In the Vale do Amanhecer settlement, malaria was highly prevalent in 2005, with about 47% of the settlement's 718 inhabitants affected by the disease. Therefore, the study area provides a clear example of the focal nature of malaria occurrence in the Amazon region, where malaria is often concentrated in settlements and areas of mining activity. The average prevalence in the Juruena municipality is about five times lower than in Vale do Amanhecer.
The comparison of the spatial pattern of malaria occurrence with geographic layers representing vegetation distribution and distances to watercourses and mining areas showed variable findings in this fine-scale epidemiological study.
Numerous studies have shown that malaria infection is influenced by environmental factors, such as temperature, precipitation, humidity and altitude. In tropical regions, such as the Amazon region, year-round high temperatures and precipitation favor malaria transmission [14–16, 2]. Most studies have been large-scale surveys on a regional or country scale [14, 17, 7]. As variations at these scales can be governed by other external factors, local-scale studies, such as those carried out within a single settlement , are crucial for understanding the driving factors of malaria transmission and for community-based health planning . At this scale, transmission rates are not only governed by demographic or ecological factors but are also influenced by the social and cultural contexts of local populations .
In the studied settlement, relationships between the environment and spatial patterns of malaria occurrence were observed. For risk evaluation, the combination of land use and vegetation cover must be considered. More cases are reported in deforested areas with low NDVI and TC_3 values, but this is exclusively due to the higher local population density and population fluxes. The highest rates of malaria per domicile were reported within or near forest reminiscent with high spectral indices. Additionally, at a local scale, it must be considered that infection did not necessarily take place in the domicile.
Vegetation cover plays an important role in the biological cycles of vectors and infectious agents, particularly if other environmental conditions, such as precipitation, temperature or humidity, are altered [21, 22]. This alteration explains the elevated incidence of malaria cases in domiciles inside or near forested areas with high values of NDVI, which may be characterized by higher vector densities. The low absolute numbers of cases in these areas are caused by their low housing density (18.2% of all domiciles) and low population flux.
High TC_3 values were observed inside forested areas and areas with dense vegetation succession. The highest average case rate per domicile (1.82) was found in areas with high TC_3 values, possibly due to the presence of humid areas favoring vector proliferation. These areas mainly coincide with buffer zones near streams, explaining the concentration of cases in domiciles less than 1 km from the hydrographic network, which is dense throughout the settlement.
High malaria infection rates in the settlement are supposedly related to the changes in land use carried out by a population that originated partially from non-endemic regions. FERREIRA  identified a malaria prevalence of 56.0% in individuals who migrated to the settlement from non-endemic regions, who have an infection probability 2.9 times higher than individuals from endemic regions, a difference supposedly caused by their low immunity and lack of knowledge about measures to protect against the disease [16, 24].
Studies such as [7, 21, 25, 26] have pointed out that the distribution and dynamics of malaria cases are related to the phase of land occupation. Deforestation, aggregated with an influx of migrants, frequently produces new reproduction and principal feeding habitats, favoring the occurrence of epidemics in communities with populations characterized by high mobility, low immunity and low risk perception [24, 3].
Infection rates are also thought to be elevated due to the lack of an adequate sanitation infrastructure, which motivates inhabitants to construct their housing near streams to facilitate domestic tasks and personal hygiene. Vasconcelos et al  described a similar spatial pattern of domicile distribution in the Jacundá municipality, attributing elevated malaria infection rates to this lack of sanitation infrastructure.
The observed malaria infection rates can be explained by the great number of potential reproduction habitats and mining areas in the settlement; cases are highly concentrated near these areas, which favor the survival and circulation of the main vector, Anopheles darlingi . Close relationships between mining activities and malaria cases in the Amazon region have also been reported by Santos et al.  and Duarte & Fontes .