Plant Health and Its Effects on Food Safety and Security in a One Health Framework
Although plant health is currently a critical part of the definition of One Health, plants have typically not been well integrated into One Health approaches.
Although plant health is currently part of the definition of One Health, plants have typically not been well integrated into discussions of One Health approaches. However, plant health is vital to sustain human and animal health and a critical component of the complex interactions among the environment, humans, and animals. Recognizing the key role of plants in public health, the United Nations declared the year 2020 to be the International Year of Plant Health. The overarching purpose of this designation was to raise awareness of plant health and its effects on society. Maintaining plant health has important consequences for human and animal health as an important driver of food security and safety, as a source of livelihoods in plant-based agriculture, as a source of pharmaceuticals, and as part of healthy environments.
Plants provide more than 80% of the food consumed by humans and are the primary source of nutrition for livestock. Food security — the state of having reliable access to sufficient, safe, affordable and nutritious food at all times — is necessary to have healthy and productive societies. Food security is also a crucial aspect of One Health and is a pillar of the United Nations Sustainable Development Goals. The United Nations' definition of food security identified four key pillars: 1) availability, 2) access (both economic and sociocultural), 3) utilization, including food preparation and safety and 4) the stability of these three pillars. Food security thus reflects a complex value chain of production, food processing and distribution and food access, beginning with plant health in the field. Employing a One Health approach to ensure the safety and continuity of this value chain will result in the protection and advancement of public health.
Plant diseases and pests influence the availability and safety of plants for human and animal consumption, reduce crop yield and detrimentally affect quality. Measures to prevent or treat diseases, including application of pesticides, may adversely impact the health of agricultural workers and consumers, as well as drive the development of antimicrobial and antifungal resistance in pathogens. In addition, food plants may serve as carriers of human pathogens and harmful microbial-based toxins. For example, foodborne illnesses pose a serious global burden on human health, reportedly affecting 600 million people or generating 33 million disability-adjusted life years in a single year. Although international food standards are implemented to protect consumers’ health and fair trade, foodborne illnesses continue to affect high-, middle-, and low-income countries around the world. Plants are important origins of foodborne outbreaks; fresh vegetables and fruits can be irrigated with, washed with, or exposed to water and soil contaminated with pathogens of animal or human origin. More than half (51%) of outbreak-associated illnesses in the United States were traced to plant foods over a 10-year period, a rate higher than associated any other food commodity, such as meat, fish and dairy products. Additionally, antibiotic-resistant bacteria and resistance genes originating from animal feces can contaminate fresh produce and pose health risks for humans. A key aspect of food security therefore is timely and effective management of plant pathogens and pests and other microbes associated with plants that can cause foodborne illnesses, often disproportionately affecting the most vulnerable and health-disparate populations locally and globally.
The emergence of new variants of pathogens and pests, as well as the expansion of the geographic range of known ones, can cause significant disruption in food production and pose a burden on the global economy. Global yield losses of important staple crops to pathogens and pests can range up to 30% with estimated costs to the global economy due to lost food production in the hundreds of billions of dollars. Effective pest and disease management approaches, including pesticide management strategies, are required to successfully prevent and mitigate these issues. Recognition of and action to address the need for quantification of crop losses and their impact on humans, plants, animals and land use are critically important. Traditional surveillance strategies are often expensive and associated with a delay in problem recognition and access to actionable data. The lack of time-sensitive responses to foodborne outbreaks negatively impacts public health and the food service industry.
Case studies
To show the complex interrelationships between plants and public health and to demonstrate the value of the One Health approach, this article reviews four cases studies. One study shows the relationship between plant health and food security. Two case studies involving a naturally occurring pathogen (one plant-based and one animal-based) show the relationship between plant-food safety and human health. The final case study involving a man-made toxin represents a study of both food security and food safety. These case studies examine challenges and opportunities moving forward for mitigating negative public health consequences and ensuring health equity.
- Plant pathogens and food availability: banana Xanthomonas wilt in East and Central Africa, 2001–present.
- Food safety and mycotoxins: aflatoxicosis outbreak in Kenya, 2004–2005.
- Human pathogens associated with plants and food safety: E. coli outbreak caused by romaine lettuce in the United States and Canada, 2018–2019.
- Pesticide use in plant-based agriculture and food security and safety in Suriname, 2010–2015.
Conclusions
Threats to plant health pose challenges to population health, productivity and prosperity across the globe. Efforts to protect plants from emerging and endemic pathogens and pests help to not only increase food security and safety to ensure healthy lives, but also to alleviate poverty, promote equity, confront the impact of climate change, protect the environment, boost economic development and strengthen global partnerships. Establishing a much closer partnership among advocates for One Health, including experts in sustainable agriculture and public health practitioners, will lead to promoting a safe, sustainable and nutritious diet for families worldwide.
The case studies presented above demonstrate how management practices aimed at reducing crop losses and ensuring food safety would benefit from employment of a One Health approach. Outbreaks of emerging pathogens can be mitigated by mobilizing experts and resources from all arms of One Health to elevate integrated research and development in human, animal and plant health. For example, protecting bananas from the harmful effects of banana Xanthomonas wilt and alleviating the shortage of food caused by the disease involves a framework that highlights the interaction and interdependence of physical and sociocultural factors across all levels of a health problem. This involves effective integrated training on individual and organizational levels; collaboration with plant, environmental, and animal health specialists on the interpersonal level; and implementation of feasible policies on the community and society level. Similar approaches can be used in ensuring food safety, as evidenced in the cases of aflatoxicosis, E. coli and pesticide use. The 2004 case of aflatoxicosis in Kenya resulted in an intervention on the societal and policy level with positive effects observed by individuals, communities and organizations. Suriname’s case of pesticide use and safety concerns exhibits a need for societal policy interventions that lead to positive cascading effects on the economy and other parts of society.
The relationship between plant health and human health is especially important in public health and illustrates a need for research specifically focused on the direct and indirect effects of compromised plant health to human populations. Research and development that allows for inclusion of multiple potential causes for public health concern, including plant diseases and pests that endanger human and animal health and well-being, is vital for holistically preventing and mitigating the effects of public health threats. To successfully and effectively protect plant health and address food security, there will need to be a stronger regulatory framework, effective surveillance and monitoring systems, feasible disease management practices and effective training of food production professionals in protecting plant, animal, environmental and human health. Our case studies also point to the importance of interagency coordination in facilitating rapid responses to public health emergencies, the benefits of technological advances that facilitate data-sharing, and the value of the One Health approach in ensuring food safety and food security for the global population.
This paper is by David M. Rizzo, Maureen Lichtveld, Jonna A.K. Mazet, Eri Togami and Sally A. Miller.