Linking animal and human health burden: challenges and opportunities.

Quantifying the impact of poor animal health outcomes on human health represents a complex challenge. Using the disability-adjusted life year (DALY) metric as an endpoint, this article discusses how animal health outcomes can impact humans through three key processes: directly through zoonotic disease, indirectly via changes in yields and their impacts on nutrition and wealth, and finally, through indirect features associated with the agricultural industry, such as pharmaceuticals and climate change. For each process, the current state of the art and feasibility of global DALY-associated estimates are discussed. Existing frameworks for zoonoses already consider some key pathogens; ensuring completeness in the pathogens considered and consistency in methodological decisions is an important next step. For diet, risk factor frameworks enable a calculation of attributable DALYs; however, significant economic methodological developments are needed to ensure that local production changes are appropriately mapped to both local and global changes in dietary habits. Concerning wealth-related impacts, much work needs to be done on method development. Industry-related impacts require a focus on key research topics, such as attribution studies for animal antimicrobial resistance contributing to human outcomes. For climate change, a critical next step is identifying to what extent associated industry emissions are amenable to change should animal health outcomes improve. Allocation of finite funds to improve animal health must also consider the downstream impact on humans. Leveraging DALYs enables comparisons with other human health-related decisions and would represent a transformative way of approaching animal health decision-making should the obstacles in this article be addressed and new methods be developed.

La quantification de l'impact des problèmes de santé animale sur la santé humaine constitue un défi d'une grande complexité. En se servant de l'indicateur des années de vie ajustées sur l'incapacité (DALY) comme critère d'évaluation, les auteurs examinent trois processus essentiels illustrant l'impact que la situation zoosanitaire peut avoir sur la santé humaine : impact direct résultant des maladies zoonotiques, impact indirect résultant des mauvaises performances des animaux et de leurs conséquences sur la nutrition et la création de richesses, et enfin, effets indirects résultant de facteurs en lien avec le secteur agricole, par exemple l'utilisation de produits pharmaceutiques et le changement climatique. Pour chacun de ces processus, les auteurs font le point sur l'état actuel des connaissances et sur l'applicabilité des évaluations mondiales basées sur l'indicateur DALY. Les cadres existants relatifs aux zoonoses recouvrent déjà certains agents pathogènes majeurs ; la prochaine étape importante consistera à assurer une couverture complète des agents pathogènes et à veiller à la cohérence des décisions méthodologiques. S'agissant de l'alimentation, les cadres basés sur l'analyse des facteurs de risque permettent de calculer les DALY imputables à l'alimentation ; toutefois, d'importantes avancées méthodologiques sur les aspects économiques de cette corrélation seront nécessaires pour s'assurer que tout changement intervenant localement en matière de production animale est correctement mis en correspondance avec les modifications des habitudes alimentaires dans ce même contexte local mais aussi à l'échelle mondiale. S'agissant des impacts liés à la création de richesses, il reste beaucoup à faire dans le domaine méthodologique. La détermination des impacts liés aux filières d'élevage requiert des travaux axés sur des sujets précis, par exemple des études visant à déceler les sources de la résistance aux agents antimicrobiens qui contribuent à l'apparition d'antibiorésistances chez l'être humain. Enfin, pour ce qui concerne le changement climatique, une étape cruciale consistera à déterminer dans quelle mesure les émissions associées à l'élevage sont susceptibles de changer en cas d'amélioration de la situation zoosanitaire. Dans un contexte de ressources limitées, l'affectation de fonds à l'amélioration de la santé animale doit également prendre en compte l'impact en aval sur la santé humaine. L'utilisation de l'indicateur DALY permet des comparaisons avec d'autres décisions de santé publique et représenterait une approche transformative de la prise de décision en santé animale, dès lors que les obstacles mentionnés dans cet article sont surmontés et que de nouvelles méthodes sont mises au point.

Cuantificar el impacto de una mala sanidad animal en la salud humana es un desafío complejo. Utilizando el parámetro de años de vida ajustados en función de la discapacidad (AVAD o DALY) como criterio de valoración, en este artículo se examina cómo la sanidad animal puede repercutir en los seres humanos a través de tres procesos clave: directamente, a través de las zoonosis; indirectamente, a través de cambios en los rendimientos y sus repercusiones en la nutrición y la riqueza; y, por último, a través de factores indirectos asociados a la industria agropecuaria, como los fármacos y el cambio climático. Para cada uno de estos procesos, se examinan el estado actual y la viabilidad de estimar AVAD a escala mundial. Los marcos existentes para la zoonosis ya tienen en cuenta algunos patógenos claves; garantizar la exhaustividad de los patógenos considerados y la coherencia en las decisiones metodológicas es un próximo paso importante. En lo que respecta a la alimentación, aunque los marcos de factores de riesgo permiten calcular los AVAD atribuibles, se necesitan importantes avances metodológicos en el ámbito económico para asegurar que los cambios en la producción local se correspondan adecuadamente con los cambios locales y mundiales en los hábitos alimentarios. En cuanto a las repercusiones en la riqueza, queda mucho trabajo por hacer en el desarrollo de métodos. Para abordar las repercusiones relacionadas con la industria, es necesario centrarse en temas clave de investigación, como los estudios de atribución relativos al impacto en la salud humana de la resistencia a los antimicrobianos en los animales. En lo que se refiere al cambio climático, un próximo paso crucial es determinar en qué medida las emisiones de la industria podrían cambiar, en función de la mejora de los resultados en materia de sanidad animal. Al asignar fondos limitados para la mejora de la sanidad animal también se deben tener en cuenta las repercusiones correspondientes en los seres humanos. Utilizar los AVAD permite hacer comparaciones con otras decisiones importantes relacionadas con la salud humana y representaría una forma transformadora de enfocar la toma de decisiones en materia de sanidad animal, en caso de que se aborden los obstáculos presentados en ese artículo y se desarrollen nuevos métodos.

Travel time to health facilities in areas of outbreak potential: maps for guiding local preparedness and response.

BACKGROUND: Repeated outbreaks of emerging pathogens underscore the need for preparedness plans to prevent, detect, and respond. As countries develop and improve National Action Plans for Health Security, addressing subnational variation in preparedness is increasingly important. One facet of preparedness and mitigating disease transmission is health facility accessibility, linking infected persons with health systems and vice versa. Where potential patients can access care, local facilities must ensure they can appropriately diagnose, treat, and contain disease spread to prevent secondary transmission; where patients cannot readily access facilities, alternate plans must be developed. Here, we use travel time to link facilities and populations at risk of viral hemorrhagic fevers (VHFs) and identify spatial variation in these respective preparedness demands. METHODS AND FINDINGS: We used geospatial resources of travel friction, pathogen environmental suitability, and health facilities to determine facility accessibility of any at-risk location within a country. We considered in-country and cross-border movements of exposed populations and highlighted vulnerable populations where current facilities are inaccessible and new infrastructure would reduce travel times. We developed profiles for 43 African countries. Resulting maps demonstrate gaps in health facility accessibility and highlight facilities closest to areas at risk for VHF spillover. For instance, in the Central African Republic, we identified travel times of over 24 h to access a health facility. Some countries had more uniformly short travel times, such as Nigeria, although regional disparities exist. For some populations, including many in Botswana, access to areas at risk for VHF nationally was low but proximity to suitable spillover areas in bordering countries was high. Additional analyses provide insights for considering future resource allocation. We provide a contemporary use case for these analyses for the ongoing Ebola outbreak. CONCLUSIONS: These maps demonstrate the use of geospatial analytics for subnational preparedness, identifying facilities close to at-risk populations for prioritizing readiness to detect, treat, and respond to cases and highlighting where gaps in health facility accessibility exist. We identified cross-border threats for VHF exposure and demonstrate an opportunity to improve preparedness activities through the use of precision public health methods and data-driven insights for resource allocation as part of a country's preparedness plans.

Global distribution and environmental suitability for chikungunya virus, 1952 to 2015.

Chikungunya fever is an acute febrile illness caused by the chikungunya virus (CHIKV), which is transmitted to humans by Aedes mosquitoes. Although chikungunya fever is rarely fatal, patients can experience debilitating symptoms that last from months to years. Here we comprehensively assess the global distribution of chikungunya and produce high-resolution maps, using an established modelling framework that combines a comprehensive occurrence database with bespoke environmental correlates, including up-to-date Aedes distribution maps. This enables estimation of the current total population-at-risk of CHIKV transmission and identification of areas where the virus may spread to in the future. We identified 94 countries with good evidence for current CHIKV presence and a set of countries in the New and Old World with potential for future CHIKV establishment, demonstrated by high environmental suitability for transmission and in some cases previous sporadic reports. Aedes aegypti presence was identified as one of the major contributing factors to CHIKV transmission but significant geographical heterogeneity exists. We estimated 1.3 billion people are living in areas at-risk of CHIKV transmission. These maps provide a baseline for identifying areas where prevention and control efforts should be prioritised and can be used to guide estimation of the global burden of CHIKV.

A global dataset of publicly available dengue case count data.

OpenDengue is a global database of dengue case data collated from public sources and standardised and formatted to facilitate easy reanalysis. Dataset version 1.2 of this database contains information on over 56 million dengue cases from 102 countries between 1924 and 2023, making it the largest and most comprehensive dengue case database currently available. Over 95% of records are at the weekly or monthly temporal resolution and subnational data is available for 40 countries. To build OpenDengue we systematically searched databases, ministry of health websites, peer reviewed literature and Pro-MED mail reports and extracted denominator-based case count data. We undertake standardisation and error checking protocols to ensure consistency and resolve discrepancies. We meticulously documented the extraction process to ensure records are attributable and reproducible. The OpenDengue database remains under development with plans for further disaggregation and user contributions are encouraged. This new dataset can be used to better understand the long-term drivers of dengue transmission, improve estimates of disease burden, targeting and evaluation of interventions and improving future projections.

Utilizing general human movement models to predict the spread of emerging infectious diseases in resource poor settings.

Human mobility is an important driver of geographic spread of infectious pathogens. Detailed information about human movements during outbreaks are, however, difficult to obtain and may not be available during future epidemics. The Ebola virus disease (EVD) outbreak in West Africa between 2014-16 demonstrated how quickly pathogens can spread to large urban centers following one cross-species transmission event. Here we describe a flexible transmission model to test the utility of generalised human movement models in estimating EVD cases and spatial spread over the course of the outbreak. A transmission model that includes a general model of human mobility significantly improves prediction of EVD's incidence compared to models without this component. Human movement plays an important role not only to ignite the epidemic in locations previously disease free, but over the course of the entire epidemic. We also demonstrate important differences between countries in population mixing and the improved prediction attributable to movement metrics. Given their relative rareness, locally derived mobility data are unlikely to exist in advance of future epidemics or pandemics. Our findings show that transmission patterns derived from general human movement models can improve forecasts of spatio-temporal transmission patterns in places where local mobility data is unavailable.