One of the most daunting challenges for Chagas disease surveillance and control in Mexico is the lack of community level data on vector distributions. Although many states now have assembled representative domestic triatomine collections, only two triatomine specimens had been collected and reported previously from the state of Guanajuato. Field personnel from the stateÕs Secretarṍa de Salud conducted health promotion activities in 43 of the 46 counties in the state and received donations of a total of 2,522 triatomine specimens between 1998 and 2002. All specimens were identiÞed, and live insects examined for Trypanosoma cruzi. In an effort to develop Þne-scale distributional data for Guanajuato, collection localities were georeferenced and ecological niches were modeled for each species by using evolutionary-computing approaches. Five species were collected: Triatoma mexicana (Herrich-Schaeffer), Triatoma longipennis (Usinger), Triatoma pallidipennis (Stål), Triatoma barberi (Usinger), and Triatoma dimidiata (Latreille) from 201 communities located at elevations of 870 Ð2,200 m. Based on collection success, T. mexicana had the broadest dispersion, although niche mapping indicates that T. barberi represents the greatest risk for transmission of Chagas disease in the state. T. dimidiata was represented in collections by a single adult collected from one village outside the predicted area for all species. For humans, an estimated 3,755,380 individuals are at risk for vector transmission in the state, with an incidence of 3,500 new cases per year; overall seroprevalences of 2.6% indicate that 97,640 individuals are infected with T. cruzi at present, including 29,300 chronic cases. . Nine of these species are considered as primary vector species (Ramsey et al. 2003), and most belong to two species complexes (phyllosoma and protracta) in the genus Triatoma (Lent and Wygodzinsky 1979). Multiple triatomine species are frequently found within a single region or state in Mexico. As a result, Ͼ71% of the Mexican population is at direct risk of acquiring T. cruzi infections from triatomines, and Ͼ96% of all T. cruzi transmission occurs via these vectors (Ramsey et al. 2003). KEY WORDSOne of the most signiÞcant challenges for Chagas disease surveillance and control in Mexico is the lack of Þne-scale (at the level of local communities) vector distribution data, as well as the almost complete ignorance of the diseaseÐtransmission characteristics and risk areas, both by the public health community and by at-risk populations. With improved malaria control in the country, in the last decade, "additional" operative vector control activities have focused primarily in urban environments owing to increases in classical and hemorrhagic dengue transmission. (To date, vector-borne disease control activities are budgeted only for malaria in the country.) Moreover, the recent decentralization of primary health care services to the state level has emphasized the need and the opportunity to review local and state health care prio...

One of the most daunting challenges for Chagas disease surveillance and control in Mexico is the lack of community level data on vector distributions. Although many states now have assembled representative domestic triatomine collections, only two triatomine specimens had been collected and reported previously from the state of Guanajuato. Field personnel from the stateÕs Secretarṍa de Salud conducted health promotion activities in 43 of the 46 counties in the state and received donations of a total of 2,522 triatomine specimens between 1998 and 2002. All specimens were identiÞed, and live insects examined for Trypanosoma cruzi. In an effort to develop Þne-scale distributional data for Guanajuato, collection localities were georeferenced and ecological niches were modeled for each species by using evolutionary-computing approaches. Five species were collected: Triatoma mexicana (Herrich-Schaeffer), Triatoma longipennis (Usinger), Triatoma pallidipennis (Stål), Triatoma barberi (Usinger), and Triatoma dimidiata (Latreille) from 201 communities located at elevations of 870 Ð2,200 m. Based on collection success, T. mexicana had the broadest dispersion, although niche mapping indicates that T. barberi represents the greatest risk for transmission of Chagas disease in the state. T. dimidiata was represented in collections by a single adult collected from one village outside the predicted area for all species. For humans, an estimated 3,755,380 individuals are at risk for vector transmission in the state, with an incidence of 3,500 new cases per year; overall seroprevalences of 2.6% indicate that 97,640 individuals are infected with T. cruzi at present, including 29,300 chronic cases. . Nine of these species are considered as primary vector species (Ramsey et al. 2003), and most belong to two species complexes (phyllosoma and protracta) in the genus Triatoma (Lent and Wygodzinsky 1979). Multiple triatomine species are frequently found within a single region or state in Mexico. As a result, Ͼ71% of the Mexican population is at direct risk of acquiring T. cruzi infections from triatomines, and Ͼ96% of all T. cruzi transmission occurs via these vectors (Ramsey et al. 2003). KEY WORDSOne of the most signiÞcant challenges for Chagas disease surveillance and control in Mexico is the lack of Þne-scale (at the level of local communities) vector distribution data, as well as the almost complete ignorance of the diseaseÐtransmission characteristics and risk areas, both by the public health community and by at-risk populations. With improved malaria control in the country, in the last decade, "additional" operative vector control activities have focused primarily in urban environments owing to increases in classical and hemorrhagic dengue transmission. (To date, vector-borne disease control activities are budgeted only for malaria in the country.) Moreover, the recent decentralization of primary health care services to the state level has emphasized the need and the opportunity to review local and state health care prio...

El presente estudio se realizó con la finalidad de llevar a cabo la verificación de la existencia y la ubicación de los vectores de la enfermedad de Chagas en los municipios del Estado de Guanajuato y a través de esto, delimitar áreas de distribución espacial de las especies dentro de este territorio, contribuyendo así, a establecer zonas de riesgo y al determinar la infección del Trypanosoma cruzi en los vectores, se conocerá el riesgo para la población humana. Esta investigación se realizó a través de la información del envío etiquetado de triatominos obtenidos por personal de campo de la Secretaría de Salud de Guanajuato y enviados para su clasificación taxonómica al Laboratorio Estatal de Salud Pública del mismo estado. Se recabó información de tres años (1998 - 2000) de los municipios donde se encuentran brigadas de trabajo y la ausencia reportada de vectores en algunos de ellos, probablemente se debe a la falta de búsqueda en los mismos. No se realizó el índice de infestación de vectores debido a que el método de búsqueda no tuvo la misma intensidad en todo el territorio, ni el método de muestreo lo permitió; sólo se estableció la localización de cada una de las especies según el área de donde fue colectada. Se encontraron 5 especies de triatominos: Triatoma mexicana, T. barberi, T. longipennis, T. pallidipennis y T. dimidiata, en 162 localidades de 25 municipios del estado; en alturas que fluctuaron desde los 870 metros sobre el nivel del mar (m.s.n.m.), hasta los 2200. El sitio donde se encontró a los vectores con más frecuencia fue para T. mexicana, intradomicilio; T. barberi, corral; T. longipennis, intradomicilio; T. pallidipennis, intradomicilio; ninfas, intradomicilio y T. dimidiata que se colectó en una única ocasión, no reportó sitio de colecta.

Las construcciones civiles edificadas sobre suelos inestables son vulnerables a los procesos naturales como la geodinámica interna, externa y el cambio climático. El poblado de Tapacocha que está asentado sobre suelo deslizado es sensible a los procesos naturales. El terremoto de mayo de 1970 ocasionó fracturamiento de la planicie, destrucción de sus construcciones; las intensas lluvias de los años 1942 y 1997 ocasionaron huaycos que destruyeron algunas de sus edificaciones y terrenos de cultivo. La geodinámica interna modeló el basamento con un intenso plegamiento y fracturamiento de las rocas sedimentarias; la geodinámica externa por geoformas modeladas por los movimientos rotacionales, deslizamientos, erosión diferencial. En la actualidad el efecto del cambio climático se manifiestan por las inusuales torrenciales lluvias que erosionan periódicamente y ponen en peligro las edificaciones civiles y la agricultura. Con el presente estudio se propone alertar a las autoridades y sus pobladores para prevenir y mitigar los efectos naturales destructivos. Palabras clave.- poblado de Tapacocha, geodinámica externa, huaycos. ABSTRACT Buildings standing on unstable soils are vulnerable to natural processes such as internal and external geodynamics and climate change. The village of Tapacocha, which is settled on slid floor, would be sensitive to those natural processes. The May 1970 earthquake caused ground fracture and building destruction; heavy rains in 1942 and 1997 caused mudslides that destroyed buildings and agriculture land. The internal geodynamics gave its shape to the base rocks through intense folding and fracturing of the sedimentary rocks; the external geodynamics created shapes through rotational movements, landslides and differential erosion. Presently, climate change is causing unusual torrential rains that periodically erode and threaten buildings and agriculture. The goal of this study is to advise the authorities and the population on ways to prevent and mitigate the destructive effects of these natural events. Keywords.- village of Tapacocha, external geodynamics, mudslides.