Factores de riesgo de infestación pupal con Aedes aegypti dependientes de la comunidad en un municipio de Ciudad de La Habana / Risk factors of pupal infestation with community-based Aedes aegypti in a municipality of Havana City

Se identificaron los factores de riesgo de infestación pupal de Aedes aegypti dependientes de la comunidad en 4 áreas de salud del municipio Playa, ubicado en la zona urbana de Ciudad de La Habana. Los depósitos de mayor positividad al vector del dengue correspondieron a los depósitos artificiales y tanques bajos. Se comprobó que 99,03 por ciento de los locales visitados contenían al menos un depósito con agua, y que las 4 áreas presentaron un comportamiento muy similar en la proporción de tanques por locales, porque en todas la frecuencia de agua fue en días alternos, por lo que la diferencia en la positividad se debió a otros factores no ligados al abasto de este líquido. De los depósitos positivos, 87,17 por ciento se ubicó en los patios de los locales y 91,3 por ciento de los tanques bajos positivos se halló sin tapas o parcialmente tapados. Se encontró que en la positividad de los depósitos al vector del dengue solo 8,7 por ciento no depende de la población, por lo que de existir una participación activa de la comunidad dirigida al tapado de los tanques, el recambio de agua en los bebederos de animales y un buen saneamiento de los patios, se hubiera reducido drßsticamente la infestación pupal por Ae. aegypti en las áreas estudiadas.

The risk factors of pupal infestation with community-based Aedes aegypti were identified in four areas of Playa municipality, located in the urban zone of Havana City. The deposits with the highest positivity to the vector were the artificial ones and the low tanks. It was confirmed that 99.03 percent of the sites visited contained at least one deposit with water, and that 4 areas presented a very similar behaviour in ratio of tanks per site, since in all of them the water was supplied every other day. That is why the difference in the positivity was not due to factors related to the water supply. Of the positive deposits, 87.17 percent were located in backyards, and 91.3 percent of the positive low tanks had no cover, or were partially covered. It was found that in the positivity of the deposits to the dengue vector, only 8.7 percent were non-community dependent. If there had had an active participation of the community directed to cover the tanks, to change the water in the water troughs, and to clean the backyards, the pupal infestation due to Aedes aegypti would have drastically increased in the studied areas

Factores de riesgo de infestación pupal con Aedes aegypti dependientes de la comunidad en un municipio de Ciudad de La Habana / Risk factors of pupal infestation with community-based Aedes aegypti in a municipality of Havana City

Se identificaron los factores de riesgo de infestación pupal de Aedes aegypti dependientes de la comunidad en 4 áreas de salud del municipio Playa, ubicado en la zona urbana de Ciudad de La Habana. Los depósitos de mayor positividad al vector del dengue correspondieron a los depósitos artificiales y tanques bajos. Se comprobó que 99,03 por ciento de los locales visitados contenían al menos un depósito con agua, y que las 4 áreas presentaron un comportamiento muy similar en la proporción de tanques por locales, porque en todas la frecuencia de agua fue en días alternos, por lo que la diferencia en la positividad se debió a otros factores no ligados al abasto de este líquido. De los depósitos positivos, 87,17 por ciento se ubicó en los patios de los locales y 91,3 por ciento de los tanques bajos positivos se halló sin tapas o parcialmente tapados. Se encontró que en la positividad de los depósitos al vector del dengue solo 8,7 por ciento no depende de la población, por lo que de existir una participación activa de la comunidad dirigida al tapado de los tanques, el recambio de agua en los bebederos de animales y un buen saneamiento de los patios, se hubiera reducido drásticamente la infestación pupal por Ae. aegypti en las áreas estudiadas(AU)

The risk factors of pupal infestation with community-based Aedes aegypti were identified in four areas of Playa municipality, located in the urban zone of Havana City. The deposits with the highest positivity to the vector were the artificial ones and the low tanks. It was confirmed that 99.03 percent of the sites visited contained at least one deposit with water, and that 4 areas presented a very similar behaviour in ratio of tanks per site, since in all of them the water was supplied every other day. That is why the difference in the positivity was not due to factors related to the water supply. Of the positive deposits, 87.17 percent were located in backyards, and 91.3 percent of the positive low tanks had no cover, or were partially covered. It was found that in the positivity of the deposits to the dengue vector, only 8.7 percent were non-community dependent. If there had had an active participation of the community directed to cover the tanks, to change the water in the water troughs, and to clean the backyards, the pupal infestation due to Aedes aegypti would have drastically increased in the studied areas(AU)

[Risk factors of pupal infestation with community-based Aedes aegypti in a municipality of Havana City]. / Factores de riesgo de infestación pupal con Aedes aegypti dependientes de la comunidad en un municipio de Ciudad de La Habana.

The risk factors of pupal infestation with community-based Aedes aegypti were identified in four areas of Playa municipality, located in the urban zone of Havana City The deposits with the highest positivity to the vector were the artificial ones and the low tanks. It was confirmed that 99.03% of the sites visited contained at least one deposit with water, and that 4 areas presented a very similar behaviour in ratio of tanks per site, since in all of them the water was supplied every other day. That is why the difference in the positivity was not due to factors related to the water supply. Of the positive deposits, 87.17% were located in backyards, and 91.3% of the positive low tanks had no cover, or were partially covered. It was found that in the positivity of the deposits to the dengue vector, only 8.7% were non-community dependent. If there had had an active participation of the community directed to cover the tanks, to change the water in the water troughs, and to clean the backyards, the pupal infestation due to Aedes aegypti would have drastically increased in the studied areas.

[Ecological factors linked to the presence of Aedes aegypti larvae in highly infested areas of Playa, a municipality belonging to Ciudad de La Habana, Cuba]. / Factores ecológicos asociados con la presencia de larvas de Aedes aegypti en zonas de alta infestación del municipio Playa, Ciudad de La Habana, Cuba.

OBJECTIVES: To identify local ecological factors that might have had an impact on the higher infestation rates by the vector mosquito Aedes aegypti seen in four urban health districts of Ciudad de La Habana, Cuba, and to determine the type of containers with the highest number of larvae. METHODS: This is a descriptive study that was carried out in four health areas (Docente, 28 de Enero, 26 de Julio, and 1. degrees de Enero) within Playa, a municipality belonging to Ciudad de La Habana, Cuba. These areas were chosen because of the persistent presence of the dengue vector throughout 2003. All buildings on the selected blocks were inspected between April 2004 and March 2005, and note was taken of existing water deposits (type, number, and location) and of surrounding ecological factors (existence of a patio and shade, the way tanks were covered, the presence of organic matter inside them, and the overall cleanliness of the dwelling). Using filtration, the mosquito larvae and pupae in each deposit were counted. Pupae were typified as to their taxonomic species under a stereoscopic microscope. RESULTS: The types of deposits where larvae and pupae of A. aegypti were most often found in all areas were low tanks and small artificial containers. In three of the study areas the greatest numbers of pupae were found in low tanks (88.6%, 100%, and 56.6%), 90.9% of which were uncovered or only partially covered. On the other hand, in the fourth study area small artificial deposits were the most commonly infested (85.7%). A correlation was noted between the number of deposits in infested houses and the presence of a patio (chi(2) = 29.59; P = 0.0001), partial shade (chi(2) = 4.108; P = 0.0001), shrubbery (chi(2) = 43.59; P = 0.0001) and trees (chi(2) = 101.459; P = 0.0001), as well as poor hygiene (chi(2) = 53.76; P = 0.0001). CONCLUSIONS: Artificial deposits, especially low tanks and small containers, are the most frequent breeding sites for A. aegypti and are therefore risk factors for infestation with this vector species. Uncovered tanks containing organic matter and located in the shade on the outside of homes were found to present the highest risk in this respect.

Factores ecológicos asociados con la presencia de larvas de Aedes aegypti en zonas de alta infestación del municipio Playa, Ciudad de La Habana, Cuba / Ecological factors linked to the presence of Aedes aegypti larvae in highly infested areas of Playa, a municipality belonging to Ciudad de La Habana, Cuba

OBJETIVOS: Identificar los factores ecológicos locales que pudieron incidir en la mayor infestación vectorial con Aedes aegypti observada en cuatro áreas de salud urbanas de Ciudad de La Habana, Cuba, así como los tipos de depósitos con mayor número de larvas. MÉTODOS: Estudio descriptivo en cuatro áreas de salud (Docente, 28 de Enero, 26 de Julio y 1.° de Enero) del municipio Playa, Ciudad de La Habana, Cuba, seleccionadas por la presencia reiterada del vector del dengue en el año 2003. Entre abril de 2004 y marzo de 2005 se inspeccionaron todos los locales de las manzanas seleccionadas. Se caracterizaron los depósitos existentes con agua (tipo, cantidad y ubicación) y los factores ecológicos observados (existencia de patio y de sombra, forma en que estaban tapados los tanques, presencia de materia orgánica en ellos e higiene de la vivienda). Se contaron las larvas y pupas de mosquitos de cada depósito mediante filtración. La identificación taxonómica de las pupas se realizó con microscopio estereoscópico. RESULTADOS: Los depósitos en que se encontraron larvas y pupas de A. aegypti con mayor frecuencia en todas las áreas fueron los tanques bajos y los pequeños depósitos artificiales. En tres de las áreas estudiadas la mayor cantidad de pupas se encontró en los tanques bajos (88,6 por ciento, 100 por ciento y 56,6 por ciento), de los cuales 90,9 por ciento se encontraban destapados o tapados solo parcialmente, mientras que en el área restante los pequeños depósitos artificiales fueron los más frecuentes (85,7 por ciento). Se encontró correlación entre el número de depósitos infestados en las viviendas con la presencia de patio (ji2 = 29,59; P = 0,0001), de sombra parcial (ji2 = 4,108; P = 0,0001), de vegetación (ji2 = 43,59; P = 0,0001) y de árboles (ji2 = 101,459; P = 0,0001), así como con la mala higiene (c² = 53,76; P = 0,0001). CONCLUSION: Los depósitos artificiales, especialmente los tanques bajos y los recipientes pequeños, son las criaderos más frecuentes de A. aegypti, por lo que constituyen un factor de riesgo de infestación con ese vector. Los tanques destapados con materia orgánica y situados a la sombra y en el exterior fueron los más peligrosos en ese sentido.