Our world is undergoing rapid planetary changes driven by human activities, often mediated by economic incentives and resource management, affecting all life on Earth. Concurrently, many infectious diseases have recently emerged or spread into new populations. Mounting evidence suggests that global change-including climate change, land-use change, urbanization, and global movement of individuals, species, and goods-may be accelerating disease emergence by reshaping ecological systems in concert with socioeconomic factors. Here, we review insights, approaches, and mechanisms by which global change drives disease emergence from a disease ecology perspective. We aim to spur more interdisciplinary collaboration with economists and identification of more effective and sustainable interventions to prevent disease emergence. While almost all infectious diseases change in response to global change, the mechanisms and directions of these effects are system specific, requiring new, integrated approaches to disease control that recognize linkages between environmental and economic sustainability, and human and planetary health.

Coronaviruses cause respiratory and digestive diseases in vertebrates. The recent pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2, is taking a heavy toll on society and planetary health, and illustrates the threat emerging coronaviruses can pose to the wellbeing of humans and other animals. Coronaviruses are constantly evolving, crossing host species barriers, and expanding their host range. In the last few decades, several novel coronaviruses have emerged in humans and domestic animals. Novel coronaviruses have also been discovered in captive wildlife or wild populations, raising conservation concerns. The evolution and emergence of novel viruses is enabled by frequent cross-species transmission. It is thus crucial to determine emerging coronaviruses’ potential for infecting different host species, and to identify the circumstances under which cross-species transmission occurs in order to mitigate the rate of disease emergence. Here, I review (broadly across several mammalian host species) up-to-date knowledge of host range and circumstances concerning reported cross-species transmission events of emerging coronaviruses in humans and common domestic mammals. All of these coronaviruses had similar host ranges, were closely related (indicative of rapid diversification and spread), and their emergence was likely associated with high-host-density environments facilitating multi-species interactions (e.g., shelters, farms, and markets) and the health or wellbeing of animals as end- and/or intermediate spillover hosts. Further research is needed to identify mechanisms of the cross-species transmission events that have ultimately led to a surge of emerging coronaviruses in multiple species in a relatively short period of time in a world undergoing rapid environmental change.

Human-mediated changes to natural ecosystems have consequences for both ecosystem and human health. Historically, efforts to preserve or restore ‘biodiversity’ can seem to be in opposition to human interests. However, the integration of biodiversity conservation and public health has gained significant traction in recent years, and new efforts to identify solutions that benefit both environmental and human health are ongoing. At the forefront of these efforts is an attempt to clarify ways in which biodiversity conservation can help reduce the risk of zoonotic spillover of pathogens from wild animals, sparking epidemics and pandemics in humans and livestock. However, our understanding of the mechanisms by which biodiversity change influences the spillover process is incomplete, limiting the application of integrated strategies aimed at achieving positive outcomes for both conservation and disease management. Here, we review the literature, considering a broad scope of biodiversity dimensions, to identify cases where zoonotic pathogen spillover is mechanistically linked to changes in biodiversity. By reframing the discussion around biodiversity and disease using mechanistic evidence—while encompassing multiple aspects of biodiversity including functional diversity, landscape diversity, phenological diversity, and interaction diversity—we work toward general principles that can guide future research and more effectively integrate the related goals of biodiversity conservation and spillover prevention. We conclude by summarizing how these principles could be used to integrate the goal of spillover prevention into ongoing biodiversity conservation initiatives.  

Vector-borne diseases (VBDs) are embedded within complex socio-ecological systems. While research has traditionally focused on direct effects of VBDs on morbidity and mortality, it is increasingly clear that VBD impacts are much more pervasive, dynamically linked to feedbacks between environmental conditions, vector ecology, disease burden, and societal responses that drive transmission. VBDs have had profound influence on human history via mechanisms that include: (1) killing or debilitating large numbers of people, with direct demographic and population-level impacts; (2) differentially affecting populations based on prior history of disease exposure, immunity, and resistance; (3) being weaponized to promote or justify existing hierarchies of power, colonialism, racism, classism, and sexism; (4) catalyzing changes in ideas, institutions, infrastructure, technologies, and social practices in efforts to control disease outbreaks; and (5) changing human relationships with the land and environment. We use historical and archaeological evidence interpreted through an ecological lens to illustrate how four major VBDs have shaped society and culture: plague, malaria, yellow fever, and trypanosomiasis. By comparing across diseases, time periods, and geographies, this review highlights the enormous scope and variety of mechanisms by which VBDs have influenced human history from the age of early Homo sapiens to the modern context.

Accurately predicting and mitigating the effects of climate change on species ranges and interactions is a critical challenge. In particular, mosquito-borne diseases like malaria and dengue are poised to shift with climate change. Understanding this impact hinges on a key open question: How will mosquitoes adapt to climate change? Here we adapt a simple framework widely used in conservation biology—evolutionary rescue models—to investigate the potential for mosquito climate adaptation, and we synthesize current evidence, focusing on adaptation to rising temperatures. Short mosquito generation times, high population growth rates, and strong temperature-imposed selection favor mosquito thermal adaptation. However, knowledge gaps about the extent of phenotypic and genotypic variation in thermal tolerance within mosquito populations, the environmental sensitivity of selection, and the role of phenotypic plasticity constrain our ability to make more precise estimates. Future research efforts should prioritize filling these data gaps. Specifically, we outline how common garden and selection experiments can be used to this end. Collecting and incorporating these data into an evolutionary rescue framework will improve estimates of mosquito adaptive potential and of changes in mosquito-borne disease transmission under climate change, and this approach can be applied more broadly to pests as well as species of conservation concern.

The extent to which vector-borne diseases (VBDs) have shaped human history remains under-recognized, even in the disease ecology community, despite several well-known examples. Although they represent a significant threat to global human health, accounting for more than one billion cases and one million deaths annually, VBDs have coexisted with humans since the advent of civilization and have migrated with humans around the world. Here, we synthesize historical, anthropological, and archaeological evidence and examine it through an ecological lens to illustrate how four major VBDs—plague, malaria, yellow fever, and trypanosomiasis—have shaped the course of human history through three main pathways: (1) outcomes of colonialism, imperialism, war, and conflict; (2) human interactions with the environment; and (3) intrasocietal human interactions. For example, malaria tipped the American Revolution toward the Continental Army; plague promoted reforestation in Europe; yellow fever entrenched African slavery in colonies in the Americas; trypanosomiasis impeded large settlements and central governments in pre-colonial sub-Saharan Africa. By drawing comparisons across diseases, time periods, and geographic locations, we show how VBDs have historically affected human populations, from the age of early Homo sapiens to the modern context, and how they continue to impact the world.