Arboalvo: estratificação territorial para definição de áreas de pronta resposta para vigilância e controle de arboviroses urbanas em tempo oportuno / Arboalvo: territorial stratification for definition of areas for prompt response by surveillance and timely control of urban arbovirus infections / Arboalvo: estratificación territorial para la definición de áreas de respuesta rápida para la vigilancia y control de arbovirosis urbanas en el momento oportuno

O objetivo deste trabalho foi apresentar a proposta metodológica denominada de "Pronta Resposta" modelada nas cidades de Belo Horizonte (Minas Gerais) e Natal (Rio Grande do Norte), Brasil. A metodologia visa identificar e delimitar áreas prioritárias para o direcionamento das ações de vigilância em tempo oportuno, buscando a redução da intensidade e velocidade da dispersão de epidemias em áreas urbanas endêmicas. Para tanto, a metodologia utiliza três variáveis, que representam as causas necessárias para a produção e reprodução da dengue: casos notificados (vírus), ovos de Aedes (vetor) e população (hospedeiro). Trata-se de um estudo ecológico que utilizou os dados dos três planos de informações agregados em escalas temporais e espaciais mais finas, de três a quatro semanas e grades de 400 a 600 metros respectivamente. As áreas de pronta resposta foram definidas por meio de análise estatística de varredura Scan, com definição de clusters espaciais simultâneos para os três planos por meio do programa SaTScan. Os resultados observados foram: na cidade de Natal, as áreas definidas como pronta resposta ocuparam em média 15,2% do território do município e concentraram 67,77% dos casos de dengue do período posterior ao utilizado na delimitação das áreas de pronta resposta, e em Belo Horizonte, os números observados foram de 64,16% dos casos em 23,23% do território. Esses resultados foram obtidos em duas cidades com realidades socioambientais e geográficas diferentes e com perfis epidemiológicos também distintos, apontando que a metodologia pode ser aplicada em diferentes realidades urbanas, criando a possibilidade de os programas de controle atuarem em porções reduzidas do território e impactar num alto percentual de casos em tempo oportuno.

The study aimed to present the methodological proposal entitled "Prompt Response", modelled in the cities of Belo Horizonte (Minas Gerais State) and Natal (Rio Grande do Norte State), Brazil. The proposal aims to identify and demarcate priority areas for timely targeting of surveillance activities, aiming to reduce the intensity and velocity in the spread of epidemics in endemic urban areas. The methodology uses three variables that represent the necessary causes for the production and reproduction of dengue: notified cases (virus), Aedes eggs (vector), and population (host). This was an ecological study that used data from three information planes aggregated in finer temporal and spatial scales of 3 to 4 weeks and 400 to 600-meter grids, respectively. The prompt response areas were defined by Scan statistical analysis with definition of simultaneous spatial clusters for the three planes via the SaTScan program. In Natal, the areas defined as prompt response occupied, on average, 15.2% of the city's territory and concentrated 67.77% of the dengue cases in the period following demarcation of the prompt response areas. In Belo Horizonte, the observed proportions were 64.16% of cases in 23.23% of the territory. These results were obtained in two cities with different socioenvironmental and geographic realities and distinct epidemiological profiles, indicating that the methodology can be applied to different urban realities, allowing control programs to concentrate on reduced portions of the territory and impacting a high percentage of cases in timely fashion.

El objetivo del trabajo fue presentar la propuesta metodológica, denominada de "Resposta Rápida", modelada en las ciudades de Belo Horizonte (Minas Gerais) y Natal (Rio Grande do Norte), Brasil. Esta última tiene como meta identificar y delimitar áreas prioritarias para la ejecución de acciones de vigilancia en el momento oportuno, buscando la reducción de la intensidad y velocidad de la dispersión de epidemias en áreas urbanas endémicas. Para tal fin, la metodología utiliza tres variables, que representan las causas necesarias para la producción y reproducción del dengue: casos notificados (virus), huevos de Aedes (vector) y población (huésped). Se trata de un estudio ecológico que utilizó los datos de los tres planos de información agregados en escalas temporales y espaciales más finas, de 3 a 4 semanas y tablas de 400 a 600 metros respectivamente. Las áreas de respuesta rápida se definieron a través del análisis estadístico de exploración Scan, con definición de clústeres espaciales simultáneos para los tres planos mediante el programa SaTScan. Los resultados observados fueron: en la ciudad de Natal, las áreas definidas como de respuesta rápida ocuparon de media un 15,2% del territorio del municipio y concentraron un 67,77% de los casos de dengue del período posterior al utilizado en la delimitación de las áreas de respuesta rápida y, en Belo Horizonte, los números observados fueron un 64,16% de los casos en un 23,23% del territorio. Estos resultados se obtuvieron en dos ciudades con realidades socioambientales y geográficas diferentes y con perfiles epidemiológicos también distintos, apuntando que la metodología se puede aplicar en diferentes realidades urbanas. Dando la posibilidad de que los programas de control actúen en secciones reducidas del territorio e impactar en un alto porcentaje de casos en el momento oportuno.

Oogenic development and gonotrophic cycle of Aedes aegypti and Aedes albopictus in laboratory / Desarrollo oogénico y ciclo gonotrófico de Aedes aegypti y Aedes albopictus en laboratorio

Abstract: Objective: To determine the time of oogenic development and the length of the gonotrophic cycle of Ae. aegypti and Ae. albopictus in laboratory. Materials and methods: Bloodfed females of Ae. aegypti and Ae. albopictus were dissected every 4 h to determine the development status of the follicles according to the Christophers' stages. Results: The minimum time of oocyte maturation in Ae. aegypti and Ae. albopictus was 64-82 h and 52-64 h post-feeding, respectively. We found that the gonotrophic cycle of Ae. aegypti (3.7-4.2 d) is longer than that of Ae. albopictus (3.2-3.7 d). The follicle length showed significant differences between species at Christophers' stages 2" and 5, whereas follicle amplitude was different between the two mosquitoes at stages 2", 3 and 4. Conclusions: The study provided new evidence on the reproductive strategies of Ae. aegypti and Ae. albopictus females that coexist in the Neotropical region of Mexico.

Resumen: Objetivo: Determinar el tiempo de desarrollo oogénico y del ciclo gonotrófico de Aedes aegypti y Aedes albopictus en laboratorio. Material y métodos: Hembras de Ae. aegypti y Ae. albopictus alimentadas con sangre fueron disecadas cada cuatro horas para determinar el estado de desarrollo folicular, según los estadios de Christophers. Resultados: El tiempo mínimo de maduración del oocito en Ae. aegypti y Ae. albopictus fue de 64-82 h y 52-64 h post-alimentación, respectivamente. El ciclo gonotrófico de Ae. aegypti (3.7-4.2 d) fue mayor que el de Ae. albopictus (3.2-3.7 d). La longitud folicular presentó diferencias significativas entre las especies en los estadios de Christophers 2" y 5, mientras que la amplitud folicular fue diferente entre ambos mosquitos en los estadios 2", 3 y 4. Conclusiones: El estudio proporcionó nueva evidencia sobre la estrategia reproductiva de las hembras de Ae. aegypti y Ae. albopictus que coexisten en la región neotropical de México.

Avaliação da armadilha ovitrampa iscada com atraente natural para o monitoramento de Aedes spp. em Dili, capital do Timor-Leste / Evaluation of the baited ovitrap with natural attractant for monitoring Aedes spp. in Dili, capital of East Timor

Resumo A dengue ocorre no Timor-Leste desde 2005, porém não existe um programa de monitoramento e controle do "Aedes aegypti". O objetivo deste estudo foi de avaliar a armadilha ovitrampa iscada com atraente natural como uma possível ferramenta para monitorar o vetor das arboviroses: Dengue (DENV), Chikungunya (CHIKV) e Zika (ZIKV). O estudo foi realizado na cidade de Dili, capital do Timor-Leste, entre as semanas epidemiológicas 32 (02/08) a 48 (02/12) de 2016. Foram instaladas 70 armadilhas Ovitrampa, em residências de 15 sucos (ruas), de quatro Postos Administrativos (bairros) da cidade. Para as analises dos dados utilizou-se os indicadores entomológicos: Índice de Positividade de Ovitrampa (IPO), Índice de Densidade Vetorial (IDV) e Índice de Densidade de Ovos (IDO). Durante o experimento foram coletados 158.904 ovos de Aedes spp.. O IPO demonstrou que todas as áreas tiveram 98% a 100% de armadilhas contendo ovos de Aedes spp.. Os indicadores IDO e IPO apresentaram correlações positivas e significativa com a temperatura. A defasagem de duas e três semanas para precipitação indicou correlação positiva significativa para IDV e IDO. Portanto, a armadilha ovitrampa é uma ferramenta que pode integrar as ações de um programa de monitoramento e controle de Aedes spp. no Timor-Leste.

The influence of meteorological variables on the oviposition dynamics of Aedes aegypti (Diptera: Culicidae) in four environmentally distinct areas in northeast Brazil

BACKGROUND Fluctuations in climate have been associated with variations in mosquito abundance. OBJECTIVES To analyse the influence of precipitation, temperature, solar radiation, wind speed and humidity on the oviposition dynamics of Aedes aegypti in three distinct environmental areas (Brasília Teimosa, Morro da Conceição/Alto José do Pinho and Dois Irmãos/Pintos) of the city of Recife and the Fernando de Noronha Archipelago northeastern Brazil. METHODS Time series study using a database of studies previously carried out in the areas. The eggs were collected using spatially distributed geo-referenced sentinel ovitraps (S-OVTs). Meteorological satellite data were obtained from the IRI climate data library. The association between meteorological variables and egg abundance was analysed using autoregressive models. FINDINGS Precipitation was positively associated with egg abundance in three of the four study areas with a lag of one month. Higher humidity (β = 45.7; 95% CI: 26.3 - 65.0) and lower wind speed (β = −125.2; 95% CI: −198.8 - −51.6) were associated with the average number of eggs in the hill area. MAIN CONCLUSIONS The effect of climate variables on oviposition varied according to local environmental conditions. Precipitation was a main predictor of egg abundance in the study settings.

Infestation of an endemic arbovirus area by sympatric populations of Aedes aegypti and Aedes albopictus in Brazil

BACKGROUND Aedes aegypti and Aedes albopictus are the most important arbovirus vectors in the world. OBJECTIVES This study aimed to investigate and compare the infestation pattern of these species in a neighbourhood of Recife, Brazil, endemic for arboviruses in 2005 (T1) and 2013 (T2). METHODS Infestation, distribution and relative abundance of these sympatric species were recorded by egg collection using a network of 59 sentinel ovitraps (s-ovt) at fixed sampling stations for 12 months in T1 and T2. FINDINGS A permanent occupation pattern was detected which was characterised by the presence of egg-laying females of one or both species with a high ovitrap positivity index (94.3 to 100%) throughout both years analysed. In terms of abundance, the total of eggs collected was lower (p < 0.005) in T2 (146,153) than in T1 (281,103), although ovitraps still displayed a high index of positivity. The spatial distribution showed the presence of both species in 65.1% of the 148 s-ovt assessed, while a smaller number of traps exclusively contained Ae. aegypti (22%) or Ae. albopictus (13.2%) eggs. MAIN CONCLUSIONS Our comparative analysis demonstrated the robustness of the spatial occupation and permanence of Ae. aegypti and Ae. albopictus populations in this endemic urban area.

Health education in Aedes aegypti: case study / Educación en salud en torno al Aedes aegypti: un reporte de experiencia / Educação em saúde sobre o Aedes aegypti: relato de experiência

ABSTRACT Objectives: Reporting the experience of health education regarding Aedes aegypti in the Federal District. Methods: This is a case report, with descriptive approach, about the experience of nursing practice with education actions against the Aedes aegypti in communities of the Federal District, carried out between 2015 and 2018. Subjects of the research were undergraduate students in nursing, healthcare professionals, and the community. Results: There have been 24 educational interventions against Aedes aegypti, adapted to the needs of each population, using a "giant" sculpture of the mosquito, theater performances, lectures, booklets, and home visits. Conclusions: The project trained teachers, healthcare professionals, graduate students in nursing, and the community through the empowerment of this population, aiming at combating the Aedes aegypti vector.

RESUMEN Objetivos: Reportar la experiencia en torno a la educación en salud relacionada con el Aedes aegypti en el Distrito Federal (Brasil). Métodos: Se trata de un reporte de experiencia, de abordaje descriptivo, sobre la vivencia de la práctica de enfermería con acciones educativas contra el Aedes aegypti en comunidades del Distrito Federal, realizado en el período entre 2015 y 2018. Participaron en este estudio los estudiantes del grado en enfermería, los profesionales de los servicios de salud y la comunidad. Resultados: Se realizaron 24 acciones educativas contra el Aedes aegypti, las cuales se adaptaron a las necesidades de cada público y se utilizó una escultura "gigante" del mosquito, presentaciones de teatro, charlas, cartillas y visitas domiciliarias. Conclusiones: El proyecto capacitó a los docentes, a los profesionales de salud, a los estudiantes de grado en enfermería y a la comunidad, por medio del empoderamiento para combatir el vector Aedes aegypti.

RESUMO Objetivos: Relatar a experiência sobre educação em saúde em relação ao Aedes aegypti no Distrito Federal. Métodos: Trata-se de um relato de experiência, com abordagem descritiva, sobre a vivência da prática de enfermagem com ações educativas contra o Aedes aegypti em comunidades do Distrito Federal, realizada entre 2015 a 2018. Os sujeitos da pesquisa foram os graduandos de enfermagem, os profissionais dos serviços de saúde e a comunidade. Resultados: Realizaram-se 24 atuações educativas contra o Aedes aegypti, adaptadas às necessidades de cada público, utilizando-se uma escultura "gigante" do mosquito, apresentações de teatro, palestras, cartilhas e visitas domiciliares. Conclusões: O projeto capacitou docentes, profissionais de saúde, graduandos de enfermagem e comunidade por meio do empoderamento dessa população, com vistas ao combate ao vetor Aedes aegypti.

Importance of microenvironment to arbovirus vector distribution in an urban area, São Paulo, Brazil

Abstract INTRODUCTION: The study of the landscape ecology, biological microhabitat, and epidemiological implications for the distribution of the main vectors Aedes aegypti and Aedes albopictus contribute to the prevention and control actions regarding the diseases they transmit. METHODS: This study sought to assess data on positive properties of the vector control program activities from 1998 to 2010. An entomological survey was also carried out on a sample of buildings collecting larvae and pupae from containers between October and April (spring / summer) from 2002 to 2005. We assessed the physico-chemical data of the water in 20% of positive containers. The vegetation and urbanization were assessed with the aid of satellite images and microenvironments were classified as urbanized, woods, and shrubs. The data were analyzed using statistical and geoprocessing software. RESULTS: Ae. aegypti and Ae. albopictus colonized all types of microhabitats and microenvironments, predominantly in the urbanized area, in isolation and in coexistence. The microhabitat of Ae. aegypti showed a temperature gradient greater than that of Ae. albopictus, and there was an association with urbanized areas for the first species and wooded areas for the last species. CONCLUSIONS: Landscape ecology and intra-urban differences favor different microclimates, which contribute to the coexistence of species in the urban environment in an area close to the forest, raising the risk of other arbovirus infections in urban areas. The ecological niche should be considered for Ae. albopictus. Entomological and virologic monitoring are suggested as arbovirus surveillance actions in urban infested centers near preserved forests.

Influence of climatic variables on the Aedes aegypti and Culex quinquefasciatus populations in Mato Grosso, Brazil

Abstract INTRODUCTION: Aedes aegypti and Culex quinquefasciatus are vector species responsible for the transmission of important arboviruses. METHODS: Adult mosquitoes were collected in the urban areas of four municipalities in Mato Grosso within 1 year. RESULTS: A total of 19,110 mosquitoes were collected. Among them, 16,578 (86,8%) were C. quinquefasciatus (44% female and 56% male); 2,483 (13%), A. (Stegomyia) aegypti (54% female and 46% male); and 49 (0,30%), from the genus Psorophora, Anopheles, Coquilettidia, and Sabethes. A significant correlation was observed between the number of mosquitoes from all species and dew point (female mosquitoes, p = 0.001; male mosquitoes, p = 0.001). CONCLUSIONS: The results of this study may be used as environmental indicators of mosquito populations.

Dengue: 30 years of cases in an endemic area

The present study aimed to review literature on studies of dengue cases conducted over 30 years in the state of Ceará. Between November 2015 and January 2016, articles published in Portuguese and English in 7 databases were searched using keywords and a Boolean operator. A total of 191 articles were identified in the databases; 133 were excluded according to the exclusion criteria, and 58 were included in the study. Of the 58 articles analyzed, 6 reported data from Brazil; including the Northeast region and the state of Ceará; 41 reported data for only the city of Fortaleza; 7 reported data for the state of Ceará; 4 reported data for cities in the interior of the state; and 3 included only children. The studies adopted different approaches and focused on different aspects of the disease. Study outcomes included the identification of serological, epidemiological, clinical, and laboratory characteristics; potential larvicides and biological predators of mosquitoes; potential antiviral agents; vector density characteristics; and educational dengue prevention and control strategies. Additionally, one vaccine trial was included. Although studies on dengue in the state of Ceará are scarce, they are encompassing, including several lines of research, and the number of studies and reports on dengue in the state of Ceará continues to increase.

Spatial distribution of Aedes aegypti (Diptera: Culicidae) in vulnerable areas for the transmission of arboviruses

Abstract INTRODUCTION: Areas at risk of transmission of arboviruses have been monitored using ovitraps. This study aimed to evaluate the spatial distribution of Aedes aegypti in vulnerable areas for the transmission of arboviruses and assess the influence of climatic conditions on the infestation of these culicids. METHODS: Ovitraps were installed in Agrestina, Pernambuco, Northeastern Brazil. RESULTS: Overall, 44,936 eggs were collected, and the indexes of infestation varied. Relative humidity was significantly associated with the infestations. CONCLUSIONS: Using ovitraps, entomologic indexes and analysis of climatic factors might be good strategies for monitoring vulnerable areas for the transmission of arboviruses.

Mosquito species occurrence in association with landscape composition in green urban areas / Ocorrência de espécies de mosquitos associada à composição de paisagem em áreas verdes urbanas

Abstract Aedes aegypti prefers densely populated habitats, but has been shown to explore less anthropogenic environments. We investigated composition of the abundance of mosquitoes in forested areas and assessed relationships between species occurrences and different types of land use and land cover at three spatial scales (100m, 500m and 1000m). Mosquitoes were collected from October 2012 to March 2013 using oviposition traps. We collected 4,179 mosquitoes in total including at least 10 species. Aedes albopictus and Limatus durhami were eudominant species, representing 90% of all collected individuals. We found intraspecific differences in response to land use and land cover, and species response patterns were similar at all spatial scales. Ae. albopictus relative abundance was associated with urbanized areas, while Li. durhami, Haemagogus leucocelaenus and Toxorhynchites sp., abundances were associated with native forest. Aedes aegypti were found in five of the eight areas studied, including in an Atlantic forest fragment at a considerable distance from the forest edge (370 m). Aedes aegypti occurrence was not influenced by type of land use or land cover.

Resumo Aedes aegypti tem como habitat preferencial áreas densamente povoadas, mas que tem se mostrado capaz de explorar ambientes menos antropizados. O objetivo desse trabalho foi investigar a abundância de mosquitos em áreas florestadas e avaliar a relação dos diferentes tipos de uso e cobertura do solo, em três escalas de paisagem (buffer de 100m, 500m e 1000m). Os mosquitos foram coletados entre outubro de 2012 a março de 2013 utilizando armadilhas de oviposição. Foram coletados 4,179 culicídeos, de pelo menos 10 espécies, destas, Aedes albopictus e Limatus durhami foram eudominantes, representando 90% do total de indivíduos coletados. As espécies de culicídeos respondem de maneira diversa aos tipos de uso e cobertura do solo, indicando que as afinidades mais evidentes se mantém nas três escalas avaliadas. A abundância relativa de Ae. albopictus se mostrou relacionada às áreas mais urbanizadas, enquanto a de Li. durhami, Haemagogus leucocelaenus e Toxorhynchites sp., à presença da mata nativa. Aedes aegypti esteve presente em cinco das oito áreas estudadas, incluindo um fragmento de Mata Atlântica a uma distância considerável da borda (370m). A ocorrência de Aedes aegypti nas áreas analisadas não demonstrou ser influenciada pelo tipo de uso e cobertura do solo.

Antropologia das doenças transmissíveis: interpretações do contágio e diferenças culturais / Anthropology of communicable diseases: interpretations of contagion and cultural differences

Este livro apresenta os resultados de diversas pesquisas realizadas pelo autor sobre o tema do contágio ao longo das últimas duas décadas, em diversos países. Trata-se de material inédito na língua portuguesa e reorganizado no intuito de identificar um único fio condutor e elementos comuns entre material recolhido em contextos socioculturais bem diversificados, bem diferenciados.Os diversos capítulos expõem, a seu modo, conclusões parcialmente publicadas em periódicos e capítulos de livros

Saberes e práticas sobre controle do Aedes aegypti por diferentes sujeitos sociais na cidade de Salvador, Bahia, Brasil / Knowledge and practices in Aedes aegypti control among different social subjects in Salvador, Bahia State, Brazil / Conocimientos y prácticas sobre el control del Aedes aegypti realizado por diferentes sujetos sociales en la ciudad de Salvador, Bahía, Brasil

Resumo: Devido à persistência da dengue e de outras arboviroses no Brasil, o poder público tem intensificado as ações de combate ao mosquito vetor Aedes aegypti. Os agentes de combate às endemias (ACE) e agentes comunitários de saúde (ACS), dentre outras atribuições, tornaram-se interlocutores e disseminadores de conhecimento na comunidade. O objetivo deste trabalho foi analisar os saberes e práticas sobre controle da dengue por diferentes sujeitos sociais: moradores e agentes. Foram realizadas entrevistas com moradores, ACE de campo e de mobilização e ACS em dois bairros de Salvador, Bahia, por meio da metodologia de grupo focal. Os moradores demonstraram incerteza sobre a forma de contágio e o perigo da dengue. Os ACE de campo apresentam-se em conflito, pela necessidade de informar à comunidade sobre aspectos que não dominam e demonstram um descontentamento pessoal no trabalho com um sentimento de desvalorização pela falta de qualificação. Os ACE de mobilização culpam a população e enfatizam a importância de si próprios como solução para o controle da dengue. Os ACS não apropriaram sua experiência de campo em seu discurso e se sentem desobrigados com respeito ao controle vetorial. Todos os grupos entrevistados concordam que a culpa da dengue recai sobre o poder público, e a solução para o problema está na educação. Percebe-se uma grande necessidade de intervenções educativas regulares, pautadas no diálogo e na sensibilização para lidar com a realidade cotidiana dos moradores, trazendo os indivíduos (moradores e agentes) como sujeitos do processo de construção de conhecimento. Pois, na metodologia atual, a disseminação de informação e conhecimento não é suficiente para promover melhorias na comunidade para o controle da dengue.

Abstract: Due to the persistence of dengue and other arbovirus infections in Brazil, the government has stepped up measures to combat the Aedes aegypti mosquito vector. The responsibilities of community endemic disease workers (CEDW) and community health workers (CHW) include acting as intermediaries and disseminating knowledge in the community. The aim of this study was to analyze knowledge and practices in dengue control by different social subjects: residents and CEDW/CHW. Interviews were held with residents, field and mobilization CEDW, and CHW in two neighborhoods in Salvador, Bahia State, using focus groups. Residents expressed uncertainty on the form of transmission and hazards of dengue. Field CEDW voiced conflicting feelings due to the need to inform the community on issues over which they lack any control, while expressing personal dissatisfaction with their work and a feeling of underappreciation due to their lack of training. Mobilization CEDW blamed the population and emphasized their own importance as the solution to dengue control. CHW failed to reflect their field experience in their discourse and felt they had no responsibility over vector control. All the groups agreed that government is to blame for dengue and that the solution lies in education. There is an evident need for regular educational interventions, based on dialogue and awareness-raising to deal with residents' daily reality, drawing individuals (residents and CHW) into the knowledge-building process. Under the prevailing methodology, the dissemination of information and knowledge is insufficient to promote community improvements for dengue control.

Resumen: Debido a la persistencia del dengue y de otras arbovirosis en Brasil, el poder público ha intensificado las acciones de combate al mosquito vector Aedes aegypti. Los ACE (agentes de combate a endemias) y los ACS (agentes comunitarios de salud), entre otras atribuciones, se convirtieron en interlocutores y promotores de conocimiento sobre enfermedades en sus comunidades. El objetivo de este trabajo fue analizar los conocimientos y prácticas sobre el control del dengue por parte de los diferentes sujetos sociales implicados: residentes y agentes. Se realizaron entrevistas a residentes, ACE de campo y de movilización, así como ACS, en dos barrios de Salvador, Bahía, mediante una metodología de grupo focal. Los residentes mostraron inseguridad sobre la forma de contagio, así como el peligro que supone el dengue. Los ACE de campo se encontraron en conflicto, por su necesidad de informar a la comunidad sobre aspectos que no dominan, además de demostrar un descontento personal en el trabajo, unido a un sentimiento de desvalorización, por su falta de cualificación. Los ACE de movilización culpan a la población y enfatizan la importancia de ellos mismos como solución para el control del dengue. Los ACS no se apropiaron de su experiencia de campo en su discurso y no se sienten obligados al control vectorial. Todos los grupos entrevistados concuerdan en que la culpa del dengue recae sobre el poder público, y la solución para el problema está en la educación. Se percibe una gran necesidad de intervenciones educativas regulares, pautadas en el diálogo y en la sensibilización para lidiar con la realidad cotidiana de los residentes, considerando a los individuos (residentes y agentes) como sujetos del proceso de construcción del conocimiento. Así pues, en la metodología actual, la divulgación de información y conocimiento no es suficiente para promover mejoras en las comunidades, con el fin de controlar el dengue.

Zika: probabilidad de establecimiento de su vector, Aedes aegypti, en Chile / Zika: probability of establishment of its vector, Aedes aegypti, in Chile

Resumen El virus Zika ha despertado una alarma mundial en los últimos años, representando un problema importante para la salud pública. En este estudio evaluamos el riesgo potencial de exposición a virus Zika en Chile, asociado a la probabilidad de establecimiento del vector Aedes aegypti en el país. Se utilizaron técnicas de modelación de nicho para proyectar los requerimientos bioclimáticos del vector (nicho global), identificando las zonas de alta idoneidad para la especie en el país. Luego, se superpuso la distribución potencial del vector en Chile con la densidad de población humana, estimando en forma espacialmente explícita el riesgo asociado a la co-ocurrencia potencial de ambos. Identificamos que existe idoneidad bioclimática para A. aegypti en Chile continental, desde el área tropical del norte hasta regiones templadas, principalmente en zonas costeras. La población potencialmente expuesta podría alcanzar 1,8 millones de personas, con 1,3 millones en nivel medio y 21.000 en niveles altos de riesgo potencial de exposición. Los resultados expuestos aquí muestran que existe una significativa probabilidad de éxito de colonización del vector principal de virus Zika en Chile continental en caso de una introducción. Por lo tanto, la prevención, monitoreo y control se vuelven un tema importante para evitar la llegada de este vector a Chile continental.

The Zika virus has raised world alarm in recent years, representing a major public health problem. In this study we evaluated the potential risk of exposure to Zika virus in Chile, associated with the probability of establishment of the vector Aedes aegypti in the country. Niche modelling techniques were used to project the bioclimatic requirements of the vector (global niches), identifying zones of high suitability for the species within the country. Then, the potential distribution of the vector in Chile was overlapped with the human population density, estimating the risk associated to the potential co-occurrence of both in a spatially explicit manner. We identified bioclimatic suitability for A. aegypti in continental Chile, from the northern tropical area to temperate regions, mainly in coastal zones. The exposed population could reach 1.8 million people, with 1.3 million in a medium level of potential risk and 21,000 in a high level. These results support that there is a significant probability of success for the Zika virus main vector to colonize continental Chile in case of an introduction. Therefore, prevention, monitoring, and control play an important role in avoiding the arrival of this vector to our country.

Distribución espacial de criaderos positivos y potenciales de Aedes aegypti / Spatial distribution of potential and positive Aedes aegypti breeding sites

Resumen Introducción. La distribución espacial de Aedes aegypti es heterogénea, y la interacción entre criaderos positivos y potenciales en el intradomicilio y el extradomicilio es uno de los aspectos más difíciles de caracterizar en los programas de control vectorial. Objetivo. Describir la relación espacial entre los criaderos potenciales y positivos de A. aegypti en el intradomicilio y en el extradomicilio en un sector de Cali, Colombia. Materiales y métodos. Se hizo una encuesta entomológica con el objetivo de recolectar datos de los criaderos en el intradomicilio y el extradomicilio. El análisis exploratorio de los datos espaciales incluyó la localización, la tendencia espacial, la autocorrelación espacial local, la continuidad espacial y la correlación espacial de los criaderos positivos y potenciales según el hábitat. Resultados. Se determinaron las tendencias espaciales. Mediante el análisis de autocorrelación espacial local se ubicaron los conglomerados de criaderos potenciales y positivos del extradomicilio. Se encontró una correlación positiva entre los criaderos potenciales y los positivos y una correlación negativa entre el intradomicilio y el extradomicilio. Conclusiones. La relación espacial entre criaderos positivos y potenciales de A. aegypti en el intradomicilio y el extradomicilio es dinámica y muy sensible a las características de cada territorio, por lo que establecer su distribución en el espacio contribuye a la priorización de recursos y acciones en los programas de control vectorial.

Abstract Introduction: The spatial distribution of Aedes aegypti is heterogeneous, and the interaction between positive and potential breeding sites located both inside and outside homes is one of the most difficult aspects to characterize in vector control programs. Objective: To describe the spatial relationship between potential and positive breeding sites of A. aegypti inside and outside homes in Cali, Colombia. Materials and methods: We conducted an entomological survey to collect data from both indoor and outdoor breeding sites. The exploratory analysis of spatial data included location, spatial trends, local spatial autocorrelation, spatial continuity and spatial correlation of positive and potential breeding sites according to habitat. Results: Spatial trends were identified, as well as clusters of potential and positive breeding sites outdoors using local spatial autocorrelation analysis. A positive correlation was found between potential and positive breeding sites, and a negative correlation existed between indoor and outdoor sites. Conclusions: The spatial relationship between positive and potential A. aegypti breeding sites both indoors and outdoors is dynamic and highly sensitive to the characteristics of each territory. Knowing how positive and potential breeding sites are distributed contributes to the prioritization of resources and actions in vector control programs.

Eggs viability of Aedes aegypti Linnaeus (Diptera, Culicidae) under different environmental and storage conditions in Manaus, Amazonas, Brazil / Viabilidade de ovos de Aedes aegypti (Diptera, Culicidae) em diferentes condições de armazenamento em Manaus, Amazônia, Brasil

Abstract The viability of Aedes aegypti eggs was assessed in the Amazon region. The eggs were maintained under different conditions: indoors (insectarium) and outdoors (natural environment), as well as in different storage types (plastic cup, paper envelope, plastic bag) for different days. Egg viability was measured as the mean of hatchings observed from egg-bearing sheets of filter paper immersed in water, using three sheets randomly selected from each storage type and at both sites. There were significant differences in the viability of Ae. aegypti eggs with respect to the location (F=30.40; DF=1; P<0.0001), storage type (F=17.66; DF=2; P<0.0001), and time of storage (F=49.56; DF=9; P<0.0001). The interaction between storage site versus storage type was also significant (F=15.96; DF=2; P<0.0001). A higher hatching mean was observed for the eggs kept in the insectarium than for those outdoors (32.38 versus 7.46). Hatching rates of egg batches stored for 12 to 61 days ranged between 84 and 90%. A reduction was observed between 89 and 118 days, with values of 63 and 48%, respectively. With respect to type of storage, mean egg hatching was higher for the eggs in plastic cups (44.46). It was concluded that the viability of the eggs of Ae. aegypti in the Amazon region remains high up to 4 months, after which it declines drastically, although in this study hatching occurred for up to 8 months in very low percentages.

Resumo Testou-se a viabilidade dos ovos de Ae. aegypti na região amazônica armazenados em copos plásticos, envelopes de papel e sacos plásticos que foram mantidos em área interna e em área externa por dias diferentes. Verificaram-se diferenças significativas na viabilidade dos ovos considerando-se a localização (F=30,40; GL=1; P<0,0001), os tipos de armazenamento (F=17,66; GL=2; P<0,0001) e os tempos (F=49,56; GL=9; P<0,0001) e na interação localização versus tipo de armazenamento (F=15,96; GL=2; P<0,0001). A média de eclosão dos ovos armazenados no insetário foi maior: 32,38, do que a dos lotes armazenados na área externa: 7,46. As taxas de eclosão dos ovos armazenados de 12 a 61 dias ficaram entre 90% e 84% com reduções a partir de 89 e 118 dias, quando atingiu de 63% e 48%, respectivamente. Em relação aos tipos de armazenamento a média de ovos dos copos foi significativa (44,46). Conclui-se que a viabilidade dos ovos de Ae. aegypti na região amazônica é mantida em níveis elevados até 4 meses, e a partir daí ocorrem reduções drásticas, com eclosões até 8 meses em percentuais muito baixos.

São Paulo urban heat islands have a higher incidence of dengue than other urban areas

Urban heat islands are characterized by high land surface temperature, low humidity, and poor vegetation, and considered to favor the transmission of the mosquito-borne dengue fever that is transmitted by the Aedes aegypti mosquito. We analyzed the recorded dengue incidence in Sao Paulo city, Brazil, in 2010-2011, in terms of multiple environmental and socioeconomic variables. Geographical information systems, thermal remote sensing images, and census data were used to classify city areas according to land surface temper- ature, vegetation cover, population density, socioeconomic status, and housing standards. Of the 7415 dengue cases, a majority (93.1%) mapped to areas with land surface temperature >28 ◦ C. The dengue incidence rate (cases per 100,000 inhabitants) was low (3.2 cases) in high vegetation cover areas, but high (72.3 cases) in low vegetation cover areas where the land surface temperature was 29 ± 2 ◦ C. Interestingly, a multiple cluster analysis phenogram showed more dengue cases clustered in areas of land surface temperature >32 ◦ C, than in areas characterized as low socioeconomic zones, high population density areas, or slum-like areas. In laboratory experiments, A. aegypti mosquito larval development, blood feeding, and oviposition associated positively with temperatures of 28-32 ◦ C, indicating these temperatures to be favorable for dengue transmission. Thus, among all the variables studied, dengue incidence was most affected by the temperature.

Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama

Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed.