron la presencia de una correlación negativa y significativa entre la abundancia de larvas de An. darlingi y la precipitación acumulada el mes anterior a la colecta. En esa misma localidad, la precipitación acumulada el mes anterior a la colecta, se correlacionó positivamente con la abundancia de la familia Naucoridae (Hemiptera). Asimismo, la abundancia de larvas de An. darlingi presentó una correlación negativa y significativa con la abundancia de la familia Naucoridae. En este hábitat (quebrada del Granzón), la densidad de larvas An. darlingi fue mayor en los meses de menor precipitación, aunque tanto en la época de menor precipitación como en la temporada lluviosa, hubo presencia de larvas de esta especie. Por otro lado, el criadero típico de An. darlingi, donde éste presentó su mayor abundancia y hubo presencia de larvas durante todo el año, fue clasificado como “Quebrada con sombra”. Esta presentó mucha sombra (90-100%), abundante materia orgánica sumergida o flotante (hojarasca, palitos, hojas, semillas), profundidad promedio de 65,22 cm, un pH promedio de 6,16, contenido medio de oxigeno disuelto de 6,40 g/L y una temperatura promedio del agua de 26ºC.

Anopheles darlingi Root has been considered under natural conditions as human malaria’s principal vector in South America. In Venezuela, Amazonas and Bolivar States, it is responsible for 90 % of malaria cases reported in the country. Field surveys and mosquito larvae sampling of mosquito breeding sites in mining areas, were carried out in seven localities of Sifontes county, Bolívar state during one month, between 2 and 29 June 1999. The breeding sites were a priori classified into four larval habitat categories: lagoons, streams, rivers and herbaceous swamps. At each breeding site, 30 dips for mosquito larvae samples were made. Simultaneously with mosquito larvae sampling, four selected variables of water were measured: temperature, dissolved oxygen, pH and water depth. On the other hand, a longitudinal study was carried out in the typical An. darlingi breeding site (shaded streams) in El Granzón (Sifontes county). Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding site over a one-year period (July, 1999 to June, 2000). At this breeding site, Anopheles larvae and aquatic insects were collected monthly. During the study, 12 samples were taken from this larval habitat of An. darlingi. Seasonal and temporal variations of An. darlingi larvae and aquatic insects were determined. Relationships among the rain in the previous month, abundance of aquatic insects and abundance of An. darlingi larvae, were investigated using the Spearman nonparametric test (Spearman rank correlation). Results of the analysis revealed that the abundance of An. darlingi mosquito larvae was negatively correlated with the rainfall in the previous month. On the other hand, the results indicate that the abundance of An. darlingi larvae was negatively correlated with the abundance of the family Naucoridae (Hemiptera), and this family was positively correlated with the rainfall in the previous month. The typical An. darlingi larval habitat was classified into the category “streams shaded”. This streams were very shaded (90-100%), with a water depth of 65.22 cm, with abundant floating organic debris (dry foliage, leaves, trash, small stick), a pH of 6.16, dissolved oxygen of 6.40 g/L, and a water temperature of 26ºC.

Índices maláricos como factores de riesgo en el Departamento del Petén Norte, Guatemala / Malarial indexes as risk factors existing in Petén Norte district, Guatemala

Introducción: más de 37 por ciento de la población de la región de las Américas vive en zonas maláricas, lo que constituye un serio problema de salud para el hombre. Objetivo: describir los principales indicadores entomoepidemiológicos que ayudarán a redefinir zonas estratificadas con riesgo malárico, en los distintos niveles de exposición en un área de salud de la región norte guatemalteca entre 1999 y 2000. Métodos: se realizaron análisis factoriales según criterio de Kaiser para la selección del número de componentes principales. Se aplicó una prueba t para muestras dependientes, y un análisis discriminante de los parámetros incluidos para determinar la(s) variable(s) de mayor incidencia entre los grupos de municipios bajo estudio. Para verificar si era necesario habilitar estrategias epidemiológicas diferenciadas por municipios, se realizó un análisis de conglomerados. Resultados: se reportó hacia 2000 una disminución de los indicadores epidemiológicos; se destacaron el índice de láminas positivas (t= 5,07159; p= 0,003862) e índice Plasmodium vivax anual (t= 3,48982; p= 0,0175), junto con una reducción de la morbilidad más pronunciada en el índice parasitario anual, lo que permitió redefinir las localidades según riesgo. Plasmodium vivax fue la principal causa de morbilidad en ambos años y P. falciparum resultó más resistente a las medidas de control. Los análisis de conglomerados mostraron una clara división del departamento en 2 grupos, el índice Plasmodium vivax anual resultó el más discriminante (lambda de Wilk (l)= 0,14778, p< 0,008631). Se detectaron 5 especies de anofelinos, los más abundantes Anopheles albimanus (62 L/m2) en las charcas estacionales y An. eiseni (17,8 L/m2), respectivamente. Conclusiones: con la estrategia implementada no se han producido brotes epidémicos por más de 2 años, a pesar de estar en una zona endémica...

Background: Over 37 percent of the population in the Americas is living in malaria-affected areas, which is a serious health problem for mankind. Objective: to describe the main entomological and epidemiological indicators that support the redefinition of stratified areas with malarial risk at different levels of exposure in a health area of Guatemala´s northern region from 1999 to 2000. Methods: factorial analysis was made following Kaiser´s criterion for the selection of the number of main components. A t test for depending samples and a discriminating analysis of included parameters to determine the highest incidental variable(s) in the municipalities under study were made. In order to verify if differentiated municipal epidemiological studies were necessary, a cluster analysis was made. Results: a reduction of epidemiological indications was reported in 2000 such as index of positive plates t= 5,07159; p= 0,003862) and annual Plasmodium vivax index (t= 3,48982; p= 0,0175) together with a more pronounced morbidity reduction in the annual parasitic index, all of which allowed redefining the locations according to existing risks. Plasmodium vivax was the main cause of morbidity in both years and P. falciparum turned to be the most resistant to all the control actions. Cluster analyses proved a clear-cut division of the district into two groups; annual Plasmodium vivax index was the most discriminatory (Wilk´s lambda(l)= 0,14778, p< 0,008631). Five anopheline species were detected, being Anopheles albimanus (62 L/m2) in seasonal pools and An. eiseni (17,8 L/m2) the most abundant. Conclusions: As a result of the implemented strategy, no outbreak has occurred for two years in spite of this being an endemic area. Improvement and strengthening of intersectoral and intrasectoral relationships are encouraged to support the reduction of the economic burden of the anti-vector control program...

Modern medicine and indigenous health beliefs: malaria control alongside "Sadsana-phee" (animist belief system) in Lao PDR.

The major religion in Lao PDR is Buddhism, but many ethnic groups in rural Lao PDR hold an animist belief system called "Sadsana-pee". At the same time, the Bourapar District study site in Khammouane Province, Lao PDR is at high risk of malaria infection. Due to their belief in traditional ways of healing, the promotion of malaria prevention and treatment with modern medicine was not always welcomed by the villagers. Based on the results of questionnaire interviews with 240 heads of households from February to March of 2003, the effect of local beliefs on malaria control activities was discussed. Despite widely available western medicine and widely conducted health education, some people still believe that evil spirits cause malaria and rely on traditional medicine and/or religious ceremonies for treatment. Based on our findings, we recommend that future education and malaria control programs be revised and made sensitive to those people holding indigenous beliefs.

KAP surveys and malaria control in Vietnam: findings and cautions about community research.

The malaria disease burden is increasing in many countries despite the existence of effective preventative strategies and antimalarial drugs. An understanding of community perspectives and practices is one of the essential components of a successful malaria control program. This paper reports on a KAP (Knowledge, Attitudes and Practices) survey among the Raglai ethnic minority population in Ninh Thuan Province, Vietnam, which in 2003 had one of the country's highest confirmed rates of malaria. We found high levels of correct knowledge about malaria's transmission and symptoms, and self-reports of adequate bed net usage and appropriate health-seeking behavior. While the survey generated useful findings, an initial, qualitative investigation (eg, observation and focus group discussions) to explore the large numbers of potential influences on behavior and exposure risk would have provided a more robust underpinning for the design of survey questions. This would have strengthened its validity and generated additional information. The adoption of rigorous, multi-disciplinary research methods offers the best chance of contributing to the development of successful malaria control programs and effective policies.

Malaria infection among the migrant population along the Thai-Myanmar border area.

A population based case-control study was performed to determine factors associated with malaria infection among the migrant population, foreign nationals aged 15 years or over. Data were obtained from 217 malaria and 217 non-malaria patients attending the Vector-Borne Disease Control Units 6-9 (Thong Pha Phum and Sangkhla Buri districts) in Kanchanaburi Province and at the Vector-Borne Disease Control Units 1,9 (Mae Fa Luang and Mae Sai districts) in Chiang Rai Province, between June and December 2002. All study subjects were interviewed by trained interviewers using a structured interview form. The statistical analysis was carried out by the chi-square test and multivariate logistic regression: a p-value of less than 0.05 was considered to be statistically significant. The results showed that the study subjects were predominantly Thai-Yai and Myanmar. Plasmodium falciparum was the major type of the malaria (60.8%). Logistic regression analysis, controlling for possible confounding factors, revealed that residence located in the forest increased the risk of malaria infection by a factor of 6.29 (OR = 6.29, 95% CI = 1.56-25.42); outdoor stay < 7 and > 7 days prior to the blood examination also increased the risk by a factor of 4.34 and 4.13 respectively (OR = 4.34, 95% CI = 1.05-17.99; OR = 4.13, 95% CI = 1.29-13.13).

Social and cultural aspects of malaria.

This paper examines the impact of social and cultural factors on malaria control in rural Thailand. It contends that standard vertical malaria control programs tend to ignore local workplace and living conditions instead of recruiting traditional practices into the planning scenario for more effective control. Careful attention to these practices in the context of local economic capacity can serve to offset the common failure to take the major causative factor of poverty into account.

Blood groups and malaria

Con el presente estudio se evalua la relacion existente antre la infeccion por P. vivax y P. falciparum y los antigenos eritrocitos de cuatro diferentes grupos etnicos en Colombia. P. falciparum se encontro causando malaria en el 91,4 por ciento de los individuos de raza negra que tuvieron malaria. No hubo diferenciais significativas entre la infeccion malaria y los antigenos ABO...