Anopheles darlingi and Anopheles marajoara (Diptera: Culicidae) susceptibility to pyrethroids in an endemic area of the Brazilian Amazon.

INTRODUCTION: This study aimed to evaluate the susceptibility of Anopheles darlingi Root (1926) and Anopheles marajoara Galvão & Damasceno (1942) to pyrethroids used by the National Malaria Control Program in Brazil. METHODS: Mosquitoes from Amapá, Brazilian Amazon, were assessed for resistance to cypermethrin, deltamethrin, and alpha-cypermethrin. Insecticide-impregnated bottles were used as suggested by the CDC/Atlanta. RESULTS: Diagnostic dose for Anopheles darlingi was 12.5µg/bottle during 30 min of exposure. Concentrations for Anopheles marajoara were 20µg/bottle of cypermethrin and deltamethrin and 12.5µg/bottle of alpha-cypermethrin. CONCLUSIONS: No resistance was recorded for Anopheles darlingi , but Anopheles marajoara requires attention.

Oxime derivatives with larvicidal activity against Aedes aegypti L.

Oximes containing secondary metabolites constitute an important group of bioactive compounds and have been described and frequently updated in the literature due to their pharmacological properties. Thus, the aim of this study was to evaluate the larvicidal activity of a series of fourteen structurally related [1,4]-Benzoquinone mono-oximes on third-instar Aedes aegypti larvae and to investigate structure-activity relationships (SAR) of these compounds. Results of larvicidal assay revealed that all oximes were found to have larvicidal activity. Compound 2,6-dimethyl-[1,4]-benzoquinone oxime tosylate (11) was the most bioactive (LC50 = 9.858 ppm), followed by 2-methyl-[1,4]-benzoquinone oxime tosylate (9) (LC50 = 14.450 ppm). [1,4]-benzoquinone oxime (1) exhibited the lowest potency, with an LC50 = 121.181 ppm. The molecular characteristics which may help to understand the assayed compounds larvicidal activity were identified. SAR indicates that the addition of alkyl groups attached to the ring, number, position in the unsaturated cyclic structure, and size of these groups influence the larvicidal activity. Moreover, the lipophilicity seems to play an important role in increasing the larvicidal effect, because, in general, tosyl-containing products were more potent than products containing free OH.

Larvicidal activity of Mentha x villosa Hudson essential oil, rotundifolone and derivatives.

The aim of this study was to evaluate the larvicidal activity of Mentha x villosa essential oil (MVEO) and its major constituent, rotundifolone, against larvae of Aedes aegypti. Additionally, a set of 15 analogues of the rotundifolone were evaluated to identify the molecular characteristics which contribute to the larvicidal effect. The results from the present study showed that the MVEO exhibited outstanding toxic effects against Ae. aegypti larvae (LC50=45.0ppm). Rotundifolone exhibited reasonable larvicidal activity (LC50=62.5ppm). With respect to comparative study of rotundifolone and its analogues, all tested compounds were less potent than rotundifolone, except (-)-limonene. In general, replacement of C-C double bonds by epoxides groups decreases the larvicidal potency. The presence of α,ß-unsaturated carbonyls contributes to the larvicidal toxicity. The addition of hydroxyl groups in the chemical structure resulted in less potent compounds. Furthermore, the enantioselectivity seems to play an important role for the larvicidal toxicity.

Underreporting of Dengue-4 in Brazil due to low sensitivity of the NS1 Ag test in routine control programs.

We have identified fifty-eight samples that were positive for Dengue-4 among 119 samples with negative diagnoses for dengue via the Platelia™ dengue NS1 Ag in Aracaju, State of Sergipe, Brazil. We determined that the low sensitivity of the NS1 Ag test could be related to secondary dengue infections in the studied population. Therefore, we concluded that the sensitivity and specificity of the Platelia™ dengue NS1 Ag test as a screening method for monitoring circulating dengue serotypes must be reevaluated. In addition, regional endo-epidemic profiles should also be considered due to the prevalence of secondary responses.

[Identification and spatial distribution of key premises for Aedes aegypti in the Porto Dantas neighborhood, Aracaju, Sergipe State, Brazil, 2007-2008]. / Identificação e distribuição espacial de imóveis-chave de Aedes aegypti no bairro Porto Dantas, Aracaju, Sergipe, Brasil entre 2007 e 2008.

Currently the best way to avoid new dengue epidemics is to control the mosquito vector Aedes aegypti. This study thus aimed to identify and analyze the spatial distribution of "key premises" for Ae. aegypti in Aracaju, Sergipe State, Brazil. Three entomological surveys were performed prior to, during, and after the dengue epidemic and in different conditions of precipitation: the end of the rainy season, beginning of the rainy season, and the dry season. Key premises were identified by positivity in more than one survey and presence of pupae. Spatial distribution and dispersal of mosquitoes used analysis of point patterns, with the kernel and buffer density estimator. Key premises were responsible for maintaining infestation of the area, independently of environmental conditions and the period in the epidemic, serving as foci generating mosquitoes that can spread to areas adjacent to the neighborhood. Thus, in order to be more effective, vector control measures should target these properties.

Identificação e distribuição espacial de imóveis-chave de Aedes aegypti no bairro Porto Dantas, Aracaju, Sergipe, Brasil entre 2007 e 2008 / Identification and spatial distribution of key premises for Aedes aegypti in the Porto Dantas neighborhood, Aracaju, Sergipe State, Brazil, 2007-2008 / Identificación y distribución espacial de recipientes-clave de Aedes aegypti en el barrio Porto Dantas, Aracaju, Sergipe, Brasil entre 2007 y 2008

A melhor forma de evitar novas epidemias de dengue é controlar o vetor, o mosquito Aedes aegypti. Assim, este estudo objetivou identificar e analisar a distribuição espacial dos imóveis-chave para Ae. aegypti em Aracaju, Sergipe, Brasil. Para isso, três levantamentos entomológicos foram realizados em períodos antes, durante e após a epidemia de dengue e em diferentes condições de precipitação: fim do período chuvoso, início da estação chuvosa e estiagem. Para identificar os imóveis-chave, foram consideradas as variáveis: positividade em mais de um levantamento e presença de pupas; e para verificar a distribuição espacial e dispersão dos mosquitos, foi realizada análise de padrões pontuais, por meio do estimador de densidade de kernel e buffer. Constatou-se que os imóveis-chave são responsáveis pela manutenção da infestação na localidade independente das condições ambientais e do período epidêmico e são focos geradores de mosquitos que podem se dispersar para áreas vizinhas ao bairro. Dessa forma, as ações de controle vetorial, para serem mais efetivas, devem ser direcionadas para esses imóveis.

Currently the best way to avoid new dengue epidemics is to control the mosquito vector Aedes aegypti. This study thus aimed to identify and analyze the spatial distribution of "key premises" for Ae. aegypti in Aracaju, Sergipe State, Brazil. Three entomological surveys were performed prior to, during, and after the dengue epidemic and in different conditions of precipitation: the end of the rainy season, beginning of the rainy season, and the dry season. Key premises were identified by positivity in more than one survey and presence of pupae. Spatial distribution and dispersal of mosquitoes used analysis of point patterns, with the kernel and buffer density estimator. Key premises were responsible for maintaining infestation of the area, independently of environmental conditions and the period in the epidemic, serving as foci generating mosquitoes that can spread to areas adjacent to the neighborhood. Thus, in order to be more effective, vector control measures should target these properties.

La mejor forma de evitar nuevas epidemias de dengue es controlar el vector, el mosquito Aedes aegypti. Por ello, este estudio tuvo por objetivo identificar y analizar la distribución espacial de los recipientes-clave para Ae. aegypti en Aracaju, Sergipe, Brasil. Con este fin, tres estudios entomológicos se realizaron en períodos anteriores, durante y después de la epidemia de dengue y en diferentes condiciones de precipitación pluvial: fin del período lluvioso, inicio de la estación de lluvias y período seco. Para identificar los recipientes-clave, se consideraron las variables: positividad en más de un estudio y presencia de crisálidas; y para verificar la distribución espacial y la dispersión de los mosquitos, se realizó un análisis de padrones puntuales, por medio del estimador de densidad de kernel y buffer. Se constató que los recipientes-clave son responsables del mantenimiento de la infestación en la localidad, independientemente de las condiciones ambientales y del período epidémico, además, son focos generadores de mosquitos que pueden dispersarse hacia áreas vecinas del barrio. De esta forma, las acciones de control vectorial, para ser más efectivas, deben estar dirigidas hacia esos inmuebles.

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.

Quality of essential drugs in tropical countries: evaluation of antimalarial drugs in the Brazilian Health System.

INTRODUCTION: The emergence of drug resistance is one of the main problems concerning malaria treatment. The use of counterfeit and/or substandard antimalarial drugs can contribute to the development of parasite resistance. Thus, the aim of this study was to evaluate the quality of antimalarial drugs distributed in Brazil. METHODS: Samples containing chloroquine phosphate, mefloquine hydrochloride, primaquine phosphate, and quinine sulfate tablets were delivered to the Rio de Janeiro central storeroom (CENADI), state storerooms (SS), and Basic Health Units (BHUs) in the north region of Brazil - a total of 10 sample sets. After 5 months of storage, the samples were collected, and in vitro quality control analyses according to official and published methods were performed. RESULTS: Inadequate drug storage conditions were found in two SS and in all BHUs evaluated. There were no quality deviations found in the chloroquine samples. The quinine samples exhibited weight variation above the allowed limits. The primaquine samples were found to have packaging deficiency. The release of mefloquine in samples from some regions showed a statistically significant difference when compared with the CENADI samples. CONCLUSIONS: It is important to periodically evaluate the quality and storage conditions of essential drugs. The quality deviations found with the primaquine and quinine samples are not related to storage conditions and must be addressed urgently. The decreased mefloquine release from tablets is related to formulation problems or influenced by inadequate storage conditions, prompting further investigation. Even with the mentioned problems, the samples would probably not contribute to resistant parasite selection.

Quality of essential drugs in tropical countries: evaluation of antimalarial drugs in the Brazilian Health System / Qualidade de medicamentos essenciais em países tropicais: avaliação de medicamentos antimaláricos no Sistema de Saúde do Brasil

INTRODUCTION: The emergence of drug resistance is one of the main problems concerning malaria treatment. The use of counterfeit and/or substandard antimalarial drugs can contribute to the development of parasite resistance. Thus, the aim of this study was to evaluate the quality of antimalarial drugs distributed in Brazil. METHODS: Samples containing chloroquine phosphate, mefloquine hydrochloride, primaquine phosphate, and quinine sulfate tablets were delivered to the Rio de Janeiro central storeroom (CENADI), state storerooms (SS), and Basic Health Units (BHUs) in the north region of Brazil - a total of 10 sample sets. After 5 months of storage, the samples were collected, and in vitro quality control analyses according to official and published methods were performed. RESULTS: Inadequate drug storage conditions were found in two SS and in all BHUs evaluated. There were no quality deviations found in the chloroquine samples. The quinine samples exhibited weight variation above the allowed limits. The primaquine samples were found to have packaging deficiency. The release of mefloquine in samples from some regions showed a statistically significant difference when compared with the CENADI samples. CONCLUSIONS: It is important to periodically evaluate the quality and storage conditions of essential drugs. The quality deviations found with the primaquine and quinine samples are not related to storage conditions and must be addressed urgently. The decreased mefloquine release from tablets is related to formulation problems or influenced by inadequate storage conditions, prompting further investigation. Even with the mentioned problems, the samples would probably not contribute to resistant parasite selection.

INTRODUÇÃO: O aparecimento de resistência aos medicamentos é um dos maiores problemas do tratamento da malária. O uso de medicamentos falsos e/ou de má qualidade pode contribuir para o desenvolvimento de resistência no parasita. Este estudo tem por objetivo avaliar a qualidade dos medicamentos antimaláricos distribuídos no Brasil. MÉTODOS: Amostras contendo comprimidos de difosfato de cloroquina, cloridrato de mefloquina, difosfato de primaquina e sulfato de quinina foram enviadas ao almoxarifado central na Cidade do Rio de Janeiro (CENADI), almoxarifados estaduais (SS) e Unidades Básicas de Saúde (UBS) nos estados da região norte do Brasil, totalizando dez amostras. Após cinco meses de armazenamento, as amostras foram coletadas e analisadas segundo métodos oficiais e da literatura. RESULTADOS: Foram encontradas condições inadequadas de armazenamento de medicamentos em duas SS e em todas as UBS avaliadas. Não foram encontrados problemas de qualidade com as amostras de cloroquina. As amostras de quinina apresentaram variação de peso acima dos limites permitidos. Amostras de primaquina foram encontradas com problemas na embalagem. A cedência de mefloquina de comprimidos, em algumas regiões, apresentou diferença estatisticamente significativa quando comparada com a amostra do CENADI. CONCLUSÕES: É importante avaliar, periodicamente, a qualidade e as condições de armazenamento de medicamentos essenciais. Desvios de qualidade encontrados com as amostras de primaquina e quinina não estão relacionados às condições de armazenamento e devem ser corrigidos urgentemente. O decréscimo na cedência de mefloquina dos comprimidos está relacionado com a formulação ou foi influenciada por condições de armazenamento inadequadas, necessitando de uma investigação posterior. Apesar dos problemas mencionados, as amostras provavelmente não contribuiriam para a seleção de parasitas resistentes.

Chemical composition and antioxidant, antimicrobial, and larvicidal activities of the essential oils of Annona salzmannii and A. pickelii (Annonaceae).

The essential oils from the leaves of Annona salzmannii and A. pickelii (Annonaceae) growing in Sergipe, northeastern region of Brazil, were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS and GC/FID. Thirty-four compounds were identified in the essential oil of A. salzmannii and twenty-seven in that of A. pickelii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (20.3%), (E)-caryophyllene (19.9%), delta-cadinene (15.3%), alpha-copaene (10.0%), and allo-aromadendrene (5.7%) were the main components of A. salzmannii, and bicyclogermacrene (45.4%), (E)-caryophyllene (14.6%), and alpha-copaene (10.6%) of A. pickelii. The essential oils showed significant antioxidant capacity in the ORAC(FL) and DPPH assays. The antimicrobial activity of these essential oils was also evaluated against bacteria and fungi, as well as the larvicidal activity against Aedes aegypti larvae.

Risk of dengue occurrence based on the capture of gravid Aedes aegypti females using MosquiTRAP.

We assessed the risk classification of dengue fever based on the capture of Aedes aegypti adults using MosquiTRAP, a type of sticky trap, in comparison with traditional larval infestation indices. A total of 27 MosquiTRAPs were installed, with one trap per block, and were inspected weekly between November 2008-February 2009. Infestation baseline data were obtained from a survey conducted prior to trap installation. The index generated by MosquiTRAP and house index (HI) classified the area "in alert situation". The set for risk of dengue occurrence proposed by the use of MosquiTRAP classify areas in the same way of the traditional HI.

Risk of dengue occurrence based on the capture of gravid Aedes aegypti females using MosquiTRAP

We assessed the risk classification of dengue fever based on the capture of Aedes aegypti adults using MosquiTRAP, a type of sticky trap, in comparison with traditional larval infestation indices. A total of 27 MosquiTRAPs were installed, with one trap per block, and were inspected weekly between November 2008-February 2009. Infestation baseline data were obtained from a survey conducted prior to trap installation. The index generated by MosquiTRAP and house index (HI) classified the area "in alert situation". The set for risk of dengue occurrence proposed by the use of MosquiTRAP classify areas in the same way of the traditional HI.

Malaria vectors in two indigenous reserves of the Brazilian Amazon.

OBJECTIVE: To describe the composition, ecological and behavioral characteristics and infectivity of Anopheles species in indigenous reserves of the Amazon region. METHODS: The study was performed in villages of the Nhamundá-Mapuera and Cuminapanema indigenous reserves, in the state of Pará, Northern Brazil, in 2002. A total of three two-week collections were conducted in each reserve, with the capture of adult and immature forms. Adult Anopheles specimens were captured using a Castro sucking tube with human landing trap in indoor and outdoor environments, from 6.00 pm to 9.00 pm and from 6.00 pm to 6.00 am, and subsequently assessed to verify parity and infectivity by plasmodiums using dissection and ELISA. Water collections near the villages were surveyed using 500 ml ladles, with 20 ladlefuls for each 10 m, covering the maximum extent of 200 m of perimeter around the breeding spot. RESULTS: Adding up the collections from both reserves, a total of 8,668 females were captured. Anopheles darlingi was the most frequent species, with higher frequency around the homes. In the Mapuera reserve, blood feeding activity was concentrated between 8.00 pm and 12.00 am, while, in Cuminapanema, it remained high until 12.00 am, decreasing after this time and increasing again early in the morning. Of all the 6,350 An. darlingi females analyzed, 18 were infected with Plasmodium vivax VK247, VK210, P. falciparum and P. malariae. In addition, other 1,450 females of other species were analyzed, but none was found infected. An. nuneztovari and Chagasia bonnae were the most frequent species in the breeding spots of the Mapuera and Cuminapanema villages, respectively. Immature An. darlingi forms were not located in Mapuera and were captured in only one of the collections of the Cuminapanema reserve. CONCLUSIONS: An. darlingi populations in the two reserves showed exophilic behavior and intense nocturnal activity. The occurrence of immature forms was little frequent and larval density was low. Vector behavioral characteristics were not favorable for the usual vector control activities.

Vetores de malária em duas reservas indígenas da Amazônia Brasileira / Vectores de malaria en dos reservas indígenas del Amazonas Brasilero / Malaria vectors in two indigenous reserves of the Brazilian Amazon

OBJETIVO: Descrever a composição, características ecológicas e comportamentais e infectividade das espécies de anofelinos em reservas indígenas da região Amazônica. MÉTODOS: O estudo foi conduzido no ano de 2002 em aldeias das reservas indígenas Nhamundá-Mapuera e Cuminapanema no estado do Pará. Foram realizadas três coletas de duas semanas em cada reserva, com capturas de adultos e de imaturos. Anofelinos adultos foram capturados com capturador de Castro por atração humana nos ambientes intra e peridomiciliares, no período das 18h às 21h e das 18 às 06h e avaliados para verificação da paridade e infectividade para plasmódios por dissecção e ELISA. As coleções hídricas próximas às aldeias foram pesquisadas utilizando conchas de 500 ml, sendo 20 conchadas a cada 10 m, cobrindo-se a extensão máxima de 200 m de perímetro do criadouro. RESULTADOS: Foram capturadas 8.668 fêmeas somando-se as coletas das duas reservas. Anopheles darlingi foi a espécie predominante, com maior freqüência no peridomicílio. Na reserva Mapuera, a atividade hematofágica concentrou-se entre as 20h e 24h e, em Cuminapanema, manteve-se elevada até as 24h, diminuindo após esse horário e voltando a elevar-se no início da manhã. Das 6.350 fêmeas de An. darlingi examinadas, 18 estavam infectadas por Plasmodium vivax VK 247, VK 210, P. falciparum e P. malariae. Outras 1.450 fêmeas de outras espécies foram examinadas, mas nenhuma foi encontrada infectada. An. nuneztovari e Chagasia bonnae foram as espécies mais freqüentes nos criadouros das aldeias Mapuera e Cuminapanema, respectivamente. Imaturos de An. darlingi não foram localizados em Mapuera e foram capturados em apenas uma das coletas da reserva Cuminapanema. CONCLUSÕES: As populações de An. darlingi das duas reservas apresentaram comportamento exofílico e intensa atividade noturna. A ocorrência de imaturos foi pouco freqüente e a densidade larvária foi baixa. As características comportamentais dos vetores não se mostraram ...

OBJECTIVE: To describe the composition, ecological and behavioral characteristics and infectivity of Anopheles species in indigenous reserves of the Amazon region. METHODS: The study was performed in villages of the Nhamundá-Mapuera and Cuminapanema indigenous reserves, in the state of Pará, Northern Brazil, in 2002. A total of three two-week collections were conducted in each reserve, with the capture of adult and immature forms. Adult Anopheles specimens were captured using a Castro sucking tube with human landing trap in indoor and outdoor environments, from 6.00 pm to 9.00 pm and from 6.00 pm to 6.00 am, and subsequently assessed to verify parity and infectivity by plasmodiums using dissection and ELISA. Water collections near the villages were surveyed using 500 ml ladles, with 20 ladlefuls for each 10 m, covering the maximum extent of 200 m of perimeter around the breeding spot. RESULTS: Adding up the collections from both reserves, a total of 8,668 females were captured. Anopheles darlingi was the most frequent species, with higher frequency around the homes. In the Mapuera reserve, blood feeding activity was concentrated between 8.00 pm and 12.00 am, while, in Cuminapanema, it remained high until 12.00 am, decreasing after this time and increasing again early in the morning. Of all the 6,350 An. darlingi females analyzed, 18 were infected with Plasmodium vivax VK247, VK210, P. falciparum and P. malariae. In addition, other 1,450 females of other species were analyzed, but none was found infected. An. nuneztovari and Chagasia bonnae were the most frequent species in the breeding spots of the Mapuera and Cuminapanema villages, respectively. Immature An. darlingi forms were not located in Mapuera and were captured in only one of the collections of the Cuminapanema reserve. CONCLUSIONS: An. darlingi populations in the two reserves showed exophilic behavior and intense nocturnal activity. The occurrence of immature forms was little ...

OBJETIVO: Describir la composición, características ecológicas y de comportamiento e infectividad de las especies de anofelinos en reservas indígenas en la región Amazónica. MÉTODOS: El estudio fue conducido en el año de 2002 en aldeas de las reservas indígenas Nhamundá-Mapuera y Cuminapanema en el estado Pará (Norte de Brasil). Fueron realizadas tres colectas de dos semanas en cada reserva, con capturas de adultos e inmaduros. Anofelinos adultos fueron capturados con capturador de Castro por atracción humano en los ambientes intra y peridomiciliares, en el período de las 18 h a 21 h y de las 18 h a 6 h y evaluados para verificación de la paridad e infectividad para plasmodios por disección y ELISA. Las colecciones hídricas próximas a las aldeas fueron evaluadas utilizando cucharones de 500 mL, siendo 20 cucharones a cada 10 m, cubriéndose la extensión máxima de 200 m de perímetro del criadero. RESULTADOS: Fueron capturadas 8.668 hembras sumándose las colectas de las dos reservas. Anopheles darlingi fue la especie predominante, con mayor frecuencia en el peridomicilio. En la reserva Mapuera, la actividad hematofágica se concentró entre las 20 h y 24 h y en Cuminapanema, se mantuvo elevada hasta las 24 h, disminuyendo posterior a ese horario y volviendo a elevarse en el inicio de la mañana. De las 6.350 hembras de An. darlingi examinadas, 18 estaban infectadas por Plasmodium vivax VK 247, VK 210, P. falciparum y P. malariae. Otras 1.450 hembras de otras especies fueron examinadas, pero ninguna fue encontrada infectada. An. nuneztovari y Chagasia bonnae fueron las especies más frecuentes en los criaderos de las aldeas Mapuera y Cuminapanema, respectivamente. Inmaduros de An. darlingi no fueron localizados en Mapuera y fueron capturados en sólo una de las colectas de la reserva Cuminapanema. CONCLUSIONES: Las poblaciones de An. darlingi de las dos reservas presentaron comportamiento exofílico e intensa actividad nocturna. La ocurrencia de ...

Avaliação do efeito residual de piretróides sobre anofelinos da Amazônia brasileira / Evaluation of the residual effect of pyrethroids on Anopheles in the Brazilian Amazon

OBJETIVO: Avaliar a duração do efeito residual de piretróides sobre a mortalidade de anofelinos e verificar sua efetividade na borrifação intradomiciliar em regiões da Amazônia Brasileira. OBJETIVO: O estudo foi desenvolvido no conjunto habitacional, município de Belém, Pará, em 2003. Foram sorteadas 12 casas, três de cada uma das quatro áreas estabelecidas. Foram aplicados nas paredes internas das casas os inseticidas: piretróides cipermetrina pó molhável, deltametrina suspensão concentrada, lambdacialotrina pó molhável e etofemprox pó molhável. Seu efeito sobre a mortalidade de anofelinos foi avaliado durante os meses de julho a novembro. Utilizou-se a técnica de prova biológica de parede com a utilização de cones plásticos e mosquitos selvagens do município de Peixe Boi. RESULTADOS: A taxa de mortalidade variou de acordo com o tipo de parede e inseticida aplicado. Os aplicados em madeira e paredes de tijolo sem reboco foram mais estáveis e duradouros. O lambdacialotrina apresentou efeito mais curto que os demais inseticidas e o etofemprox apresentou efeito residual de quatro meses e foi mais efetivo em paredes de tijolo sem reboco. Não houve diferença estatística entre deltametrina e cipermetrina em todas as superfícies testadas, e a duração do efeito residual foi satisfatória até três meses após a borrifação. CONCLUSÕES: Os inseticidas deltametrina e etofemprox apresentaram melhor desempenho quando comparados aos demais. Para esses inseticidas e formulações, deve considerar-se seguro o intervalo de três meses entre aplicações sucessivas. Em comunidades com predomínio de casas de alvenaria rebocadas, deve ser considerada a menor efetividade das formulações, bem como a pertinência do emprego da borrifação residual como método para o controle vetorial na área.

OBJECTIVE: To evaluate the residual effect of pyrethroids on the mortality rates of Anopheles in order to check their efficacy in indoor residual spraying in the Amazon Region, Brazil. METHODS: The study was conducted in public housing unities in the city of Belem, Northern Brazil, in 2003. Twelve houses were randomly chosen, three in each of the four established areas. Pyrethroids cypermethrin wettable powder, deltamethrin suspension concentrate, lambda-cyhalothrin wettable powder, and etofenprox wettable powder, were sprayed on the indoor wall surface of local houses. Their effects on the mortality of Anopheles were assessed from July to November. Wall bioassay was performed using plastic cones attached to insecticide and wild mosquitoes from the town of Peixe Boi. RESULTS: Mortality rate varied according to the type of wall that received the insecticide. Those inseticides applied to wood and non-plastered brick surfaces were more stable and lasted longer. Lambda-cyhalothrin presented shorter effect than the other insecticides, and Etofenprox had residual effects up to four months and was more effective in non-plastered brick surfaces. There was no statistical difference between the effect of deltamethrin and cypermethrin in all surfaces tested, and the duration of the residual effect was satisfactory up to three months after spraying. CONCLUSIONS: Deltamethrin and Etofenprox presented grater performance when compared to the others. For these insecticides and formulations, a three- month interval between successive applications can be considered safe. In communities with predominance of houses with plastered brick surfaces, the smaller effectiveness of formulations should be considered, together with the importance of residual spraying as a vector control method in the area.

[Evaluation of the residual effect of pyrethroids on Anopheles in the Brazilian Amazon]. / Avaliação do efeito residual de piretróides sobre anofelinos da Amazônia brasileira.

OBJECTIVE: To evaluate the residual effect of pyrethroids on the mortality rates of Anopheles in order to check their efficacy in indoor residual spraying in the Amazon Region, Brazil. METHODS: The study was conducted in public housing units in the city of Belem, Northern Brazil, in 2003. Twelve houses were randomly chosen, three in each of the four established areas. Pyrethroids cypermethrin wettable powder, deltamethrin suspension concentrate, lambda-cyhalothrin wettable powder, and etofenprox wettable powder, were sprayed on the indoor wall surface of local houses. Their effects on the mortality of Anopheles were assessed from July to November. Wall bioassay was performed using plastic cones attached to insecticide and wild mosquitoes from the town of Peixe Boi. RESULTS: Mortality rate varied according to the type of wall that received the insecticide. Those insecticides applied to wood and non-plastered brick surfaces were more stable and lasted longer. Lambda-cyhalothrin presented shorter effect than the other insecticides, and etofenprox had residual effects up to four months and was more effective in non-plastered brick surfaces. There was no statistical difference between the effect of deltamethrin and cypermethrin in all surfaces tested, and the duration of the residual effect was satisfactory up to three months after spraying. CONCLUSIONS: Deltamethrin and etofenprox presented greater performance when compared to the others. For these insecticides and formulations, a three-month interval between successive applications can be considered safe. In communities with predominance of houses with plastered brick surfaces, the smaller effectiveness of formulations should be considered, together with the importance of residual spraying as a vector control method in the area.

[Entomological survey and infectivity during malaria outbreak in the Anajás municipality, Pará State]. / Inquérito entomológico e infectividade durante epidemia de malária no município de Anajás, Estado do Pará.

An entomological survey was conducted in the urban area of Anajás municipality, Para State, in order to verify the risk of malaria transmission. Although the density of Anopheles species was low, the anopheline infectivity rate of 6% demonstrated there is a high risk of infection by the malaria parasites.