Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in Amazon basin communities.

BACKGROUND: Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS) and mefloquine (MQ) combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance. METHODS: The effectiveness of a fixed-dose combination of AS and MQ (ASMQ) in reducing malaria transmission was tested in isolated communities of the Juruá valley in the Amazon region.Priority municipalities within the Brazilian Legal Amazon area were selected according to pre-specified criteria. Routine national malaria control programmatic procedures were followed. Existing health structures were reinforced and health care workers were trained to treat with ASMQ all confirmed falciparum malaria cases that match inclusion criteria. A local pharmacovigilance structure was implemented. Incidence of malaria and hospitalizations were recorded two years before, during, and after the fixed-dose ASMQ intervention. In total, between July 2006 and December 2008, 23,845 patients received ASMQ. Two statistical modelling approaches were applied to monthly time series of P. falciparum malaria incidence rates, P. falciparum/Plasmodium vivax infection ratio, and malaria hospital admissions rates. All the time series ranged from January 2004 to December 2008, whilst the intervention period span from July 2006 to December 2008. RESULTS: The ASMQ intervention had a highly significant impact on the mean level of each time series, adjusted for trend and season, of 0.34 (95% CI 0.20 - 0.58) for the P. falciparum malaria incidence rates, 0.67 (95% CI 0.50 - 0.89) for the P. falciparum/P. vivax infection ratio, and 0.53 (95% CI 0.41 - 0.69) for the hospital admission rates. There was also a significant change in the seasonal (or monthly) pattern of the time series before and after intervention, with the elimination of the malaria seasonal peak in the rainy months of the years following the introduction of ASMQ. No serious adverse events relating to the use of fixed-dose ASMQ were reported. CONCLUSIONS: In the remote region of the Juruá valley, the early detection of malaria by health care workers and treatment with fixed-dose ASMQ was feasible and efficacious, and significantly reduced the incidence and morbidity of P. falciparum malaria.

Malária em Cruzeiro do Sul (Amazônia Ocidental brasileira): análise da série histórica de 1998 a 2008 / Malaria in Cruzeiro do Sul (Western Brazilian Amazon): analysis of the historical series from 1998 to 2008

OBJETIVO. Descrever as características epidemiológicas da malária e seus principais determinantes no Município de Cruzeiro do Sul, no Estado do Acre, Brasil, entre 1998 e 2008 MÉTODOS. Este estudo descritivo, retrospectivo, utilizou dados secundários disponíveis nos sistemas de informação em malária desenvolvidos pelo Ministério da Saúde do Brasil (SISMAL/SIVEP-Malária). Os dados foram analisados no software TABLEAU®. Dados geo-espaciais foram obtidos para avaliar a distribuição dos casos de malária. RESULTADOS: A incidência parasitária anual (IPA) de 27 casos/1-000 habitantes em 1998 chegou a 571,5 casos/1-000 habitantes em 2006, quando a cidade registrou sua maior epidemia, subsequente ao estabelecimento de um programa estadual de incentivo à perfuração de tanques para piscicultura, em 2005. As localidades rurais apresentaram maior número de casos. Entretanto, as localidades periurbanas que possuíam tanques de piscicultura tiveram IPAs mais elevadas do que áreas sem tanques. Após a intensificação das ações do Programa Nacional de Controle da Malária, a IPA diminuiu para 152,9 casos/1-000 habitantes em 2008. CONCLUSÕES. O incentivo a atividades econômicas em áreas periurbanas de transmissão instável de malária, típicas da América Latina, deve ser muito bem planejado. O controle da malária em Cruzeiro do Sul baseou-se em estratégias integradas implementadas simultaneamente pelos governos federal, estadual e municipal, como preconizado pelo Plano Nacional de Controle da Malária. É importante ressaltar a utilidade de um bom sistema de informação como o SIVEP-Malária para estimar a carga de doença e monitorar de forma eficiente o impacto das intervenções.

OBJECTIVE: To describe the epidemiological characteristics of malaria and its main determinants in the municipality of Cruzeiro do Sul, State of Acre, Brazil, between 1998 and 2008. METHODS: This descriptive, retrospective study was carried out with secondary data available from the malaria information systems developed by the Brazilian Ministry of Health (SISMAL/SIVEP-Malária). The data were analyzed using the TABLEAU® software. Geospatial data were obtained to assess the distribution of malaria cases. RESULTS: The annual parasite incidence (API) of 27 cases/1 000 population in 1998 reached 571.5 cases/1 000 population in 2006, the year in which the city recorded its largest epidemics, following the establishment of a state program that encouraged the digging of tanks for fish farming in 2005. Rural sites had the highest number of cases. However, peri-urban locations with fish tanks had higher APIs than peri-urban areas without tanks. Following the strengthening of control actions by the National Malaria Control Program, the API in Cruzeiro do Sul dropped to 152.9 cases/1 000 population in 2008. CONCLUSIONS: The type of economic activity fostered in peri-urban areas characterized by unstable malaria transmission, which are typical of Latin America, must be very well planned. Malaria control in Cruzeiro do Sul relied on integrated strategies implemented simultaneously by federal, state, and city governments, as recommended by the National Malaria Control Program. It is important to underscore the usefulness of a reliable information system such as SIVEP-Malária to estimate the burden of disease and efficiently monitor the impact of interventions.

[Malaria in Cruzeiro do Sul (Western Brazilian Amazon): analysis of the historical series from 1998 to 2008]. / Malária em Cruzeiro do Sul (Amazônia Ocidental brasileira): análise da série histórica de 1998 a 2008.

OBJECTIVE: To describe the epidemiological characteristics of malaria and its main determinants in the municipality of Cruzeiro do Sul, State of Acre, Brazil, between 1998 and 2008. METHODS: This descriptive, retrospective study was carried out with secondary data available from the malaria information systems developed by the Brazilian Ministry of Health (SISMAL/SIVEP-Malária). The data were analyzed using the TABLEAU® software. Geospatial data were obtained to assess the distribution of malaria cases. RESULTS: The annual parasite incidence (API) of 27 cases/1,000 population in 1998 reached 571.5 cases/1,000 population in 2006, the year in which the city recorded its largest epidemics, following the establishment of a state program that encouraged the digging of tanks for fish farming in 2005. Rural sites had the highest number of cases. However, peri-urban locations with fish tanks had higher APIs than peri-urban areas without tanks. Following the strengthening of control actions by the National Malaria Control Program, the API in Cruzeiro do Sul dropped to 152.9 cases/1,000 population in 2008. CONCLUSIONS: The type of economic activity fostered in peri-urban areas characterized by unstable malaria transmission, which are typical of Latin America, must be very well planned. Malaria control in Cruzeiro do Sul relied on integrated strategies implemented simultaneously by federal, state, and city governments, as recommended by the National Malaria Control Program. It is important to underscore the usefulness of a reliable information system such as SIVEP-Malária to estimate the burden of disease and efficiently monitor the impact of interventions.