One Health: Implementation Challenges and Need

Abstract

One Health is based upon the core principle of collaboration and interdisciplinary work when relating to public health- specifically communicable diseases and illnesses. The One Health framework was initially established to address the transmittance of disease from animal reservoirs to human vectors. When animals, humans, and the environment coexist in various areas of life, emphasis should be placed on their codependency and interactions- both healthy and potentially threatening. The COVID-19 pandemic has further enhanced the need for an interdisciplinary workforce in all public health sectors to combat future threats and address the impacts of the recent pandemic. One Health is not only rooted in disease prevention, but also in solutions. Doctors, veterinarians, politicians, public health workers, and all other stakeholders must increase communication to establish such a framework. Once accepted by stakeholders, the One Health framework can be utilized in addressing both communicable illnesses and non-communicable illnesses. In this paper, the background and usage of the One Health framework will be analyzed, and case studies, such as food security and maternal and child health, and associated problems and solutions will be outlined through a One Health framework, one that is not conventionally applied to such non-communicable issues.

1. Introduction

The foundations of the One Health framework were initially introduced to public health and medical fields in 1964 by veterinarian Dr. Calvin Schwabe. Dr. Schwabe formulated the term ‘One Medicine’ which was used to emphasize similarities between human and veterinary medicine [1]. As ‘One Medicine’ became an accepted idea, the thinking did not become widely practiced until 2003 when ‘One Health’ was introduced during the emergence of severe acute respiratory diseases (SARS) and the H5N1 avian influenza. The term was formalized through the Manhattan principles which outlined the initial understanding of the connection among major areas- disease, environment, humans, and economic development [1, 2]. Recently, a framework has been developed by multiple global agencies including the World Health Organization, UNICEF, Food and Agriculture Organization, and World Organization for Animal Health, to formalize the ideology. This framework has increased global interest in the approach and its potential implementation areas [3]. The framework describes the connection between people, animals, and our shared ecosystems. As new social determinants of health relating to overall wellness have been addressed including food security, poverty, gender roles, and health systems, the definition of the framework has evolved to consider each of these factors. This has allowed the implementation of the framework in non-communicable areas when looking for prevention and improvement [4, 5].

The foundation of the One Health approach lies in the coexistence and interactions between humans and animals. Many animal species provide a shared reservoir for pathogen exchange and growth, causing infectious diseases to harbor through human-animal interactions [6]. Such interactions include those with pets, during outdoor activities, bug bites, or human consumption of animal products. According to a journal article published in the Indian Journal of Medical Research, 60% of all human diseases are transmitted from animals and 75% of all emerging infectious diseases originate from animals [3]. An example of this link between human and animal health can be seen with bovine tuberculosis (TB) and brucellosis. Both diseases are bacterial zoonotic diseases that are commonly found in cattle and other livestock like sheep and bison [7]. Such diseases can be spread to humans through the consumption of contaminated animal products such as meat or dairy, or through direct contact with infected animals or carcasses. A One Health approach to eliminate the disease in cattle, through vaccination and antibiotics, has significantly reduced the number of TB cases among animals and thus humans, showing the relationship between infections [7].

Another prominent area of zoonotic infection is seen in domesticated animals or pets. Domesticated animals often serve as intermediate hosts for disease transmission. Cats and dogs provide emotional support and comfort for many families globally. While cases of pets, especially cats and dogs, have been noted for playing a role in disease transmission, public health officials have struggled to address the concern, as a strong bond between domesticated animals and humans exists for a large portion of the population. For successful intervention, officials must consider this bond when implementing changes to reduce the risks of these animals serving as disease vectors [2]. While domesticated animals have not been associated with many of the more widespread zoonotic outbreaks, assessing potential disease transmission through pet-human interaction is important in understanding the animal-human interface that the One Health approach discusses.

The environment is another key component of the One Health approach. Changes in climate and other environmental conditions cause animal species to migrate and inhabit new regions. This can create a wide range of human and animal interactions and prove to be dangerous for other species in various niches [2]. Ecological determinants play an important role in determining disease vectors including but not limited to “climate, vegetation, soil, and other conditions that influence habitat suitability [2].”

Environmental health is associated with levels of environmental pollutants and toxins in the air and climate which are often a result of human behavior. As countries interconnect, the risk of communicable disease is obvious, however the indirect implications on climate and vegetation create a large threat to the longevity of the environment and thus human and animal health and security. Clean air, water cleanliness, and plant purity are all aspects of the environment that are vital to the production of food and resources that humans and animals live and interact with. When these aspects are minimized due to human development and activity such as construction, technological development, usage of greenhouse gasses, plants and living resources are negatively burdened with the indirect consequences [8]. Increase in such human behavior and urbanization has led to an increase in climate change resulting in many of the vital environmental features such as rainforests and ice caps to diminish, slowly resulting in irreversible changes in weather and climate. As these changes occur and environmental threats increase, many chronic diseases related to food, water, and air pollution increase. Some of associated diseases includes Lyme disease, cancer, gastric disease, heart disease, and diabetes [9]. For animals, changes in the environment directly impact their habitats, available nutrients and food, and overall health due to displacement. Looking to how environmental health interacts with human and animal health, may lead to motivation to address such behaviors, as seen with food safety.

While the environment is relevant in all areas, socioeconomic determinants are also important to consider when assessing the level of environmental exposure for individual families and thus associated disease contraction. Those with higher economic security, often live in areas less affected by environmental determinants or can protect themselves from environmental changes. For example, the Chagas disease, said to originate from countries in Latin America, is associated with poor housing living conditions due to inadequate sanitation and less maintained communities, while wealthier communities are less prone to outbreaks [2]. While these discrepancies can be applied within small communities, they can also be applied when looking at the differences in health outcomes across nations. As discussed in this paper, global health of non-communicable diseases often varies drastically by region. Health outcomes in low-and-middle-income (LMIC) countries are often lower than that of wealthier nations such as America. This can be attributed to the differences in exposure to the three main roots of the framework, as well as the resources available to protect from certainly associated threats [1].

As the world continues to become more interconnected through trade, travel, and shared routes of knowledge, the threat of disease has increased on local, regional, and global levels [1].

The 1999 emergence of encephalitis cases in people and birds, which was linked to the emergence of the West Nile virus in the US, left public health officials challenged with controlling the outbreak and identifying its origin. Insight from the veterinary community who was investigating associated bird mortalities helped public health officials determine the origin [1]. This outbreak proved to officials that the need for communication between practitioners is vital for understanding disease epidemiology and treatment. Rabies is another disease that is associated with the interaction between humans and animals. However, parts of North America and Western Europe have controlled rabies using the One Health approach. Canine vaccinations have proved to be an effective strategy to reduce disease by reducing the risk of human infection through the reduction of disease within the animal reservoirs themselves [1].

Connections between animals, humans, and the environment have also been shown through the COVID-19 pandemic. Initially, the virus was traced to an animal reservoir, and mutations of the virus through these reservoirs have been noted. Additionally, cases of the virus were found in different animals globally, affecting both human and animal populations [10]. The lack of a robust One Health approach in dealing with the virus, led to universal impacts on all nations and countries, socially, politically, and economically. The inability of governments to address the outbreak effectively has further exposed gaps in the healthcare systems and the existing public health response plans.

Implementation of the One Health framework has been difficult to establish due to various perspectives of the framework, lack of formal institutionalization, various understandings of the approach, and limited case study examples of its implementation. The US Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) Program PREDICT project has worked to address this issue by using a One Health approach that is focused on early detection and response to zoonotic threats before they widely impact humans. The PREDICT project surveys hot spots for emerging infectious diseases, this data is then shared across platforms for coordination of response by multiple stakeholders including government agencies and university partners [1]. According to a study published in Biomed Central (BMC), the PREDICT Project “empowered health care providers in more than 30 LMIC by connecting them with animal and environmental health professionals [1].” The PREDICT project collects data about the environment, animals, and humans when looking at a specific problem with all three prongs of One Health in mind. For example, weather conditions have been studied to predict Rift Valley fever and other outbreaks of disease relating to climate change. This was done through vaccination and mosquito control campaigns at a time close to when the findings concerning weather conditions were approaching to reduce the risk of human infection [1].

Additionally, the recent emergence of the Monkeypox virus, a variation of the once-eradicated smallpox virus, has also shown the link between infection and transmission between humans and animals. While Monkeypox is still fairly novel and research is still limited on the virus, its contraction, spread, and treatment, it has been proven and reported by the CDC that disease transmission to humans can occur between infected animals or humans [11]. While the exact disease host has not been identified, the CDC suggests it is likely that the virus mutated in rodents and spread to humans through animals [11]. As public health officials work to address this new outbreak, they are looking to the animal-human interaction, hoping to understand mutations when designing treatment.

2. Framework in practice

2.1 Importance of one health in maternal and child health

The One Health framework has many applications for a broad range of public health issues, as previously discussed, many of the common applications of the approach are related to communicable zoonotic diseases. However, the framework is also relevant and necessary to understand the complexities of other health conditions globally, including maternal, newborn, and child health. Complex systems with interlinkages between the environment, human health, agriculture, and zoonosis influence many aspects of population health. A notable reflection of the One Health framework within maternal and child health is that of child stunting.

Stunting, which is low height for age, is a historic and pervasive global nutrition health issue – roughly 22 percent of children under age five are stunted, translating to 149.2 million children [12] Stunting is associated with several negative health outcomes, including the risk of mortality from common infections, impaired motor, and cognitive development, the risk of future chronic disease, and contracting infections [13]. Though traditional interventions such as nutrition education and counseling, immunization programs, school feeding programs, distribution of nutrition packets, and water, sanitation, and hygiene (WASH) programs have attempted to reduce stunting in LMIC, there still remains a gap in sustained reductions in stunting in these settings [14].

Utilizing a One Health approach may better address the root causes of childhood stunting and offer solutions that address multiple potential leverage points in the animal, environmental, and human systems that impact childhood nutrition [15]. Animal-human links through livestock, a common exposure for communities in rural areas of LMIC, provide opportunities for fecal contamination, which can spur the vicious infection-malnutrition cycle [16, 17]. However, livestock can also be valuable for child nutrition as they can act as a source of essential micronutrients through milk, eggs, and meat [18]. Next, animal-environmental links such as unregulated management of animal feces can lead to contamination of food sources in the absence of adequate WASH infrastructure, further impacting childhood stunting by contributing to the infection-malnutrition cycle [19, 20]. The impact of a balanced diet through healthy agriculture and the environment also impacts livestock health, which in turn affects the quality of dairy and meat consumption by children [21, 22].

Lastly, the environmental-human links are notable factors contributing to stunting Human fecal contamination from poor WASH systems, contamination from bacteria in soils, and exposure to fecal contamination from livestock put young children at higher risk for infections that exacerbate stunting [23, 24, 25]. This is especially problematic for young infants that often engage in the exploratory behavior of hand- and object-mouthing as they develop, which increases the risk of infections through fecal and soil contamination [26]. Additionally, the quality of crops influences the quality and diverse diet for children, further impacting nutrition and subsequent stunting [27, 28].

Especially in the face of climate change, public health interventions to address prominent maternal and child health issues can utilize a One Health approach combined with systems thinking to analyze interactions between the environment, humans, and animals to order to design better multi-pronged programs to intervene in multiple areas that influence maternal and child health and identify potential leverage points for interventions [29]. A notable benefit of a One Health approach is in the many improvements to multiple facets of health that would occur given shared root causes of poor health outcomes and inequities – a One Health method to designing public health programs would not only lead to positive health outcomes but potentially poverty reduction and education and social outcome improvements as well [30].

2.2 Food security and Rwanda

Another example of the potential of the One Health framework being applied to nonconventional and nonzoonotic issues is food security. Rwanda is one of the most densely populated countries with an average of 415 people per square mile. This has caused disasters to occur on a large scale and affect a large number of people. The high population density has also led to increased food insecurity, soil erosion, decreased grazing land, and forest degradation, which in turn has caused issues with food insecurity and thus poorer health outcomes [31]. In a report by the World Food Programme, it was estimated that 38.2% of the country lived below the poverty line, with about one-fifth of the 12 million population being considered food insecure, leading to developmental and growth issues in adults and children [32].

While Rwanda is a densely populated country, its economic resources are not substantial to support the large population, which consistently changes as pastoral communities increase. This has contributed to the high levels of poverty and food insecurity [33]. A large portion of the land in Rwanda is used for pastoral communities as the number of travelers, especially in the Eastern region of Rwanda is vast. Rwanda thus experiences an influx of many novel interactions between people, animals, practices, and microbes. This further contributed to the food insecurity that occurs due to changes in agriculture, population density, and consistent changes in the land and soil (Nyatanyi). Pastoralists often pick up animal pathogens and carry them as they migrate, affecting livestock populations and leading to disease in communities (Nyatanyi). This leaves many travelers and natives at risk of contracting diseases and spreading them as they migrate. Rwanda also has a high number of refugee communities, which often increases the demand for resources such as food and water, however, is difficult to supply as the natives of the country also have trouble receiving such resources [34].

In order to combat many of these challenges, Rwanda has adopted initiatives rooted in the One Health principles to help eliminate some of these food access concerns in order to provide a sustainable food source for families, while limiting the risk of unsafe food contamination and microbial diseases. One way this has been achieved is through the Girinka system [31]. Through the Girinka program, one cow is gifted to each family in an attempt to alleviate malnutrition [31, 32]. The Girinka program has helped provide a stable source of food and security to families and contributed to various other stakeholders involved in the public health sector to combat the issue of food security. In addition to the Girinka program, improvements in public health indicators such as maternal health and HIV cases have been identified, and efforts towards environmental sustainability to improve the soil and agricultural land in Rwanda have been initiated [31]. Through analysis of each component of the framework, Rwanda’s public health sectors have been successful in working towards solving the issue of food security.

The goals established to improve food security and associated health risks are all rooted in promoting overall health and wellness to account for the large population density of the country and to protect neighboring countries as pastoral culture exists in this region of the world. Collaboration between the University of Rwanda, the Ministries of Health, Agriculture and Animal Resources and Education, The Wildlife Unit of the Rwanda Development Board, and other ministries and civil society have been reported and are increasing efforts on the problem as stakeholders are united in their work through an interdisciplinary approach [31]. Using the animal-human-environment relationship to study how food security has been linked to each of these components has led to successful solutions for Rwanda. Continued efforts through programs such as Girinka are promising in further decreasing food insecurity.

3. Implementation challenges of the one health framework

While the One Health approach is gaining traction and being supported by governmental agencies such as WHO and APHA, there are various challenges that prevent communities and governments from implementing the framework. One large concern from agencies is socio-political factors. An emphasis on a direct-harm approach rather than prevention is prevalent in many countries and is reflected by disproportionate focus and resources towards medical treatment rather than public health system strengthening [6]. Political beliefs can also be an obstacle faced by stakeholders attempting to establish a One Health-based framework, as governments emphasize public health research and importance differently.

Much of the One Health approach is surrounded around the “precautionary principle” to reduce the risk of harm. However, this requires upfront sacrifices such as financial investments that the governments of most countries are not willing to make, despite the long-term benefits where an initial investment can save millions of dollars and lives [6]. According to an analysis by the World Bank, upfront global investments of $3.4 billion per year for One Health, through veterinary and public health services, could save over $30 billion in response and treatment of zoonotic diseases annually worldwide [1]. However, often these upfront investments seem too large for already struggling governments. This has led to weakened public health sectors, causing outbreaks to reach levels of endemism and even pandemics.

Another large implementation challenge for One Health is seen in ethics. During a significant outbreak of disease, resources are limited and decisions about which groups receive supplies and treatments need to be made. This can create ethical concerns and raise questions regarding decisions of distribution of resources. This may also create disagreement about who is qualified to make such decisions [6]. For example, in Canada during the SARS outbreak, leaders were not prepared for the range of ethical concerns that were brought to their attention. These concerns included individual freedom versus the common good, healthcare workers’ safety versus their duty to care for the sick, and economic costs versus the need for containment.

Additionally, for many religious groups, the desire to go to their place of worship was also something government officials had to make decisions about, creating two groups of people, one content with the decision and another angered by it [6]. These issues resurfaced during COVID-19 as the symptoms and transmission of SARS and COVID-19 are rooted in similar physiology. Considering these factors is vital for the successful implementation of a risk management technique rooted in One Health as community members must oblige to recommendations in order for its success.

Finally, legal challenges are another major factor that government workers, public health professionals, and medical practitioners must consider when implementing the framework. Different states, countries, and other leading bodies have individual laws and expectations for addressing re-emerging and emerging health concerns. This can create conflicting plans and further lead to chaos among citizens and confusion about which guidelines to follow [6]. Confusion between state and national laws can lead to prolonged responses in dealing with crises and increase risk and damage. Additionally, majority of laws regarding the emergence of disease and public health crises look at preventing cross-border pathogen transfer and community outbreaks, rather than interactions between animals, the environment, and people [6]. To combat this, there must be organized and widely accepted guidelines for governing bodies to refer to, which would increase likelihood of stakeholder participation in implementation and thus success of a One Health approach to prevention and solution.

4. Looking forward and conclusions

An important aspect of One Health’s implementation is the need for globalized and institutionalized definitions and guidelines that can be available to all nations through public health organizations. A variety of interpretations of the framework and its practice have left nations skeptical of adopting it into their emergency plans when health concerns erupt [35]. A standardized framework would help with the identification of the value of interdisciplinary work in addressing communicable and noncommunicable concerns by eliminating discussion about how this can be done. Efforts of various health sectors must be united to create a globally understood and accessible framework with a breakdown of how each stakeholder plays a role in practical application [35, 36].

Another way to increase One Health awareness is by including its teachings in the curriculum and training potential stakeholders of the approach such as doctors, veterinarians, policymakers, lawyers, etc. These stakeholders should be trained in the framework and gain a deeper understanding of its applications through the advocacy of case studies that have proven its effectiveness and potential application such as those outlined in this paper. While the One Health framework has become increasingly accepted due to increased public health education, many practicing doctors and veterinarians were not taught the framework - this is problematic as they are often the first line of defense in controlling zoonosis. Increasing public health curricula in medical and veterinary schools will better equip the next generation of officials to understand a preventative outlook, this is especially important as once eradicated diseases are reemerging.

The establishment of clinics and partnerships that function using a combined approach is another way to increase One Health usage for communicable and noncommunicable areas of concern. A clinic in California, Knights Landing One Health Monthly Clinic, provides both animal and human services for economically disadvantaged communities [37]. This clinic was developed by the UC Davis School of Medicine and Veterinary Medicine and is run by students who desire the promotion of a One Health approach that harbors holistic treatment. Clinics and health services such as this promote communication and the vision of a united goal for health that includes animals, humans, and the environment [37]. With proper execution and medical practice, clinics such as this can be successful in looking at treatment and prevention as an extension of the codependent relationship humans and animals live within.

As previously emphasized, the interaction between humans, animals, and the environment is what makes the One Health approach different from others - this means the public sector of nations must be involved in the implementation of a successful outcome as they harbor this trifold interaction. The public should be educated about the risk of disease to increase awareness about the animal, human, and environmental interface. This will not only help promote the framework, but also help with risk assessment. Community members being involved in their own health has proven to show improved health outcomes, this is especially important for developing countries as their threat to community safety is larger due to living conditions and large populations [37]. Through increased training and education on the framework, different stakeholders will be united in their efforts, harboring stronger communication.

The One Health framework is widely known among public health officials, however, is not often seen as a solution by stakeholders previously mentioned. This has limited capabilities and applications of a potentially vital component of risk management. As outlined in this paper, the One Health framework is most often applied to zoonotic diseases which can be transferred from humans to animals. These diseases are communicable and pose a great threat to communities, especially those which are close-knit with dense populations. While the approach can be successful to limit such outbreaks, the core principles of the framework make it adaptable to other areas of concern as well. Studying the interface between three major interacting components of our world can help to explain other illnesses as well, such as those explained in the paper with maternal and child health and food security. Addressing how the three areas coexist and influence noncommunicable areas of concern can help provide public health officials and medical practitioners with robust and multifaceted solutions to both communicable and chronic health issues.