Microclimate factors related to dengue virus burden clusters in two endemic towns of Mexico.

In dengue-endemic areas, transmission control is limited by the difficulty of achieving sufficient coverage and sustainability of interventions. To maximize the effectiveness of interventions, areas with higher transmission could be identified and prioritized. The aim was to identify burden clusters of Dengue virus (DENV) infection and evaluate their association with microclimatic factors in two endemic towns from southern Mexico. Information from a prospective population cohort study (2·5 years of follow-up) was used, microclimatic variables were calculated from satellite information, and a cross-sectional design was conducted to evaluate the relationship between the outcome and microclimatic variables in the five surveys. Spatial clustering was observed in specific geographic areas at different periods. Both, land surface temperature (aPR 0·945; IC95% 0·895-0·996) and soil humidity (aPR 3·018; IC95% 1·013-8·994), were independently associated with DENV burden clusters. These findings can help health authorities design focused dengue surveillance and control activities in dengue endemic areas.

Technical Efficiency of Mexico's Public Health System in the Delivery of Obstetric Care, during 2012-2018.

The objective of this study was to evaluate the technical efficiency of Mexico's public health system in the delivery of obstetric care from 2012 to 2018. A multi-stage quantitative study of the public health institutions responsible for 95% of the system's obstetric services was conducted using data envelopment analysis. The efficiency of state-level productive units (decision-making units, or DMUs) was calculated and juxtaposed with the DMUs' maximum (0.82) and minimum (0.22) scores. Using the outcomes of the initial stage, the average technical efficiency of each institution at the national level was estimated and compared. The results were also utilized to estimate and compare the average efficiency of each state-level health system based on economic characteristics (state GDP per capita). Outputs included prenatal visits and deliveries, while inputs comprised gynecologists, exam rooms, and delivery rooms. Institutional efficiency ranged from 0.16 to 0.82, with an average of 0.417. The Ministry of Health (0.82) and the Mexican Social Security Institute (0.747) exhibited the highest efficiency scores, while the remaining institutions (Institute for Social Security and Services for State Workers [ISSSTE]; Mexican Petroleum [PEMEX]; the Secretary of National Defense [SEDENA]; and the Navy [SEMAR]) scored below the health system average. Of the 153 DMUs, 20% surpassed the maximum (0.82) and 40.6% fell below the minimum (0.22). These findings indicate that 80% of DMUs have unused operational capacity that could be utilized to enhance technical efficiency. No relationship was found between efficiency and the GDP of Mexico's 32 politico-administrative divisions. The efficiency gap between institutions (0.66) shows that while some DMUs are saturated (exhibiting high efficiency scores), the majority have unused operational capacity. Leveraging this untapped capacity could address the needs of vulnerable populations facing restricted access due to health system fragmentation.

Web Geographic Information System: A Support Tool for the Study, Evaluation, and Monitoring of Foci of Malaria Transmission in Mexico.

Malaria is currently an endemic disease in Mexico. The country joined the WHO's E-25 initiative for the elimination of Plasmodium vivax to achieve elimination and certification within the established period. Having a Web-based information system was, therefore, deemed necessary to assist in the detection, investigation, and elimination of transmission in the foci, as well as for the timely treatment of malaria-positive cases. The "Information System for the Elimination of Malaria in Mexico" was designed, developed, and implemented with a geographic vision, which includes a Web tool to georeference homes and aquatic systems, a dashboard and an indicator evaluation card for monitoring activities, notification of probable cases, and vector control among other indicators. The implementation of the system was gradual in the seven states that are currently in the malaria elimination phase; subsequently, the system was implemented in non-transmission states. In 2020, the system implementation stage began; first, the basic data of more than 96,000 homes throughout the country were georeferenced, and then the primary data capture tools of 17 formats, 32 reports, and 2 geographic viewers were enabled for information queries. A total of 56 active foci have been identified in 406 localities as well as 71 residual foci in 320 localities. Recently, the Foci Manager was developed, which is a specific tool for the study, evaluation, and monitoring of active foci through a GIS, a dashboard, and a systematized evaluation certificate. Georeferencing tools decreased the cost of spatial data collection.

Neighborhood features and depression in Mexican older adults: A longitudinal analysis based on the study on global AGEing and adult health (SAGE), waves 1 and 2 (2009-2014).

A growing body of literature shows that neighborhood characteristics influence older adults' mental health. Therefore, the aim of this study was to examine the association between structural and social characteristics of the neighborhood, and depression in Mexican older adults. A longitudinal study was conducted based on waves 1 (2009-2010) and 2 (2014) of the Mexican sample from the Study on global AGEing and adult health (SAGE). A street-network buffer around each participant's household was used to define neighborhood, so that built environment and social characteristics were assessed within it. Depression was ascertained by using an algorithm based on the Composite International Diagnostic Interview. In the analysis, multilevel logistic regression models were constructed separately for each built and social environments measurement, adjusted for socioeconomic, demographic and health-related covariates, and stratified by area of residence (urban versus rural). The results showed that a length of space between 15-45 meters restricted to vehicles was significantly associated with a lower risk of depression in older adults from the urban area (OR: 0.44; IC 95% 0.23-0.83) and the protective association appeared to be larger with increasing space with this restriction, although it lacked significance. Contrarily, the built environment measures were not predictive of depression in the rural setting. On the other hand, none of the variables from the social environment had a significant association, although safety appeared to behave as a risk factor in the overall (OR: 1.48; CI 95% 0.96-2.30; p = 0.08) and rural (OR: 3.44; CI 95% 0.95-12.45; p = 0.06) samples, as it reached marginal significance. Research about neighborhood effects on older adults' mental health is an emergent field that has shown that depression might be treated not only from the individual-level, but also from the neighborhood-level. Additionally, further research is needed, especially in low- and middle-income countries, to help guide neighborhood policies.

Urban and semi-urban mosquitoes of Mexico City: A risk for endemic mosquito-borne disease transmission.

Since past century, vector-borne diseases have been a major public health concern in several states of Mexico. However, Mexico City continues to be free of endemic mosquito-borne viral diseases. The city is the most important politic and economic state of Mexico and one of the most important city of Latin America. Its subtropical highland climate and high elevation (2240 masl) had historically made the occurrence of Aedes species unlikely. However, the presence of other potential disease vectors (Culex spp, Culiseta spp), and the current intermittent introductions of Aedes aegypti, have revealed that control programs must adopt routine vector surveillance in the city. In this study, we provide an updated species list from a five-years of vector surveillance performed in Mexico City. A total of 18,553 mosquito larvae were collected. Twenty-two species from genus Culex, Aedes, Culiseta, Anopheles, Lutzia and Uranotaenia were observed. Nine new mosquito records for the city were found. Ae. albopictus was recorded for the first time in Mexico City. Interestingly, a new record, Ae. epactius was the most frequent species reported. Cx. pipiens quinquefasciatus exhibited the highest number of individuals collected. We detected six areas which harbor the highest mosquito species records in the city. Cemeteries included 68.9% of our collection sites. Temporarily ponds showed the highest species diversity. We detected an increasing presence of Ae. aegypti, which was detected for three consecutive years (2015-2017), predominantly in the warmer microclimates of the city. We found a possible correlation between increasing temperature and Ae. aegypti and Ae. albopictus expanding range. This study provides a starting point for developing strategies related to environmental management for mosquito control. The promotion of mosquito control practices through community participation, mass media and education programmes in schools should be introduced in the city.

Association of dengue fever with Aedes spp. abundance and climatological effects.

OBJECTIVE: To analyze the association of dengue fever incidence with Aedes mosquito's abundance, and the effect of climatological and geographical variables, in a region in Morelos State, Mexico. MATERIALS AND METHODS: Weekly data during the period 2010 to 2014 was used. Mosquito abundance was determined using ovitraps. Confirmed dengue cases were obtained from the Epidemiological Surveillance System. Climatic variables were obtained from weather monitoringstations. The correlation between climate variables and ovitraps data was estimated using a multivariate regression model. RESULTS: A correlation of mosquito abundance with dengue fever incidence, and a yearly pattern with seasonal variations were observed. The daily mean temperature, relative humidity and rainfall parameters were associated with mosquito egg abundance. Time lags of three and four weeks between egg counts and dengue fever incidence were observed. CONCLUSION: Time lags between egg counts and dengue incidence could be useful for prevention and control interventions.

Association of dengue fever with Aedes spp. abundance and climatological effects / Asociación de casos de dengue con variación en la abundancia de Aedes y clima

Abstract: Objective: To analyze the association of dengue fever incidence with Aedes mosquito's abundance, and the effect of climatological and geographical variables, in a region in Morelos State, Mexico. Materials and methods: Weekly data during the period 2010 to 2014 was used. Mosquito abundance was determined using ovitraps. Confirmed dengue cases were obtained from the Epidemiological Surveillance System. Climatic variables were obtained from weather monitoring stations. The correlation between climate variables and ovitraps data was estimated using a multivariate regression model. Results: A correlation of mosquito abundance with dengue fever incidence, and a yearly pattern with seasonal variations were observed. The daily mean temperature, relative humidity and rainfall parameters were associated with mosquito egg abundance. Time lags of three and four weeks between egg counts and dengue fever incidence were observed. Conclusion: Time lags between egg counts and dengue incidence could be useful for prevention and control interventions.

Resumen: Objetivo: Analizar la asociación de la incidencia de dengue con la abundancia de mosquitos Aedes y el efecto de variables climatológicas, en una región de Morelos, México. Material y métodos: Se utilizaron datos semanales durante el 2010-2014. La abundancia de mosquitos se determinó utilizando ovitraps. Los casos de dengue se obtuvieron del Sistema de Vigilancia Epidemiológica. Las variables climáticas se obtuvieron de estaciones climatológicas locales. La correlación entre las variables climáticas y los datos de ovitrampas se estimó mediante un modelo de regresión multivariado. Resultados: Se observó una correlación de la abundancia de mosquitos con la incidencia de dengue. La temperatura media diaria, humedad relativa y la precipitación pluvial se asociaron con abundancia de mosquitos. Se observó un desfase temporal de tres a cuatro semanas entre cuentas de huevos y la incidencia de dengue. Conclusión: Los intervalos entre las cuentas de huevos y la incidencia de dengue podrían ser utilizados para planear intervenciones de prevención y control.

Analysis of spatial mobility in subjects from a Dengue endemic urban locality in Morelos State, Mexico.

INTRODUCTION: Mathematical models and field data suggest that human mobility is an important driver for Dengue virus transmission. Nonetheless little is known on this matter due the lack of instruments for precise mobility quantification and study design difficulties. MATERIALS AND METHODS: We carried out a cohort-nested, case-control study with 126 individuals (42 cases, 42 intradomestic controls and 42 population controls) with the goal of describing human mobility patterns of recently Dengue virus-infected subjects, and comparing them with those of non-infected subjects living in an urban endemic locality. Mobility was quantified using a GPS-data logger registering waypoints at 60-second intervals for a minimum of 15 natural days. RESULTS: Although absolute displacement was highly biased towards the intradomestic and peridomestic areas, occasional displacements exceeding a 100-Km radius from the center of the studied locality were recorded for all three study groups and individual displacements were recorded traveling across six states from central Mexico. Additionally, cases had a larger number of visits out of the municipality´s administrative limits when compared to intradomestic controls (cases: 10.4 versus intradomestic controls: 2.9, p = 0.0282). We were able to identify extradomestic places within and out of the locality that were independently visited by apparently non-related infected subjects, consistent with houses, working and leisure places. CONCLUSIONS: Results of this study show that human mobility in a small urban setting exceeded that considered by local health authority's administrative limits, and was different between recently infected and non-infected subjects living in the same household. These observations provide important insights about the role that human mobility may have in Dengue virus transmission and persistence across endemic geographic areas that need to be taken into account when planning preventive and control measures. Finally, these results are a valuable reference when setting the parameters for future mathematical modeling studies.

A Multisite Study of Environmental Correlates of Active Commuting to School in Mexican Children.

BACKGROUND: Mexican children often use active commuting to school (ACS). In order to maintain high levels of ACS it is important to understand correlates of ACS in this population. However, most evidence comes from high-income countries (HICs). We examined multilevel correlates of ACS in children attending public schools in 3 Mexican cities. METHODS: Information on 1191 children (grades 3 to 5) attending 26 schools was retrieved from questionnaires, neighborhood audits, and geographic information systems data. Multilevel logistic modeling was used to explore individual and environmental correlates of ACS at 400-m and 800-m buffers surrounding schools. RESULTS: Individual positive correlates for ACS included age (6-8 years vs 9-11 years, odds ratio [OR] = 1.5; 6-8 years vs ≥12 years: OR = 2.1) and ≥ 6 adults at home (OR = 2.0). At the 400-m buffer, more ACS was associated with lower walkability (OR = 0.87), presence of posted speed limits (< 6% vs > 12%: OR = 0.36) and crossing aids (< 6% vs 6-20%: OR = 0.25; > 20%: OR = 0.26), as well as higher sidewalk availability (< 70% vs > 90%: OR = 4.5). Similar relationships with speed limits and crossing aids were observed at the 800m buffer. CONCLUSIONS: Findings contrast with those reported in HICs, underscoring the importance of considering the local context when developing strategies to promote ACS. Future studies are needed to replicate these relationships and investigate the longitudinal impact of improving active transportation infrastructure and policies.

Peridomestic Infection as a Determining Factor of Dengue Transmission.

BACKGROUND: The study of endemic dengue transmission is essential for proposing alternatives to impact its burden. The traditional paradigm establishes that transmission starts around cases, but there are few studies that determine the risk. METHODS: To assess the association between the peridomestic dengue infection and the exposure to a dengue index case (IC), a cohort was carried out in two Mexican endemic communities. People cohabitating with IC or living within a 50-meter radius (exposed cohort) and subjects of areas with no ICs in a 200-meter radius (unexposed cohort) were included. RESULTS: Exposure was associated with DENV infection in cohabitants (PRa 3.55; 95%CI 2.37-5.31) or neighbors (PRa 1.82; 95%CI 1.29-2.58). Age, location, toilets with no direct water discharge, families with children younger than 5 and the House Index, were associated with infection. Families with older than 13 were associated with a decreased frequency. After a month since the IC fever onset, the infection incidence was not influenced by exposure to an IC or vector density; it was influenced by the local seasonal behavior of dengue and the age. Additionally, we found asymptomatic infections accounted for 60% and a greater age was a protective factor for the presence of symptoms (RR 0.98; 95%CI 0.97-0.99). CONCLUSION: The evidence suggests that dengue endemic transmission in these locations is initially peridomestic, around an infected subject who may be asymptomatic due to demographic structure and endemicity, and it is influenced by other characteristics of the individual, the neighborhood and the location. Once the transmission chain has been established, dengue spreads in the community probably by the adults who, despite being the group with lower infection frequency, mostly suffer asymptomatic infections and have higher mobility. This scenario complicates the opportunity and the effectiveness of control programs and highlights the need to apply multiple measures for dengue control.

Nation-wide, web-based, geographic information system for the integrated surveillance and control of dengue fever in Mexico.

Dengue fever incidence and its geographical distribution are increasing throughout the world. Quality and timely information is essential for its prevention and control. A web based, geographically enabled, dengue integral surveillance system (Dengue-GIS) was developed for the nation-wide collection, integration, analysis and reporting of geo-referenced epidemiologic, entomologic, and control interventions data. Consensus in the design and practical operation of the system was a key factor for its acceptance. Working with information systems already implemented as a starting point facilitated its acceptance by officials and operative personnel. Dengue-GIS provides the geographical detail needed to plan, asses and evaluate the impact of control activities. The system is beginning to be adopted as a knowledge base by vector control programs. It is used to generate evidence on impact and cost-effectiveness of control activities, promoting the use of information for decision making at all levels of the vector control program. Dengue-GIS has also been used as a hypothesis generator for the academic community. This GIS-based model system for dengue surveillance and the experience gathered during its development and implementation could be useful in other dengue endemic countries and extended to other infectious or chronic diseases.

[Automated geospatial model for health services strategic planning]. / Modelo geoespacial automatizado para la regionalización operativa en planeación de redes de servicios de salud.

OBJECTIVE: To develop an automated model for the operational regionalization needed in the planning of the health service networks proposed by the new Mexican health care model (Modelo Integrador de Servicios de Salud MIDAS). MATERIAL AND METHODS: Using available data for México during 2005 and 2007, a geospatial model was developed to estimate potential catchment areas around health facilities based on access travel time. The results were compared with an operational regionalization (ERO) study manually carried out in Oaxaca with 2005 data. RESULTS: The ERO assigned 48% of villages to health care centers further away than those assigned by the geospatial model, and 23% of these health centers referred patients to more distant hospitals. CONCLUSIONS: The model calculated by this study generated a more efficient regionalization than the ERO model, minimizing travel time to access health services. This model has been adopted by the General Department of Health Planning and Development of the Mexican Ministry of Health for the implementation of the Health Sector Infrastructure Master Plan.

Modelo geoespacial automatizado para la regionalización operativa en planeación de redes de servicios de salud / Automated geospatial model for health services strategic planning

Objetivo. Desarrollar un modelo automatizado de regionalización operativa para la planeación de las redes de servicios de salud propuestas en el Modelo Integrador de Atención a la Salud (MIDAS). Material y métodos. Con información disponible para México en 2005 y 2007 se realizó un modelo geoespacial para estimar el área potencial de influencia alrededor de cada unidad de atención médica, con base en el menor tiempo de viaje. Los resultados se compararon con un Estudio de Regionalización Operativa (ERO) para Oaxaca llevado a cabo en 2005. Resultados. Comparado con el modelo geoespacial, el ERO asignó 48 por ciento de las localidades a centros de salud más lejanos y 23 por ciento de los centros de salud a hospitales más lejanos. Conclusiones. El modelo calculado en este estudio generó una regionalización más eficiente que el ERO de Oaxaca, minimizando el tiempo de viaje para el acceso a los servicios de salud. Este modelo ha sido adoptado por la Dirección General de Planeación y Desarrollo en Salud para la instrumentación del Plan Maestro Sectorial de Recursos para la Atención de la Salud.

Objective. To develop an automated model for the operational regionalization needed in the planning of the health service networks proposed by the new Mexican health care model (Modelo Integrador de Servicios de Salud MIDAS). Material and Methods. Using available data for México during 2005 and 2007, a geospatial model was developed to estimate potential catchment areas around health facilities based on access travel time. The results were compared with an operational regionalization (ERO) study manually carried out in Oaxaca with 2005 data. Results. The ERO assigned 48 percent of villages to health care centers further away than those assigned by the geospatial model, and 23 percent of these health centers referred patients to more distant hospitals. Conclusions. The model calculated by this study generated a more efficient regionalization than the ERO model, minimizing travel time to access health services. This model has been adopted by the General Department of Health Planning and Development of the Mexican Ministry of Health for the implementation of the Health Sector Infrastructure Master Plan.

[Monitoring strategy for control of tobacco in Mexico: advertising, promotion and sponsorship, packaging and labeling]. / Estrategia de vigilancia para el control del tabaco en México: publicidad, promoción y patrocinio, empaque y etiquetado.

OBJECTIVE: To describe strategies used in the publicity, marketing, and sale, of tobacco products in 12 cities in Mexico. MATERIAL AND METHODS: Tobacco products points of sale (POS) were identified within a 500 m radius of Global Youth Tobacco Survey (2005-2006) schools. We used observational surveys and an online Geographic Information System (GIS). RESULTS: In the 257 schools visited, we found, on average, 8.3 stores and 5 street vendors around each of them. Forty-four percent of the stores had interior tobacco publicity, 8.3% had tobacco products at children's eye level, 6.5% had some promotion, 33.6% had a no selling to minors sign, and 44.4% of stores and 58.8% of street vendors sold single cigarettes. CONCLUSIONS: Tobacco products are largely publicized and marketed around schools. There is no compliance of tobacco control legislation in regards to selling to minors and single cigarettes. It is necessary to implement a surveillance system to monitor strategies for tobacco control and the tobacco industry.

Estrategia de vigilancia para el control del tabaco en México: publicidad, promoción y patrocinio, empaque y etiquetado / Monitoring estrategy for control of tobacco in Mexico: advertising, promotion and sponsorship, packaging and labeling

Objetivo. Describir las estrategias de publicidad, mercadeo, y venta productos del tabaco en 12 ciudades de México. Material y métodos. Los puntos de venta de tabaco, a 500mts alrededor de escuelas participantes de la Encuesta de Tabaquismo en Jóvenes (2005-2006), fueron identificados usando formatos observacionales y un Sistema de Información Geográfica en línea. Resultados. En promedio se encontraron 8 establecimientos y 5 puestos de calle alrededor de las 257 escuelas visitadas. 44.4 por ciento de los establecimientos tenía publicidad en interior, 8.3 por ciento poseían productos a la altura de los ojos de los niños y 6.5 por ciento tenía alguna promoción. El 33.6 por ciento tenía letrero de prohibición de venta a menores, en tanto que 44.4 por ciento de los establecimientos y 58.8 por ciento puestos de calle vendían cigarros sueltos. Conclusiones. Los productos de tabaco son ampliamente publicitados y comercializados alrededor de las escuelas. Existe un alto incumplimiento de las leyes referentes a la venta a menores y por menores. Es urgente implementar un sistema que permita una vigilancia continua de las estrategias de la industria y para el control del tabaco.

Objective. To describe strategies used in the publicity, marketing, and sale, of tobacco products in 12 cities in Mexico. Material and Methods. Tobacco products points of sale (POS) were identified within a 500 m radius of Global Youth Tobacco Survey (2005-2006) schools. We used observational surveys and an online Geographic Information System (GIS). Results. In the 257 schools visited, we found, on average, 8.3 stores and 5 street vendors around each of them. Forty-four percent of the stores had interior tobacco publicity, 8.3 percent had tobacco products at children's eye level, 6.5 percent had some promotion, 33.6 percent had a no selling to minors sign, and 44.4 percent of stores and 58.8 percent of street vendors sold single cigarettes. Conclusions. Tobacco products are largely publicized and marketed around schools. There is no compliance of tobacco control legislations in regards to selling to minors and single cigarettes. It is necessary to implement a surveillance system to monitor strategies for tobacco control and the tobacco industry.

Use of Geographical Information Systems for billboards and points-of-sale surveillance in two Mexico cities

OBJECTIVE: To assess the degree of compliance with current legislation using Geographic Information Systems. MATERIAL AND METHODS: Schools and billboards advertising tobacco were geo-referenced and the distance to schools were measured. StudentsÆ access to purchasing tobacco products was observed. RESULTS: In Cuernavaca, billboards were found within 250 meter from schools and students had access to buying cigarettes. In Culiacan, students were less exposed to tobacco advertising. CONCLUSIONS: Geographic Information Systems were useful for studying compliance with the law and could also be useful for its continuous monitoring and for suggesting changes for diminishing tobacco advertising exposure. This exposure and the ease of access to purchasing cigarettes could explain the higher prevalence of active smokers among students in Cuernavaca. This suggests that current legislation is still not enough enforced for diminishing Mexican adolescentsÆ exposure to tobacco advertising and products.

OBJETIVO: Determinar el grado de cumplimiento de la legislación y su impacto mediante la utilización de Sistemas de Información Geográfica (GIS). MATERIAL Y MÉTODOS: Se georreferenciaron escuelas y espectaculares con propaganda de tabaco en Culiacán y Cuernavaca. Se midió la distancia a las escuelas. Se observó si los estudiantes tenían acceso a comprar productos de tabaco. RESULTADOS: En Cuernavaca se encontraron espectaculares a 250 m de escuelas. Los estudiantes tenían acceso a adquirir productos del tabaco. En Culiacán los estudiantes estuvieron menos expuestos a propaganda y productos del tabaco. CONCLUSIONES: Los GIS fueron útiles para estudiar la observancia de la legislación actual y podrían serlo para monitorear su cumplimiento, así como para sugerir modificaciones que disminuyan la exposición a la propaganda de tabaco. Esta exposición y la facilidad para adquirir cigarrillos podrían explicar la prevalencia de fumadores activos más elevada en los estudiantes de Cuernavaca. Esto sugiere que la legislación vigente no es suficiente para la disminución de la exposición de los jóvenes mexicanos a propaganda y productos del tabaco.