Abstract: Objective: To describe the design of the Mexican 2021 National Health and Nutrition Survey (Ensanut 2021). Materials and methods: The Ensanut 2021 is a probabilistic household survey that is part of the continuous Ensanut 2020-2024; survey outreach, sampling, measurement and logistic organization are described. Results: It is planned to obtain at least 12 060 complete household interviews and 9 837 samples to determine SARS-CoV-2 seropositivity at the national level. Conclusions: Ensanut 2021 will allow to estimate the seroprevalence of SARS-CoV-2 antibodies at regional and national level; also, it will accumulate information to make state inferences for the year 2024.

Resumen: Objetivo: Describir el diseño de la Encuesta Nacional de Salud y Nutrición 2021 (Ensanut 2021). Material y métodos: La Ensanut 2021 es una encuesta probabilística de hogares que forma parte de la serie de Ensanut Continua 2020-2024. En esta ocasión se describen el alcance, el muestreo, la medición y la organización logística. Resultados: Se planea obtener al menos 12 060 entrevistas de hogar completas a nivel nacional y 9 837 muestras para determinar seropositividad a SARS-CoV-2 a nivel nacional. Conclusiones: La Ensanut 2021 permitirá realizar inferencias regionales sobre la prevalencia de seropositividad a SARS-CoV-2 y también acumular información para realizar inferencias estatales en el año 2024.

Abstract: Objective: To estimate the willingness to vaccinate against Covid-19 (acceptance) in the Mexican population and to identify socioeconomic factors associated with vaccine hesitancy and refusal. Materials and methods: We estimated the acceptance, refusal and hesitancy proportions using data from the Covid-19 National Health and Nutrition Survey conducted from August to November 2020. Factors associated with refusal and hesitancy were explored using multinomial logistic regression. Results: Covid-19 vaccination acceptance was 62.3%, refusal 28.2% and hesitancy 9.5%. Refusal and hesitancy were associated with being female, having older age, lower educational level, lower socioeconomic status and working in the informal sector. Conclusion: National campaigns to incentivize vaccine acceptance need to consider specific subgroups were the likelihood of hesitancy and refusal is high. In Mexico, refusal and hesitancy were higher in vulnerable groups, and people at a higher risk of Covid-19 complications and death.

Resumen: Objetivo: Estimar la aceptabilidad de la vacunación contra Covid-19 en la población mexicana e identificar factores socioeconómicos asociados con el rechazo o la duda. Material y métodos: Se estimó la proporción de aceptabilidad, rechazo y duda utilizando los datos de la Encuesta Nacional de Salud y Nutrición 2020 sobre Covid-19 levantada durante agosto y noviembre de 2020. Se exploraron los factores asociados con rechazo y duda mediante un modelo de regresión multinomial. Resultados: La aceptabilidad de la vacunación contra Covid-19 fue de 62.3%, el rechazo de 28.2% y la duda de 9.5%. El rechazo y la duda se asociaron con ser mujer, tener mayor edad, menor nivel de educación, menor nivel socioeconómico y trabajar en el sector informal. Conclusión: Las campañas para incentivar la aceptabilidad de la vacuna necesitan considerar los subgrupos específicos con una alta proporción de rechazo y duda. En México observamos un mayor rechazo y duda en grupos con mayor riesgo de complicaciones y muerte por Covid-19.

Resumen Objetivo: Describir el diseño y los resultados de campo de la Encuesta Nacional de Salud y Nutrición (Ensanut) 2020 sobre Covid-19. Material y métodos: La Ensanut Covid-19 es una encuesta probabilística de hogares. En este artículo se describen los siguientes elementos del diseño: alcance, muestreo, medición, inferencia y logística. Resultados: Se obtuvieron 10 216 entrevistas de hogar completas y 9 464 resultados sobre seropositividad a SARS-CoV-2. La tasa de respuesta de hogar fue 80% y la de prueba de seropositividad de 44%. Conclusiones: El diseño probabilístico de la Ensanut Covid-19 permite hacer inferencias estadísticas válidas sobre parámetros de interés para la salud pública a nivel nacional y regional; en particular, permitirá hacer inferencias de utilidad práctica sobre la prevalencia de seropositividad a SARS-CoV-2 en México. Además, la Ensanut Covid-19 podrá ser comparada con Ensanut previas para identificar potenciales cambios en los estados de salud y nutrición de la población mexicana.

Abstract Objective: To describe the design and field results of the National Health and Nutrition Survey (Ensanut, for its Spanish acronym) Covid-19. Materials and methods: Ensanut Covid-19 is a probabilistic household survey. The following elements of the design are described in this article: scope, sampling, measurement, inference, and logistic organization. Results: Ensanut, Covid-19 got 10 216 completed household interviews and 9 464 individual results on SARS-CoV-2 seropositivity. The household response rate was 80%. The response rate to the seropositivity test was 44%. Conclusions: The probabilistic design of Ensanut Covid-19 allows to make valid statistical inferences on parameters of interest to public health at the national and regional levels. In particular, Ensanut, Covid-19 will enable to make inferences of practical utility on the prevalence of seropositivity to SARS-CoV-2 in Mexico. In addition, Ensanut Covid-19 2020 can be compared to previous Ensanut, in order to identify potential changes in the health and nutrition status of the Mexican population.

There have recently been safety concerns regarding an increased risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) following administration of SARS-CoV-2 adenoviral vector vaccines. The Southern African Society of Thrombosis and Haemostasis reviewed the emerging literature on this idiosyncratic complication. A draft document was produced and revised by consensus agreement by a panel of professionals from various specialties. The recommendations were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of VITT.

There have recently been safety concerns regarding an increased risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) following administration of SARS-CoV-2 adenoviral vector vaccines. The Southern African Society of Thrombosis and Haemostasis reviewed the emerging literature on this idiosyncratic complication. A draft document was produced and revised by consensus agreement by a panel of professionals from various specialties. The recommendations were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of VITT.

Death is a medical occurrence that has social, legal, religious and cultural consequences requiring common clinical standards for its diagnosis and legal regulation. This document compiled by the Critical Care Society of Southern Africa outlines the core standards for determination of death in the hospital context. It aligns with the latest evidence-based research and international guidelines and is applicable to the South African context and legal system. The aim is to provide clear medical standards for healthcare providers to follow in the determination of death, thereby promoting safe practices and high-quality care through the use of uniform standards. Adherence to such guidelines will provide assurance to medical staff, patients, their families and the South African public that the determination of death is always undertaken with diligence, integrity, respect and compassion, and is in accordance with accepted medical standards and latest scientific evidence. The consensus guidelines were compiled using the AGREE II checklist with an 18-member expert panel participating in a three-round modified Delphi process. Checklists and advice sheets were created to assist with application of these guidelines in the clinical environment (https://criticalcare.org.za/resource/death-determination-checklists/). Key points • Brain death and circulatory death are the accepted terms for defining death in the hospital context. • Death determination is a clinical diagnosis which can be made with complete certainty provided that all preconditions are met. • The determination of death in children is held to the same standard as in adults but cannot be diagnosed in children <36 weeks' corrected gestation. • Brain-death testing while on extra-corporeal membrane oxygenation is outlined. • Recommendations are given on handling family requests for accommodation and on consideration of the potential for organ donation. • The use of a checklist combined with a rigorous testing process, comprehensive documentation and adequate counselling of the family are core tenets of death determination. This is a standard of practice to which all clinicians should adhere in end-of-life care.

BACKGROUND. In South Africa (SA), administrators and intensive care practitioners are faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience the consequences of limited resources daily. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are routinely necessary in SA, particularly in the publicly funded health sector. PURPOSE. The purpose of this guideline is to utilise the relevant recommendations of the associated consensus meeting document and other internationally accepted principles to develop a guideline to inform frontline triage policy and ensure the best utilisation of adult intensive care in SA, while maintaining the fair distribution of available resources. RECOMMENDATIONS. An overall conceptual framework for the triage process was developed. The components of the framework were developed on the basis that patients should be admitted preferentially when the likely incremental medical benefit derived from ICU admission justifies admission. An estimate of likely resource use should also form part of the triage decision, with those patients requiring relatively less resources to achieve substantial benefit receiving priority for admission. Thus, the triage system should maximise the benefits obtained from ICU resources available for the community. Where possible, practical examples of what the consensus group agreed would be considered appropriate practice under specified South African circumstances were provided, to assist clinicians with practical decision-making. It must be stressed that this guideline is not intended to be prescriptive for individual hospital or regional practice, and hospitals and regions are encouraged to develop specified local guidelines with locally relevant examples. The guideline should be reviewed and revised if appropriate within 5 years. CONCLUSION. In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, this guideline has been developed to guide policy-making and assist frontline triage decision-making in SA. This document is not a complete plan for quality practice, but rather a template to support frontline clinicians, guide administrators and inform the public regarding appropriate triage decision-making.

BACKGROUND. In South Africa (SA), intensive care is faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience daily the consequences of limited resources. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are frequently necessary in SA, particularly in the publicly funded health sector. PURPOSE. The purpose of this consensus statement is to examine key questions that arise when considering the status of ICU resources in SA, and more specifically ICU admission, rationing and triage decisions. The accompanying guideline in this issue is intended to guide frontline triage policy and ensure the best utilisation of intensive care in SA, while maintaining a fair distribution of available resources. Fair and efficient triage is important to ensure the ongoing provision of high-quality care to adult patients referred for intensive care. RECOMMENDATIONS. In response to 14 key questions developed using a modified Delphi technique, 29 recommendations were formulated and graded using an adapted GRADE score. The 14 key questions addressed the status of the provision of ICU services in SA, the degree of resource restriction, the efficiency of resource management, the need for triage, and how triage could be most justly implemented. Important recommendations included the need to formally recognise and accurately quantify the provision of ICU services in SA by national audit; actively seek additional resources from governmental bodies; consider methods to maximise the efficiency of ICU care; evaluate lower level of care alternatives; develop a triage guideline to assist policy-makers and frontline practitioners to implement triage decisions in an efficient and fair way; measure and audit the consequence of triage; and promote research to improve the accuracy and consistency of triage decisions. The consensus document and guideline should be reviewed and revised appropriately within 5 years. CONCLUSION. In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, recommendations and a guideline have been developed to guide policy-making and assist frontline triage decision-making in SA. These documents are not a complete plan for quality practice but rather the beginning of a long-term initiative to engage clinicians, the public and administrators in appropriate triage decision-making, and promote systems that will ultimately maximise the efficient and fair use of available ICU resources.

Abstract: Objective: To describe three relevant aspects of household food insecurity (FI) in Mexico: its magnitude, its distribution by social and nutritional vulnerability characteristics; its evolution between 2012 and 2016 and the effect of food assistance programs on FI in Mexican households. Materials and methods: Data on 9 019 households were drawn from the 2016 National Health and Nutrition Survey (Ensanut 2016 for its Spanish initials) and were compared with data from the 2012 Ensanut. An analysis of differences in differences was made to measure the effect of food assistance programs on the evolution of FI. Results: As many as 69.5% of households were classified as FI. Families located in rural areas (78.0%) and residing in southern Mexico (76.3%). Households with support from a food assistance program experienced a decrease in moderate and severe FI between 2012 and 2016. Conclusion: Findings can be used to design and target public policies seeking to improve food security governance in Mexico.

Resumen: Objetivo: Describir tres aspectos importantes de la inseguridad alimentaria (IA) en México: la magnitud y distribución de acuerdo con características de vulnerabilidad social, su evolución entre 2012 y 2016 y el efecto de los programas sociales de ayuda alimentaria en la IA de los hogares mexicanos. Material y métodos: Se incluyó información de 40 809 y 9 019 hogares provenientes de la Ensanut 2012 y 2016, respectivamente. Se realizó un análisis de diferencias en diferencias para medir el efecto de los programas de ayuda alimentaria en la evolución de la IA. Resultados: El 69.5% de los hogares se clasificó en IA. Los más afectados por la IA fueron hogares más pobres (85.8%) y de áreas rurales (78.0%). En el periodo 2012-2016, la prevalencia de IA moderada y severa disminuyó en hogares con apoyo de programas de ayuda alimentaria. Conclusión: Los resultados presentados son una herramienta para mejorar el diseño y focalización de políticas públicas y fortalecer la gobernanza de la seguridad alimentaria en México.

Abstract: Objective: To estimate the recommendable and non-recommendable food groups for usual consumption by sociodemographic characteristics in Mexican population. Materials and methods: Through a 7-day, semi-quantitative food frequency questionnaire used in 2016 National Health and Nutrition Survey, we estimated the proportions of population (preschool and school children, adolescents and adults) who consumed food groups that are relevant for public health by area, region and socioeconomic status (SES). Results: Less than 50% of population consumed vegetables daily; almost 80% of the population consumed plain water daily and sweetened beverages (3 d/week). Center and Mexico City regions had the highest percentage of fruits and vegetables consumers (p<0.012). High SES had the highest consumer´s percentage of recommendable and non-recommendable food groups. Conclusions: A high percentage of the population do not consume fruits, vegetables and plain water daily.

Resumen: Objetivo: Estimar el consumo de alimentos recomendables y no recomendables para consumo cotidiano, por características sociodemográficas en la población mexicana. Material y métodos: Se utilizó información del cuestionario semicuantitativo de frecuencia de consumo de alimentos (de siete días), de la Encuesta Nacional de Salud y Nutrición de Medio Camino 2016. Se estimó el porcentaje de consumidores en preescolares, escolares, adolescentes y adultos, por área, región y nivel socioeconómico (NSE). Resultados: Menos de 50% de la población consumió de verduras diariamente. Alrededor de 80% de la población consumió agua sola diariamente y bebidas endulzadas al menos tres días a la semana. Las regiones Centro y Ciudad de México tuvieron el mayor porcentaje de consumidores de frutas y verduras (p<0.012). El NSE alto presentó el mayor porcentaje de consumidores de grupos de alimentos recomendables y no recomendables. Conclusiones. Un porcentaje importante de la población no consume frutas, verduras, ni agua sola diariamente.

Abstract: Objective: To describe three relevant aspects of household food insecurity (FI) in Mexico: its magnitude, its distribution by social and nutritional vulnerability characteristics; its evolution between 2012 and 2016 and the effect of food assistance programs on FI in Mexican households. Materials and methods: Data on 9 019 households were drawn from the 2016 National Health and Nutrition Survey (Ensanut 2016 for its Spanish initials) and were compared with data from the 2012 Ensanut. An analysis of differences in differences was made to measure the effect of food assistance programs on the evolution of FI. Results: As many as 69.5% of households were classified as FI. Families located in rural areas (78.0%) and residing in southern Mexico (76.3%). Households with support from a food assistance program experienced a decrease in moderate and severe FI between 2012 and 2016. Conclusion: Findings can be used to design and target public policies seeking to improve food security governance in Mexico.

Resumen: Objetivo: Describir tres aspectos importantes de la inseguridad alimentaria (IA) en México: la magnitud y distribución de acuerdo con características de vulnerabilidad social, su evolución entre 2012 y 2016 y el efecto de los programas sociales de ayuda alimentaria en la IA de los hogares mexicanos. Material y métodos: Se incluyó información de 40 809 y 9 019 hogares provenientes de la Ensanut 2012 y 2016, respectivamente. Se realizó un análisis de diferencias en diferencias para medir el efecto de los programas de ayuda alimentaria en la evolución de la IA. Resultados: El 69.5% de los hogares se clasificó en IA. Los más afectados por la IA fueron hogares más pobres (85.8%) y de áreas rurales (78.0%). En el periodo 2012-2016, la prevalencia de IA moderada y severa disminuyó en hogares con apoyo de programas de ayuda alimentaria. Conclusión: Los resultados presentados son una herramienta para mejorar el diseño y focalización de políticas públicas y fortalecer la gobernanza de la seguridad alimentaria en México.

Abstract: Objective: To estimate the recommendable and non-recommendable food groups for usual consumption by sociodemographic characteristics in Mexican population. Materials and methods: Through a 7-day, semi-quantitative food frequency questionnaire used in 2016 National Health and Nutrition Survey, we estimated the proportions of population (preschool and school children, adolescents and adults) who consumed food groups that are relevant for public health by area, region and socioeconomic status (SES). Results: Less than 50% of population consumed vegetables daily; almost 80% of the population consumed plain water daily and sweetened beverages (3 d/week). Center and Mexico City regions had the highest percentage of fruits and vegetables consumers (p<0.012). High SES had the highest consumer´s percentage of recommendable and non-recommendable food groups. Conclusions: A high percentage of the population do not consume fruits, vegetables and plain water daily.

Resumen: Objetivo: Estimar el consumo de alimentos recomendables y no recomendables para consumo cotidiano, por características sociodemográficas en la población mexicana. Material y métodos: Se utilizó información del cuestionario semicuantitativo de frecuencia de consumo de alimentos (de siete días), de la Encuesta Nacional de Salud y Nutrición de Medio Camino 2016. Se estimó el porcentaje de consumidores en preescolares, escolares, adolescentes y adultos, por área, región y nivel socioeconómico (NSE). Resultados: Menos de 50% de la población consumió de verduras diariamente. Alrededor de 80% de la población consumió agua sola diariamente y bebidas endulzadas al menos tres días a la semana. Las regiones Centro y Ciudad de México tuvieron el mayor porcentaje de consumidores de frutas y verduras (p<0.012). El NSE alto presentó el mayor porcentaje de consumidores de grupos de alimentos recomendables y no recomendables. Conclusiones. Un porcentaje importante de la población no consume frutas, verduras, ni agua sola diariamente.

Viruses of trypanosomatids are now being extensively studied because of their diversity and the roles they play in flagellates’ biology. Among the most prominent examples are leishmaniaviruses implicated in pathogenesis of Leishmania parasites. Here, we present a historical overview of this field, starting with early reports of virus-like particles on electron microphotographs, and culminating in detailed molecular descriptions of viruses obtained using modern next generation sequencing-based techniques. Because of their diversity, different life cycle strategies and host specificity, we believe that trypanosomatids are a fertile ground for further explorations to better understand viral evolution, routes of transitions, and molecular mechanisms of adaptation to different hosts.

RESUMEN Los equinoideos son un componente importante de las comunidades bentónicas y pueden llegar a modificar directamente la distribución y abundancia relativa de algas y corales, y ser un agente importante en el proceso de bioerosión. A pesar de los estudios realizados en el Pacífico colombiano sobre equinoideos, se desconoce la tasa de bioerosión por ramoneo del equinodermo Diadema mexicanum en los arrecifes de la isla Gorgona; considerando las abundancias de este equinoideo y su potencial efecto sobre el ecosistema coralino, en este trabajo se calculó la tasa de bioerosión. Para esto, se efectuaron muestreos aleatorios con cuadrantes de 1 m2 en las tres zonas (Trasarrecife ±1.0 m de profundidad, Planicie ±0.5 m y Frente ±3.0 m en marea baja) del arrecife La Azufrada (Parque Nacional Natural Isla Gorgona). Los erizos dentro del cuadrante fueron contados y medidos (ancho de la testa). En adición, se capturaron 90 individuos (30 por zona), para determinar la tasa de bioerosión. La densidad y talla promedio fueron de 8.28±11.65 ind./m2 y 19.62±5.02 mm, respectivamente. La tasa promedio de bioerosión fue de 0.083 KgCaCO3/m2/año, y se vio afectada significativamente por el tamaño del equinoideo (p0.001) y la zona arrecifal (p=0.0002). También se observó una relación directa entre la cantidad de carbonato de calcio intestinal y la profundidad (p=0.043) y la talla (p0.001). Finalmente, se puede afirmar que, aunque los erizos grandes pueden ocasionar un efecto importante sobre el arrecife, debido a su baja abundancia relativa es probable que la erosión causada por D. mexicanum no sea una amenaza para el arrecife La Azufrada, lo que se ve reflejado en una tasa de bioerosión relativamente baja en comparación con otros arrecifes del Pacífico Oriental Tropical.

ABSTRACT Echinoids are an important component of benthic communities; they can directly modify the distribution and relative abundance of algae and corals as well as be an agent in the process of bioerosion. Despite research on echinoids in the Colombian Pacific, the bioerosion rate due to grazing by Diadema mexicanum on the coral reefs of Gorgona Island remains unknown. Therefore, considering the relative high abundance of this echinoid and its potential negative effects on coral reefs, the main objective of this study was to determine the rate of bioerosion. To accomplish this, 1-m2 quadrats were randomly established in each of three reef zones (at low tide, Backreef: ±1 m depth, Reef plain: ±0.5 m and Reef front: ±3.0 m) of La Azufrada fringing reef (Gorgona Island National Natural Park). Sea urchins were counted and measured (test diameter) inside the quadrats, and 30 urchins per zone (90 in total) were collected to estimate the bioerosion rate. The average sea urchin density and size (±SD) were 8.28±11.65 ind/m2 and 19.62±5.02 mm, respectively. The average bioerosion rate for the reef was 0.083 kg CaCO3/m2/yr, and it was significantly affected by echinoid size (p<0.001) and reef zone (p=0.0002). Additionally, a direct relationship was observed between intestinal calcium carbonate (CaCO3) and depth (p=0.043) and size (p<0.001). Finally, although large sea urchins may have important effects, it is unlikely that the bioerosion caused by D. mexicanum presents a threat to La Azufrada fringing reef due to its low relative abundance; this is reflected by the relatively low bioerosion rate relative to other reefs in the Tropical Eastern Pacific.

Abstract: Objective: To estimate changes in prices associated with the implementation of the tax to sugar sweetened beverages (SSB) and to nonessential energy dense food in 2014. Materials and methods: Price data were collected in rural and semi-rural areas in December 2013, and April and December 2014. Fixed effects models were used to estimate changes in prices of beverages and nonessential energy dense food, stratified by region, retailer and package size. Results: The SSB tax did not pass completely through prices: prices increased on average 0.73 pesos per liter. For nonessential energy dense food, the tax passed completely or was overshifted for cookies, cereal bars and cereal boxes. Conclusion: The potential effect of the taxes on consumption could be attenuated in rural areas as the pass through prices was incomplete.

Resumen: Objetivo: Analizar cambios en precios asociados con la implementación de los impuestos a bebidas azucaradas y alimentos no básicos con alta densidad energética implementados en 2014. Material y métodos: Se recolectaron precios en áreas rurales y semiurbanas en diciembre de 2013, y abril y diciembre de 2014. Se analizaron cambios en precios por tipo de bebidas y alimento con impuesto usando modelos de efectos fijos y estratificando por región, tipo de establecimiento y tamaño de presentación. Resultados: El impuesto a bebidas azucaradas no pasó por completo a los precios; en promedio, los precios aumentaron 0.73 pesos por litro. Para alimentos con alta densidad energética, el impuesto pasó igual o mayor al monto del impuesto para galletas, barras de cereal y cereales de caja. Conclusión: El potencial efecto de los impuestos en consumo podría ser menor al esperado en áreas rurales dado que los impuestos no pasaron por completo a los precios.