“ONE WORLD, ONE HEALTH: PREVENT ZOONOSES”

“ONE WORLD, ONE HEALTH: PREVENT ZOONOSES”

Swagat Patnaik^1*

^1*Siksha ‘O’ Anusandhan, Bhubaneshwar-751003

Introduction: –

In an increasingly interconnected and globalized world, the health of humans, animals, and the environment is intricately linked. Zoonoses, diseases that can be transmitted between animals and humans, have emerged as a significant threat to public health. The concept of “One World, One Health” has gained momentum as a holistic approach to addressing zoonotic diseases, recognizing the interdependence of human, animal, and environmental health. This article explores the importance of the One World, One Health initiative in combating zoonoses and safeguarding the well-being of our plan.

Understanding Zoonoses: –

A Zoonosis is any disease or infection that is naturally transmissible from vertebrate animals to humans. There are over 200 known types of zoonoses. Zoonoses comprise a large percentage of new and existing diseases in humans. Some zoonoses, such as Rabies, are 100% preventable through vaccination and other methods. Zoonotic diseases have been a part of human history, with outbreaks like the bubonic plague and influenza pandemics demonstrating their devastating impact. In recent years, diseases such as Ebola, SARS (severe acute respiratory syndrome), MERS (Middle East Respiratory Syndrome), and, most notably, COVID-19, have highlighted the urgency of addressing zoonoses.

Zoonotic diseases can originate from various sources, including wildlife, domesticated animals, and livestock. Pathogens can cross species barriers through direct contact, consumption of contaminated food or water, or vectors such as mosquitoes and ticks. Factors like deforestation, habitat destruction, illegal wildlife trade, and intensive animal farming practices can increase the likelihood of zoonotic spillover.

Zoonoses are infectious diseases that can be transmitted between animals and humans. These diseases can be caused by bacteria, viruses, parasites, or fungi, and they can spread through direct contact with an infected animal or through vectors such as mosquitoes, ticks, or fleas. Zoonotic diseases have been responsible for numerous outbreaks and pandemics throughout history, and they continue to pose significant public health challenges globally.

ETIOLOGY OF ZOONOSES

The aetiology of zoonoses refers to the various microorganisms that can cause these infectious diseases. Zoonotic diseases can be caused by different types of pathogens, including bacteria, viruses, parasites, and fungi. Here’s an overview of the aetiology of zoonoses:

Bacterial Zoonoses:

Salmonella: Salmonella species, such as Salmonella enterica, can cause foodborne zoonotic infections. Contaminated food products, especially poultry, eggs, and unpasteurized dairy products, are common sources of infection.

Brucella: Brucella species, including Brucella abortus and Brucella melitensis, can cause brucellosis, a bacterial infection primarily transmitted through contact with infected animals or their products (e.g., raw milk, unpasteurized cheese).

Escherichia coli (E. coli): Certain strains of E. coli, such as Shiga toxin-producing E. coli (STEC), can cause severe foodborne illnesses. Contaminated meat, dairy products, and fresh produce are common sources of infection.

Viral Zoonoses:

Influenza: Influenza viruses, including avian influenza viruses (e.g., H5N1, H7N9) and swine influenza viruses, can be transmitted from animals to humans. Direct contact with infected animals or their secretions/excretions is the primary route of transmission.

Rabies: Rabies is caused by lyssa viruses, which are primarily transmitted through the bite or scratch of an infected animal, most commonly dogs, bats, and wildlife.

Hendra and Nipah Viruses: These viruses, belonging to the Paramyxoviridae family, are associated with severe respiratory and neurological diseases. Fruit bats (also known as flying foxes) are considered natural reservoirs, and transmission to humans can occur through contact with contaminated fluids or tissues of infected animals.

Parasitic Zoonoses:

Toxoplasmosis: Toxoplasma gondii, a protozoan parasite, can cause toxoplasmosis. Infection can occur through the ingestion of undercooked meat containing tissue cysts or exposure to cat faeces.

Leishmaniasis: Leishmania parasites, transmitted through the bite of infected sandflies, can cause various forms of leishmaniasis in humans and animals.

Taeniasis/Cysticercosis: Taenia solium, a tapeworm, can cause taeniasis (intestinal infection) in humans. The larval form, cysticercosis, can develop in various tissues, including the brain and muscles, when humans ingest eggs through contaminated food or water

TRANSMISSION OF ZOONOTIC DISEASES: –

Zoonotic diseases can be transmitted through various routes, depending on the type of pathogen and the specific disease. Here are the primary modes of transmission for different types of zoonotic diseases:

Direct Contact:

Rabies: Transmitted through the bite or scratch of an infected animal, usually a mammal-like dog, bat, or raccoon.

Brucellosis: Contracted through direct contact with infected animals, their bodily fluids (e.g., blood, milk, urine), or tissues and commonly associated with livestock such as cattle, goats, and sheep.

Vector-Borne Transmission:

Lyme disease: Transmitted through the bite of infected black-legged ticks carrying the bacterium Borrelia burgdorferi.

Malaria: Transmitted through the bite of infected female Anopheles mosquitoes carrying the Plasmodium parasite.

West Nile fever: Spread through the bite of infected mosquitoes, primarily Culex species, carrying the West Nile virus.

Foodborne Transmission:

Salmonellosis: Acquired through consuming contaminated food products, particularly raw or undercooked eggs, poultry, meat, or dairy.

Campylobacteriosis: Usually associated with consuming undercooked poultry, unpasteurized milk, or contaminated water.

1. coli infections: Ingesting contaminated food or water, especially undercooked ground beef, raw vegetables, or unpasteurized dairy products.

Waterborne Transmission:

Leptospirosis: Contracted by coming into contact with water, soil, or food contaminated with the urine of infected animals, especially rodents.

Cryptosporidiosis: Caused by ingesting water or food contaminated with the Cryptosporidium parasite, often found in recreational water sources or livestock faeces.

Airborne Transmission:

Tuberculosis (TB): Can be transmitted through inhalation of respiratory droplets containing the bacteria Mycobacterium tuberculosis, usually from infected humans but also from animals like cattle.

Avian Influenza: Primarily spread through inhalation of respiratory droplets or direct contact with infected birds, particularly poultry.

It is important to note that these are just a few examples, and there are numerous other zoonotic diseases with unique modes of transmission. Additionally, some zoonotic diseases can have multiple transmission routes, further highlighting the complexity of these diseases and the need for comprehensive prevention and control measures.

PATHOGENESIS OF ZOONOTIC DISEASES: –

Zoonoses are diseases that can be transmitted from animals to humans. The pathogenesis, or the process by which these diseases develop and spread within the human body, can vary depending on the specific zoonotic agent involved. However, there are some general patterns and mechanisms that are commonly seen in the pathogenesis of zoonotic diseases. Here’s an overview of the pathogenesis of zoonoses:

Transmission: Zoonotic diseases are typically transmitted to humans through direct or indirect contact with infected animals or their products. Direct transmission can occur through bites, scratches, or close contact with bodily fluids or tissues of infected animals. Indirect transmission can occur through exposure to contaminated environments, such as consuming contaminated food or water, or through the bites of arthropod vectors like mosquitoes or ticks.

Entry and colonization: Once the zoonotic agent enters the human body, it needs to establish a foothold and start replicating. This often involves the pathogen overcoming various barriers, such as the skin, respiratory tract, gastrointestinal tract, or mucous membranes. Different zoonotic agents have evolved different strategies to breach these barriers and colonize specific tissues or organs.

Replication and dissemination: Zoonotic pathogens then replicate within the human host, often leading to localized or systemic infection. The pathogen may target specific cells or tissues, depending on its tropism. During replication, the pathogen may produce toxins or induce an inflammatory response, which can contribute to the development of symptoms.

Immune response: The human immune system recognizes the presence of the zoonotic pathogen and mounts a response to control and eliminate the infection. The immune response can involve both innate and adaptive mechanisms, including the activation of various immune cells, production of antibodies, and release of cytokines. The outcome of the immune response can vary, ranging from complete clearance of the pathogen to chronic infection.

Pathological effects: Zoonotic diseases can cause a wide range of pathological effects in humans. These effects can be direct, resulting from the action of the pathogen itself, or indirect, resulting from the immune response mounted against the pathogen. Examples of direct effects include tissue damage caused by viral replication or the production of bacterial toxins. Indirect effects can include inflammation, immunopathology, or autoimmune responses triggered by the immune system’s reaction to the infection.

Transmission to others: Zoonotic diseases can be contagious and spread from person to person, leading to outbreaks or epidemics. Transmission between humans can occur through various routes, including direct contact, respiratory droplets, or contaminated objects. Some zoonotic diseases, such as influenza or COVID-19, are highly transmissible among humans, while others have limited human-to-human transmission.

HOW ZOONOSES AFFECT HUMAN HEALTH AND SOCIETY: –

Zoonoses, which are diseases transmitted from animals to humans, can have significant harmful effects on the human world. Here are some ways in which zoonoses can negatively impact human health and society:

Public Health Impact: Zoonotic diseases can cause widespread illness and potentially lead to public health emergencies. Outbreaks and pandemics caused by zoonoses can result in high numbers of infections, hospitalizations, and deaths, leading to significant social and economic burdens.

Mortality and Morbidity: Zoonoses can cause severe illness and have high mortality rates. Diseases like rabies, Ebola, and highly pathogenic avian influenza (e.g., H5N1) have been associated with high fatality rates, leading to loss of human lives and devastating impacts on affected communities.

Economic Losses: Zoonotic diseases can have substantial economic consequences. Outbreaks can disrupt trade and commerce, impact tourism, and lead to loss of productivity due to illness, hospitalization, and death. Costs associated with disease surveillance, treatment, control measures, and public health interventions can be substantial.

Impact on Livelihoods: Zoonotic diseases can directly affect people’s livelihoods, especially those involved in agriculture, livestock farming, and wildlife-related industries. Outbreaks can result in trade restrictions, loss of livestock, reduced productivity, and loss of income for farmers and other stakeholders in the food production chain.

Social Disruption: Zoonotic disease outbreaks can cause fear, panic, and social disruption. Public health measures such as quarantine, travel restrictions, and social distancing can impact daily life, disrupt social activities, and strain social and community relationships.

Environmental Consequences: Zoonotic diseases often have environmental factors associated with their emergence and transmission. Factors such as deforestation, habitat destruction, and climate change can contribute to the spillover of pathogens from animals to humans. Addressing zoonoses requires considering the impact of human activities on ecosystems and the environment.

Antimicrobial Resistance: Some zoonotic diseases are treated with antimicrobial drugs. However, misuse and overuse of antibiotics in both human and animal health can contribute to the development of antimicrobial resistance. This can lead to treatment failures and make infections more difficult to manage, posing a threat to public health.

Addressing zoonotic diseases requires a comprehensive and interdisciplinary approach that includes surveillance, prevention, control measures, and global cooperation. The One Health approach, which recognizes the interconnection between human, animal, and environmental health, is crucial in combating zoonoses and minimizing their harmful effects on the human world. By investing in research, strengthening healthcare systems, improving hygiene practices, promoting responsible antimicrobial use, and implementing effective preventive measures, we can mitigate the impact of zoonotic diseases and protect human health

TREATMENT OF ZOONOSES: –

The treatment of zoonoses depends on the specific disease and its causative agent. Different types of zoonotic diseases require different approaches for effective treatment. Here is a general overview of the treatment strategies for zoonoses:

Bacterial Zoonoses:

Antibiotics: Bacterial zoonoses caused by bacteria, such as Salmonella, Campylobacter, and Brucella, are often treated with appropriate antibiotics. The choice of antibiotic depends on the specific pathogen and its susceptibility to different drugs.

Viral Zoonoses:

Antiviral Medications: Some viral zoonotic diseases, like influenza, may be treated with antiviral medications. These medications, such as oseltamivir (Tamiflu), can help reduce the severity and duration of the illness if administered early.

Supportive Care: For many viral zoonoses, there may not be specific antiviral treatments available. In such cases, supportive care is provided to manage symptoms and complications. This includes rest, hydration, and medications to relieve symptoms like fever, pain, and respiratory distress.

 Parasitic Zoonoses:

Antiparasitic Medications: Parasitic zoonoses caused by organisms like Toxoplasma gondii or Leishmania parasites may require treatment with specific antiparasitic medications. These drugs target the parasites and help eliminate the infection.

Supportive Care: In some cases, supportive care may be necessary to manage symptoms and support the body’s immune response. This may include hydration, pain relief, and other measures to alleviate discomfort.

Fungal Zoonoses:

Antifungal Medications: Fungal zoonotic diseases caused by fungi like Histoplasma capsulatum or Cryptococcus neoformans are typically treated with antifungal medications. The choice of antifungal drug and treatment duration depends on the severity and location of the infection.

Supportive Care: Supportive care measures, such as managing symptoms and providing relief from pain or respiratory distress, may be employed in conjunction with antifungal treatment.

It’s important to note that the treatment of zoonoses should be carried out under the guidance of healthcare professionals, as they can provide an accurate diagnosis, determine the most appropriate treatment regimen, and monitor the patient’s response to therapy. Additionally, preventive measures, such as vaccination and vector control, play a crucial role in reducing the burden of zoonotic diseases and should be emphasized alongside treatment strategies.

Furthermore, it is worth mentioning that prevention and control measures are essential components in managing zoonoses. This includes practices such as proper hygiene, food safety measures, vector control, vaccination programs, and education about zoonotic disease prevention. These preventive measures can significantly reduce the occurrence and transmission of zoonoses and are crucial in minimizing the impact of these diseases on public health.

PROTECTING AGAINST ZOONOTIC DISEASES: –

Protecting against zoonotic diseases and preventing their transmission from the animal world to humans is crucial for public health. Here are some key measures for protecting against zoonoses:

Disease Surveillance: Implementing robust surveillance systems to monitor and detect zoonotic diseases is essential. This involves active monitoring of both animal and human populations for signs of emerging diseases, early detection of outbreaks, and timely reporting of cases to public health authorities.

One Health Approach: Embrace the One Health approach, which recognizes the interconnectedness of human, animal, and environmental health. Foster collaboration and coordination between human health, animal health, and environmental sectors to jointly address zoonoses through multidisciplinary efforts.

Vaccination Programs: Vaccination of animals against zoonotic diseases plays a crucial role in preventing their transmission to humans. Implement comprehensive and targeted vaccination programs, especially for domestic animals, livestock, and wildlife, based on the specific diseases prevalent in the region.

Vector Control: Implement effective vector control measures to reduce the risk of zoonotic diseases transmitted by vectors such as mosquitoes, ticks, and fleas. This may involve the use of insecticides, environmental management, and personal protective measures such as wearing protective clothing and using insect repellents.

Hygiene Practices: Promote and educate individuals and communities about good hygiene practices to prevent zoonotic diseases. Encourage frequent handwashing, safe food handling and preparation, and proper sanitation practices. Education about the risks associated with close contact with animals, including handling, consumption, and exposure to animal waste, is also important.

Responsible Antimicrobial Use: Encourage responsible use of antimicrobial drugs in both human and animal healthcare. Overuse and misuse of antibiotics can contribute to the development of antimicrobial resistance, making infections harder to treat. Promote adherence to appropriate prescribing guidelines and discourage the use of antibiotics as growth promoters in animal agriculture.

Wildlife Conservation and Habitat Protection: Preserve biodiversity and protect natural habitats to minimize the disruption of ecosystems. This includes addressing deforestation, habitat destruction, and illegal wildlife trade, which can increase the risk of zoonotic spillover events. Public Awareness and Education: Raise awareness among the general public, healthcare professionals, policymakers, and relevant stakeholders about zoonotic diseases, their prevention, and the importance of the One Health approach. Promote behaviour change through educational campaigns, emphasizing the risks associated with zoonoses and the actions individuals can take to protect themselves and others.

International Cooperation: Foster international collaboration and information sharing to detect and respond to zoonotic diseases on a global scale. Support capacity-building efforts in countries with limited resources to strengthen their surveillance, diagnostic, and response capabilities. By implementing these measures, we can reduce the risk of zoonotic disease transmission, protect public health, and ensure a safer and healthier world for both humans and animals.

PREVENTING ZOONOTIC DISEASES: –

• Proper Personal Hygiene
• Wash hands before and after animal handling.
• Do not eat or drink in the animal housing areas.
• Wear coveralls, farm-specific clothing, or laboratory coats when handling animals.
• Avoid handling sick animals or animals with lesions unless gloved.
• Wear a mask if you are allergic to animal hair or dander or if feed or bedding dust is present.
• If you are sick, DO NOT enter the agricultural animal facilities. You are more susceptible to other infective agents and you may transfer pathogens to the animals.
• Routinely wear gloves when cleaning animal areas.
• Note the progression of any illness. Report illnesses to your supervisor.
• Inform the physician of your animal-related activities.
• Environmental Maintenance
• Keep animal housing areas well organized and clean.
• Avoid urine and faecal build-up. Dry faeces result in faecal dust which may be inhaled.
• Clean rooms have a lower likelihood of horizontal or zoonotic transfer.
• Proper ventilation protects the animal and workers.
• Clean feed and bedding from floors. Litter attracts vermin which may introduce a zoonotic disease into the facility.
• Herd/Flock Maintenance
• Observe animals for health status daily.
• Report sick or dead animals.
• Note health problems such as diarrhoea, difficulty breathing, depression, and immobile.
• Take extra caution in cleaning the areas around ill animals. Don’t spread possible pathogens.
• Isolate affected animals as appropriate.
• Record the history or progression of animal disease.

CAN HUMAN DISEASES TRANSFER TO ANIMALS?

Yes, human diseases can sometimes transfer to animals, resulting in what is known as reverse zoonosis or anthroponomic. In these cases, a disease that primarily affects humans can be transmitted to animals, leading to infections in animal populations. The transfer of human diseases to animals can occur through various mechanisms, including direct contact with infected individuals, exposure to contaminated environments, consumption of contaminated food or water, or through vectors such as mosquitoes or ticks.

There have been several documented cases of reverse zoonosis. For example, tuberculosis, caused by the bacterium Mycobacterium tuberculosis, can be transmitted from humans to animals, including primates, elephants, and lions. Influenza viruses, such as the H1N1 influenza virus, have also been transmitted from humans to various animal species, including pigs, cats, dogs, and even tigers in captivity. When a human disease transfers to animals, it can have significant implications for both animal and human health. Infected animals may experience illness, and in some cases, the disease can spread within animal populations, leading to outbreaks or epizootics. Additionally, infected animals can serve as a reservoir for the disease, potentially reintroducing it to humans or facilitating further transmission to other animals. Understanding the potential for reverse zoonosis is important for disease surveillance and control efforts. It highlights the need for monitoring and studying both human and animal populations to detect and prevent the spread of diseases across species.

WHO RESPONSE: –

WHO works with national governments, academia, non-governmental and philanthropic organizations, and regional and international partners to prevent and manage zoonotic threats and their public health, social and economic impacts. These efforts include fostering cross-sectoral collaboration at the human-animal-environment interface among the different relevant sectors at regional, national and international levels. WHO also works to develop capacity and promote practical, evidence-based and cost-effective tools and mechanisms for zoonoses prevention, surveillance and detection through reporting, epidemiological and laboratory investigation, risk assessment and control, and assisting countries in their implementation. As part of the One Health approach, the World Health Organization collaborates with the Food and Agriculture Organization of the United Nations (FAO) and the World Organisation for Animal Health (OIE) on the Global Early Warning System for Major Animal Diseases (GLEWS). This joint system builds on the added value of combining and coordinating alert mechanisms of the three agencies to assist in early warning, prevention and control of animal disease threats, including zoonoses, through data sharing and risk assessment

THE ONE WORLD, ONE HEALTH APPROACH: –

The One World, One Health approach is rooted in the understanding that human health is interconnected with animal health and the environment. It emphasizes the need for collaboration and coordination between sectors to prevent, detect, and respond to zoonotic diseases effectively. Key principles of this approach include:

1. Multidisciplinary Collaboration: The One World, One Health approach brings together experts from human health, veterinary medicine, ecology, environmental sciences, and other relevant fields. By fostering interdisciplinary collaboration, a comprehensive understanding of zoonotic diseases is developed, enabling early detection and effective response.
2. Surveillance and Early Warning Systems: Robust surveillance systems are vital for the timely identification of zoonotic threats. By actively monitoring animal and human populations for emerging diseases, we can intervene before an outbreak escalates into a global crisis. Sharing data and information across sectors and countries is crucial for early warning systems.
3. Prevention and Control: Prevention plays a critical role in mitigating zoonotic diseases. This includes measures such as vaccination programs, promoting responsible antimicrobial use, improving hygiene practices, enhancing biosecurity in animal production systems, and tackling illegal wildlife trade. Strengthening veterinary services and public health infrastructure is also crucial.
4. Eco-health Approach: The eco-health approach recognizes the complex interactions between ecosystems, animals, and humans. By considering the ecological context, it aims to address the root causes of zoonotic diseases. Preserving biodiversity, protecting natural habitats, and promoting sustainable agricultural practices contribute to reducing zoonotic risks.

Achieving One World, One Health: –

To achieve the vision of One World, One Health, international cooperation is vital. Collaboration between governments, international organizations, research institutions, and non-governmental organizations (NGOs) is essential for a coordinated response to zoonotic threats. This includes sharing data, expertise, and resources, and supporting capacity-building efforts in countries with limited resources. Investments in research and development are crucial for advancing our understanding of zoonoses and developing effective diagnostics, treatments, and vaccines. Furthermore, raising awareness among the public, policymakers, and healthcare professionals about the interconnectedness of human, animal, and environmental health is paramount to fostering behavioural changes and supporting policy reforms.

Conclusion: –

Zoonotic diseases pose a significant threat to global health security. The One World, One Health approach offers a comprehensive and collaborative framework to address these challenges. By recognizing the interconnectedness of human, animal, and environmental health, we can proactively prevent, detect, and respond to zoonotic diseases, creating a safer and healthier future for all. Through international cooperation, research advancements, and public awareness, we can work towards a world where zoonoses are effectively controlled, and the well-being of all species is safeguarded.

Reference:-

1. Bora Shin,Woojun Park(2018).Zoonotic Diseases and Phytochemical Medicines For Microbial Infections In Veterinary Science:Current State and Future Perspective.Front Vet Science.National Center For Biotechnology Information
2. S.R.Pamer,Lord Soulsby,paul Torgerson,David W.G. Brown(2021). Oxford Textbook Of Zoonoses: Biology, Clinical Practice and Public Health Control.
3. Jill Seladi,Tom Seymour(2023).Types of Zoonotic Diseases.Medical News Today
4. Haregua Teshome,Shineles Abeguaz Addis (2019).Review On Principles Of Zoonoses Precention,Control and Eradication. American Journal Of Biomedical Scinece & Research.
5. Sarah Shanks,May Cl van Schalkwyk Andrew A.Cunnigham(2022).A Call To Prioritise Prevention: Action Is Needed To Reduce The Risk Of Zoonotics Diseases Emergence. THE LANCET Regional Health, Europe

ONE WORLD – ONE HEALTH : PREVENT ZOONOSES