OBJECTIVE: To study dengue vector breeding patterns under a variety of conditions in public and private spaces; to explore the ecological, biological and social (eco-bio-social) factors involved in vector breeding and viral transmission, and to define the main implications for vector control. METHODS: In each of six Asian cities or periurban areas, a team randomly selected urban clusters for conducting standardized household surveys, neighbourhood background surveys and entomological surveys. They collected information on vector breeding sites, people's knowledge, attitudes and practices surrounding dengue, and the characteristics of the study areas. All premises were inspected; larval indices were used to quantify vector breeding sites, and pupal counts were used to identify productive water container types and as a proxy measure for adult vector abundance. FINDINGS: The most productive vector breeding sites were outdoor water containers, particularly if uncovered, beneath shrubbery and unused for at least one week. Peridomestic and intradomestic areas were much more important for pupal production than commercial and public spaces other than schools and religious facilities. A complex but non-significant association was found between water supply and pupal counts, and lack of waste disposal services was associated with higher vector abundance in only one site. Greater knowledge about dengue and its transmission was associated with lower mosquito breeding and production. Vector control measures (mainly larviciding in one site) substantially reduced larval and pupal counts and "pushed" mosquito breeding to alternative containers. CONCLUSION: Vector breeding and the production of adult Aedes aegypti are influenced by a complex interplay of factors. Thus, to achieve effective vector management, a public health response beyond routine larviciding or focal spraying is essential.

OBJETIVO: Estudiar las características de la reproducción del vector del dengue en diversas condiciones en espacios públicos y privados; investigar los aspectos ecológicos, biológicos y sociales (ecobiosociales) que intervienen en la reproducción del vector y la transmisión del virus, y determinar las principales implicaciones para la lucha antivectorial. MÉTODOS: En cada una de las seis zonas urbanas o periurbanas de Asia estudiadas, un equipo seleccionó al azar conglomerados urbanos para realizar encuestas de hogares normalizadas, encuestas basales del vecindario y estudios entomológicos. Reunieron información sobre los criaderos de vectores, los conocimientos de la gente al respecto, las actitudes y prácticas relacionadas con el dengue, y las características de las zonas estudiadas. Se inspeccionaron todos los locales, y se usaron los índices larvarios para cuantificar los criaderos del vector, y el número de pupas para distinguir el tipo de contenedores de agua productivos y como indicador sustitutivo de la abundancia de vectores adultos. RESULTADOS: Los criaderos de vectores más productivos fueron los contenedores de agua situados al aire libre, sobre todo los que estaban sin cubrir o debajo de arbustos, y los que no habían sido utilizados por lo menos en una semana. Las áreas peridomésticas e intradomésticas contribuían a la producción de pupas mucho más que los espacios comerciales y públicos, exceptuando las escuelas y los centros religiosos. Se observó una relación compleja aunque no significativa entre el suministro de agua y el número de pupas, y la falta de servicios de evacuación de desechos se asoció a una mayor abundancia de vectores en un solo sitio. La posesión de mayores conocimientos sobre el dengue y su transmisión se asoció a una menor reproducción y producción de mosquitos. Las medidas de lucha antivectorial (principalmente la aplicación de larvicidas en un sitio) lograron reducir sustancialmente el número de larvas y pupas y «empujaron» los criaderos de mosquitos hacia otros contenedores. CONCLUSIÓN: La reproducción del vector y la producción de Aedes aegypti adulto dependen de una compleja interacción de factores. En consecuencia, para lograr controlar eficazmente los vectores, es fundamental articular una respuesta de salud pública que no se limite a la aplicación de larvicidas o el rociamiento focalizado.

OBJECTIF: Étudier les schémas de reproduction des vecteurs de la dengue dans diverses conditions et dans des espaces publics et privés, rechercher les facteurs écologiques, biologiques et sociaux impliqués dans la reproduction de ces vecteurs et la transmission virale et déterminer les principales implications pour la lutte antivectorielle. MÉTHODES: Dans six grandes villes ou zones périurbaines d'Asie, une équipe a sélectionné au hasard des groupes urbains pour mener des enquêtes auprès des ménages standardisées, des enquêtes de voisinage et des enquêtes entomologiques. Les équipes ont recueilli des informations sur les sites de reproduction des vecteurs, les connaissances des habitants, les attitudes et les pratiques à propos de la dengue et les caractéristiques des zones étudiées. Tous les lieux ont été inspectés ; les équipes ont utilisé les indices larvaires pour évaluer sur le plan quantitatif les sites de reproduction vectorielle et le décompte des pupes pour identifier les types d'objets renfermant de l'eau les plus productifs et pour servir de mesure indirecte de l'abondance des vecteurs adultes. RÉSULTATS: Les sites de reproduction les plus productifs étaient les objets renfermant de l'eau situés à l'extérieur, en particulier lorsqu'ils étaient dépourvus de couvercle, sous des broussailles et inutilisés pendant au moins une semaine. Les zones péridomestiques et intradomestiques jouaient un rôle beaucoup plus important dans la production de pupes que les espaces commerciaux et publics autres que les écoles et les édifices religieux. Une association complexe, mais non significative, a été relevée entre l'approvisionnement en eau et le nombre de pupes décomptées et on a constaté un lien entre le manque de services d'élimination des déchets et une plus grande abondance des vecteurs sur un site seulement. La présence de meilleures connaissances sur la dengue et sa transmission chez les habitants était également associée à une reproduction et à une production plus limitées des vecteurs. Les mesures de lutte antivectorielle (principalement l'application de larvicide sur le site) ont permis de réduire substantiellement les nin de larves et de pupes et a «déplacé» la reproduction des moustiques vers d'autres récipients. CONCLUSION: Un ensemble interactif complexe de facteurs influe sur la reproduction et la production de moustiques Aedes aegypti adultes. Ainsi, pour gérer efficacement les populations vectorielles, une réponse de santé publique globale, allant au-delà des traitements larvicides de routine ou de la pulvérisation focale, est indispensable.

Apesar do crescimento de esforços no controle, desde 1986, a dengue, em Fortaleza, Nordeste do Brasil, continua endêmica com esporádicos surtos epidêmicos. Diversos fatores influenciam a ecologia do vetor, como as políticas sociais, a migração, a urbanização, o abastecimento urbano de água, a coleta de resíduos sólidos, as condições das casas, assim como as interpretações e práticas da comunidade. Este estudo descritivo utiliza uma abordagem multidisciplinar conjugando a antropologia e a entomologia. Foi adotado um desenho de estudo de caso múltiplo em seis quarteirões da cidade. O abastecimento de água é irregular seja nas casas pobres, seja naquelas privilegiadas. Apesar disso, existem diferenças entre os quarteirões em áreas pobres e aqueles mais privilegiados. Nos quarteirões mais privilegiados, existem casas que não têm ligação com o sistema de abastecimento público mas têm sistemas com poço e bomba, por isso a irregularidade não os afeta. Nos domicílios mais pobres, onde o abastecimento de água é irregular, a utilização de reservatórios como caixas d'água, cisternas, tambores, potes, cria as condições ambientais para um maior número de criadouros potenciais que poderiam incrementar a sobrevivência do Aedes aegypti.

Despite increased vector control efforts, dengue fever remains endemic in Fortaleza, Northeast Brazil, where sporadic epidemic outbreaks have occurred since 1986. Multiple factors affect vector ecology such as social policy, migration, urbanization, city water supply, garbage disposal and housing conditions, as well as community level understanding of the disease and related practices. This descriptive study used a multi-disciplinary approach that bridged anthropology and entomology. A multiple case study design was adopted to include research in six study areas, defined as blocks. The water supply is irregular in households from both under-privileged and privileged areas, however, clear differences exist. In the more privileged blocks, several homes are not connected to the public water system, but have a well and pump system and therefore irregularity of supply does not affect them. In households from under-privileged blocks, where the water supply is irregular, the frequent use of water containers such as water tanks, cisterns, barrels and pots, creates environmental conditions with a greater number of breeding areas. In under-privileged homes, there are more possible breeding areas and environmental conditions that may improve the chances of Aedes aegypti survival.

Apesar do crescimento de esforços no controle, desde 1986, a dengue, em Fortaleza, Nordeste do Brasil, continua endêmica com esporádicos surtos epidêmicos. Diversos fatores influenciam a ecologia do vetor, como as políticas sociais, a migração, a urbanização, o abastecimento urbano de água, a coleta de resíduos sólidos, as condições das casas, assim como as interpretações e práticas da comunidade. Este estudo descritivo utiliza uma abordagem multidisciplinar conjugando a antropologia e a entomologia. Foi adotado um desenho de estudo de caso múltiplo em seis quarteirões da cidade. O abastecimento de água é irregular seja nas casas pobres, seja naquelas privilegiadas. Apesar disso, existem diferenças entre os quarteirões em áreas pobres e aqueles mais privilegiados. Nos quarteirões mais privilegiados, existem casas que não têm ligação com o sistema de abastecimento público mas têm sistemas com poço e bomba, por isso a irregularidade não os afeta. Nos domicílios mais pobres, onde o abastecimento de água é irregular, a utilização de reservatórios como caixas d'água, cisternas, tambores, potes, cria as condições ambientais para um maior número de criadouros potenciais que poderiam incrementar a sobrevivência do Aedes aegypti.

Despite increased vector control efforts, dengue fever remains endemic in Fortaleza, Northeast Brazil, where sporadic epidemic outbreaks have occurred since 1986. Multiple factors affect vector ecology such as social policy, migration, urbanization, city water supply, garbage disposal and housing conditions, as well as community level understanding of the disease and related practices. This descriptive study used a multi-disciplinary approach that bridged anthropology and entomology. A multiple case study design was adopted to include research in six study areas, defined as blocks. The water supply is irregular in households from both under-privileged and privileged areas, however, clear differences exist. In the more privileged blocks, several homes are not connected to the public water system, but have a well and pump system and therefore irregularity of supply does not affect them. In households from under-privileged blocks, where the water supply is irregular, the frequent use of water containers such as water tanks, cisterns, barrels and pots, creates environmental conditions with a greater number of breeding areas. In under-privileged homes, there are more possible breeding areas and environmental conditions that may improve the chances of Aedes aegypti survival.