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Abstract Background Using harmonized aggregated data on health and socioeconomic environments in Latin American cities (from the Salud Urbana en América Latina (SALURBAL) study), we assessed the association of city‐level contextual factors with the prevalence of the double burden of malnutrition (DBM) in urban settings. Methods This ecological study used aggregated survey data from 115 Latin American cities within five countries (Colombia, El Salvador, Guatemala, Mexico and Peru) collected between 2008 and 2016. DBM was defined as the coexistence of stunting in children under 5 years and overweight/obesity among adult women at the city‐level. We ran ordinal logistic regression models to examine macrolevel contextual factors that might explain the city‐level DBM. Independent variables were city‐level socioeconomic development index, women educational attainment and women labor force. Results Out of 115 Latin American cities, 19 cities from five countries were experiencing a moderate to high burden of stunting and simultaneously a very high burden of overweight/obesity in adult women. All cities had overweight/obesity prevalence above 40%. A poor social environment, higher levels of women education and greater women labor force at the city level were associated with greater levels of DBM. Conclusion Some Latin American cities are still facing moderate and high DBM, while all cities are experiencing an alarming high burden of overweight/obesity. Social macro‐level factors such as poor social environment, high women education and high women labor force were associated with the coexistence of stunting in children and overweight/obesity in adult women.

Abstract Background Latin American countries are often limited in the availability of food outlet data. There is a need to use online search engines that allow the identification of food outlets and assess their agreement with field observations. We aimed to assess the agreement in the density of food outlets provided by a web collaborative data (Google) against the density obtained from an administrative registry. We also determined whether the agreement differed by type of food outlet and by area-level socioeconomic deprivation. Methods In this cross-sectional study, we analyzed 1,693 census tracts from the municipalities of Hermosillo, Leon, Oaxaca de Juarez, and Tlalpan. The Google service was used to develop a tool for the automatic acquisition of food outlet data. To assess agreement, we compared food outlet densities obtained with Google against those registered in the National Statistical Directory of Economic Units (DENUE). Continuous densities were assessed using Bland–Altman plots and concordance correlation coefficient (CCC), while agreement across tertiles of density was estimated using weighted kappa. Results The CCC indicated a strong correlation between Google and DENUE in the overall sample (0.75); by food outlet, most of the correlations were from negligible (0.08) to moderate (0.58). The CCC showed a weaker correlation as deprivation increased. Weighted kappa indicated substantial agreement between Google and DENUE across all census tracts (0.64). By type of food outlet, the weighted kappa showed substantial agreement for restaurants (0.69) and specialty food stores (0.68); the agreement was moderate for convenience stores/small food retail stores (0.49) and fair for candy/ice cream stores (0.30). Weighted kappa indicated substantial agreement in low-deprivation areas (0.63); in very high-deprivation areas, the agreement was moderate (0.42). Conclusions Google could be useful in assessing fixed food outlet densities as a categorical indicator, especially for some establishments, like specialty food stores and restaurants. The data could also be informative of the availability of fixed food outlets, particularly in less deprived areas.

Abstract Objective: To examine food and beverage purchasing patterns across formal and informal outlets among Mexican households’ and explore differences by urbanicity and income. Design: Cross-sectional study of a nationally representative sample of households. We calculated the proportion of total food and beverage expenditure in each household by food outlet type overall and by urbanicity and income. We defined informal outlets as those which are not registered or regulated by tax and fiscal laws. Since some of the outlets within community food environments do not fall in clear categories, we defined a continuum from formal to informal outlets, adding mixed outlets as a category. Setting: Mexico. Participants: Mexican households (n 74 203) from the 2018 National Income and Expenditure Survey. Results: Of the total food and beverage purchases, outlets within the formal food sector (i.e. supermarkets and convenience stores) accounted for 15 % of the purchases, 13 % of purchases occurred in outlets within the informal food sector (i.e. street markets, street vendors and acquaintances) and 70 % in fiscally mixed outlets (i.e. small neighbourhood stores, specialty stores and public markets). Across levels of urbanicity and income, most food and beverage purchases occurred in mixed outlets. Also, purchases in informal and mixed outlets decreased as levels of urbanicity and income increased. In contrast to informal outlets, purchases in formal outlets were most likely from richer households and living in larger sized cities. Conclusions: Understanding where Mexican households shop for food is relevant to create tailored interventions according to food outlet type, accounting for regulatory and governance structures.

Background As part of a global policy response for addressing malnutrition, food system actions have been proposed. Within food system interventions, policies directed to supply chains have the potential to increase the availability and affordability of a healthy diet. This qualitative study aimed to identify opportunities to integrate nutrition as a priority into the food supply policy space in Mexico.Methods Data were collected through analysis of 19 policy documents and 20 semi-structured stakeholder interviews. As an analytical framework, we used policy space analysis and embedded the Advocacy Coalition Framework (ACF) and the steps of the food chain of the conceptual framework of food systems for diets and nutrition.Results Policy issues relevant to nutrition were viewed differently in the economic and agricultural sectors versus the health sector. Overall, the main policy objective related to nutrition within the economic and agricultural sectors was to contribute to food security in terms of food quantity. Nutrition was an objective in itself only in the health sector, with a focus on food quality. Our policy space analysis reveals an opportunity to promote a new integrated vision with the recent creation of an intersectoral group working on the public agenda for a food system transformation. This newer integrative narrative on food systems presents an opportunity to shift the existing food security narrative from quantity towards considerations of diet quality.Conclusion The political context and public agenda are favorable to pursue a food system transformation to deliver sustainable healthy diets. Mexico can provide a case study for other low- and middle-income countries (LMICs) for putting nutrition at the center of food policy, despite the ongoing constraints on achieving this.

Objetivo. Estimar la seroprevalencia de SARS-CoV-2 en población de edad escolar en México. Material y métodos. Se categorizaron a niños y adolescentes que participaron en la Encuesta Nacional de Salud y Nutrición 2020 sobre Covid-19 (Ensanut 2020 Covid-19) por edad escolar y nivel educativo. En participantes seropositivos, se identificó la proporción de infecciones asintomáticas. Se estimaron razones de prevalencia usando un modelo de regresión log-binomial. Resultados. La seroprevalencia en educación básica y media fue de 18.7% (IC95%: 14.9, 22.5) y 26.7% (IC95%: 22.1, 31.3), respectivamente. La infección asintomática fue más frecuente en educación básica (88.5% [IC95%: 80.5, 93.5]). Conclusiones. En población de educación básica la infección por SARS-CoV-2 es baja y usualmente asintomática.

Objetivo. Investigar el cumplimiento de las recomendacio­nes de aislamiento ante síntomas de Covid-19 o contacto con un caso. Material y métodos. Estudio transversal basado en la Encuesta Nacional de Salud y Nutrición 2020 sobre Covid-19. Se describió la prevalencia de aislamiento y su asociación con factores del nivel individual, hogar y contexto utilizando modelos de regresión log-binomial. Resultados. El 48.1% de la población >10 años reportó quedarse en casa ante síntomas o contacto con un caso. La prevalencia de aislamiento fue menor entre población ocupada vs. no-ocupada (RP 0.81; IC95% 0.73-0.89), mayor entre personas con alto nivel socioeconómico vs. bajo (RP 1.22; IC95% 1.08-1.38) y menor entre personas viviendo en estados sin un mensaje específico sobre aislamiento vs. estados con mensaje específico (RP 0.76; IC95% 0.63-0.91). Conclusiones. El cumplimiento de las recomendaciones de aislamiento durante la pandemia de Covid-19 estuvo asociado con factores socioeconómicos individuales y con la calidad de los mensajes de salud pública de los estados.

Este artículo propone intervenciones estructurales dirigidas a la reorganización del trabajo para evitar un repunte de casos de Covid-19, permitiendo la continuidad de la actividad económica. Se resume la evidencia disponible acerca de los ciclos de trabajo-confinamiento y la posible aplicación de ciclos de cuatro días de trabajo por tres de confinamiento (4x3) en el contexto mexicano. También se discuten otras intervenciones como la continuación del teletrabajo en algunos sectores y el escalonamiento de las jornadas de trabajo como medidas complementarias a los ciclos de trabajo-confinamiento. Esta discusión se da en el contexto de alta informalidad y escasos recursos para absorber una pérdida importante de la productividad por las empresas medianas y pequeñas en México. Se considera la necesidad de implementar apoyos para que personas y empresas puedan mitigar pérdidas en salarios y ganancias tanto del sector formal como informal.

BackgroundMost studies of the climate footprint of diets have been conducted in countries in the global north, but the majority of the world population lives in global south countries. We estimated total dietary greenhouse gas emissions (GHGE) in Mexico, examined the contribution of major food and beverage groups, and assessed variation across social groups.MethodsWe linked individual-level dietary data from the Mexican National Health and Nutrition Survey 2018 to the SHARP Indicators Database, containing GHGE estimates for 182 primary food and beverages.ResultsMean dietary GHGE was 3.9 kg of carbon dioxide equivalent per person per day. Dietary GHGE is highest among those in young adulthood and middle age versus adolescents and older adults, and among males, those with higher educational attainment, higher socioeconomic status, that do not speak an indigenous language, and that live in urban areas.ConclusionThe Mexican diet has a much lower carbon footprint than diets in other Latin American countries for which such estimates are available. In contrast to patterns observed in Argentina and Brazil, dietary GHGE was lowest in those in lower socioeconomic and educational strata and in rural areas. A better understanding of the differences in diet sustainability between and within countries will be needed for developing global and local strategies that meet the environmental sustainability goals.

El Covid-19 representa uno de los retos más grandes en la historia reciente de la salud pública. Es fundamental que se fortalezcan los lazos de cooperación científica bajo un obje­tivo común: proteger la salud de la población. En este artículo se presentan ideas que necesitan un desarrollo urgente y colaborativo. Se discute la estimación de la magnitud de la epidemia mediante un panel nacional de seroprevalencia y nuevas estrategias para mejorar el monitoreo en tiempo real de la epidemia. También se analizan las externalidades nega­tivas asociadas con la respuesta a la pandemia. Finalmente, se presenta un marco general para el desarrollo de ideas para salir del confinamiento, resaltando la importancia de implementar acciones estructurales, sostenibles y equitativas. Se hace un llamado a la solidaridad y la cooperación, donde nuestros esfuerzos y creatividad se dediquen a la resolución de los problemas que enfrentan México y el mundo.

Objective: To assess the effectiveness of using surgical masks in community settings to reduce the probability of infection by SARS-CoV-2 or other acute viral respiratory infection, compared to not using surgical masks. Material and methods: We followed the Cochrane rapid review methodology. The search strategy encompasses one academic database and pre-prints until April 1, 2020. Titles and abstracts were reviewed by one investigator. The full text review was divided among three researchers. The results were synthesized in a narrative way. Results: 713 manuscripts were identified, of which 21 met the inclusion criteria. Of six systematic reviews, four found no reduction in the probability of transmission. Experimental home studies found no differences in the probability of contagion associated with the use of mouth masks. Three modeling studies estimated reductions of 20% in the incidence of respiratory disease, assuming that 10 to 50% of the population has correct use of mouth masks. Conclusions: We did not find sufficient scientific evidence to support the general use of surgical masks to reduce the number of viral respiratory infection.

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Background: Little is known about the potential impact of climate change on food systems and diet. We aimed to estimate the association of changes in rainfall and temperatures with consumption of unprocessed and processed foods among residents of Mexican cities by climate region.Methods: We analyzed 3,312 participants of the 2012 Mexican National Health and Nutrition Survey with dietary intake and sociodemographic information linked to historical rainfall and temperature data collected by the Mexican National Weather Service. We classified foods as unprocessed, processed, or ultra-processed. We performed multilevel linear regression to estimate the association of annual change in rainfalls (for each 0.5 mm decrease) and temperatures (for each 0.1°C increase) at municipality level over the past 5 years with consumption of processed and unprocessed foods measured as the contribution to total energy intake. We investigated whether associations differed by climate region (tropical, temperate, and arid).Results: Each 0.5 mm annual decrease in precipitation was associated with lower consumption of unprocessed foods and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake −0.009% (95% CI: −0.019, < −0.001) and 0.011% (95% CI: 0.001, 0.021), respectively]. Each 0.1 degree Celsius annual increase in temperature was also associated with lower consumption of unprocessed and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake was −0.03 (95% CI: −0.05, −0.01) and 0.03% (95% CI:

Abstract Background Mexico approved mandatory nutrient-based standards for foods sold in schools in 2011. The aim of this study was to analyse the association between compliance with nutrition standards for foods sold in schools and children’s school snacks. Methods Data came from three surveys representative of Mexican elementary schools in 13 states and their students (2012, 2013 and 2015); n = 645 children from N = 99 different schools. Information on foods sold in schools and snacks consumed by children was collected through direct observation. Compliance with the standards was defined as the proportion of foods sold in school which met nutrition criteria established by the standards. Snacks were classified as healthy if they contained at least one fruit or vegetable and had no sugar-sweetened beverages. Robust logistic regression models for cross-sectional and repeated surveys aggregated at the school-level were fitted to quantify the association between school compliance with standards and healthy snacks. Results On average across waves 27% of foods sold complied with nutrition standards; 18% of children consumed a healthy snack. For snacks purchased in school, a 10% increase in school compliance with the standards was associated with a 32% increase in the odds of a healthy snack (OR = 1.32; 95%CI 1.09,1.61); no association was observed for snacks brought from home. The odds of a healthy snack increased over time in schools where compliance with the standards improved (OR = 3.89; 95%CI 1.47,10.31) but not in those where compliance remained constant or decreased. Conclusions Only a small proportion of children are eating healthy snacks in school. School compliance with standards increases the likelihood of a healthy snack if it is bought at school. Our findings support better implementation of the standards and additional strategies to enhance the policy to achieve its aim of reducing childhood obesity.

Background Childhood is considered the most important phase of human development; within it the period from birth to 5 years of age is particularly critical, given the speed at which changes occur. The context where children live can influence early childhood developmnent (ECD) by providing or limiting opportunities to learn, play and establish social interactions. This study explored the associations between characteristics of the urban environment and ECD in 2,194 children aged 36 to 59 months living in urban municipalities in Mexico Methods We obtained ECD information from the 2015 Survey of Boys, Girls, and Women (ENIM, for its Spanish acronym), measured with the Early Childhood Development Index. The urban environment was evaluated at the municipal level, considering variables from five environment domains: physical, social, service, socioeconomic, and governance. Multilevel logistic models were fitted to assess the association between urban environment characteristics and the inadequacy of ECD in general and by specific development domains: learning, socio-emotional, physical, and alpha-numeric. Results Inadequate ECD was inversely associated with the availability of libraries (OR = 0.55, 95% CI: 0.43, 0.72), and positively associated with population density (OR = 1.01, 95% CI: 1.01–1.02). For the specific ECD domains, inadequate socio-emotional development was inversely associated with the availability of libraries (OR = 0.66, 95% CI: 0.51, 0.85). Inadequate literacy-numeracy knowledge was associated inversely with the availability of daycare centers (OR = 0.56, 95% CI: 0.32, 0.97), and directly associated with the number of hospitals and clinics (OR = 1.87, 95% CI: 1.29, 2.72). Finally, the marginalization index was positively associated with inadequacy in the learning domain (OR = 1.80, 95% CI: 1.06, 3.03). Conclusions Some aspects of the urban environment associated with ECD, suggest that intervening in the urban context could improve overall child development. Investment in resources oriented to improve socio-emotional development and literacy (such as libraries and daycare), could foster ECD in Mexico.

BackgroundChildhood is considered the most important phase of human development; within it the period from birth to 5 years of age is particularly critical, given the speed at which changes occur. The context where children live can influence early childhood developmnent (ECD) by providing or limiting opportunities to learn, play and establish social interactions. This study explored the associations between characteristics of the urban environment and ECD in 2,194 children aged 36 to 59 months living in urban municipalities in Mexico.MethodsWe obtained ECD information from the 2015 Survey of Boys, Girls, and Women (ENIM, for its Spanish acronym), measured with the Early Childhood Development Index. The urban environment was evaluated at the municipal level, considering variables from five environment domains: physical, social, service, socioeconomic, and governance. Multilevel logistic models were fitted to assess the association between urban environment characteristics and the inadequacy of ECD in general and by specific development domains: learning, socio-emotional, physical, and alpha-numeric.ResultsInadequate ECD was inversely associated with the availability of libraries (OR = 0.55, 95% CI: 0.43, 0.72), and positively associated with population density (OR = 1.01, 95% CI: 1.01-1.02). For the specific ECD domains, inadequate socio-emotional development was inversely associated with the availability of libraries (OR = 0.66, 95% CI: 0.51, 0.85). Inadequate literacy-numeracy knowledge was associated inversely with the availability of daycare centers (OR = 0.56, 95% CI: 0.32, 0.97), and directly associated with the number of hospitals and clinics (OR = 1.87, 95% CI: 1.29, 2.72). Finally, the marginalization index was positively associated with inadequacy in the learning domain (OR = 1.80, 95% CI: 1.06, 3.03).ConclusionsSome aspects of the urban environment associated with ECD, suggest that intervening in the urban context could improve overall child development. Investment in resources oriented to improve socio-emotional development and literacy (such as libraries and daycare), could foster ECD in Mexico.

Abstract Background Up to a third of global road traffic deaths, and one in five in Mexico, are attributable to alcohol. In 2013, Mexico launched a national sobriety checkpoints program designed to reduce drink-driving in municipalities with high rates of alcohol-related collisions. Our study measured the association between the sobriety checkpoints program and road traffic mortality rates in 106 urban municipalities. Methods We leveraged data from the Salud Urbana en America Latina (SALURBAL), which compiles health and environmental data from cities with over 100,000 residents. Death data from 2005 to 2019 (i.e., outcome) were from official vital statistics. Among 106 Mexican municipalities defined as priority areas for intervention, 54 adopted the program (i.e., treatment) in 2013, 16 municipalities did so in 2014, 16 in 2015, 10 in 2016, 7 in 2017, and 2 in 2019. We used a difference-in-difference approach with inverse probability weighting adapted to a context where program adoption is staggered over time. Results There was a 12.3% reduction in road traffic fatalities per 10,000 passenger vehicles in the post-treatment period compared to the pre-treatment period (95% Confidence Interval, − 17.8; − 6,5). There was a clear trend of decline in mortality in municipalities that adopted the program (vs. comparison) particularly after year 2 of the program. Conclusions In this study of 106 municipalities in Mexico, we found a 12.3% reduction in traffic fatalities associated with the adoption of sobriety checkpoints. There was a clear trend indicating that this association increased over time, which is consistent with sustained changes in drink-driving behavior. These findings provide support and insight for efforts to implement and evaluate the impact of sobriety checkpoint policies across Latin America.

BackgroundThe retail food environment in Mexico is characterized by the co-existence of both, formal and informal food outlets. Yet, the contribution of these outlets to food purchases over time has not been documented. Understanding the longitudinal trends where Mexican households purchase their foods is critical for the development of future food retail policies.MethodsWe used data from Mexico’s National Income and Expenditure Survey from 1994 to 2020. We categorized food outlets as formal (supermarkets, chain convenience stores, restaurants), informal (street markets, street vendors, acquaintances), and mixed (fiscally regulated or not. i.e., small neighborhood stores, specialty stores, public markets). We calculated the proportion of food and beverage purchases by food outlet for each survey for the overall sample and stratified by education level and urbanicity.ResultsIn 1994, the highest proportion of food purchases was from mixed outlets, represented by specialty and small neighborhood stores (53.7%), and public markets (15.9%), followed by informal outlets (street vendors and street markets) with 12.3%, and formal outlets from which supermarkets accounted for 9.6%. Over time, specialty and small neighborhood stores increased 4.7 percentage points (p.p.), while public markets decreased 7.5 p.p. Street vendors and street markets decreased 1.6 p.p., and increased 0.5 p.p. for supermarkets. Convenience stores contributed 0.5% at baseline and increased to 1.3% by 2020. Purchases at specialty stores mostly increased in higher socioeconomic levels (13.2 p.p.) and metropolitan cities (8.7 p.p.) while public markets decreased the most in rural households and lower socioeconomic levels (6.0 p.p. & 5.3 p.p.). Supermarkets and chain convenience stores increased the most in rural localities and small cities.ConclusionIn conclusion, we observed an increase in food purchases from the formal sector, nonetheless, the mixed sector remains the predominant food source in Mexico, especially small-neighborhood stores. This is concerning, since these outlets are mostly supplied by food industries. Further, the decrease in purchases from public markets could imply a reduction in the consumption of fresh produce. In order to develop retail food environment policies in Mexico, the historical and predominant role of the mixed sector in food purchases needs to be acknowledged.

Abstract Background Obesity is a global health problem, and its connection with social and environmental factors is well-established. Social factors, such as urban segregation, may impact obesity through various mechanisms, including food and physical activity environments, as well as social norms and networks. This multilevel study aims to examine the effect of socio-economic residential segregation of Latin American cities on the obesity of individuals within those cities. Methods We analyzed data from national surveys for a total of 59,340 individuals of 18–70 years of age, conducted in 156 cities across Brazil, Chile, Colombia, and Mexico between 2007 and 2013. We adjusted two-level linear mixed models for body mass index (BMI) stratified by sex and country, controlling for age, educational level and poverty. Separate models were built for dissimilarity and isolation segregation indices. Results The relationships between segregation indices and BMI were mostly not statistically significant, and in some cases, they were opposite to what was expected. The only significant relationships were observed in Colombian men, using the dissimilarity index (-7.5 [95% CI: -14.4, -0.5]) and in Colombian women, using the isolation index (-7.9 [95% CI: -14.1, -1.7]). Conclusions While individual-level factors cannot fully explain differences among people in the same city, segregation indices may help. However, we found that in some cases, the relationship between BMI and segregation indices is opposite to what is expected based on prior literature. This should be considered in examining the phenomenon. Further research on obesogenic environments in segregated neighborhoods could provide valuable evidence.

Purpose: This paper aims to enrich understanding of the obesity transition among socioeconomic status (SES) strata by gender and age in cities of Colombia and Mexico. The study uses harmonized data from the Salud Urbana en América Latina (SALURBAL) study. Methods: A population-level system dynamics model was developed using 2010 and 2015 data from Colombia and 2012 and 2016 data from Mexico (national health surveys). The model simulates the prevalence of different BMI categories (i.e., not overweight, overweight, obese) stratified by gender, age, and SES, in the SALURBAL cities (aggregated to the country level) of Colombia and Mexico from 2010 to 2050. Sample sizes for Colombia in 2010 and Mexico in 2012 were 7420 and 5785 children (

Abstract Background The association of the built environment and the structural availability of services/amenities with adolescent birth rates (ABR) has been overlooked in Latin America. We investigated the association of the availability, and changes in the availability, of services/amenities with ABR in 92 Mexican cities. Methods We estimated ABR using data on live birth registration linked to municipality of residence at the time of birth from 2008–2017. The number of services/amenities were obtained from the National Statistical Directory of Economic Units in 2010, 2015, and 2020 and grouped as follows: education, health care, pharmacies, recreation, and on- and off-premises alcohol outlets. Data were linearly interpolated to obtain yearly estimates. We estimated densities per square km by municipality. We fitted negative binomial hybrid models, including a random intercept for municipality and city, and adjusted for other social environment variables. Results After adjustment a 1-unit increase in the density of recreation facilities, pharmacies, and off-premises alcohol outlets within municipalities was associated with a 5%, 4% and 12% decrease in ABR, respectively. Municipalities with higher density of education, recreational and health care facilities had a lower ABR; in contrast, municipalities with a higher density of on-premises alcohol experienced a higher ABR. Conclusion Our findings highlight the importance of economic drivers and the need to invest in infrastructure, such as pharmacies, medical facilities, schools, and recreation areas and limit the availability of alcohol outlets to increase the impact of current adolescent pregnancy prevention programs.

Summary: Background: Childhood obesity is a rising global health problem. The rapid urbanization experienced in Latin America might impact childhood obesity through different pathways involving urban built and social features of cities. We aimed to evaluate the association between built and social environment features of cities and childhood obesity across countries and cities in Latin America. Methods: Cross-sectional analysis of data from 20,040 children aged 1–5 years living in 159 large cities in six Latin American countries. We used individual-level anthropometric data for excess weight (overweight or obesity) from health surveys that could be linked to city-level data. City and sub-city level exposures included the social environment (living conditions, service provision and educational attainment) and the built environment (fragmentation, isolation, presence of mass transit, population density, intersection density and percent greenness). Multi-level logistic models were used to explore associations between city features and excess weight, adjusting for age, sex, and head of household education. Findings: The overall prevalence of excess weight among preschool children was 8% but varied substantially between and within countries, ranging from 4% to 25%. Our analysis showed that 97% of the variability was between individuals within sub-city units and around 3% of the variance in z-scores of weight for height was explained by the city and sub-city levels. At the city-level, a higher distance between urban patches (isolation, per 1 SD increase) was associated with lower odds of excess weight (OR 0.90, 95% CI 0.82–0.99). Higher sub-city education was also associated with lower odds of excess weight, but better sub-city living conditions were associated with higher odds of excess weight. Interpretation: Built and social environment features are related to excess weight in preschool children. Our evidence from a wide range of large Latin American cities suggests that urban health interventions may be suitable alternatives towards attaining the goal of reducing excess weight early in the life course. Funding: The SALURBAL project (Salud Urbana en América Latina, Urban Health in Latin America) is funded by Wellcome [205177/Z/16/Z].

Objetivo. Analizar la asociación entre seropositividad a SARS-CoV-2 y enfermedades crónicas en adultos y adultos mayores mexicanos. Material y métodos. Se utilizó la Encuesta Nacional de Salud y Nutrición 2020 sobre Covid-19 (Ensanut 2020 Covid-19) para evaluar la asociación de seropositividad a SARS-CoV-2 con hipertensión arterial sistémica, diabetes tipo 2, índice de masa corporal, LDL-c elevado, HDL-c bajo, colesterol total elevado e hipertrigliceridemia. Resultados. Se observó una mayor seropositividad en personas con mayor índice de masa corporal. La seroprevalencia fue 25% mayor entre los adultos que presentaban obesidad en comparación con aquellos de peso normal en modelos ajustados (RP: 1.25 IC95%: 1.08,1.46). No se observó asociación entre seropositividad y otras enfermedades crónicas en adultos o adultos mayores. Conclusiones. Las personas con obesidad podrían tener una mayor susceptibilidad a la infección por SARS-CoV-2. Este hallazgo debe ser confirmado con estudios longitudinales. No se encontró evidencia de asociación para otras enfermedades.

Objetivo. Determinar el nivel de evidencia sobre la proba­bilidad de transmisión de enfermedades respiratorias agudas en el transporte público colectivo. Material y métodos. Se utilizó la metodología de revisiones rápidas de Cochrane. La estrategia de búsqueda abarcó una base de datos acadé­mica hasta el 10 de diciembre de 2020. Resultados. Se identificaron 16 manuscritos que cumplieron los criterios de selección. En estudios de cohorte agrupados se encontró que el momio de seroconversión por influenza A o B fue 54% mayor en personas con uso frecuente de transporte público colectivo en comparación con las personas con un uso poco frecuente (razón de momios: 1.54; IC95%:1.06-2.01). Conclusión. La probabilidad de contagio por enfermeda­des respiratorias agudas puede incrementar con el uso del transporte público colectivo. Algunas recomendaciones para reducir la probabilidad de contagio en el transporte público colectivo son el uso de cubrebocas y reducir el número de pasajeros y tiempo de traslado.

Introduction The prevalence of childhood obesity has risen dramatically in recent years. A proportion of this burden has been attributed to factors that occur during the first 1000 days of life such as genetic predisposition, breast feeding and complementary feeding. Although the mechanisms by which these factors affect weight and adiposity are less well understood, appetite and satiety regulation may be a key to understanding them. This cohort study aims to investigate the role of appetite and satiety regulation as a mediator in the association between infant feeding practices and genetic polymorphisms with children’s growth, adiposity and metabolic risk factors.Methods and analysis ‘MAS-Lactancia’ (the first word means ‘more’ and is also an acronym in Spanish for ‘Appetite and Satiety Mechanisms’, the second word is ‘breastfeeding’) is an open, ongoing, prospective birth cohort that began the enrolment in 2016 of mother–child pairs affiliated to the Mexican Social Security Institute and that live in the city of Cuernavaca, Mexico. Pregnant women between 16-week and 22-week gestation are followed during the second half of their pregnancies, at birth and throughout their infant’s first 48 months of life (at 1 month, 3 months, 6 months, 9 months, 12 months, 18 months, 24 months, 36 months and 48 months) at the clinic and at-home visits that include questionnaires, anthropometric measurements and biospecimen collection. The main exposure variables are infant feeding (breast feeding and complementary feeding) and genetic polymorphisms (fat mass and obesity-associated, leptin and adiponectin genes). Outcome variables include infant’s growth, adiposity and metabolic risk factors. We will conduct longitudinal models and path analyses to identify the potential mediating role of satiety and appetite indicators (leptin, adiponectin, insulin concentrations, appetite and satiety perception).Ethics and dissemination The study protocol, data collection instruments, consent forms and procedures were approved by the institutional review boards of the National Institute of Public Health and the Mexican Social Security Institute in Mexico. Findings will be disseminated through conferences, peer-reviewed publications and meetings with stakeholders.