Epidemiologia e distribuição espacial da mortalidade relacionada à doença de Chagas no Brasil, 1999 a 2007

Abstract

Chagas’ disease is a Neglected Tropical Disease and a public health problem with significant socioeconomic implications in most Latin American countries, including Brazil. This study aimed to characterize the magnitude and patterns of mortality associated with Chagas disease in Brazil. A descriptive and analytical study was performed based on mortality data obtained from the Mortality Information System of the Ministry of Health (SIM/DATASUS/MS), and a spatial analysis with municipalities as the unit of observation. We studied all deaths occurring in Brazil from 1999 to 2007, where Chagas’ disease was mentioned as underlying or associated cause of death. We calculated mortality rates and proportional mortality and described time trends, using polynomial regression. Factors associated with death from Chagas’ disease were identified, as compared to deaths by other causes. We also described causes of death frequently associated with Chagas disease. For spatial analysis we used the following methods: Global Moran, Getis-Ord General G, local Moran and Gi* statistic. Between 1999 and 2007, 53,930 deaths occurred related to Chagas disease in Brazil (44,543 as underlying cause of death, and 9.387 as associated cause), with a mean mortality of 3.78/100,000/year, and a proportional mortality of 0.6%. Mortality showed a declining trend at national level (p=0.011), but with different patterns between regions. There was a reduction of mortality in the Central West (p=0.001), Southeast (p=0.007) and South (p=0.028), whereas the Northeast showed an increasing trend (p=0.047), and the North a tendency of stabilization (p=0.309). In multivariable analysis, factors independently associated with mortality were: age >30 years (adjusted OR = 10.60; 95% CI: 9.90-11.33, p <0.001); residence in the states of Minas Gerais, Goiás and Distrito Federal (adjusted OR = 4.89; 95% CI: 4.81-4.98, p <0.001); not living in a state capital (adjusted OR = 1.04; 95% CI: 1,02-1,06; p<0,001); and male sex (adjusted OR=1.02; 95% CI: 1,00-1,03; p=0,045). The main conditions associated with Chagas disease as underlying cause of death were cardiac complications, such as conduct disorders/arrhythmias (41.4%) and heart failure (37.7%). Cerebrovascular complications(13.2%), ischemic heart disease (13.2%) and hypertensive disorders (9.3%) were the main underlying causes of death in which Chagas’ disease was an associated cause. Spatial analysis identified a major cluster of high risk for mortality related to Chagas’ disease involving eight states in the central region of Brazil, and four smaller clusters of high risk in the surrounding area. Despite the decline in mortality associated with Chagas’ disease in Brazil, the disease remains an important cause of death in endemic areas and with marked regional differences. With decreasing importance of vector-borne transmission, the deficiencies of the public system in prevention, control and treatment of Chagas disease, mainly in North and Northeast regions, remain a challenge. Adequate access to health services and social assistance need to be guaranteed for the large number of individuals with chronic Chagas’ disease that have accumulated during the last decades.