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Objective: The objective of this study is to estimate the prevalence of chronic Chagas disease (CCD) in Brazil: in the general population, in women, and in women of childbearing age. Methods: A meta-analysis of the literature was conducted to extract data on the prevalence of CCD in municipalities in Brazil in the 2010-2022 period: in the general population, in women, and in women of childbearing age. Municipal-level CCD indicators available in health information systems were selected. Statistical modeling of the data extracted from the meta-analysis (based on data obtained from information systems) was applied to linear, generalized linear, and additive models. Results: The five most appropriate models were selected from a total of 549 models tested to obtain a consensus model (adjusted R2 = 54%). The most important predictor was self-reported CCD in the primary health care information system. Zero prevalence was estimated in 1 792 (32%) of Brazil's 5 570 municipalities; in the remaining 3 778 municipalities, average prevalence of the disease was estimated at 3.25% (± 2.9%). The number of carriers of CCD was estimated for the Brazilian population (~3.7 million), for women (~2.1 million) and for women of childbearing age (~590 000). The disease reproduction rate was calculated at 1.0336. All estimates refer to the 2015-2016 period. Conclusions: The estimated prevalence of CCD, especially among women of childbearing age, highlights the challenge of vertical transmission in Brazilian municipalities. Mathematical projections suggest that these estimates should be included in the national program for the elimination of vertical transmission of Chagas disease.
Objetivo: El objetivo de este estudio fue estimar la prevalencia de la enfermedad de Chagas crónica en la población brasileña en general, en las mujeres y en las mujeres en edad fértil. Métodos: Se realizó un metanálisis de la bibliografía para extraer datos sobre la prevalencia de la enfermedad de Chagas crónica en la población brasileña en general, en las mujeres y en las mujeres en edad fértil, en los municipios de Brasil durante el período 2010-2022. Se seleccionaron los indicadores relacionados con esa enfermedad disponibles en los sistemas municipales de información de salud. La modelización estadística de los datos extraídos del metanálisis, en función de los obtenidos de los sistemas de información, se aplicó a modelos lineales, lineales generalizados y aditivos. Resultados: Se seleccionaron los cinco modelos más apropiados de un total de 549 modelos evaluados, para obtener un modelo de consenso (R2 ajustado = 54%). El factor predictor más importante fue el registro de la enfermedad de Chagas crónica autodeclarada en el sistema de información de atención primaria de salud. De los 5570 municipios brasileños, en 1792 (32%) la prevalencia estimada fue nula y en los 3778 restantes la prevalencia media fue del 3,25% (± 2,9%). El número estimado de pacientes con enfermedad de Chagas crónica en la población brasileña en general, en las mujeres y en las mujeres en edad fértil fue de ~3,7 millones, ~2,1 millones y ~590 000, respectivamente. La tasa calculada de reproducción de la enfermedad fue de 1,0336. Todas las estimaciones se refieren al período 2015-2016. Conclusiones: La prevalencia estimada de la enfermedad de Chagas crónica, especialmente en las mujeres en edad fértil, pone de manifiesto el desafío que representa la transmisión vertical en los municipios brasileños. Estas estimaciones están en línea con los patrones de las proyecciones matemáticas, y sugieren la necesidad de incorporarlas al Pacto Nacional para la Eliminación de la Transmisión Vertical de la Enfermedad de Chagas.
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BACKGROUND: Malaria elimination in Brazil poses several challenges, including the control of Plasmodium falciparum foci and the hidden burden of Plasmodium vivax in pregnancy. Maternal malaria and fetal health outcomes were investigated with a perinatal surveillance study in the municipality of Cruzeiro do Sul, Acre state, Brazilian Amazon. The research questions are: what are the causal effects of low birth weight on low Apgar at 5-min and of perinatal anaemia on stillbirth? METHODS: From November 2018 to October 2019, pregnant women of ≥ 22 weeks or puerperal mothers, who delivered at the referral maternity hospital (Juruá Women and Children's Hospital), were recruited to participate in a malaria surveillance study. Clinical information was obtained from a questionnaire and abstracted from medical reports. Haemoglobin level and presence of malarial parasites were tested by haematology counter and light microscopy, respectively. Low Apgar at 5-min and stillbirth were the outcomes analysed in function of clinical data and epidemiologic risk factors for maternal malaria infection using both a model of additive and independent effects and a causal model with control of confounders and use of mediation. RESULTS: In total, 202 (7.2%; N = 2807) women had malaria during pregnancy. Nearly half of malaria infections during pregnancy (n = 94) were P. falciparum. A total of 27 women (1.03%; N = 2632) had perinatal malaria (19 P. vivax and 8 P. falciparum). Perinatal anaemia was demonstrated in 1144 women (41.2%; N = 2779) and low birth weight occurred in 212 newborns (3.1%; N = 2807). A total of 75 newborns (2.7%; N = 2807) had low (< 7) Apgar scores at 5-min., and stillbirth occurred in 23 instances (30.7%; n = 75). Low birth weight resulted in 7.1 higher odds of low Apgar at 5-min (OR = 7.05, 95% CI 3.86-12.88, p < 0.001) modulated by living in rural conditions, malaria during pregnancy, perinatal malaria, and perinatal anaemia. Stillbirth was associated with perinatal anaemia (OR = 2.56, 95% CI 1.02-6.42, p = 0.0444) modulated by living in rural conditions, falciparum malaria during pregnancy, perinatal malaria, and perinatal fever. CONCLUSIONS: While Brazil continues its path towards malaria elimination, the population still faces major structural problems, including substandard living conditions. Here malaria infections on pregnant women were observed having indirect effects on fetal outcomes, contributing to low Apgar at 5-min and stillbirth. Finally, the utility of employing multiple statistical analysis methods to validate consistent trends is vital to ensure optimal public health intervention designs.
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Índice de Apgar , Malária Falciparum/epidemiologia , Saúde Materna/estatística & dados numéricos , Assistência Perinatal/estatística & dados numéricos , Complicações Parasitárias na Gravidez/epidemiologia , Natimorto/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Feminino , Humanos , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Pessoa de Meia-Idade , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Prevalência , Adulto JovemRESUMO
OBJETIVE: Several biomarkers of ovarian reserve have been proposed as possible predictors of the response to controlled ovarian stimulation (COS). We aimed to evaluate age, FSH, AMH, antral follicle count (AFC), and ovarian response prediction index (ORPI), as potential predictors of response to COS. METHODS: Cross-sectional study enrolling of 188 infertile women who underwent the first cycle of IVF/ICSI. AFC was evaluated; serum FSH and AMH levels were measured by ELISA. ORPI was calculated as AMH x AFC/patient´s age. RESULTS: As expected, hypo-responder group had less retrieved oocytes, MII, and embryos compared to the good responders. The hyper-response patients were younger, with lower FSH, increased AMH, AFC, and ORPI values. Regarding the assessment of the predictive capacity of ovarian reserve tests, none of them individually or combined showed a good predictive capacity for hypo-response. With respect to the hyper-responder group, individually AMH was the best predictor, while in the multivariable model, ORPI demonstrated the best predictive capacity. Furthermore, patients with serum AMH < 2.09 ng/mL (p25) had fewer AFC than patients with higher AMH values. CONCLUSIONS: Our findings suggest that none of the ovarian reserve tests showed a good predictive capacity for hypo-response, while the ORPI was the strongest predictor of hyper-response in normovulatory infertile women.
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Hormônio Antimülleriano/sangue , Infertilidade/terapia , Folículo Ovariano/diagnóstico por imagem , Reserva Ovariana , Indução da Ovulação/métodos , Adulto , Estudos Transversais , Transferência Embrionária , Feminino , Fertilização in vitro , Humanos , Infertilidade/sangue , Testes de Função Ovariana , Gravidez , Taxa de Gravidez , Prognóstico , Estudos Prospectivos , Injeções de Esperma IntracitoplásmicasRESUMO
Ecosystem health and zoonotic diseases are closely interwoven. Even as we grapple with the SARS-Coronavirus-2 pandemic, which may have its origins in wildlife, weakening environmental policies in the Brazilian Amazon are elevating the risk of additional zoonotic spillover events. We examine the links between deforestation and disease emergence in the Amazon, as illustrated by outbreaks of yellow fever virus, Venezuelan equine encephalitis virus, and Oropouche virus. It has been well established that in Brazil, indigenous territories exhibit lower rates of forest conversion and degradation than in areas designated for sustainable use. In this way, Amazonia's indigenous tribes promote public health while sustaining ecosystem services. However, indigenous land rights are under attack due to current policies enabling illegal land grabbing, mining and logging. Further adding to the existential struggle of indigenous tribes, malaria and SARS-Coronavirus-2 are wreaking havoc on these vulnerable populations. There is a critical need for protection of indigenous people's rights and health, as well as a sustained effort to support the study of mechanisms underlying anthropogenic land use change and zoonotic disease risk.
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BACKGROUND: Plasmodium falciparum malaria is a threat to public health, but Plasmodium vivax malaria is most prevalent in Latin America, where the incidence rate has been increasing since 2016, particularly in Venezuela and Brazil. The Brazilian Amazon reported 193,000 cases in 2017, which were mostly confirmed as P. vivax (~ 90%). Herein, the relationships among malaria incidence rates and the proportion of accumulated deforestation were contrasted using data from the states of Acre and Rondônia in the south-western Brazilian Amazon. The main purpose is to test the hypothesis that the observed difference in incidence rates is associated with the proportion of accumulated deforestation. METHODS: An ecological study using spatial and temporal models for mapping and modelling malaria risk was performed. The municipalities of Acre and Rondônia were the spatial units of analysis, whereas month and year were the temporal units. The number of reported malaria cases from 2009 until 2015 were used to calculate the incidence rate per 1000 people at risk. Accumulated deforestation was calculated using publicly available satellite images. Geographically weighted regression was applied to provide a local model of the spatial heterogeneity of incidence rates. Time-series dynamic regression was applied to test the correlation of incidence rates and accumulated deforestation, adjusted by climate and socioeconomic factors. RESULTS: The malaria incidence rate declined in Rondônia but remained stable in Acre. There was a high and positive correlation between the decline in malaria and higher proportions of accumulated deforestation in Rondônia. Geographically weighted regression showed a complex relationship. As deforestation increased, malaria incidence also increased in Acre, while as deforestation increased, malaria incidence decreased in Rondônia. Time-series dynamic regression showed a positive association between malaria incidence and precipitation and accumulated deforestation, whereas the association was negative with the human development index in the westernmost areas of Acre. CONCLUSION: Landscape modification caused by accumulated deforestation is an important driver of malaria incidence in the Brazilian Amazon. However, this relationship is not linearly correlated because it depends on the overall proportion of the land covered by forest. For regions that are partially degraded, forest cover becomes a less representative component in the landscape, causing the abovementioned non-linear relationship. In such a scenario, accumulated deforestation can lead to a decline in malaria incidence.
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Meio Ambiente , Malária/epidemiologia , Fatores Socioeconômicos , Brasil/epidemiologia , Humanos , Incidência , Malária/parasitologia , Modelos Teóricos , Análise Espaço-TemporalRESUMO
BACKGROUND: The multidrug therapy (MDT) for leprosy treatment adopted by Brazil in the 1990s was important for reducing leprosy in the country; however, recurrent cases remained problematic. Mechanisms involved in leprosy recurrence are heterogeneous and can be sorted into three groups: insufficient therapy, bacillary persistence and new infections. This study aimed to analyse the time interval of leprosy recurrence in relation to the therapeutic scheme in the state of Acre. The hypotheses were as follows: 1) treatments (a) rifampicin, ofloxacin and minocycline (ROM) and (b) dapsone (DDS) have a short leprosy recurrence time, 2) treatments based on MDT have a long leprosy recurrence time, 3) there is a dose-response relationship between MDT and the time interval between leprosy episodes. METHODS: This retrospective cohort study included 201 patients with a second episode of clinical leprosy at the reference centers for leprosy control in the state of Acre. Exposure was the type of therapeutic scheme as follows: 1) ROM, 2) DDS, 3) MDT0-9 doses, 4) MDT10-19 doses, 5) MDT20-29 doses, and 6) MDT30+ doses. Outcome was the time interval between release from treatment and a diagnosis of a recurrent leprosy case. Incidence rate ratios and relative risk Poisson regressions adjusted by age and sex were calculated with 95% confidence intervals. RESULTS: The 201 patients studied during this retrospective follow-up resulted in a total of 224 cases of recurrent leprosy. Incidence rate ratios within this therapeutic scheme were as follows: 3.3 (2.39, 4.2; ROM/MDT30+), 1.12 (0.33, 1.92; DDS/MDT30+), 2.17 (1.39, 2.94; MDT0-9/MDT30+), 1.94 (1.13, 2.75; MDT10-19/MDT30+) and 1.26 (0.47, 2.05; MDT20-29/MDT30+). Relative risk Poisson regressions showed a protective effect of MDT30+ in comparison with ROM (0.22; 0.07, 0.72), MDT0-9 (0.42; 0.21, 0.85), and MDT10-19 (0.44; 0.21, 0.92). No differences among MDT30+ and DDS (0.71; 0.36, 1.41) and MDT20-29 (0.76; 0.38, 1.49) were observed. CONCLUSIONS: New infection is an important-yet neglected-mechanism in leprosy recurrence in the state of Acre and can challenge the leprosy elimination plan in Brazil. MDT with few doses might be associated with leprosy recurrence due to insufficient therapy or bacillary persistence.
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Hansenostáticos/uso terapêutico , Hanseníase/tratamento farmacológico , Hanseníase/etiologia , Adulto , Brasil/epidemiologia , Estudos de Coortes , Dapsona/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Hanseníase/epidemiologia , Masculino , Pessoa de Meia-Idade , Minociclina/uso terapêutico , Ofloxacino/uso terapêutico , Recidiva , Estudos Retrospectivos , Rifampina/uso terapêutico , Fatores de Tempo , Resultado do TratamentoRESUMO
The Malaria Frontier Hypothesis (MFH) is the current model for predicting malaria emergence in the Brazilian Amazon. It has two important dimensions, 'settlement time' and 'malaria incidence', and its prediction are: malaria incidence peaks five years after the initiation of human settlement and declines towards zero after an estimated 10 years. Although MFH is currently accepted, it has been challenged recently. Herein, we described a novel method for estimating settlement timeline by using remote sensing technology integrated in an open-software geographic information system. Surprisingly, we found that of the majority of the rural settlements with high malaria incidence are more than 10 years old.
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Conservação dos Recursos Naturais , Florestas , Malária/transmissão , Brasil/epidemiologia , Conservação dos Recursos Naturais/tendências , Sistemas de Informação Geográfica , Humanos , Incidência , Malária/epidemiologia , Malária/parasitologia , Carga Parasitária , População Rural , Fatores de TempoRESUMO
BACKGROUND: Recently an unexpectedly high prevalence of Plasmodium falciparum was found in asymptomatic blood donors living in the southeastern Brazilian Atlantic forest. The bromeliad-malaria paradigm assumes that transmission of Plasmodium vivax and Plasmodium malariae involves species of the subgenus Kerteszia of Anopheles and only a few cases of P. vivax malaria are reported annually in this region. The expectations of this paradigm are a low prevalence of P. vivax and a null prevalence of P. falciparum. Therefore, the aim of this study was to verify if P. falciparum is actively circulating in the southeastern Brazilian Atlantic forest remains. METHODS: In this study, anophelines were collected with Shannon and CDC-light traps in seven distinct Atlantic forest landscapes over a 4-month period. Field-collected Anopheles mosquitoes were tested by real-time PCR assay in pools of ten, and then each mosquito from every positive pool, separately for P. falciparum and P. vivax. Genomic DNA of P. falciparum or P. vivax from positive anophelines was then amplified by traditional PCR for sequencing of the 18S ribosomal DNA to confirm Plasmodium species. Binomial probabilities were calculated to identify non-random results of the P. falciparum-infected anopheline findings. RESULTS: The overall proportion of anophelines naturally infected with P. falciparum was 4.4% (21/480) and only 0.8% (4/480) with P. vivax. All of the infected mosquitoes were found in intermixed natural and human-modified environments and most were Anopheles cruzii (22/25 = 88%, 18 P. falciparum plus 4 P. vivax). Plasmodium falciparum was confirmed by sequencing in 76% (16/21) of positive mosquitoes, whereas P. vivax was confirmed in only 25% (1/4). Binomial probabilities suggest that P. falciparum actively circulates throughout the region and that there may be a threshold of the forested over human-modified environment ratio upon which the proportion of P. falciparum-infected anophelines increases significantly. CONCLUSIONS: These results show that P. falciparum actively circulates, in higher proportion than P. vivax, among Anopheles mosquitoes of fragments of the southeastern Brazilian Atlantic forest. This finding challenges the classical bromeliad-malaria paradigm, which considers P. vivax circulation as the driver for the dynamics of residual malaria transmission in this region.
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Anopheles/parasitologia , Bromeliaceae/fisiologia , Florestas , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Animais , Brasil , Humanos , Dados de Sequência Molecular , Plasmodium falciparum/genética , Plasmodium vivax/genética , Proteínas de Protozoários/genética , Análise de Sequência de DNARESUMO
A recent paper in Malaria Journal reported the observation of unexpected prevalence rates of healthy individuals carrying Plasmodium falciparum (5.14%) or Plasmodium vivax (2.26%) DNA among blood donors from the main transfusion centre in the metropolitan São Paulo, a non-endemic area for malaria. The article has been challenged by a group of authors who argued that the percentages reported were higher than those found in blood banks of the endemic Amazon Region and also that that paper had not considered the literature on the classical dynamics of malaria transmission in the Atlantic Forest, which involves Anopheles (Kerteszia) cruzii and bromeliad malaria, due to P. vivax and Plasmodium malariae parasites, but not P. falciparum. The present commentary paper responds to this challenge and brings evidence and literature data supporting that the observed prevalence ratios may indicate a proportion of individuals that are exposed to Plasmodium transmission in permissive environments; that blood carrying parasite DNA may not be necessarily infective if used in transfusion; and that in the literature, there are examples supporting the circulation of P. falciparum in the area.
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Infecções Assintomáticas/epidemiologia , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Reação Transfusional , HumanosRESUMO
BACKGROUND: Species coexistence in mosquito assemblages may depend on mechanisms related to interspecific resource partitioning occurring at multiple scales. In the present work we investigated co-occurrence or spatial segregation in mosquito assemblages sharing resources at micro-habitat, habitat and landscape scales. Environmental characteristics, mosquito fauna as adults and larvae were assessed along vegetation gradient in a natural landscape of tropical rainforest. Huisman-Olff-Fresco (HOF) and Generalized Additive (GAM) models were employed to explore relationships between abundances of potential competitors in mosquito assemblages and vegetation gradient (e.g., scrublands, mixed arboreal vegetation and dense ombrophilous forest). We tested hypotheses concerning mosquito species co-occurrence or spatial segregation employing binomial logistic regression models. RESULTS: Co-occurrences and spatial segregation of mosquito species showed evidences of three scales of coexistence mechanisms: 1) micro-habitat--scale 1: different behaviors in response to food availability in specific vertical strata within larval container; 2) habitat--scale 2: specialized strategies related to heterogeneity of resource availability among larval containers and 3) landscape--scale 3: asymmetrical competition dependent upon the context of abiotic and biotic variables. CONCLUSION: Results of the present work suggest that coexistence mechanisms can concomitantly work at multiple scales.
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Culicidae/fisiologia , Ecossistema , Animais , Brasil , Comportamento Competitivo , Culicidae/crescimento & desenvolvimento , Feminino , Larva/fisiologia , Dinâmica PopulacionalRESUMO
OBJECTIVE: The objective of this study was to assess the predictors of survival among patients with coronavirus disease 2019 who underwent tracheal intubation, as part of a hospital cohort study. METHODS: This retrospective cohort study in the Rio do Sul County Hospital, Santa Catarina, Brazil, from April 2020 to May 2021, focused on patients aged 18 years or older intubated for coronavirus disease 2019. We assessed the 90-day survival of intubated patients by estimating the hazard ratio using a Cox proportional hazards regression model. RESULTS: The study included 132 participants, with an average age of approximately 60 years. Tracheal intubation was successfully accomplished in 97% of cases within two attempts. The overall mortality rate was 62.9%. Notably, mortality rates were significantly higher in patients aged over 60 years (hazard ratio=2.57; 95%CI 1.54-4.29; p<0.001), those with blood oxygen saturation below 85% (hazard ratio=1.92; 95%CI 1.03-3.57; p=0.04), instances where tracheal intubation was carried out using a conventional laryngoscope (hazard ratio=2.59; 95%CI 1.22-5.48; p=0.013), and when performed by emergency physicians (hazard ratio=3.96; 95%CI 1.51-10.4; p=0.005). CONCLUSION: Our analysis unveiled that the risk of death in intubated coronavirus disease 2019 patients is four times higher when an emergency physician, as opposed to an anesthesiologist, leads the tracheal intubation team.
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COVID-19 , Intubação Intratraqueal , Humanos , Intubação Intratraqueal/estatística & dados numéricos , Intubação Intratraqueal/mortalidade , COVID-19/mortalidade , Masculino , Pessoa de Meia-Idade , Feminino , Estudos Retrospectivos , Brasil/epidemiologia , Idoso , Adulto , SARS-CoV-2 , Modelos de Riscos Proporcionais , Fatores de Risco , Estudos de CoortesRESUMO
Introduction: In the WHO eligibility criteria, there is agreement that hypertensive women taking Oral Contraceptive Hormonal Combined (OCHC) may be at increased risk of cardiovascular disease. The risk-to-benefit ratio hinges on the severity of the condition. While a mild increase in blood pressure is a common occurrence in consumers of OCHC, the potential for developing high blood pressure exists during oral contraceptive use. Consequently, there is a possibility of increased cardiovascular risk, with limited available data on this issue. Objective: To evaluate the potential effects of OCHC on blood pressure through a systematic review with statistical analysis of existing randomized controlled trials. Method: This systematic review with statistical comparison adheres to the recommendations outlined in the PRISMA (Principal Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The analysis strategy involves comparing the mean difference in blood pressure change according to the type of treatment, in addition to the calculation of clinically relevant outcomes (CRO). Results: Our findings suggest a clinically relevant outcome related to the increase in blood pressure in users of ethinyl estradiol combined with gestodene in a cyclic regimen over 6 months. Conversely, a decrease in blood pressure was observed among users of ethinyl estradiol combined with chlormadinone over 24 months of usage. Conclusion: While our study found minor variations in blood pressure across varying forms of oral contraceptives, these differences are not significant enough to warrant specific clinical recommendations. However, the results suggest that individuals with hypertension should exercise caution with ethinyl estradiol, particularly when administered cyclically alongside gestodene, due to the potential risk of increased blood pressure. Additionally, the use of oral contraceptives containing ethinyl estradiol paired with chlormadinone acetate or ethinyl estradiol combined with drospirenone may be more suitable for individuals at a high risk of developing hypertension.
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The Guiana Shield, a small region of South America, is currently one of the main hotspots of malaria transmission on the continent. This Amazonian area is characterised by remarkable socioeconomic, cultural, health, and political heterogeneity and a high degree of regional and cross-border population mobility, which has contributed to the increase of malaria in the region in the past few years. In this context, regional cooperation to control malaria represents both a challenge and an indispensable initiative. This Viewpoint advocates for the creation of a regional cooperative mechanism for the elimination of malaria in the Guiana Shield. This strategy would help address operational and political obstacles to successful technical cooperation in the region and could contribute to reversing the regional upsurge in malaria incidence through creating a functional international control and elimination partnership.
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Malária , Humanos , Malária/epidemiologia , Malária/prevenção & controle , Equipamentos de ProteçãoRESUMO
The intense process of deforestation in tropical forests poses serious challenges for the survival of biodiversity, as well as for the human species itself. This scenario is supported by the increase in the incidence of epidemics of zoonotic origin observed over the last few decades. In the specific case of sylvatic yellow fever (YF), it has already been shown that an increase in the transmission risk of the causative agent (yellow fever virus - YFV) is associated with areas with a high degree of forest fragmentation, which can facilitate the spread of the virus. In this study we tested the hypothesis that areas with more fragmented landscapes and a higher edge density (ED) but a high degree of connectivity between forest patches favor YFV spread. To this end, we used YF epizootics in non-human primates (NHPs) in the state of São Paulo to build direct networks, and used a multi-selection approach to analyze which landscape features could facilitate YFV spread. Our results showed that municipalities with the potential to spread the virus exhibited a higher amount of forest edge. Additionally, the models with greater empirical support showed a strong association between forest edge density and the risk of occurrence of epizootic diseases, as well as the need for a minimum threshold of native vegetation cover to restrict their transmission. These findings corroborate our hypothesis that more fragmented landscapes with a higher degree of connectivity favor the spread of YFV, while landscapes with fewer connections tend to act as dead zones for the circulation of the virus.
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Febre Amarela , Vírus da Febre Amarela , Animais , Humanos , Surtos de Doenças , Brasil/epidemiologia , Primatas , FlorestasRESUMO
BACKGROUND: Since 2015, the Global Technical Strategy (GTS) for Malaria 2016-2030 has been adopted by the World Health Organization (WHO) as a comprehensive framework to accelerate progress for malaria elimination in endemic countries. This strategy sets the target of reducing global malaria incidence and mortality rates by 90% in 2030. Here it is sought to evaluate Brazil's achievements towards reaching the WHO GTS milestone in 2030. Considering the total number of new malaria cases in 2015, the main research question is: will Brazil reach the malaria elimination goal in 2030? METHODS: Analytical strategies were undertaken using the SIVEP-malaria official databases of the Brazilian Malaria Control Programme for the Brazilian Amazon region from 2009 to 2020. Spatial and time-series analyses were applied for identifying municipalities that support the highest numbers of malaria cases over the years. Forecast analysis was used for predicting the estimated number of new cases in Brazil in 2025-2050. RESULTS: Brazil has significantly reduced the number of new malaria cases in 2020 in comparison with 2015 in the states of Acre (- 56%), Amapá (- 75%), and Amazonas (- 21%); however, they increased in the states of Pará (156%), Rondônia (74%), and Roraima (362%). Forecast of the predicted number of new malaria cases in 2030 is 74,764 (95% CI: 41,116-141,160) in the Brazilian Amazon. CONCLUSIONS: It is likely that Brazil will reduce the number of new malaria cases in the Brazilian Amazon in 2030 in relation to that in 2015. Herein forecast shows a reduction by 46% (74,754 in 2030 forecast/137,982 in 2015), but this reduction is yet far from the proposed reduction under the WHO GTS 2030 milestone (90%). Stable and unbeatable transmission in the Juruá River Valley, Manaus, and Lábrea still support endemic malaria in the Brazilian Amazon. Today's cross-border malaria is impacting the state of Roraima unprecedently. If this situation is maintained, the malaria elimination goal (zero cases) may not be reached before 2050. An enhanced political commitment is vital to ensure optimal public health intervention designs in the post-2030 milestones for malaria elimination.
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Objetivos , Malária , Brasil/epidemiologia , Humanos , Incidência , Malária/epidemiologia , Malária/prevenção & controle , Análise EspacialRESUMO
Man-made changes to the landscape play a crucial role in altering the epidemiologic patterns of infectious diseases, mainly as a result of pathogen spillover. Sylvatic yellow fever is ideally suited to modeling of this phenomenon as the risk of transmission of the disease as well as its circulation and dispersal are associated with forest fragmentation. In this study we investigated the temporal dispersal pattern of yellow fever virus (YFV) by means of confirmed cases of epizootics in non-human primates in municipalities in the state of São Paulo where there was no recommendation for vaccination in 2017. We analyzed the resistance to dispersal associated with different classes of land use and the geographic distances between the different locations where epizootics were recorded. The model that best explained the temporal dispersal pattern of YFV in the study area indicated that this was influenced by the geographic distance between collection locations and by the permeability of the forest edges (150 m) at the interface with the following core areas: Water, Agricultural, Non-Forest Formation and Forestry. Water, Agricultural, Urban and Forest core areas and the interfaces between the latter two formed important barriers to circulation of the virus. These findings indicate that fragmentation of vegetation tends to decrease the time taken for pathogens to spread, while conservation of forest areas has the opposite effect.
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Febre Amarela , Vírus da Febre Amarela , Animais , Brasil/epidemiologia , Florestas , Humanos , PrimatasRESUMO
Every year, autochthonous cases of Plasmodium vivax malaria occur in low-endemicity areas of Vale do Ribeira in the south-eastern part of the Atlantic Forest, state of São Paulo, where Anopheles cruzii and Anopheles bellator are considered the primary vectors. However, other species in the subgenus Nyssorhynchus of Anopheles (e.g., Anopheles marajoara) are abundant and may participate in the dynamics of malarial transmission in that region. The objectives of the present study were to assess the spatial distribution of An. cruzii, An. bellator and An. marajoara and to associate the presence of these species with malaria cases in the municipalities of the Vale do Ribeira. Potential habitat suitability modelling was applied to determine both the spatial distribution of An. cruzii, An. bellator and An. marajoara and to establish the density of each species. Poisson regression was utilized to associate malaria cases with estimated vector densities. As a result, An. cruzii was correlated with the forested slopes of the Serra do Mar, An. bellator with the coastal plain and An. marajoara with the deforested areas. Moreover, both An. marajoara and An. cruzii were positively associated with malaria cases. Considering that An. marajoara was demonstrated to be a primary vector of human Plasmodium in the rural areas of the state of Amapá, more attention should be given to the species in the deforested areas of the Atlantic Forest, where it might be a secondary vector.
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Anopheles/fisiologia , Ecossistema , Insetos Vetores/fisiologia , Plasmodium/classificação , Árvores , Animais , Anopheles/classificação , Anopheles/parasitologia , Brasil , Humanos , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Malária/transmissão , Distribuição de Poisson , População RuralRESUMO
There has been substantial interest on the effect of large-scale environmental change, such as deforestation, on human health. An important and relatively recent development has been the use of causal-inference approaches (e.g., instrumental variables [IVs]) to more properly analyze this type of observational data. Here, we discuss an important study that attempted to disentangle the effect of malaria on deforestation from the effect of deforestation on malaria using an IV approach. The authors found that deforestation increases malaria (e.g., they estimate that a 10% increase in deforestation leads to a 3.3% increase in malaria incidence) through ecological mechanisms, whereas malaria reduces deforestation through socioeconomic mechanisms. An important characteristic of causal-inference approaches is that they are critically dependent on the plausibility of the underlying assumptions and that, differently from standard statistical models, many of these assumptions are not testable. In particular, we show how important assumptions of the IV approach adopted in the study described earlier were not met and that, as a result, it is possible that the correct conclusion could have been the opposite of that reported by the authors (e.g., deforestation decreases, rather than increasing, malaria through ecological mechanisms). Causal-inference approaches may be critical to characterize the relationship between environmental change and disease risk, but conclusions based on these methods can be even more unreliable than those from traditional methods if careful attention is not given to the plausibility of the underlying assumptions.
Assuntos
Meio Ambiente , Medicina Tropical/métodos , Brasil , Conservação dos Recursos Naturais , Microbiologia Ambiental , Humanos , Incidência , TemperaturaRESUMO
OBJECTIVE: To evaluate the predictive power of different malaria case time-series models in the state of Amapá, Brazil, for the period 1997-2016. METHODS: This is an ecological time series study with malaria cases recorded in the state of Amapá. Ten deterministic or stochastic statistical models were used for simulation and testing in 3, 6, and 12 month forecast horizons. RESULTS: The initial test showed that the series is stationary. Deterministic models performed better than stochastic models. The ARIMA model showed absolute errors of less than 2% on the logarithmic scale and relative errors 3.4-5.8 times less than the null model. It was possible to predict future malaria cases 6 and 12 months in advance. CONCLUSION: The ARIMA model is recommended for predicting future scenarios and for earlier planning in state health services in the Amazon Region.
Assuntos
Malária , Brasil/epidemiologia , Previsões , Humanos , Malária/epidemiologia , Modelos Estatísticos , PesquisaRESUMO
Inter-relationships among mosquito vectors, Plasmodium parasites, human ecology, and biotic and abiotic factors, drive malaria risk. Specifically, rural landscapes shaped by human activities have a great potential to increase the abundance of malaria vectors, putting many vulnerable people at risk. Understanding at which point the abundance of vectors increases in the landscape can help to design policies and interventions for effective and sustainable control. Using a dataset of adult female mosquitoes collected at 79 sites in malaria endemic areas in the Brazilian Amazon, this study aimed to (1) verify the association among forest cover percentage (PLAND), forest edge density (ED), and variation in mosquito diversity; and to (2) test the hypothesis of an association between landscape structure (i.e., PLAND and ED) and Nyssorhynchus darlingi (Root) dominance. Mosquito collections were performed employing human landing catch (HLC) (peridomestic habitat) and Shannon trap combined with HLC (forest fringe habitat). Nyssorhynchus darlingi abundance was used as the response variable in a generalized linear mixed model, and the Shannon diversity index (H') of the Culicidae community, PLAND, and the distance house-water drainage were used as predictors. Three ED categories were also used as random effects. A path analysis was used to understand comparative strengths of direct and indirect relationships among Amazon vegetation classes, Culicidae community, and Ny. darlingi abundance. Our results demonstrate that Ny. darlingi is negatively affected by H´ and PLAND of peridomestic habitat, and that increasing these variables (one-unit value at ß0 = 768) leads to a decrease of 226 (P < 0.001) and 533 (P = 0.003) individuals, respectively. At the forest fringe, a similar result was found for H' (ß1 = -218; P < 0.001) and PLAND (ß1 = -337; P = 0.04). Anthropogenic changes in the Amazon vegetation classes decreased mosquito biodiversity, leading to increased Ny. darlingi abundance. Changes in landscape structure, specifically decreases in PLAND and increases in ED, led to Ny. darlingi becoming the dominant species, increasing malaria risk. Ecological mechanisms involving changes in landscape and mosquito species composition can help to understand changes in the epidemiology of malaria.