Situação epidemiológica da malária na Amazônia brasileira entre 2003 e 2012

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Núcleo de Medicina Tropical, 2014.Introdução: A malária permanece como uma das mais importantes causas de morbidade e mortalidade nas regiões tropicais do mundo, com uma estimativa de 2,4 bilhões de pessoas expostas ao risco de infecção pelo Plasmodium falciparum e 2,9 bilhões de pessoas expostas ao risco de infecção pelo Plasmodium vivax. No Brasil, chegaram a ser registrados seis milhões de casos por ano na década de 1940, com transmissão em 70% dos municípios. O processo de ocupação desordenada da Amazônia iniciado na década de 1960 favoreceu o aumento de casos da doença na região. O Programa Nacional de Controle da Malária do Ministério da Saúde do Brasil (CGPNCM), criado em 2003, recomenda, por orientação da Organização Mundial da Saúde, três intervenções principais para alcançar os objetivos traçados no controle da doença: diagnóstico rápido dos casos de malária e tratamento com medicamentos efetivos; a distribuição de mosquiteiros impregnados com inseticida de longa duração para atingir cobertura total da população em risco; e o uso de borrifação residual intradomiciliar com inseticidas para reduzir ou eliminar a transmissão. Objetivos: Descrever a situação epidemiológica da malária na Região Amazônica Brasileira entre os anos 2003 e 2012. Métodos: Análise das bases de dados de mortalidade (SIM), internação (SIH) e notificação de casos de malária (SIVEP_MALÁRIA) entre os anos 2003 e 2012 nos nove estados da Região Amazônica Brasileira. Resultados: Em 2012 foram notificados 241.806 casos no Sistema de Informação SIVEP_MALÁRIA, representando redução de 60,1% quando comparado com o ano de 2005 e de 9,1% em relação a 2011. Entre os anos 2003 a 2005 houve um aumento considerável no número de casos de malária chegando ao registro de 606.069 casos em 616 municípios da região Amazônica em 2005. Desde 2006, observa-se uma tendência à redução no número de casos de malária na região Amazônica. Houve diminuição de modo mais acentuado na transmissão do P. falciparum, com notificação de 155.169 casos em 2005 e 35.385 casos em 2012, mostrando redução de 77,2%. Entre 2005 e 2012 houve redução (74,6%) no número de internações e no número de óbitos (54,4%) por malária. Entretanto, foi registrado aumento na taxa de letalidade dos casos internados. Em 2003 e 2005, a taxa de letalidade dos casos internados foi de 2,33 óbitos por 1.000, em 2011 de 4,36 e em 2012 de 3,61. Em 2012, 84,8% da transmissão da malária na Região Amazônica ocorreu em área rural. Conclusões: As principais intervenções que podem ter impactado na transmissão são o aumento da rede de diagnóstico, mudança nos esquemas terapêuticos e utilização de mosquiteiros impregnados. Ante um possível surgimento de P .falciparum resistentes às drogas e pelo fato desta espécie reponder pelo menor número de casos de malária no Brasil, porém apresentar maior gravidade clínica, é recomendado que novas estratégias de vigilância como, a utilização de ferramentas de identificação de "clusteres" e "hot spots", utilização de ferramentas de diagnóstico mais sensíveis e o manejo integrado de vetores sejam utilizadas na ousada mas não impossível perspectiva de eliminação do P. falciparum.Introduction: Malaria remains one of the most important causes of morbidity and mortality in tropical regions of the world, with an estimated 2.4 billion people at risk of infection with Plasmodium falciparum and 2.9 billion people at risk of Plasmodium vivax infection. In Brazil, six million cases per year were registered in the forties decade, with transmission in 70% of municipalities. The disorderly process of occupation of Amazon Regionstarted in the sixties decade favored the increase of cases of the disease. The National Malaria Control Program of the Ministry of Health of Brazil, created in 2003, recommends, under guidance of the World Health Organization, three main interventions to achieve the objectives outlined incontrolling the disease: rapid diagnosis of malaria cases and treatment with effective drugs; distribution of long-lasting insecticide-treated nets to achieve full coverage of the population at risk; and the use of indoor residual spraying with residual insecticides to reduce or eliminate transmission. Objectives: This work aimed to describe the epidemiological situation of malaria in the Brazilian Amazon Region between 2003 and 2012. Methods: Analysis of mortality (SIM), hospitalization (SIH) and notification of malaria cases in(SIVEP_MALÁRIA) databases between 2003 and 2012 in nine states of theBrazilian Amazon Region. Results: In 2012, 241,806 cases of malaria werereported in the SIVEP_MALARIA database, representing a reduction in60.1% compared to 2005 and 9.1% compared to 2011. From 2003 to 2005,there was a considerable increase of malaria cases with 606,069 cases registered in 616 Amazonian municipalities in 2005. Since 2006, the number of malaria cases has been showing downward trend, particularly in the transmission of P. falciparum with 155,169 cases in 2005 and 35,385 cases in 2012, decrease of 77.2%. From 2005 and 2012 there was a decrease(74.6%) in the number of hospitalizations and deaths (54.4%) by malaria. However, increase in the lethality rate of hospitalized cases was found. In2003 and in 2005, the lethality rate of hospitalized cases was 2.33 deaths per1,000, in 2011 was 4.36 and in 2012 was 3.61. In 2012, 84.8% of malariatransmission in the Amazon Region was in rural area. Conclusions: The main interventions that may have impacted on the transmission were: increasing diagnostic network, change in treatment policies and the use longlastinginsecticide-treated nets. Regarding the possibility of emergence of drug-resistant parasites and the lowest number of P. falciparum malariacases is recommended that new surveillance strategies as "clusters" and hotspots, more sensitive diagnostic tools and the integrated vector managementcould be used in audacious, but not impossible, perspective of elimination of P. falciparum

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

Current vector control challenges in the fight against malaria in Brazil

Abstract In Brazil, malaria is an important public health problem first reported in 1560. Historically, fluctuations in malaria cases in Brazil are attributed to waves of economic development; construction of railroads, highways, and hydroelectric dams; and population displacement and land occupation policies. Vector control measures have been widely used with an important role in reducing malaria cases. In this review article, we reviewed the vector control measures established in the Brazilian territory and aspects associated with such measures for malaria. Although some vector control measures are routinely used in Brazil, many entomological and effectiveness information still need better evidence in endemic areas where Plasmodium vivax predominates. Herein, we outlined some of the needs and priorities for future research: a) update of the cartography of malaria vectors in Brazil, adding molecular techniques for the correct identification of species and complexes of species; b) evaluation of vector competence of anophelines in Brazil; c) strengthening of local entomology teams to perform vector control measures and interpret results; d) evaluation of vector control measures, especially use of insecticide-treated nets and long-lasting insecticidal nets, estimating their effectiveness, cost-benefit, and population acceptance; e) establishment of colonies of malaria vectors in Brazil, i.e., Anopheles darlingi, to understand parasite-vector interactions better; f) study of new vector control strategies with impacts on non-endophilic vectors; g) estimation of the impact of insecticide resistance in different geographical areas; and h) identification of the relative contribution of natural and artificial breeding sites in different epidemiological contexts for transmission