ABSTRACT
Abstract Due to intense ongoing urbanization in the Amazon, the urban pattern of malaria may be changing, both in its spatial distribution and epidemiological profile. The purpose of this paper is to analyze how the process of production of urban space in Porto Velho, the capital of the state of Rondonia, Brazil has contributed to the occurrence and maintenance of urban malaria. Using data collected from the Malaria Epidemiological Surveillance System (SIVEP-Malaria), we calculated malaria indices for the districts of Porto Velho from 2005 to 2018. We also developed two typologies for classifying urban space based on functional characteristics and features of the landscape. While the former considers characteristics of urban space in Porto Velho, the latter is based on suitability for malaria vectors. We found that the annual parasite index declined in Porto Velho during the study period. However, changes in the index were not uniform across the districts of the city. Periurban areas showed no decline in the index, which we attribute to these areas' high vegetation density and hydrological characteristics.
Resumo A Amazônia tem passado por um intenso processo de urbanização em anos recentes, produzindo transformações na organização espacial da região que podem estar refletindo no padrão espaço temporal da malária urbana. O objetivo deste trabalho é compreender como o processo de produção do espaço urbano do município de Porto Velho-RO, tem corroborado para a ocorrência e manutenção da malária urbana. Os dados levantados no Sistema de Vigilância Epidemiológica (SIVEP-Malária) possibilitaram o cálculo do Índice Parasitário Anual (IPA) de malária para os bairros da cidade de Porto Velho dos anos de 2005 a 2018 e a construção de duas tipologias da paisagem do espaço urbano. A primeira considerou o processo de produção do espaço urbano de Porto Velho; a segunda se baseou nas condições de receptividade para o vetor da malária. A ocorrência da malária em Porto Velho vem declinando de forma diferenciada ao longo do território, havendo uma tendência de permanência nas áreas periurbanas com maior densidade de vegetação e hidrografia.
Subject(s)
Humans , Malaria/epidemiology , Brazil/epidemiology , Longitudinal Studies , Cities/epidemiologyABSTRACT
Background: Socio-demographic and environmental factors are associated with the malaria prevalence. Hence assessment of these factors would potentially help in identification of the possible risk factors among households with their health seeking behavior and would help to adopt the most suitable and appropriate malaria control strategies.Methods: A baseline household survey was carried out in the study site Lingappayakadu, Mulki, Manglore involving all study population (n=4954) from July to September 2017. Total 1043 households were interviewed with predesigned semi- structured questionnaire with informed written consent. Blood samples were collected from fever cases and results were confirmed for malaria within 24 hours. Anti-malarial drugs including the Primiaquine were given to all the positive cases. Data regarding socio-demographic characteristics and health seeking behavior were also collected from study population.Results: The prevalence of malaria in the study was 1.41% and slide positivity was 51.09%. The presence of malaria cases was statistically significant with number of members present in the family (p=0.00001, X2=199.37), age group (p=0.0168, X2=8.17) type of working status (p=0.0293, X2=7.06). Environmental factors like type of housing (p=0.3366, OR=1.3854), peri-domestic sanitation (p=0.1646, OR=0.554), Mosquito breeding (p=0.4504, OR=0.6757), indoor mosquitoes (p=1.000, OR=0.6173) and mosquito bite prevention methods were (p=0.1910, OR=1.7316) not showing any significant difference. Out of 137 fever cases, 70 cases were diagnosed with malaria amongst which 94.3% cases completed anti-malaria drug treatment.Conclusions: A survey provides data regarding socio-demographic, environmental and health seeking behavior of population. The study did not show any statistically significant association of malaria with many environmental parameters. Health seeking behavior could be analyzed and improved with frequent surveillance methods.
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Objective: To estimate risk factors of urban malaria in Blantyre, Malawi, with the goal of understanding the epidemiology and ecology of the disease, and informing malaria elimination policies for African urban cities that have markedly low prevalence of malaria. Methods: We used a case-control study design, with cases being children under the age of five years diagnosed with malaria, and matched controls obtained at hospital and communities. The data were obtained from Ndirande health facility catchment area. We then fitted a multivariate spatial logistic model of malaria risk. Covariate and risk factors in the model included child-specific, household and environmental risk factor (nearness to garden, standing water, river and swamps). The spatial component was assumed to follow a Gaussian process and model fitted using Bayesian inference. Results: Our findings showed that children who visited rural areas were 6 times more likely to have malaria than those who did not [odds ratio (OR) = 6.66, 95% confidence interval (CI): 4.79-9.61]. The risk of malaria increased with age of the child (OR = 1.01, 95% CI: 1.003-1.020), but reduced with high socio-economic status compared to lower status (OR = 0.39, 95% CI: 0.25-0.54 for the highest level and OR = 0.67, 95% CI: 0.47-0.94 for the medium level). Although nearness to a garden, river and standing water showed increased risk, these effects were not significant. Furthermore, significant spatial clusters of risk emerged, which does suggest other factors do explain malaria risk variability apart from those established above. Conclusions: As malaria in urban areas is highly fuelled by rural-urban migration, emphasis should be to optimize information, education and communication prevention strategies, particularly targeting children from lower socio-economic position.
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Se analizaron las características epidemiológicas y factores asociados con la transmisión de la malaria urbana en el mundo, mediante la revisión de literatura publicada, en la cual se incluyeron libros, artículos científicos, revisiones de temas y reportes técnicos. La metodología aplicada se basó en la búsqueda de documentos y gestores en fuentes bibliográficas. Con los resultados se espera retratar la actualidad del fenómeno de malaria urbana en función de su carga de morbilidad y mortalidad, que sirve de base para el desarrollo de las investigaciones y estrategias pertinentes para su control.
A study was conducted of the epidemiological characteristics of urban malaria and the factors associated to its transmission worldwide by means of a review of published materials, including books, scientific papers, topic reviews and technical reports. The methodology applied was based on the search for documents and managers in bibliographic sources. Results are expected to provide a current picture of the morbidity and mortality burden of urban malaria, laying the foundations for relevant research into the topic and the development of control strategies.
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Malaria control in India has occupied high priority in health sector consuming major resources of the Central and State governments. Several new initiatives were launched from time to time supported by foreign aids but malaria situation has remained static and worsened in years of good rainfall. At times malaria relented temporarily but returned with vengeance at the local, regional and national level, becoming more resilient by acquiring resistance in the vectors and the parasites. National developments to improve the economy, without health impact assessment, have had adverse consequences by providing enormous breeding grounds for the vectors that have become refractory to interventions. As a result, malaria prospers and its control is in dilemma, as finding additional resources is becoming difficult with the ongoing financial crisis. Endemic countries must contribute to make up the needed resources, if malaria is to be contained. Malaria control requires long term planning, one that will reduce receptivity and vulnerability, and uninterrupted financial support for sustained interventions. While this seems to be a far cry, the environment is becoming more receptive for vectors, and epidemics visit the country diverting major resources in their containment, e.g. malaria, dengue and dengue haemorrhagic fevers, and Chikungunya virus infection. In the last six decades malaria has taken deep roots and diversified into various ecotypes, the control of these ecotypes requires local knowledge about the vectors and the parasites. In this review we outline the historical account of malaria and methods of control that have lifted the national economy in many countries. While battles against malaria should continue at the local level, there is a need for large scale environmental improvement. Global Fund for AIDS, Tuberculosis and Malaria has provided huge funds for malaria control worldwide touching US$ 2 billion in 2011. Unfortunately it is likely to decline to US$ 1.5 billion in the coming years against the annual requirement of US$ 5 billion. While appreciating the foreign assistance, we wish to highlight the fact that unless we have internal strength of resources and manpower, sustained battles against malaria may face serious problems in achieving the final goal of malaria elimination.
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Cross sectional studies on malaria prevalence was performed in 2001, 2002, and 2004 in Vila Candelária, an urban riverside area of Porto Velho, Rondônia, in the Brazilian Western Amazon, followed by longitudinal surveys on malaria incidence. Vila Candelária is a working class district, provided with electricity, water supply, and basic sanitation. Previous preliminary surveys indicated high malaria incidence in this community. At the end of year 2000 regular diagnostic and treatment measures for malaria were introduced, with active search of febrile cases among residents. Despite of both rapid treatment of cases and relative good sanitary and housing conditions, the malaria incidence persisted at high levels during the following years with an annual parasite index of 150 to 300/1000 inhabitants. Parasite surveys in 2001, 2002, and 2004 achieved through microscopy and polymerase chain reaction to diagnose malaria showed a constant high prevalence of asymptomatic carriers for both Plasmodium falciparum and P. vivax parasites. It was concluded that asymptomatic carriers represent an important reservoirs of parasites and that the carriers might contribute to maintaining the high level of transmission. Comparing our findings to similar geo-demographic situations found in other important urban communities of the Brazilian Amazon, we propose that asymptomatic carriers could explain malaria's outbreaks like the one recently observed in Manaus.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Carrier State/epidemiology , Malaria, Falciparum/epidemiology , Malaria, Vivax/epidemiology , Brazil/epidemiology , Carrier State/diagnosis , Epidemiologic Methods , Malaria, Falciparum/diagnosis , Malaria, Vivax/diagnosis , Seasons , Urban PopulationABSTRACT
Longitudinal entomological surveys were performed in Vila Candelária and adjacent rural locality of Bate Estaca concomitantly with a clinical epidemiologic malaria survey. Vila Candelária is a riverside periurban neighborhood of Porto Velho, capital of the state of Rondônia in the Brazilian Amazon. High anopheline densities were found accompanying the peak of rainfall, as reported in rural areas of the region. Moreover, several minor peaks of anophelines were recorded between the end of the dry season and the beginning of the next rainy season. These secondary peaks were related to permanent anopheline breeding sites resulting from human activities. Malaria transmission is, therefore, observed all over the year. In Vila Candelária, the risk of malaria infection both indoors and outdoors was calculated as being 2 and 10/infecting bites per year per inhabitant respectively. Urban malaria in riverside areas was associated with two factors: (1) high prevalence of asymptomatic carriers in a stable human population and (2) high anopheline densities related to human environmental changes. This association is probably found in other Amazonian urban and suburban communities. The implementation of control measures should include environmental sanitation and better characterization of the role of asymptomatic carriers in malaria transmission.