The Need to Prioritize Prevention of Viral Spillover in the Anthropopandemicene: A Message to Global Health Researchers and Policymakers

Abstract

Increased anthropogenic activities including changes in land use and unrelenting ecosystem services related to animal husbandry, wildlife trade, and deforestation are driving the emergence of viral zoonosis. This is primarily due to human–animal interaction which is facilitating the spillover of viral zoonotic pathogens from animals (domestic and wildlife) to humans that could result in epidemics or pandemics. Scientific reports so far have revealed that viral epidemics and pandemics in recent years such as H1N1 Swine Influenza, H5N1 Avian Influenza, Ebola, Zika, Severe Acute Respiratory Syndrome (SARS), and the ongoing SARS-CoV-2 were all zoonotic, and their emergence has been linked with spillover events arising from human–animal interaction. This increased interaction and the increased spillover event could facilitate future pandemic risk, and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, “IPBES”, has declared this “the era of pandemics”. Furthermore, since future pandemics would be triggered by anthropogenic activities, we have called this “anthropopandemicene”, i.e., an era of pandemics driven by anthropogenic activities. To minimize the risk of future pandemics, it is important to prioritize the prevention of viral spillover events. Here, we outline five priority areas for global health researchers and policymakers. These areas include improvement of biosecurity at livestock farms, imposing a moratorium or strictly banning wildlife trade that poses a public health risk, conservation of biodiversity by halting deforestation, investing in community-based research for infectious disease control, and strengthening community healthcare systems in precarious ecosystems and infectious diseases hotspots. Finally, we acknowledge the efforts of other renowned global and legally binding frameworks such as IHR, the Paris Agreement, and CITES with regard to addressing the public health risk of infectious diseases, and we provide recommendations for their improvement.

1. Introduction

Concerns about the prevention of anthropozoonosis, also referred to as spillover—a phenomenon that describes the transmission of pathogens from animals to humans—have grown throughout the ongoing Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2— the causative agent of coronavirus disease 2019 i.e., COVID-19) pandemic [1,2,3,4]. This concern arises from the effort of global health researchers in trying to minimize the risk of future pandemics that are likely to be zoonotic in origin, as revealed in the report published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (“IPBES”) [1]. Consequently, in their report, experts convened by the IPBES have clearly stated that humanity has entered the “era of pandemics”, which literally means that pandemics will emerge more repeatedly, be zoonotic in origin (the ability of pathogens from vertebrate animals to cause disease in humans), spread at alarming rates, and cause enormous health and socio-economic damage [1].

Over the last four decades, several publications show that the global widespread of viral pandemics and epidemics such as H5N1 Avian Influenza virus, H1N1 Swine Influenza virus, Ebola Virus, Zika virus, and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) were triggered by spillover events arising from greater human-to-animal interaction related to human activities including animal husbandry, wildlife hunting and trade, and deforestation [1,4,5]. The ongoing SARS-CoV-2 was thought to have its origin in wildlife, i.e., bats. Although the intermediate host has yet to be unearthed, some reports point to pangolins for its molecular sequence similarity to SARS-CoV-2, ranging from 85.5% to 92.4% [6,7,8,9], while other research studies are still underway investigating other hosts such as minks and turtles [5,7,8,9]. All these studies were reported in 2020. However, in a recent study by Nga et al. [10] in 2022, the authors investigated the likely animal sources of SARS-related coronaviruses using the specimen of Malayan pangolins (Manis javanica) and Chinese pangolins (Manis pentadactyla) confiscated from the illegal wildlife trade in Vietnam [10]. Their result revealed that the coronaviruses identified in these pangolins have a close similarity with the coronaviruses previously detected in some pangolins confiscated due to illegal wildlife trade in provinces of China such as Yunnan and Guangxi. This raised concerns that anthropogenic activities such as the movement of wildlife through legal and illegal trade poses a risk of spillover of pathogens in the human population which is capable of initiating epidemics or pandemics.

Against the above-mentioned background, an amalgamation of the Anthropocene era and pandemics coined as “anthropopandemicene”, i.e., an era of pandemics driven by anthropogenic activities was co-created by the authors to augment the link between them. These ever-increasing anthropogenic activities in turn have a profound effect on the planet’s ecosystems and this is obvious from biodiversity loss and climate change, which have been revealed to further accelerate viral spillover [3,11,12,13]. The rapid transmissibility, human health impact, and socio-economic effect of COVID-19—the preeminent pandemic to occur in the 21st century—have highlighted the need to minimize the risk of future pandemics; to achieve this, viral spillover of pathogens must be prevented. However, the risk of spillover is increasing due to the frequent human–animal interaction arising from anthropogenic activities as well as ecosystem services [4,6,11,14]. These activities leading to deforestation of forested areas increase people’s susceptibility to zoonotic diseases as a result of close contact with infected wildlife—shedding the virus and vectors—transmitting the disease [2,11,15,16]. To minimize the risk of spillover events and effectively prevent future pandemics, global health researchers and policymakers should consider focusing on the following priority areas such as improvement of biosecurity at livestock farms, imposing a moratorium or strictly banning wildlife trade that poses a public health risk, conservation of biodiversity by halting deforestation, investing in community-based research for infectious disease control, and strengthening community healthcare systems in precarious ecosystems and infectious diseases hotspots. In this article, we address the need for global health researchers and policymakers to prioritize spillover prevention in the “anthropopandemicene” for global health and biosecurity purposes with a focus on these aforementioned key areas which are further discussed in the paragraph below. Finally, we acknowledge the ongoing efforts of global and legally binding frameworks such as International Health Regulations, CITES (Convention on International Trade in Endangered Species of Wild Flora and Fauna), Paris Agreement, and other relevant intergovernmental organizations such as the World Organization for Animal Health (WOAH, formerly OIE) and IPBES in curtailing the spread of zoonotic infectious diseases and recommendations for improvement were provided.

2. Improvement of Biosecurity at Livestock Farms

Biosecurity, i.e., the prevention of pathogen spread between (and within) herds, is a critical component of disease control in livestock farming [17]. The emergence of highly pathogenic infectious diseases such as avian influenza, Ebola virus disease, H1N1 flu, and, most recently, COVID-19 underscores why biosecurity has become a global public health priority [17]. The widespread prevalence of these diseases as epidemics and pandemics negatively impacts global trade and exports, while also threatening human, livestock, and plant life [18,19]. Specific biosecurity practices, such as the following, reduce the risk of new pathogens being introduced into the farms and their spread within livestock raised for breeding or trading: having and using a herd health plan; limiting and controlling farm visitors; cleaning and disinfecting vehicles and visitor clothing; limiting contact with neighboring livestock; reducing contact with wildlife; proper disposal of dead livestock; sourcing and isolation practices [20] along the production chain.

The WOAH, formerly OIE is saddled with the responsibility of monitoring the infectious diseases that pose a threat to livestock within the trade of animals as well as their products across the globe [2]. Additionally, through the efforts of its over 180 member states, the organization usually provides lists of the diseases that pose a significant threat to livestock and wildlife as notifiable—a precautionary step to prevent zoonotic diseases [2]. To greatly reduce spillover risk, the OIE should work in collaboration with CITES and other organizations at the national level—i.e., those charged with conducting disease surveillance in traded animals—to conduct research aimed at identifying and detecting wildlife carrying zoonosis and implementing effective laws to reduce such risky trade [2].

Socio-cultural approaches have shown the ability to expand more widely used behavioral approaches and lead to enhanced biosecurity policy and on-farm practice design [18,20,21]. These include strengthening the understanding of good farming concepts, tacit knowledge, farmer influence networks, and reformulating biosecurity as localized care practices [21]. Improvements in on-farm biosecurity as biosecure farming care techniques would provide a new approach to managing and containing infections in livestock farms. Additionally, improved surveillance for livestock diseases, quarantine, and adequate treatment of infected livestock are important steps toward limiting the risk of livestock pathogens transmission and the risk of spillover. This is because approximately 80% of estimated livestock pathogens can be transmitted to humans and wildlife during interaction [3,22].

3. Imposing a Moratorium or Strictly Banning Wildlife Trade That Poses a Public Health Risk

In recent years, there have been several health crises occurring from zoonotic transmission, and several deadly diseases such as COVID-19 are believed to have originated from live animals or wet markets [23]. A science reporter once reported that the “life meat market is a perfect laboratory for creating new viruses” [23,24]. According to a recent report, of all zoonotic pathogens, the highest risk of spillover usually arises from viruses, and humans, birds, and mammals are the common hosts [1,23]. As revealed in the IPBES pandemic workshop report, mammals are host to approximately 320,000 viruses that can spread to humans during trade [1]. Wildlife trade, either legally or illegally performed, usually involves unhygienic practices that expose animals, especially mammals and birds—which are highly traded—to conditions that create a Petri dish for the spread of diseases [23]. A recent study that analyzed the data on wildlife trade, obtained from the International Union of Conservation of Nature (IUCN) and CITES, reported that an estimated 18% of all extant terrestrial species are traded globally [24]. However, an increased trading rate was reported for mammals and birds when compared to other species of amphibians and reptiles analyzed [24]. This calls for an urgent need to close the global wildlife markets because the ongoing COVID-19 crisis has been associated with this practice [25]. A moratorium or strict trade policy should be imposed on the wild mammals and birds that pose a significant spillover risk, this is due to their genetic proximity to humans that could facilitate spillover of pathogens [1,26].

However, this policy should aim to impose strict deterrents on the trading of endangered species on the CITES lists, and illegal wildlife trading should be prohibited at all costs. To facilitate the global zoonotic diseases detection effort, such policy also needs to consider wildlife management and strengthening infectious disease surveillance in wildlife. This will allow an effective identification of pathogens and risk factors associated with their transmission from animals to humans. A targeted ban without compromising the food security of local communities and indigenous people would be more effective than a strict ban, and it would also have fewer adverse effects [4]. For example, China has placed a targeted ban on the trade and consumption of terrestrial wildlife, while Gabon has prohibited the sale and consumption of mammal species, in response to the COVID-19 pandemic [3]. In addition, recent guidelines proposed by the World Health Organization (WHO), OIE, and the United Nations Environment Programme have recommended that all countries in the world should place a ban on the trade of live wild animals, especially the mammalian species either for food or breeding purposes [27]. Since these measures are necessary to minimize spillover risk and in preventing an outbreak, it is important to place a focus on known reservoir host species of zoonotic diseases as this will further protect public health from the negative effects of a strict ban [28,29]. The negative effect of a strict ban includes but is not limited to the surfacing of underground markets facilitated by corruption or disguising exotic meats as domestic animals—activities that promote higher risks of spillover [29]. There will be a continuous spread of diseases and loss of lives globally if collaborative, detailed, and regulated policies are not implemented.

Regarding the spread of infectious diseases linked with increased international travel and trade (not limited to wildlife), the World Health Assembly (WHA) of the WHO called for the revision of the International Health Regulation (IHR) in 1995 to expand the scope of diseases of public health significance regardless of the source [30,31]. This led to the implementation of IHR (2005) with the objective of preventing, protecting, controlling, and providing adequate public health response to diseases of international concern without interfering with international trade and traffic [30,31]. The IHR (2005) provide a legally binding framework to countries for event coordination that may result in international public health risk and for improving their preparedness to manage any global health risk [31]. For IHR (2005) to be more effective against the emerging risk of zoonotic infectious diseases, there is a need to seek strong synergies with other relevant agencies and sectors at the global, national, and local levels. The pandemic caused by COVID-19 could serve as a lesson on the need for collaborative efforts across all scales to achieve sustainable preparedness and containment effort for disease outbreaks.

4. Conservation of Biodiversity by Halting Deforestation

One of the most serious threats to biodiversity is habitat degradation or loss which is caused by deforestation [32,33]. Deforestation is followed by dominant anthropogenic processes such as the alternation of natural landscapes for agriculture and urbanization, encroachment of human activities into natural regions, the intentional or unintentional introduction of non-native species, and direct harvesting of wildlife [34]. Encroachment into wildlife habitats for agricultural purposes can result in deforestation—an important driver of climate change—which in itself helps to facilitate the risk of spillover [3,6,13]. This usually happens by forcing animals such as bats out of their degraded habitat into human settlements [3]. These processes present new challenges in the sense that novel pathogens may originate through spillover, which can affect preexisting pathogens. These challenging threats have a significant impact on plant and animal ecosystems, changing the transmission of zoonotic pathogens that they carry [34]. According to Morand et al. [35], most outbreaks of infectious and vector-borne zoonotic diseases are linked to deforestation. For example, in a study by Rulli et al. [36], the authors reported a significant relationship between outbreaks of Ebola virus disease in rainforests of Central and West Africa and deforestation of forested areas that could have led to increased human contact with bats—the animal reservoir of the Ebola virus.

Halting deforestation to conserve biodiversity is a potential strategy to maintain the ecosystem health and protect public health. Public health policymakers should consider implementing international governance of forests and their contributions to the health of the planet and people to halt deforestation [35]. In addition to this, policymakers should consider promoting policies that halt deforestation. This can be in the form of enhancing and supporting better monitoring of forested areas, provision of market incentive measures such as certification of logging concessions as well as financial incentives for farmers to prevent further loss of forest habitat and biodiversity [3]. Deforestation results in the emission of greenhouse gases (GHGs) such as CO₂ (carbon dioxide), which facilitates the risk of climate change. Fluctuating temperatures create a favorable condition for zoonotic pathogens to thrive, leading to potential spillover risk [3,6]. Climate change, deforestation, and loss of biodiversity are interlocking crises that can be addressed holistically in a multisectorial planetary health fashion [6]. One satisfying solution is for countries to remain committed to the global framework set out by the Paris Agreement (a legally binding global climate change treaty), particularly article 5, paragraph 2, which emphasized the need for parties to take action in providing support for the implementation of policy approaches and positive incentives on anthropogenic activities that could result in decreased emission of GHGs from deforestation and forest degradation, the importance of conservation of forest carbon stocks, and affirming the essentiality of sustainable management of forests and enhancement of forest carbon stocks through the emission reduction programs such as RDDT+ initiatives in developing countries [37]. The climate change treaty also explicitly acknowledged the importance of joint mitigation and adaptation approaches as an integral component of forest management and conservation, which could lead to a decrease in the spillover rate [37].

The development of research into the effects of forests on disease regulation would aid in the better management of forests and planted areas [35]. It is also important to understand that forests contribute much to biodiversity and that their conservation would help in safeguarding the health of humans by reducing the risks of zoonotic diseases [34]. Conservation of biodiversity can be achieved through political will and investment of financial resources in measures to keep the biodiversity as well as its wildlife inhabitants intact by limiting anthropogenic encroachment. Governments across the world should realize that the return on this investment is human health security, hence the need for investment [8].

5. Investing in Community-Based Research for Infectious Disease Control

Community-based research involves the consideration of the cultural, structural, social, and environmental inequalities through the active engagement of community members, community representatives, and local scientists in all aspects of the research process [38]. In relation to infectious disease control, particularly zoonosis, such research is expected to focus on the eco-epidemiology, diagnosis, treatment, and prevention of pathogens of public health importance in community-acquired infections for the optimal health benefit of the community [38]. It is widely recognized in the academic literature that the initial identification of emerging zoonotic infectious disease outbreaks usually occurs at the community level [14,36]. Despite this, there are fewer published data comprehensively describing the risk of disease emergence in local communities [14,39,40].

This research is very important in addressing the socio-cultural barriers associated with public health programs [41,42,43]. It is also essential in understanding the knowledge, attitude, and perception of the local communities on sociological and ecological factors that drive zoonotic infectious diseases and the health-seeking behavior of the local communities that could result in informed action for change [14]. Beyond this, it could also lead to the identification of potential infectious disease hotspots for adequate surveillance measures, and early prevention of zoonotic disease outbreaks before they escalate to an epidemic or pandemic—once they cross the international boundaries [14,36]. Furthermore, ethnographic data obtained through infectious disease research may reveal the potentially risky behaviors and practices of local communities to better understand the trend of zoonotic infectious diseases risk and sustainable measures to address this risk [14,36,44]. Unfortunately, community-based research for infectious diseases control is very low in both developing and developed countries, as evidenced by the scant published data that report this [40]. However, report findings in less-developed countries are considerably fewer when compared to those in well-developed countries. This has been associated with poor research funding for public health and infectious disease researchers in less-developed countries [45].

This poor research funding provides an avenue for researchers from well-developed countries in the Global North, with more financial power over local scientists and collaborators from the less-developed countries in the Global South, to conduct research and published their findings. Most times, the research is conducted with no involvement from local scientists and does not provide any benefit to the local community, a phenomenon known as “helicopter research” [46]. For example, in an analysis carried out on different studies on infectious diseases in Africa, the result revealed that less than half of these publications featured an African author as first or last contributor [47]. To limit this unethical practice, the availability of sufficient financial resources for researchers in the Global South is one step forward that could allow local scientists and researchers to conduct infectious disease research for adequate prevention of disease outbreaks in the nick of time.

6. Strengthening Community Healthcare Systems in Precarious Ecosystems and Infectious Diseases Hotspots

Epidemics and pandemics of infectious diseases have periodically threatened the health and livelihoods of people in developed countries and developing countries [48,49]. Studies have shown that the risk of emerging infectious diseases has increased over time, due to increased international travel, trade, animal husbandry, rising human population density, and changes in interactions between humans and wild animals [49,50,51]. The emergence of these drivers of disease is likely to intensify [49] due to ecological change and disruption such as global warming, which will further increase the risk of disease emergence [52]. Given the public health risk posed by these epidemics and pandemics, it is critical to strengthen the community healthcare systems in infectious disease hotspots such as low and middle-income countries in the Global South region such as Southeastern Asia, and West and Central Africa, where the standard of healthcare facilities is low compared to the global standard. Tackling these existing health inequalities will allow for effective disease containment [52].

Consequently, the holistic understanding of a health system building blocks identified by the WHO such as essential service delivery, quality health workforce, health information systems, accessibility to medicines, financing, and governance will help in addressing the challenges associated with community health systems [53,54]. Furthermore, communities must be integrated and engaged in planning, delivering, and evaluating health services, and this has become even more evident with recent outbreaks of infectious diseases such as Ebola and the ongoing COVID-19 pandemic [53,54,55]. The pandemic could have been significantly mitigated if the community health systems had been better prepared. South and Southeastern Asia, West and Central Africa, and Latin America have been identified as potential global hotspots for zoonosis; therefore, health capacities for disease surveillance, monitoring, and reporting of cases need to be further strengthened in these regions for adequate control [56].

7. Recommendations and Conclusions

The COVID-19 pandemic has revealed the devastating impact of zoonotic infectious diseases on the human population. The experts convened by the IPBES have revealed that future infectious diseases will originate from wildlife and be zoonotic in origin. However, the ever-increasing anthropogenic activities and ecosystem services are important factors triggering spillover events and the emergence of zoonotic infectious diseases. To ensure an adequate response to emergencies through public health approaches, and to improve the baseline health and wellbeing of the population against future outbreaks, it is necessary to strengthen the community health capacities and increase investments in public health emergency preparedness. Additionally, enhancing the international cooperation and solidarity, implementation and multisectoral action of global commitments at the national level is a better way forward for early response to zoonotic diseases. Addressing health inequities by prioritizing the needs of vulnerable populations and improving health literacy and the responsiveness of the health system to people’s cultural and socioeconomic context is a vital step in winning the fight against zoonosis [56]. The overarching efforts of intergovernmental organizations such as IPBES and WOAH, as well as other relevant legally binding frameworks such as IHR, CITES, and Paris Agreement, in curbing zoonotic disease outbreaks are very much acknowledged; however, their impact on the community level is not adequately translated into action. Therefore, this calls for the involvement of community-based practices and education to better understand the undermining factors that trigger spillover risk. One of the best ways to achieve this is through rigorous research and development that empowers a new road map of grassroots initiatives that aligns with the objectives of existing initiatives at the global level. In conclusion, global solidarity and cooperation among governments, civil society, international health organizations private sectors, and local communities are essential to overcome the health challenges of the 21st century [57,58].