The potential impact of PM2.5 on the covid-19 crisis in the Brazilian Amazon region

OBJECTIVE

This study aims to assess covid-19 morbidity, mortality, and severity from 2020 to 2021 in five Brazilian Amazon states with the highest records of wildfires.

METHODS

A distributed lag non-linear model was applied to estimate the potential exposure risk association with particulate matter smaller than 2.5-µm in diameter (PM2.5). Daily mean temperature, relative humidity, percentual of community mobility, number of hospital beds, days of the week, and holidays were considered in the final models for controlling the confounding factors.

RESULTS

The states of Para, Mato Grosso, and Amazonas have reported the highest values of overall cases, deaths, and severe cases of covid-19. The worrying growth in the percentual rates in 2020/2021 for the incidence, severity, and mortality were highlighted in Rondônia and Mato Grosso. The growth in 2020/2021 in the estimations of PM2.5 concentrations was higher in Mato Grosso, with an increase of 24.4%, followed by Rondônia (14.9%).

CONCLUSION

This study establishes an association between wildfire-generated PM2.5 and increasing covid-19 incidence, mortality, and severity within the studied area. The findings showed that the risk of covid-19 morbidity and mortality is nearly two times higher among individuals exposed to high concentrations of PM2.5. The attributable fraction to PM2.5 in the studied area represents an important role in the risk associated with covid-19 in the Brazilian Amazon region.

Trypanosoma cruzi infection in triatomines (Hemiptera: Reduviidae) from rural areas of the state of Pará, Brazil

The present study aimed to identify the triatomine species and evaluate Trypanosoma cruzi infection in insects captured in endemic areas of Pará State, Brazil. Triatomines were captured in nine rural communities in the municipality of São Domingos do Capim in August, September and December 2014 using active searches and Malaise and Noireau traps. Additionally, from 2014 to 2018, residents and community health agents submitted captured triatomines to the study team. The analysis of T. cruzi infection in the insects was performed by direct parasitological examination and nested-PCR. A total of 225 triatomines were captured and identified: Rhodnius robustus (n = 111), Rhodnius pictipes (n = 54), Panstrongylus geniculatus (n = 44), Eratyrus mucronatus (n = 11), Panstrongylus lignarius (n = 4), and Panstrongylus rufotuberculatus (n = 1). Direct parasitological examination was performed in 27 living triatomines R. robustus (n = 14), P. geniculatus (n = 7) and R. pictipes (n = 6) and metacyclic trypomastigote forms similar to those of T. cruzi were observed in 66.6% (18/27) samples. Of 174 samples analysed by nested-PCR, 81.6% were positive for T. cruzi DNA: R. robustus (84.7%; 72/85), R. pictipes (84.1%; 37/44), P. geniculatus (69.4%; 25/36), P. lignarius (100%; 4/4), E. mucronatus (75%; 3/4) and P. rufotuberculatus (100%; 1/1). R. robustus, R. pictipes and P. geniculatus were the main vectors of T. cruzi in the studied areas; however, the detection of infections in P. lignarius, E. mucronatus and P. rufotuberculatus indicated that these species can also act as potential vectors of T. cruzi in the study areas.

Molecular genotyping of G6PD mutations and Duffy blood group in Afro-descendant communities from Brazilian Amazon

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) and Duffy-negative blood group are two red blood cells variants that confer protection against malaria. In this study, the distribution of the most common G6PD variants (G6PD*A-, GGPD*A and G6PD Mediterranean) and the major alleles of the Duffy blood group (FY*A, FY*B and FY*BES) were investigated in an Afro-descendant population from state of Pará, Brazilian Amazon. G6PD variants and Duffy blood group alleles were determined by TaqMan SNP genotyping assay. Overall, molecular genotyping revealed the presence of G6PD variants in 126 (24%) of the individuals studied (5% male and 19% female), and frequencies of the G6PD*A- and G6PD*A alleles were 0.061 and 0.104, respectively. Duffy blood group genotyping showed that 24.3% of people were Duffy-negative and 41.3% were heterozygous for FY*BES. The frequency of allele FY*BES was 41.0%. The results emphasize the need to monitor G6PD deficiency for the use of primaquine in the routine care of the Afro-descendant communities of the Trombetas, Erepecuru and Cumná rivers, evaluating the risks of hemolytic crisis in case of recurrence of malaria in the region. In addition, the possible greater protection against malaria conferred by these erythrocyte polymorphisms deserves to be better investigated and explored among these Afro-descendants.

Time trends and changes in the distribution of malaria cases in the Brazilian Amazon Region, 2004-2013

Recent efforts to reduce malaria incidence have had some successes. Nevertheless, malaria persists as a significant public health problem in the Brazilian Amazon. The objective of this study was to describe changes in malaria case characteristics and to identify trends in malaria incidence in the Brazilian Amazon. This study used data from the Malaria Epidemiological Surveillance and Case Notification Information System from 2004 to 2013. The annual parasite incidence (API) was calculated and joinpoint regression was used to assess the trends in API over time. There was a sharp increase in API in the state of Acre, followed by two periods of decrease. Pará also presented inconsistent decreases over the study period. Amapá, Amazonas, Rondônia, and Roraima showed statistically significant decreases over the period. The sharpest decrease occurred in Rondônia, with a reduction of 21.7% in the average annual percent change (AAPC) (AAPC: -21.7%; 95% confidence interval: -25.4%, -17.8%; p < 0.05). This panorama of malaria incidence highlights the importance of integrating evidence-based malaria surveillance and control. Malaria is highly preventable, and eliminating its transmission should be a goal in coming decades.

Agricultural settlement and soil quality in the Brazilian Amazon

This paper discusses the implications of poor or non-existent information on soil quality, at the proper scale, during the planning and implementation of settlement projects in the Brazilian Amazon. Based on data from the Machadinho settlement project, Rondônia, we show that most settlers had no knowledge about the agricultural capability of the area, did not receive technical information, could not afford agricultural inputs, planted inadequate crops in the early years of occupation, and did not manage to stay in their plot for a long period of time. Satellite images indicated that patches of land with good soil quality were not necessarily the first to be utilized. Inadequately planned settlements face many challenges (poor soil being one of them) and are likely to result in land turnover, conversion of land into pasture, land concentration among wealthier persons, invasion of areas by poorer people, and deforestation, defying the main purpose of agrarian reform.

Out-migration and land-use change in agricultural frontiers: insights from Altamira settlement project

One of Daniel Hogan's lasting impacts on international demography community comes through his advocacy for studying bidirectional relationships between environment and demography, particularly migration. We build on his holistic approach to mobility and examine dynamic changes in land use and migration among small farm families in Altamira, Pará, Brazil. We find that prior area in either pasture or perennials promotes out-migration of adult children, but that out-migration is not directly associated with land-use change. In contrast to early formulations of household life cycle models that argued that aging parents would decrease productive land use as children left the farm, we find no effect of out-migration of adult children on land-use change. Instead, remittances facilitate increases in area in perennials, a slower to pay off investment that requires scarce capital, but in pasture. While remittances are rare, they appear to permit sound investments in the rural milieu and thus to slow rural exodus and the potential consolidation of land into large holdings. We would do well to promote the conditions that allow them to be sent and to be used productively to keep families on the land to avoid the specter of extensive deforestation for pasture followed by land consolidation.

Telemedicine experience in the Brazilian Amazon

Introduction

Objective

Methodology

Results

Conclusion

Poverty and Inequality in the Rural Brazilian Amazon: A Multidimensional Approach

This paper analyses poverty and inequality dynamics among smallholders along the Transamazon High-way. We measure changes in poverty and inequality for original settlers and new owners, contrasting income-based with multidimensional indices of well-being. Our results show an overall reduction in both poverty and inequality among smallholders, although poverty decline was more pronounced among new owners, while inequality reduction was larger among original settlers. This trend suggests that families have an initial improvement in livelihood and well-being which tends to reach a limit later-a sign of structural limitations common to rural areas and maybe a replication of boom and bust trends in local economies among Amazonian municipalities. In addition, our multidimensional estimates of well-being reveal that some economically viable land use strategies of smallholders (e.g., pasture) may have important ecological implications for the regional landscape. These findings highlight the public policy challenges for fostering sustainable development among rural populations.

Decoupling of deforestation and soy production in the southern Amazon during the late 2000s

From 2006 to 2010, deforestation in the Amazon frontier state of Mato Grosso decreased to 30% of its historical average (1996-2005) whereas agricultural production reached an all-time high. This study combines satellite data with government deforestation and production statistics to assess land-use transitions and potential market and policy drivers associated with these trends. In the forested region of the state, increased soy production from 2001 to 2005 was entirely due to cropland expansion into previously cleared pasture areas (74%) or forests (26%). From 2006 to 2010, 78% of production increases were due to expansion (22% to yield increases), with 91% on previously cleared land. Cropland expansion fell from 10 to 2% of deforestation between the two periods, with pasture expansion accounting for most remaining deforestation. Declining deforestation coincided with a collapse of commodity markets and implementation of policy measures to reduce deforestation. Soybean profitability has since increased to pre-2006 levels whereas deforestation continued to decline, suggesting that antideforestation measures may have influenced the agricultural sector. We found little evidence of direct leakage of soy expansion into cerrado in Mato Grosso during the late 2000s, although indirect land-use changes and leakage to more distant regions are possible. This study provides evidence that reduced deforestation and increased agricultural production can occur simultaneously in tropical forest frontiers, provided that land is available and policies promote the efficient use of already-cleared lands (intensification) while restricting deforestation. It remains uncertain whether government- and industry-led policies can contain deforestation if future market conditions favor another boom in agricultural expansion.

Selenium and mercury in the Brazilian Amazon: opposing influences on age-related cataracts

BACKGROUND

Age-related cataracts (ARCs) are an important cause of blindness in developing countries. Although antioxidants may be part of the body's defense to prevent ARC, environmental contaminants may contribute to cataractogenesis. In fish-eating populations of the lower Tapajós region, elevated exposure to mercury (Hg) has been reported, and blood levels of selenium (Se) range from normal to very high (> 1,000 microg/L).

OBJECTIVES

We examined ARCs in relation to these elements among adults (> or = 40 years of age) from 12 riverside communities.

METHODS

Participants (n = 211) provided blood samples and underwent an extensive ocular examination. Inductively coupled plasma mass spectrometry was used to assess Hg and Se in blood and plasma.

RESULTS

One-third (n = 69; 32.7%) of the participants had ARC. Lower plasma Se (P-Se; < 25th percentile, 110 microg/L) and higher blood Hg (B-Hg; > or = 25th percentile, 25 microg/L) were associated with a higher prevalence odds ratio (POR) of ARC [adjusted POR (95% confidence interval), 2.69 (1.11-6.56) and 4.45 (1.43-13.83), respectively]. Among participants with high P-Se, we observed a positive but nonsignificant association with high B-Hg exposure, whereas among those with low B-Hg, we observed no association for P-Se. However, compared with the optimum situation (high P-Se, low B-Hg), the POR for those with low P-Se and high B-Hg was 16.4 (3.0-87.9). This finding suggests a synergistic effect.

CONCLUSION

Our results suggest that persons in this population with elevated Hg, the cataractogenic effects of Hg may be offset by Se. Because of the relatively small sample size and possible confounding by other dietary nutrients, additional studies with sufficient power to assess multiple nutrient and toxic interactions are required to confirm these findings.

Revisiting the hierarchy of urban areas in the Brazilian Amazon: a multilevel approach

The Legal Brazilian Amazon, while the largest rainforest in the world, is also a region where most residents are urban. Despite close linkages between rural and urban processes in the region, rural areas have been the predominant focus of Amazon-based population-environment scholarship. Offering a focus on urban areas within the Brazilian Amazon, this paper examines the emergence of urban hierarchies within the region. Using a combination of nationally representative data and community based surveys, applied to a multivariate cluster methodology (Grade of Membership), we observe the emergence of sub-regional urban networks characterized by economic and political inter-dependency, population movement, and provision of services. These networks link rural areas, small towns, and medium and large cities. We also identify the emergence of medium-size cities as important nodes at a sub-regional level. In all, the work provides insight on the proposed model of 'disarticulated urbanization' within the Amazon by calling attention to the increasing role of regional and sub-regional urban networks in shaping the future expansion of land use and population distribution in the Amazon. We conclude with a discussion of implications for increasing intra-regional connectivity and fragmentation of conservation areas and ecosystems in the region.

Transferências intergeracionais privadas na Amazônia rural brasileira

What motivates family members to share resources? Past research argues for, on the one hand, love and altruism, and on the other, the expectation of reciprocity. Drawing on this literature, this paper examines intergenerational transfers between small farmers and their non-coresident children in the rural area around the city of Altamira, Pará, Brazil. We apply GoM (Grade of Membership) models to create profiles of private transfers, using data collected in 2005 by a team from Indiana University. The results show three profiles: low intergenerational transfers, high levels of transfers of visits and help, and high levels of transfers of visits and money. There is no clear difference in profile by birth order, but we do find sex differences in profile. Men are more likely to send money while women provide time transfers (work and visits). Upward transfers are most common from children with high levels of education or living in urban areas, suggesting a repayment of prior investments made by parents. Thus, our empirical evidence supports theories arguing that transfers are motivated by intertemporal contracts between parents and children, and that altruistic theories of family transfers should be rethought among rural agricultural populations in contexts characterized by many environmental and institutional challenges.

Collecting Sketch Maps to Understand Property Land Use and Land Cover in Large Surveys

This article describes a method to collect data on the spatial organization of land use within a rural property as part of a large-scale project examining the linkages between household demographic change and land use and land cover change in the Brazilian Amazon. Previous studies used several different spatial approaches, including maps and satellite images, to improve the information collected in standard survey questionnaires. However, few used sketch maps to obtain information from the point of view of the survey respondent about the spatial organization of land use and infrastructure. We developed a method of creating sketch maps with respondents to describe their properties. These maps then provided a spatially referenced database of the social and land use organization of the properties from the perspective of the respondent. Systematic rules allowed sketches to be used in subsequent spatial analyses in combination with satellite images and Global Positioning System reference points.

Bat-transmitted human rabies outbreaks, Brazilian Amazon

We describe 2 bat-transmitted outbreaks in remote, rural areas of Portel and Viseu Municipalities, Pará State, northern Brazil. Central nervous system specimens were taken after patients' deaths and underwent immunofluorescent assay and histopathologic examination for rabies antigens; also, specimens were injected intracerebrally into suckling mice in an attempt to isolate the virus. Strains obtained were antigenically and genetically characterized. Twenty-one persons died due to paralytic rabies in the 2 municipalities. Ten rabies virus strains were isolated from human specimens; 2 other cases were diagnosed by histopathologic examination. Isolates were antigenically characterized as Desmodus rotundus variant 3 (AgV3). DNA sequencing of 6 strains showed that they were genetically close to D. rotundus–related strains isolated in Brazil. The genetic results were similar to those obtained by using monoclonal antibodies and support the conclusion that the isolates studied belong to the same rabies cycle, the virus variants found in the vampire bat D. rotundus.

Bat-transmitted human rabies outbreaks, Brazilian Amazon

We describe 2 bat-transmitted outbreaks in remote, rural areas of Portel and Viseu Municipalities, Pará State, northern Brazil. Central nervous system specimens were taken after patients' deaths and underwent immunofluorescent assay and histopathologic examination for rabies antigens; also, specimens were injected intracerebrally into suckling mice in an attempt to isolate the virus. Strains obtained were antigenically and genetically characterized. Twenty-one persons died due to paralytic rabies in the 2 municipalities. Ten rabies virus strains were isolated from human specimens; 2 other cases were diagnosed by histopathologic examination. Isolates were antigenically characterized as Desmodus rotundus variant 3 (AgV3). DNA sequencing of 6 strains showed that they were genetically close to D. rotundus-related strains isolated in Brazil. The genetic results were similar to those obtained by using monoclonal antibodies and support the conclusion that the isolates studied belong to the same rabies cycle, the virus variants found in the vampire bat D. rotundus.

Malaria risk on the Amazon frontier

Frontier malaria is a biological, ecological, and sociodemographic phenomenon operating over time at three spatial scales (micro/individual, community, and state and national). We explicate these linkages by integrating data from remote sensing surveys, ground-level surveys and ethnographic appraisal, focusing on the Machadinho settlement project in Rondônia, Brazil. Spatially explicit analyses reveal that the early stages of frontier settlement are dominated by environmental risks, consequential to ecosystem transformations that promote larval habitats of Anopheles darlingi. With the advance of forest clearance and the establishment of agriculture, ranching, and urban development, malaria transmission is substantially reduced, and risks of new infection are largely driven by human behavioral factors. Malaria mitigation strategies for frontier settlements require a combination of preventive and curative methods and close collaboration between the health and agricultural sectors. Of fundamental importance is matching the agricultural potential of specific plots to the economic and technical capacities of new migrants. Equally important is providing an effective agricultural extension service.