One World, One Health: Prevent Zoonoses, Stop the Spread

One World, One Health: Prevent Zoonoses, Stop the Spread

Deepali G. Kalambhe, Assistant Professor

Department of Veterinary Public Health and Epidemiology

Centre for One Health ,Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana

The idea of “One Health” has become more and more popular in today’s globalised society as zoonotic diseases transferring from animals to humans become more and more of a threat to human health. The notion of “One World, One Health” embodies a comprehensive strategy for public health that highlights the mutual dependence of human, animal, and environmental well-being. Human health is inextricably linked to the health of animals and the environment in a world where connections are growing. The COVID-19 pandemic provided a striking example of how a zoonotic virus may quickly develop into a global health emergency that affects people’s daily lives, economies, and healthcare systems around the globe. We can control and lessen the effects of zoonotic illnesses by identifying and addressing these relationships. The emergence and reappearance of zoonotic infections during the past 20 years have brought attention to the need for a comprehensive strategy to stop their spread. This article delves into the principles of One Health, the importance of preventing zoonoses, and strategies to mitigate their spread.

Understanding Zoonoses as a Global Threat:

Pathogens including bacteria, viruses, parasites, and fungi that can move from animals to humans are the source of zoonotic diseases. The World Health Organisation (WHO) estimates that animal origins account for 75% of newly emerging infectious diseases and around 60% of all human infectious diseases. Direct contact with infected animals, eating or drinking contaminated food or water, or coming into contact with vectors like ticks, mosquitoes, and rats can all result in zoonotic transmission. Significant outbreaks in the past, such as Ebola, SARS, MERS, and the most recent COVID-19 pandemic all have zoonotic origins. The interplay between environmental, animal, and human health is crucial in the spread of zoonoses. The emergence and spread of these diseases are facilitated by factors that promote human-animal contact, such as urbanisation, deforestation, climate change, and international travel. For example, human exposure to new infections arises from the invasion of wildlife habitats, and the danger of animal-to-human transmission is increased by intensive farming practices.

The One Health Approach: Integrating Human, Animal, and Environmental Health

The goal of the integrative “One World, One Health” approach is to attain optimal health outcomes by acknowledging the interdependence of people, animals, plants, and their shared environment. Collaboration between several fields and sectors, such as environmental health, veterinary medicine, public health, and wildlife conservation, is a key component of this strategy. The cornerstone of One Health’s approach is the monitoring and early identification of zoonotic illnesses. Rapid response and containment are made possible by keeping an eye out for new disease indicators in human, domestic animals, and wildlife populations. Programmes like the Global Outbreak Alert and Response Network (GOARN) and the Global Early Warning System for Major Animal Diseases (GLEWS), for instance, enable prompt information sharing and coordinated responses to possible outbreaks. This strategy seeks to encourage preventative measures that can lessen the risk of zoonotic illnesses, strengthen response capacities, and improve disease surveillance through interdisciplinary collaboration.

Drivers for the Emergence of Zoonotic Diseases:

A complex interplay of ecological, biological, and socioeconomic factors drives the genesis of zoonotic infections. It is essential to comprehend these drivers to anticipate, stop, and manage upcoming zoonotic outbreaks. The main causes of the emergence of zoonotic diseases are listed below, along with pertinent instances.

Environmental Changes:Ecological changes have a major influence on the emergence of zoonotic infections, especially those related to habitat alteration and biodiversity loss.

1. 1. Deforestation and Land Use Change:Natural ecosystems are disturbed by deforestation for infrastructure, urbanisation, and agriculture, which puts people and wildlife in closer proximity. This raises the possibility of animal-to-human disease transmission. For instance, it is believed that human encroachment into forest areas in Central and West Africa gave rise to the Ebola virus outbreak, which spread through contact with bats and primates.
   2. Biodiversity Loss:A decrease in biodiversity may cause a rise in the population of pathogen-hosting reservoir species. This is possible because these reservoir species’ competitors and predators frequently go extinct first. The bacterium Borrelia burgdorferi, which causes Lyme disease, is spread by ticks and is more common in locations where there are fewer mice population which serves as a primary host for Borrelia.

ClimateChange: The dynamics of zoonotic disease transmission are altered as a result of changes in the distribution and behaviour of hosts and vectors.

1. 1. Variations in Temperature and Precipitation:Variations in temperature and precipitation have the potential to increase the habitats of vectors, including ticks and mosquitoes. For example, rising temperatures have made it possible for Aedes mosquitoes, which spread dengue, chikungunya, and Zika, to previously colder areas, raising the possibility of epidemics.
   2. Extreme Weather Events:Droughts and floods are two examples of extreme weather events that are becoming more common and severe due to climate change. Droughts can concentrate animal populations around scarce water supplies, raising the risk of zoonotic transmission, whereas flooding can accelerate the development of illnesses like leptospirosis.

AgriculturalPractices: The management of livestock and intensive farming methods can foster the emergence of zoonotic diseases.

1. 1. Intensive Livestock production: The risk of disease transmission between animals and humans is increased in high-density animal production systems. For example, the 2009 H1N1 influenza pandemic is thought to have emerged as a result of the re-assortment of viruses in pigs reared under an intensive production system.
   2. Wildlife Trade and consumption of Bush meat:The capture, trade, and consumption of wild animals can expose people to new infections. The coronavirus causing Severe Acute Respiratory Syndrome (SARS) first emerged in 2002–2003, most likely from Chinese wildlife markets where the civet cats which serve as the reservoir hosts for the virus were traded.

Increased international travel and trade:Increased international travel and trade have the potential to quickly spread zoonotic illnesses across national boundaries. Originating in Africa, the West Nile Virus made its way to North America in the late 1990s via infected birds and mosquitoes, helped along by global travel and trade.

4. Microbial Evolution and Adaptation:Pathogens can undergo evolutionary changes adaptations and genetic alterations through reassortment or mutation, which can result in the creation of novel strains that can infect humans. For instance, the reassortment of influenza viruses in pigs, humans, and birds led to the emergence of the novel H1N1 influenza virus.
5. Antimicrobial Resistance:The overuse and misuse of antibiotics in animal husbandry and human medicine both lead to the emergence of organisms that are resistant to antibiotics, which can make treating zoonotic infections more difficult. The Methicillin-resistant Staphylococcus aureus (MRSA) is an example of a pathogen that has emerged in livestock and can infect humans.
6. Social Behaviour and Economic Elements: The genesis and transmission of zoonotic illnesses are significantly influenced by human activities, behaviours, and socioeconomic factors. Living conditions become crowded due to rapid urbanisation and population growth, which might promote the spread of infectious diseases. The SARS-CoV-2 virus, which is responsible for the COVID-19 pandemic, is believed to have started in Wuhan, China, a heavily populated city with a high degree of human-animal interaction.

Historical significance of zoonotic outbreaks in India:

India, a country with enormous ecological diversity, witnessed the emergence of several zoonotic diseases attributed to anthropogenic activities. Among the noteworthy instances are

1. Nipah outbreak:The Nipah virus was first identified during an outbreak in Malaysia in 1998-1999 but emerged in India in 2001 and has since caused several outbreaks, most notably in Kerala in 2018 and 2019. Human intrusions into bat habitats through deforestation and land use increase contact between bats and humans. In Kerala, the outbreaks were associated with closer proximity between bats and human populations due to habitat loss. Contamination of raw date palm sap with bat saliva or urine has been linked to the transmission of the virus.
2. KyasanurForest Disease (KFD): Also referred to as Monkey Fever, KFD was initially identified in 1957 in the Karnataka region’s Kyasanur Forest and resulted in sporadic epidemics. Deforestation is the primary factor for the emergence of KFD in the area. The logging and deforestation in the Western Ghats have disrupted the habitats of ticks and monkeys which serve as the vector and reservoir respectively for the KFD virus. Human exposure to infected ticks has grown as a result of the conversion of wooded regions into agricultural lands.
3. Rabies: Rabies is endemic in India, accounting for almost one-third of all rabies deaths worldwide each year. It is primarily transmitted through dog bites. Rapid urbanization and inadequate waste management have led to an increase in stray dog populations. These canines serve as rabies virus reservoirs which increase the risk of human infection.
4. Leptospirosis: Leptospirosis is prevalent in several parts of India, especially in regions prone to flooding and heavy rainfall. Poor urban planning and inadequate drainage systems lead to frequent flooding in cities. Farmers working in flooded fields are at higher risk of exposure to Leptospira bacteria, especially in states like Kerala, Gujarat, and Maharashtra where outbreaks have been documented.
5. Crimean–Congo Hemorrhagic Fever (CCHF):The CCHF virus was first reported in India in 2011 in Gujarat and has since caused sporadic outbreaks. The virus is transmitted by livestock ectoparasites called Hyalomma ticks. Intensive farming and trade of livestock facilitate the spread of these ticks and the CCHF virus.
6. Scrub Typhus: Orientia tsutsugamushi is a rickettsial pathogen which causes scrub typhus in humans. The chigger mites are the main carrier vector for Orientia species. The disease is endemic in Tamil Nadu, Uttarakhand, and Himachal Pradesh. Human exposure to chigger mites has increased due to the clearing of forests for agricultural and residential purposes. Changes in land use and agricultural practices have increased the human proximity to mite-infested areas.

Prevention Strategies for Building Resilience against Zoonoses: Preventing zoonotic diseases requires a multi-faceted approach that includes:

1. Encouraging the Conservation of Wildlife and the Protection of Natural Habitats:Maintaining natural habitats lowers the likelihood of spillover events and decreases human-wildlife contact.
2. Boosting Biosecurity Measures:Strict hygienic regulations in markets, farms, and slaughterhouses can curtail the spread of diseases from animals to people.
3. Improving Veterinary and Public Health Capabilities:Investing in public health infrastructure and veterinary services enhances the ability to timely detect, diagnose, and respond to animal diseases. The health systems must be equipped to respond to zoonotic diseases which include training healthcare workers, improving diagnostic capabilities, and ensuring access to necessary medical supplies and treatments.
4. Enhanced Surveillance:The early identification of zoonotic infections depends on the presence of strong surveillance systems. Integrated surveillance that includes monitoring of wildlife, livestock, and human populations can provide early warnings and facilitate rapid response to outbreaks.
5. Encouraging One Health Education and Advocacy:Raising awareness among communities, policymakers, and healthcare professionals fosters a shared responsibility for zoonotic disease prevention. Educating communities about the risks of zoonotic diseases and promoting healthy practices is essential. This includes safe handling of animals, proper food preparation, and hygiene measures to prevent zoonotic infection.
6. Research and Development:It is essential to fund research to comprehend the processes underlying the spread of zoonotic diseases and to provide novel diagnostic tools, prophylactics, and therapeutic interventions. Collaborative research efforts can lead to innovative solutions that address the root causes of zoonotic diseases.
7. Policy and Legislation:Policy and Legislation: Implementing and enforcing policies that regulate wildlife trade, improve animal welfare, and protect natural habitats can reduce the risk of zoonotic disease emergence. International cooperation and harmonized regulations are essential for effective control measures.

Case Studies: Successes and Challenges for “One Health Approach”

The significance of a One Health approach has been highlighted by the COVID-19 pandemic. The virus, believed to have originated in bats and possibly transmitted to humans through an intermediate host, has wreaked havoc on the planet never seen before leading to unprecedented global disruption. The pandemic has highlighted the need for better zoonotic disease surveillance, more robust international collaboration, and better preparedness and response procedures. Numerous triumphant endeavours underscore the efficacy of the One Health strategy.

Through the PREDICT programme, the EcoHealth Alliance could identify over 800 new viruses in Ugandan animals and strengthen local capacity to identify possible pandemics in advance. Similarly, the Southeast Asia One Health University Network (SEAOHUN) improves interregional cooperation in zoonotic disease research and education.

Despite these advancements, challenges persist. Coordinated efforts to combat zoonotic threats are frequently hampered by sociopolitical obstacles, limited resources, and poor healthcare systems. In addition, the emergence of antimicrobial resistance poses a growing concern, necessitating integrated strategies to combat infectious diseases and antibiotic misuse.

Towards Creating a Resilient Future:

One Health concept should be a top priority in global health agendas as the world struggles to recover from the COVID-19 pandemic. To reduce the likelihood of zoonotic epidemics in the future, infrastructural resilience, surveillance, and research investments are crucial. Developing sustainable solutions that safeguard animal and human populations requires international cooperation and knowledge exchange. Several global organisations and campaigns are supporting the One Health paradigm. To address health concerns at the interface of humans, animals, and the environment, the World Health Organisation (WHO), the Food and Agriculture Organisation (FAO), and the World Organisation for Animal Health (OIE) have formed a tripartite partnership. This partnership encourages concerted efforts to improve the security of global health. Additionally, the Global Health Security Agenda (GHSA) also seeks to improve the ability to recognise, avoid, and respond to threats from infectious diseases. The public health, veterinary, and environmental sectors are all included in the multisectoral approach that is emphasised by the GHSA.

Conclusion:

In conclusion, the “One World, One Health” approach provides a comprehensive framework for addressing the intricate problems brought on by zoonotic diseases. As the world continues to face a threat from emerging infectious diseases, adopting and putting into practice a One Health approach is not only advantageous but essential for global health security. We can strengthen our capacity to avoid, identify, and respond to dangers posed by zoonotic diseases by recognizing the interdependence of human, animal, and environmental health and encouraging interdisciplinary collaboration. The prevention and control of zoonoses require concerted efforts, shared knowledge, and sustained commitment from all sectors of society to ensure a healthier, safer world for all. This article explores the critical need for a unified approach to address zoonotic diseases through the lens of One Health, advocating for proactive measures to prevent future pandemics and ensure global health security.

References

1. World Health Organization (WHO). (2020). One Health. Retrieved from [https://www.who.int/news-room/q-a-detail/one-health]
2. Centers for Disease Control and Prevention (CDC). (2021). Zoonotic Diseases. Retrieved from [https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html].
3. EcoHealth Alliance. (2020). PREDICT Project. Retrieved from [https://www.ecohealthalliance.org/programs/56-predict-project]
4. Southeast Asia One Health University Network (SEAOHUN). (2021). Retrieved from [https://seaohun.org/](https://seaohun.org/).

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