Knowledge, attitudes, and practices regarding vector-borne diseases in central Mexico.

BACKGROUND: While vector-borne diseases (VBDs) pose an important public health problem worldwide, there is a limited and conflicting knowledge about such illnesses in rural or urban settings. The present study aimed to explore the social representations (SRs) held by people in the state of Puebla, Mexico on insects and the diseases they transmit. Understood as the group of ideas held and shared by a group of human beings which enable them to understand and interpret the world, SRs constitute what could be called a collective science or knowledge of everyday life. METHODS: The present study was conducted in six municipalities in the state of Puebla, wherein an open-ended questionnaire was applied with three age ranges. A total of 360 questionnaires were applied with people dedicated to a variety of activities. The survey data was analyzed to identify the SR's structure (the central nucleus of the SR and its peripheral system) and the level of organization in order to explore the degree to which the ideas that constitute it are shared and based on consensus. To describe the structure of the SR, a network analysis was conducted and complemented by a correspondence analysis, which also enables the differences between social groups to be identified. RESULTS: Popular knowledge on insects and VBDs is often limited, even in communities in which more than one-vector insect is found. The elements that were most frequently mentioned in the data, as pertaining to the insect-disease relationship, were mosquitoes and dengue fever, with scorpions (which are arachnids and not insects) receiving the second-highest number of mentions, while other insects such as kissing bugs, flies, and cockroaches were also mentioned as transmitting VBDs. While television was the main information source on VBDs for the residents of these communities, biology books were also mentioned. Chemical control measures (insect repellents) were the most used prevention method, and traditional medicine was the remedy most commonly used to treat insect bites and transmitted diseases. Entomophobia was the main cause for the respondents' fear and rejection of insects. Beyond the deleterious effects of many insects, those surveyed also recognized a positive relationship with insects due to economic and nutritional benefits they provide. CONCLUSIONS: The present study provides relevant information on how insects and the diseases they transmit are perceived by rural and urban communities. Although the population is aware of dengue fever and the role of mosquitoes in transmitting it, information campaigns are required for other historically neglected VBDs, such as leishmaniasis, Chagas disease, and, even, rickettsiosis. As it is important to understand the impact that these illnesses have on communities further research is required to ensure that better information and guidance is provided on VBDs in order to develop a culture of illness prevention in not only the rural but also the metropolitan communities of the state of Puebla.

Host ecology moderates the specialization of Neotropical bat-fly interaction networks.

The transmission of diseases through parasites is a key mechanism in the regulation of plant and animal populations in ecosystems. Therefore, it is necessary to investigate the relative effect of the variables that can shape the specificity of host-parasite interactions. Previous studies have found that specialization of antagonistic interactions between fly ectoparasites and bats changes according to forest type, host richness, and roosting ecology of bats. In this study, we tested these hypotheses using data from 48 bat communities. In general, our results support previous findings that bat-fly interactions are specialized, resulting in lower niche overlap among bat flies species. In addition, we found that the specificity of bat-fly interactions is lower in tropical mountain forests and is positively related with the richness of bat host species of each study site. Finally, there was a higher bat flies niche overlap in smaller bat-fly interaction networks recorded in bat roosts in caves. We conclude that the roosting ecology of bats could be a key factor to understand the mechanisms related to the horizontal transmission of ectoparasitic flies among bats.

Data documenting the potential distribution of Aedes aegypti in the center of Veracruz, Mexico.

The data presented in this article are related to the research article entitled "Establishment of Aedes aegypti (L.) in mountainous regions in Mexico: Increasing number of population at risk of mosquito-borne disease and future climate conditions" (M. Equihua, S. Ibáñez-Bernal, G. Benítez, I. Estrada-Contreras, C.A. Sandoval-Ruiz, F.S. Mendoza-Palmero, 2016) [1]. This article provides presence records in shapefile format used to generate maps of potential distribution of Aedes aegypti with different climate change scenarios as well as each of the maps obtained in raster format. In addition, tables with values of potential distribution of the vector as well as the average values of probability of presence including data of the mosquito incidence along the altitudinal range.

The effects of seasonality on host-bat fly ecological networks in a temperate mountain cave.

Changes in the specialization of parasite-host interactions will be influenced by variations in host species composition. We evaluated this hypothesis by comparing the composition of bats and bat flies within a roost cave over one annual. Five bat and five bat fly species occupied the cave over the course of the study. Bat species composition was 40% different in the rainy season compared with the dry-cold and dry-warm seasons. Despite the incorporation of three new bat species into the cave during the rainy season, bat fly species composition was not affected by seasonality, since the bats that arrived in the rainy season only contributed one new bat fly species at a low prevalence. Bat-bat fly ecological networks were less specialized in the rainy season compared with the dry-cold and dry-warm seasons because of the increase of host overlap among bat fly species during this season. This study suggests that seasonality promote: (1) differences in host species composition, and (2) a reduction in the specialization of host-parasite ecological networks.

Establishment of Aedes aegypti (L.) in mountainous regions in Mexico: Increasing number of population at risk of mosquito-borne disease and future climate conditions.

The study was conducted in the central region of Veracruz Mexico, in the metropolitan area of Xalapa. It is a mountainous area where Aedes aegypti (L.) is not currently endemic. An entomological survey was done along an elevation gradient using the Ae. aegypti occurrences at different life cycle stages. Seven sites were sampled and a total of 24 mosquito species were recorded: 9 species were found in urban areas, 18 in non-urban areas with remnant vegetation, and 3 occurred in both environments. Ae. aegypti was found only in the urban areas, usually below 1200m a.s.l., but in this study was recorded for the first time at 1420m a.s.l. These occurrences, together with additional distribution data in the state of Veracruz were used to developed species distribution models using Maxlike software in R to identify the current projected suitable areas for the establishment of this vector and the human populations that might be affected by dengue transmission at higher elevations. Its emergence in previously unsuitable places appears to be driven by both habitat destruction and biodiversity loss associated with biotic homogenization. A border study using data from the edges of the vector's distribution might allow sensitive monitoring to detect any changes in this mosquito's distribution pattern, and any changes in the anthropic drivers or climate that could increase transmission risk.

The specificity of host-bat fly interaction networks across vegetation and seasonal variation.

Vegetation type and seasonality promote changes in the species composition and abundance of parasite hosts. However, it is poorly known how these variables affect host-parasite interaction networks. This information is important to understand the dynamics of parasite-host relationships according to biotic and abiotic changes. We compared the specialization of host-bat fly interaction networks, as well as bat fly and host species composition between upland dry forest and riparian forest and between dry and rainy seasons in a tropical dry forest in Jalisco, Mexico. Bat flies were surveyed by direct collection from bats. Our results showed that host-bat fly interaction networks were more specialized in upland dry forest compared to riparian forest. Bat fly species composition was different between the dry and rainy seasons, while host species composition was different between upland dry forest and riparian forest. The higher specialization in upland dry forest could be related to the differences in bat host species composition and their respective roosting habits. Variation in the composition of bat fly species between dry and rainy seasons coincides with the seasonal shifts in their species richness. Our study confirms the high specialization of host-bat fly interactions and shows the importance of biotic and abiotic factors to understand the dynamics of parasite-host interactions.

Household risk factors associated to infestation of Triatoma dimidiata, the Chagas disease vector in Central Region of Veracruz, Mexico.

OBJECTIVE: To evaluate risk factors facilitating the colonization of dwellings by Triatoma dimidiata in the central region of the state of Veracruz. MATERIALS AND METHODS: We applied socioeconomic questionnaires and entomologic surveys in three localities (Chavarrillo, Soyacuautla and Arroyo Agrio) in central Veracruz involving 115 households. RESULTS: We found that the main risk factors were the predominance of unplastered walls and particularly those made of light weight aggregate concrete blocks and wood. At Chavarrillo, houses usually have unplastered walls, whereas in Soyocuautla walls are commonly manufactured with wood. In Arroyo Agrio, the phenomenon was seasonal, and bugs were commonly found in the dry season, particularly in relatively new houses, less than 20 years old. CONCLUSIONS: These results help to improve the surveillance capacity for this vector and the control strategies to reduce the transmission of Chagas disease in the state of Veracruz and other sites where this species is present.

Household risk factors associated to infestation of Triatoma dimidiata, the Chagas disease vector in Central Region of Veracruz, Mexico / Factores de riesgo intradomicialiarios para la infestación de Triatoma dimidiata, transmisor de la enfermedad de Chagas, en la región central del estado de Veracruz, México

Objective. To evaluate risk factors facilitating the colonization of dwellings by Triatoma dimidiata in the central region of the state of Veracruz. Materials and methods. We applied socioeconomic questionnaires and entomologic surveys in three localities (Chavarrillo, Soyacuautla and Arroyo Agrio) in central Veracruz involving 115 households. Results. We found that the main risk factors were the predominance of unplastered walls and particularly those made of light weight aggregate concrete blocks and wood. At Chavarrillo, houses usually have unplastered walls, whereas in Soyocuautla walls are commonly manufactured with wood. In Arroyo Agrio, the phenomenon was seasonal, and bugs were commonly found in the dry season, particularly in relatively new houses, less than 20 years old. Conclusions. These results help to improve the surveillance capacity for this vector and the control strategies to reduce the transmission of Chagas disease in the state of Veracruz and other sites where this species is present.

Objetivo. Determinar los factores de riesgo que facilitan la colonización intradomiciliaria de Triatoma dimidiata en la región central del estado de Veracruz. Material y métodos. Se aplicaron encuestas socioeconómicas y entomológicas en ll5 casas en tres localidades (Chavarrillo, Soyacuautla y Arroyo Agrio). Resultados. El principal factor de riesgo para la colonización intradomicialiaria de T. dimidiata fue la presencia de paredes sin revocar, especialmente aquellas construidas con block y madera. En Chavarrillo el factor principal fueron las paredes sin revocar, en Soyacuautla las paredes de madera y en Arroyo Agrio las casas con menos de 20 años de haber sido construidas, junto con la temporada de secas. Conclusión. Los resultados encontrados pueden coadyuvar a mejorar los programas de vigilancia y control entomológico con el fin de reducir la transmisión de la enfermedad de Chagas vía vectorial en el estado de Veracruz y otros estados donde T. dimidiata puede estar presente.