Infectious diseases are still a public health problem in Brazil, despite the proportion of total deaths that are caused by infectious diseases decreasing from 50% to 5% in the past 80 years.1 Such reductions have been more pronounced for some infectious diseases than they have for others. Figure 1 shows the proportion of deaths from all causes between 1930 and 2007, and the proportion of deaths attributable to different infectious diseases between 1980 and 2008, from which time detailed data exists.4 A large proportion of deaths from infectious diseases in Brazil are due to respiratory infections, and respiratory infection deaths have become more common in adults than in children (figure 1). There have been some pronounced decreases in proportional mortality from specific diseases—ie, diarrhoeal diseases, vaccine-preventable diseases, and pneumonia in children. Deaths from HIV/AIDS have increased since the mid 1980s, dengue has emerged as a substantial cause of death, the number of deaths from tuberculosis and Chagas disease have remained stable, and the proportion of adult deaths due to respiratory infections is increasing (figure 1). The distribution of causes of death from infectious diseases has shifted towards one more commonly seen in high-income countries, especially in the predominance of pneumonia in the adult and elderly populations.4 In this report, we do not give a comprehensive review of trends for all infectious diseases in Brazil, but assess the relative successes of policies and interventions for selected diseases.
The relative contribution of different diseases to overall mortality in a country is associated with its gross domestic product (table 1). The past 60 years were a time of much change in Brazil. In the 1950s, 64% of the Brazilian population lived in rural areas. Vector-borne diseases and intestinal parasitic diseases with transmission cycles that require a stage of development in soil or water were common, and diarrhoea, respiratory infections, and measles caused most deaths in children younger than 5 years. Living conditions in both urban and rural areas were poor, with restricted access to health care (including vaccines), adequate housing, and water and sanitation, fostering the transmission of tuberculosis, poliomyelitis, measles, mumps, diphtheria, typhoid, and leptospirosis.1, 6, 7, 8, 9
Key messages
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Brazil is undergoing a rapid and sometimes unorganised urbanisation process. Cash transfer programmes for the neediest populations, the Unified Health System (SUS), and other social and environmental improvements (such as in sanitation and education) related to this rapid urbanisation are, and should continue to be, crucial for efforts to control infectious diseases.
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Successful and moderately successful public health initiatives, such as those to control vaccine-preventable diseases, diarrhoea, respiratory infections, HIV/AIDS, and tuberculosis, have provided universal and free at the point of use vaccination, access to treatment, and primary health care. Such equitable policies must be supported and reinforced in the face of existing and renewed challenges, such as less than optimum adherence to treatment regimens and the emergence and transmission of drug-resistant pathogens.
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The control of disease vectors in areas of rapid urbanisation and poor-quality housing cannot be achieved through health policies alone. Such efforts must be fully integrated into broad policies that incorporate the mobilisation of society, health and environmental education, improvements in habitation and sewerage, and attempts to avoid further deforestation.
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Scientific research in Brazil has thrived in the past 10 years, with rapid and sustained growth in applied biomedical and epidemiological research on infectious disease prevention and management. Such academic achievements must be translated into deliverable products and policies so that they can be of benefit to the Brazilian population.
In 1953, with the creation of the Ministry of Health, a programme for rural diseases was established, which led to the systematic implementation of vector control measures.10 In the decades after industrialisation, which started in the late 1950s, many people migrated from rural areas to urban areas, amid much urbanisation, improvements in the country's infrastructure (ie, ports, energy generation, road networks), increased access to health care, and modernisation of the state, which increased its presence in different aspects of economic and social spheres (eg, industrial development, roads and communication, housing, water and sanitation, health, and science and technology). By 2000, only 19% of the population lived in rural areas—most of the burden of infectious diseases was borne by those living in urban areas. Between 1980 and 2007 the proportion of households with piped water supply increased from 52% to 84% (93% in urban areas) and the proportion with access to sewerage or a septic tank increased from 25% to 74%.11 These changes took place in a period of much social inequality—a common situation throughout much of Brazil's history—with a Gini coefficient of around 0·6, which, since only 2001, has begun to slowly decrease to 0·56.12
Such progress had some detrimental consequences. For example, much deforestation has taken place to enable agro-industrial activities, or the extraction of basic products and commodities, and increased population mobility has expanded areas of transmission for some endemic diseases (eg, yellow fever) and caused previously rural diseases to appear in urban areas (eg, visceral leishmaniasis and leprosy).13, 14, 15, 16 The reintroduction of Aedes aegypti in 1976 resulted in successive dengue epidemics since 1986.17, 18, 19 The cholera pandemic in the 1990s and the rapid spread of the influenza A H1N1 virus in 2009 are examples of international infections that affected Brazil. Finally, changes in urban and rural environments were associated with emergence of new infectious diseases (eg, Brazilian haemorrhagic fever, hantaviruses).20, 21, 22 Diseases that were previously well controlled were reintroduced to Brazil (dengue17) or underwent epidemiological changes that compromised their effective control (visceral and cutaneous leishmaniases,13 hepatitis C23).24 Reductions in mortality from some diseases were not always accompanied by reduction in incidence; tuberculosis and HIV/AIDS are still a public health problem in many regions of the country, despite substantial decreases in mortality rates since the mid-1990s.25, 26, 27 A substantial proportion (13%) of resources allocated to health care are spent on infectious diseases.28