Acceso en línea sin restricciones

El objetivo central de esta investigación fue el de relacionar actividades, condiciones de vida y trabajo de los hombres, con la actividad antropófila de vectores de enfermedades. En este caso particular estudiamos sitios de actividad de campesinos de la zona cafetalera del Soconusco, Chiapas y densidad de simúlidos transmisores, especialmente Simulium ocraceum. Se seleccionaron sitios representativos de área habitacional, cafetal, maizales y selva poco alterada, en cuatro comunidades del Soconusco donde actualmente se considera que S. ochraceum, S. metallicum y S. callidum, transmiten la oncocercosis para realizar capturas diarias durante siete días de noviembre de 1982, enero, marzo y mayo de 1983. El análisis estadístico de los resultados, basados únicamente en S. ochraceum, mostró que, como se esperaba, en los centros de población existen mayores densidades de esa especie, teniendo casi siempre una alta significación estadística al compararla con los otros espacios de actividad humana. De manera consistente en el espacio que denominamos maíz-frijol, encontramos mayores densidades de S. ochraceum que en los espacios de café. Se discuten los resultados sobre S. ochraceum, tratando de explicar cómo la concentración humana en centros de población y en sitios como maíz-frijol, aunada a los estímulos y condiciones en que se da la búsqueda de alimento de los simúlidos zoófilos o antropófilos, son un factor preponderante para la obtención de mayores densidades de picadura de esta especie. Finalmente se concluye y recomienda que para cualquier estudio sobre las condiciones en que se transmite una enfermedad por insectos vectores, se deben considerar los aspectos de comportamiento y actividad de los grupos humanos en relación con el comportamiento y hábitos de picadura de tales vectores. Español

The objective of the present investigation was to approach an aspect of entomological epidemiology which has been little studied by specialists in either field. This approach attempted to relate human activities, life styles and work sites to the anthropophilic activity of insect vectors of disease. In this particular study, we investigated the activity of peasants in the coffee region of Soconusco, Chiapas, in relation to the density of blackflies, especially Simulium ochraceum, the principal vector of Onchocerciasis in Mexico. The study sites selected represented areas with houses, coffee plantations, corn and/or beanfields, and tropical forest in 4 communities of the Soconusco region in which active transmision of Onchocerca volvulus occurs. In all sites, captures of blackflies considered to be vector species (S .ochraceum, S. metallicum and S. callidum) were made from 7 to 11 A.M. daily for 7 days during each of the following months: November, 1982; January, March and May, 1983. Captures were made using human bait and the couples serving as bait and collector alternated positions daily. A statistical analysis of the results was based only on captures for S. ochraceum, partly because it is the most important and almost exclusive vector of Onchocerciasis in the region, and partly due to the wide variation in results for the other two species. As expected, the greatest densities of S. ochraceum were obtained from areas with houses, densities which were highly significant statistically when compared to collections from the other 3 sites of human activity. In 3 of the 4 communities in which an activity site for corn or bean fields was included, the densities of S. ochraceum were consistently greater than those for the coffee plantations (although the difference was statistically significant in only 1 of the 3 communities). The results are discussed primarily with respect to S. ochraceum, and attempt to show that the most important factor involved in an increase in the number of hites, is the concentration of people in village and in work-related sites such as the corn and bean fields, together with the conditions and stimuli associated in host-seeking behavior of zoophilic or anthropophilic blackflies. Another important factor appears to be related to a condition of open spaces, where forest has been cleared for villages or fields. Finally, it is concluded and recommended, that for studies on the conditions influencing a disease transmitted by insect vectors, it is important to simultaneously consider the behavior and activities of the human population in relation to the behavior and biting habits of the vector species. Inglés