Spatial patterns of malaria in a land reform colonization project, Juruena municipality, Mato Grosso, Brazil

Abstract

BackgroundIn Brazil, 99% of malaria cases are concentrated in the Amazon, and malaria's spatial distribution is commonly associated with socio-environmental conditions on a fine landscape scale. In this study, the spatial patterns of malaria and its determinants in a rural settlement of the Brazilian agricultural reform programme called "Vale do Amanhecer" in the northern Mato Grosso state were analysed.MethodsIn a fine-scaled, exploratory ecological study, geocoded notification forms corresponding to malaria cases from 2005 were compared with spectral indices, such as the Normalized Difference Vegetation Index (NDVI) and the third component of the Tasseled Cap Transformation (TC_3) and thematic layers, derived from the visual interpretation of multispectral TM-Landsat 5 imagery and the application of GIS distance operators.ResultsOf a total of 336 malaria cases, 102 (30.36%) were caused by Plasmodium falciparum and 174 (51.79%) by Plasmodium vivax. Of all the cases, 37.6% (133 cases) were from residents of a unique road. In total, 276 cases were reported for the southern part of the settlement, where the population density is higher, with notification rates higher than 10 cases per household. The local landscape mostly consists of open areas (38.79 km²). Training forest occupied 27.34 km² and midsize vegetation 7.01 km². Most domiciles with more than five notified malaria cases were located near areas with high NDVI values. Most domiciles (41.78%) and malaria cases (44.94%) were concentrated in areas with intermediate values of the TC_3, a spectral index representing surface and vegetation humidity.ConclusionsEnvironmental factors and their alteration are associated with the occurrence and spatial distribution of malaria cases in rural settlements.

Serologically Defined Variations in Malaria Endemicity in Pará State, Brazil

“…Mining can also contribute to an increase in number of mosquito breeding sites due to extensive borrow pits dug along mining sites, mimicking the riverine floodwater impoundments [9]. The deforestation occurred in Goianésia do Pará might have been an important factor to the increased malaria risk in the municipality, as observed elsewhere [17]. The coastal city of Belém, as the state capital, is instead more likely to be affected by imported malaria cases due to migration from the surrounding areas.…”

Mapping malaria in municipalities of the Coffee Triangle region of Colombia using Geographic Information Systems (GIS)

“…Until now, studies using GIS in malaria in Latin America have been published mostly from Brazil [22][23][24][25] and Venezuela [26]. There are few previous reports specifically from Colombia [11,22].…”

“…Furthermore, based on this GIS approach, other studies linking the impact of ecological and social variables should be conducted in the region, not only describing the epidemiological distribution pattern by year but also assessing the influences of such variables on disease incidence [23][24][25]. Other demographical variables, such as age and ethnic groups, in countries such as Colombia would also be useful in the geographical assessment of malaria epidemiology.…”

“…There are few previous reports specifically from Colombia [11,22]. In the case of Brazil, GIS studies in malaria have focused on geographically characterizing the habitat suitability of the vector Anopheles darling [25], the patterns of malaria and its determinants in rural settlements [23], as well as the use of GIS analysis and logistic regression as a tool to identify and analyze the relative likelihood and its socio-environmental determinants of malaria rural settlements [24]. In Venezuela, the approach has been to develop GIS based on official cartography with thematic overlays depicting malaria distribution, socio-economic conditions, basic environmental information and specific features associated with the natural wetlands present in one area of malaria transmission [26].…”

Secular trends in the rate of low birth weight in Brazilian State Capitals in the period 1996 to 2010

“…No Município de Juruena (Mato Grosso), os habitantes de um assentamento, provenientes de áreas não endêmi-cas, tiveram probabilidade de infecção 2,9 vezes maior do que aqueles vindos de áreas endêmi-cas, possivelmente pela baixa imunidade e falta de conhecimento sobre medidas de proteção 27 . Geralmente, nos anos iniciais, o assentamento apresenta alto risco para epidemias, determinado pelas transformações ambientais.…”