[Seroprevalence survey of human Chagas' infection (1975-1980)]

Chagas disease deaths detected among garbage codes registered in mortality statistics in Brazil: a study from the buRden of ChAgas dISEase in the contemporary world (RAISE) project

OBJECTIVES

The objective of this study was to identify Brazil's most critical garbage codes (GCs) reclassified to Chagas disease (ChD) in mortality data and their proportions. We also estimated the potential impact of misclassification on the number of deaths attributed to ChD.

STUDY DESIGN

Population-based descriptive study.

METHODS

We used the Mortality Information System (SIM; in Portuguese) data before and after routine GC investigation in 2015-2019 to evaluate ChD deaths detected among them. We identified priority GCs, which contributed more than 0.1 % to the percentage of total ChD deaths registered. Spearman's correlation was used to evaluate the association between the reclassification of priority GCs and ChD prevalence. Then, we applied the GC correction factors to estimate the number of deaths attributed to ChD.

RESULTS

22,154 deaths were reported as ChD in the study period. Among them, 1004 deaths originally listed as priority GCs were deaths reclassified to ChD after an investigation in the SIM final database. Unspecific cardiomyopathy (10.2 %), unspecific heart diseases (4.7 %), and heart failure (2.8 %) were GCs with the highest proportions of reclassification to ChD in Brazil. Higher ChD prevalence at the state level was associated with a higher proportion of GC deaths reclassified as ChD. When applying correction factors identified after investigation, we estimated an increase of 26.4 % in registered ChD deaths, mostly in states with higher endemicity.

CONCLUSIONS

GCs might conceal deaths due to ChD, particularly in Brazil's states with higher endemicity. The approach suggested in this study may offer an alternative method for estimating ChD-related deaths in endemic countries.

Levels and trends in Chagas disease-related mortality in Brazil, 2000-2019

Chagas disease remains an important public health problem with high morbidity and mortality in several Latin American countries. This nationwide population-based ecological study analyzes the epidemiological characteristics and time trends of Chagas disease-related mortality in Brazil, 2000-2019. We included all deaths reported in Brazil in which Chagas disease was mentioned in the death certificate either as an underlying or associated cause of death (multiple causes of death). Crude and age-adjusted mortality rates (per 100,000 inhabitants) were calculated and time trends analysis was performed using joinpoint regression models. In the study period, a total of 22,663,092 deaths were recorded in Brazil. Chagas disease was identified in 122,291 deaths (0.54%), 94.788 (77.5%) as an underlying cause and 27,503 (22.5%) as an associated cause. Average annual age-adjusted mortality rate was 3.22 deaths/100,000 inhabitants (95% confidence interval [CI]: 3.14-3.30). Chronic Chagas disease with cardiac involvement was the predominant clinical presentation mentioned. The highest mortality rates were observed in males, age group ≥80 years, black race/skin color, schooling 1-3 years of study, and residents in the Central-West region. Age-adjusted mortality rates showed a significant declining trend at the national level in the period (Average Annual Percent Change: -3.1%; 95% CI: -3.3; -3.0), with different local patterns and a more pronounced reduction in important endemic areas in the past. The findings show that, despite a consistent decline in mortality rates in Brazil over the study period, Chagas disease remains an important and neglected cause of death in the country, showing a marked regional variation that has social and health care implications. In addition to the control measures for disease transmission, it is necessary to guarantee access, coverage, and quality of health care to Chagas disease patients, seeking to prevent the occurrence of severe forms and deaths from the disease.

[Stratification of priority territories for surveillance of chronic Chagas disease: multicriteria analysis for decision-making in health]

The identification of the magnitude of chronic Chagas disease in Brazil requires linking activities in health surveillance, seeking to develop a wide, hierarchically organized and geographically distributed network of services to provide care to thousands of individuals with Trypanosoma cruzi infection. The study aimed to elaborate a model for prioritization of municipalities for chronic Chagas disease, to offer comprehensive care for persons with the disease. A multicriteria analysis was thus performed using the PROMETHEÉ II algorithm, implemented in the Pradin software. The criteria for assessing the model consisted of three indices built from the following indicators: (a) epidemiological, directly related to chronic Chagas disease, (b) related to the evolution in chronic Chagas disease, and (c) related to access to health services. Saaty's Fundamental Scale was used to define the indicators' weights, with greater importance assigned to those directly related to chronic Chagas disease and to those with greater reliability and respective quality of information. Assessment of the models' consistency was based on comparison of the available data in historically endemic areas with the distribution of acute cases, besides other sensitivity analyses. The best model was defined by 1,345 municipalities with medium priority, 1,003 high priority, and 601 with very high priority for chronic Chagas disease, with the highest proportions in the Southeast and Northeast regions. Prioritization allows the administration to rationalize and channel resources, and it is essential to identify the territories where persons with chronic Chagas disease are living, to promote comprehensive care and improve quality of life.

PREVALENCE OF AMERICAN TRYPANOSOMIASIS AND LEISHMANIASES IN DOMESTIC DOGS IN A RURAL AREA OF THE MUNICIPALITY OF SÃO JOÃO DO PIAUÍ, PIAUÍ STATE, BRAZIL

Chagas disease and the leishmaniases are endemic zoonoses of great importance to public health in the state of Piauí, Brazil. The domestic dog (Canis familiaris) is a major reservoir, host of Trypanosoma cruzi and Leishmania spp. in both urban and rural areas, playing an important role in the transmission of these parasites. The present study evaluated the prevalence of both infectious diseases in dogs of a rural area in the municipality of São João do Piauí, Piauí State. One hundred twenty-nine blood samples were collected for serological assessment: for the leishmaniases, 49 (38%) animals tested positive by the Dual-Path Platform technology (DPP), nine (6%) by the Enzyme-linked Immunosorbent Assay (ELISA), and 19 (14.7%) by the Indirect Fluorescent Antibody test (IFA); while for American Trypanosomiasis, 36 (28%) dogs were reagent by ELISA and 21 by IFA. Of the 129 dogs sampled, 76 were submitted to xenodiagnosis, bone marrow aspiration and skin biopsy to perform parasitological tests whose results showed only one (2.3%) positive skin sample for Trypanosoma caninum and one positive xenodiagnosis for T. cruzi, both results confirmed by molecular assays. Three hundred triatomines of the species Triatoma brasiliensis and 552 phlebotomines - 509 (97%) of the species Lutzomyia longipalpis, were also captured.

Trends and spatial patterns of mortality related to neglected tropical diseases in Brazil

We analysed nationwide trends and spatial distribution of NTD-related mortality in Brazil. We included all death certificates in Brazil from 2000 to 2011, in which NTDs were recorded as any causes of death. A total of 100,814/12,491,280 (0.81%) death certificates were identified, which mentioned at least one NTD. Age-adjusted NTD-related mortality rates showed a significant decrease over time (annual percent change [APC]: − 2.1%; 95% CI: − 2.8 to − 1.3), with decreasing mortality rates in the Southeast, South, and Central-West regions, stability in the Northeast region, and increase in the North region. We identified spatial and spatiotemporal high-risk clusters for NTD-related mortality in all regions, with a major cluster covering a wide geographic range in central Brazil. Despite nationwide decrease of NTD-related mortality in the observation period, regional differences remain, with increasing mortality trends especially in the socioeconomically disadvantaged regions of the country. The existence of clearly defined high-risk areas for NTD-related deaths reinforces the need for integrated prevention and control measures in areas with highest disease burden.

Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae) in rural localities of Central-West Brazil

This study estimates the factors of artificial environments (houses and peridomestic areas) associated with Triatoma sordida occurrence. Manual searches for triatomines were performed in 136 domiciliary units (DUs) in two rural localities of Central-West Brazil. For each DU, 32 structural, 23 biotic and 28 management variables were obtained. Multiple logistic regression analysis was performed in order to identify statistically significant variables associated with occurrence of T. sordida in the study areas. A total of 1,057 specimens (99% in peridomiciles, mainly chicken coops) of T. sordida were collected from 63 DUs (infestation: 47%; density: ~8 specimens/DU; crowding: ~17 specimens/infested DU; colonisation: 81%). Only six (0.6%) out of 945 specimens examined were infected with Trypanosoma cruzi. The final adjusted logistic regression model indicated that the probability of T. sordida occurrence was higher in DU with wooden chicken coops, presence of > 30 animals in wooden corrals, presence of wood piles and presence of food storeroom. The results show the persistence of T. sordida in peridomestic habitats in rural localities of Central-West Brazil. However, the observed low intradomestic colonisation and minimal triatomine infection rates indicate that T. sordida has low potential to sustain high rates of T. cruzi transmission to residents of these localities.

Mortality due to Chagas disease in Brazil according to a specific cause

A century after its discovery, Chagas disease (CD) is still considered a public health problem. Mortality caused by CD between 2000 and 2010 was described according to the specific underlying cause, year of occurrence, gender, age range, and region of Brazil. The standardized mortality rate decreased 32.4%, from 3.4% in 2000 to 2.3% in 2010. Most of the deaths (85.9%) occurred in male patients who were > 60 years of age caused by cardiac involvement. The mortality rate caused by cardiac involvement decreased in all regions of Brazil, except in the North region, where it increased by 1.6%. The Northeast had the smallest and the Central-West had the largest decrease. The mortality rate caused by a compromised digestive tract increased in all regions. Despite the control of transmission by vector and blood transfusions, CD should remain on the list of priority diseases for the public health service in Brazil, and surveillance actions cannot be interrupted.

Avaliação da capacidade funcional dos idosos e fatores associados à incapacidade

O objetivo deste estudo foi avaliar a capacidade funcional e analisar as características associadas à incapacidade dos idosos atendidos em uma Estratégia da Saúde da Família em Montes Claros-MG. Utilizou-se a escala de Lawton e Brody e a escala de Katz, analisadas pela regressão logística multinomial. Foram entrevistados 286 idosos cuja idade variou de 60 a 103 anos, média de 71,2 anos (DP ± 8,3). Destes, 61,9% autorreferiram independentes quanto à capacidade funcional. A dependência apenas na AIVD foi positivamente associada à faixa etária ≥ 75 anos (OR = 8,38), ao sexo feminino (OR = 3,64) e com doença cardíaca (OR = 3,24). A dependência tanto nas AIVD como nas ABVD foi positivamente associada à faixa etária ≥ 75 anos (OR = 6,40), sem companheiro (OR = 3,26), aos que apresentavam AVE (OR = 51,85), doença cardíaca (OR = 4,18) e aos com diabetes (OR = 3,35). A maior proporção de idosos foi considerada independente para a realização de atividades básicas e instrumentais de vida diária. Contudo, uma parcela expressiva ainda apresenta comprometimento do estado funcional. É essencial que as equipes da Estratégia da Saúde da Família busquem a promoção da saúde e a prevenção de doenças, além de intervenções terapêuticas que possam minimizar os fatores que interferem na capacidade funcional.

Prevalence of Chagas disease in Brazil: a systematic review and meta-analysis

Chagas disease is a major public health problem in Brazil and Latin America. During the last years, it has become an emerging problem in North America and Europe due to increasing international migration. Here we describe the prevalence of Chagas disease in Brazil through a systematic review. We searched national and international electronic databases, grey literature and reference lists of selected articles for population-based studies on Chagas disease prevalence in Brazil, performed from 1980 until September 2012. Forty-two articles with relevant prevalence data were identified from a total of 4985 references. Prevalence ranged from 0% to 25.1%. Most surveys were performed in the Northeast region, especially in the state of Piauí. We observed a high degree of heterogeneity in most pooled estimates (I(2)>75%; p<0.001). The pooled estimate of Chagas disease prevalence across studies for the entire period was 4.2% (95% CI: 3.1-5.7), ranging from 4.4% (95% CI: 2.3-8.3) in the 1980s to 2.4% (95% CI: 1.5-3.8) after 2000. Females (4.2%; 95% CI: 2.6-6.8), >60 year-olds (17.7%; 95% CI: 11.4-26.5), Northeast (5.0%; 95% CI: 3.1-8.1) and Southeast (5.0%; CI: 2.4-9.9) regions and mixed (urban/rural) areas (6.4%; 95% CI: 4.2-9.4) had the highest pooled prevalence. About 4.6 million (95% CI: 2.9-7.2 million) of people are estimated to be infected with Trypanosoma cruzi. The small number of studies and small-scale samples of the general population in some areas limit interpretation, and findings of this review do not necessarily reflect the situation of the entire country. Systematic population-based studies at regional and national level are recommended to provide more accurate estimates and better define the epidemiology and risk areas of Chagas disease in Brazil.

Review: surveillance of Chagas disease

After remarkable reduction in prevalence through regional elimination of domestic vectors, the central challenge of Chagas disease control is shifting towards interruption of the disease transmission by non-eliminable vectors in Latin America. Vector surveillance with community participation was cost-effective against the eliminable vectors. But the efforts often failed against the non-eliminable vectors due to lack of surveillance coverage or sustainability. For instance, in El Salvador and Honduras, the operational vector control personnel lost access to many communities under decentralized health systems. To cover wider areas lastingly, the countries implemented the surveillance systems involving non-specialists from locally embedded resources, such as local health services, schools and community leaders. From these experiences, this paper outlines a common structure of the current community-based surveillance systems, consisting of five fundamental sequential functions. To increase scalability and sustainability, four of the five functions could be delegated to the locally available human resources, and the surveillance systems can be integrated into the general health systems. Challenges at national and regional levels are discussed for further evolution of the surveillance systems.

Mortality of Chagas' disease in Brazil: spatial patterns and definition of high-risk areas

OBJECTIVE

To describe patterns of spatial distribution of mortality associated with Chagas' disease in Brazil.

METHODS

Nationwide study of all deaths in Brazil from 1999 to 2007, where Chagas' disease was recorded as a cause of death. Data were obtained from the national Mortality Information System of the Ministry of Health. We calculated the mean mortality rate for each municipality of residence in three-year intervals and the entire period. Empirical Bayes smoothing was used to minimise random variation in mortality rates because of the population size in the municipalities. To evaluate the existence of spatial autocorrelation, global and local Moran's I indices were used.

RESULTS

The nationwide mean mortality rate associated with Chagas' disease was 3.37/100 000 inhabitants/year, with a maximum of 138.06/100 000 in one municipality. Independently from the statistical approach, spatial analysis identified a large cluster of high risk for mortality by Chagas' disease, involving nine states in the Central region of Brazil.

CONCLUSION

This study defined geographical priority areas for the management of Chagas' disease and consequently reducing disease-associated mortality in Brazil. Different spatial-analytical approaches can be integrated to provide data for planning, monitoring and evaluating specific intervention measures.

Epidemiology of mortality related to Chagas' disease in Brazil, 1999-2007

BACKGROUND

Chagas' disease is an important neglected public health problem in many Latin American countries, but population-based epidemiological data are scarce. Here we present a nationwide analysis on Chagas-associated mortality, and risk factors for death from this disease.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed all death certificates of individuals who died between 1999 and 2007 in Brazil, based on the nationwide Mortality Information System (a total of 243 data sets with about 9 million entries). Chagas' disease was mentioned in 53,930 (0.6%) of death certificates, with 44,537 (82.6%) as an underlying cause and 9,387 (17.4%) as an associated cause of death. Acute Chagas' disease was responsible for 2.8% of deaths. The mean standardized mortality rate was 3.36/100.000 inhabitants/year. Nationwide standardized mortality rates reduced gradually, from 3.78 (1999) to 2.78 (2007) deaths/year per 100,000 inhabitants (-26.4%). Standardized mortality rates were highest in the Central-West region, ranging from 15.23 in 1999 to 9.46 in 2007 (-37.9%), with a significant negative linear trend (p = 0.001; R(2) = 82%). Proportional mortality considering multiple causes of death was 0.60%. The Central-West showed highest proportional mortality among regions (2.17%), with a significant linear negative trend, from 2.28% to 1.90% (-19.5%; p = 0.001; R(2) = 84%). There was a significant increase in the Northeast of 38.5% (p = 0.006; R(2) = 82%). Bivariable analysis on risk factors for death from Chagas' disease showed highest relative risks (RR) in older age groups (RR: 10.03; 95% CI: 9.40-10.70; p<0.001) and those residing in the Central-West region (RR: 15.01; 95% CI: 3.90-16.22; p<0.001). In logistic regression analysis, age ≥30 years (adjusted OR: 10.81; 95% CI: 10.03-10.65; p<0.001) and residence in one of the three high risk states Minas Gerais, Goiás or the Federal District (adjusted OR: 5.12; 95% CI: 5.03-5.22, p<0.001) maintained important independent risk factors for death by Chagas' disease.

CONCLUSIONS/SIGNIFICANCE

This is the first nationwide population-based study on Chagas mortality in Brazil, considering multiple causes of death. Despite the decline of mortality associated with Chagas' disease in Brazil, the disease remains a serious public health problem with marked regional differences.