Zoonosis by dr azher 222222222222222.pptx

Zoonosis

1. 1 Infe ctious Diseases: Z oonoses & Bio security

2. 2 Infectious Diseases: Zoonoses & Biosecurity Dr Azher Mehmood Veterinary Assistant Surgeon BVSc & AH

3. When Animals Made Humans Sick A Story of Zoonosis and Shared Vulnerability A Silent Connection In a bustling market, a virus jumped silently from a bat to a human — setting off a chain reaction that would change the world. This story of COVID-19 echoes the ancient truth that human and animal health are deeply intertwined. The Ripple Effect From Ebola in West Africa to Nipah in Kerala, zoonotic diseases reveal how our actions — deforestation, wildlife trade, and intensive farming — can unleash hidden pathogens into human populations. Shared Future, Shared Responsibility Every outbreak reminds us that protecting animals protects humans too. This lecture explores how biosecurity, vigilance, and the One Health approach can safeguard our interconnected world.

4. What Are Zoonotic Diseases? Understanding the Human–Animal Interface Definition and Scope: Zoonotic diseases, or zoonoses, are infections that spread between animals and humans. Over 60% of all human infectious diseases are zoonotic in origin, highlighting their vast impact. Pathways of Transmission: Zoonoses can spread via direct contact, contaminated food or water, insect vectors, or through environmental exposure — making prevention a multidisciplinary challenge. Examples Across Species: Rabies, Brucellosis, Avian Influenza, Anthrax, and COVID-19 represent the diversity of zoonotic threats — ranging from viral to bacterial, parasitic, and fungal origins. One Health Connection: Zoonotic control requires a One Health approach integrating veterinary, medical, and environmental sciences to detect, prevent, and respond to outbreaks effectively.

5. Why Zoonoses Matter Today A Growing Threat in a Changing World Rising Frequency of Outbreaks: Over the past 30 years, the world has seen a 75% increase in emerging infectious diseases, with most being zoonotic in nature. Population growth, deforestation, and urbanization intensify human–animal contact. Climate Change & Migration: Global warming alters habitats, shifting wildlife patterns and expanding the range of disease vectors such as mosquitoes and ticks — amplifying zoonotic risks in new regions. Economic & Social Burden: Zoonotic diseases cost billions annually in lost productivity, trade restrictions, and healthcare demands. Rabies alone causes an estimated $8.6 billion in economic losses each year. A Call for Vigilance: Our interconnected world means a spillover anywhere can become a pandemic everywhere. Strengthening surveillance, education, and cross-sector collaboration is our best defense. Photo by Martin Sanchez on Unsplash

6. How Zoonotic Diseases Spread Understanding the Pathways of Transmission Direct Contact: Transmission occurs when humans handle or are bitten by infected animals — common in rabies, brucellosis, and anthrax. Veterinary and farm workers are especially at risk. Indirect & Environmental Routes: Pathogens can persist in contaminated soil, water, or surfaces. Anthrax spores and leptospira bacteria illustrate how the environment serves as a reservoir. Vector-Borne Transmission: Mosquitoes, ticks, and fleas serve as biological bridges, transferring diseases like Rift Valley Fever, plague, and Lyme disease between species. Food & Water Contamination: Consumption of undercooked meat, unpasteurized milk, or contaminated produce spreads pathogens such as Salmonella, Campylobacter, and E. coli. Photo by Markus Spiske on Unsplash

7. Major Zoonotic Diseases Key Examples Across Pathogen Types Rabies: A viral disease transmitted via bites from infected animals. Despite being preventable through vaccination, rabies causes nearly 59,000 human deaths annually, primarily in Asia and Africa. Brucellosis: A bacterial zoonosis causing fever and reproductive disorders in livestock. Humans acquire it through unpasteurized dairy or contact with infected animals — a persistent occupational hazard. Avian Influenza: Highly pathogenic H5N1 and H7N9 strains jump from birds to humans, leading to severe respiratory illness. Control depends on strict farm biosecurity and culling protocols. Nipah & Anthrax: Nipah virus, carried by fruit bats, has caused fatal outbreaks in South Asia. Anthrax spores from infected carcasses persist in soil, posing risks to both animals and handlers. Leptospirosis: Caused by Leptospira bacteria spread through water contaminated by animal urine. Common in tropical regions, it affects both livestock and humans, leading to liver and kidney complications.

8. Rabies: A Fatal Yet Preventable Zoonotic Disease Understanding Transmission, Symptoms, and Prevention Causative Agent and Hosts Rabies is caused by a Lyssavirus that affects mammals, primarily transmitted through the bite or saliva of infected animals such as dogs, bats, and raccoons. Pathogenesis Once introduced via bite, the virus travels through peripheral nerves to the central nervous system, causing fatal encephalitis characterized by hydrophobia, agitation, and paralysis. Global Burden Rabies causes nearly 59,000 human deaths annually, mostly in Asia and Africa. Dogs account for over 99% of human rabies transmissions. Prevention and Control Mass dog vaccination, post-exposure prophylaxis (PEP), and awareness campaigns have proven to eliminate rabies in several regions. Education of rural communities remains critical.

9. Rabies: Transmission and Pathogenesis How the Virus Infects and Affects the Body Transmission Cycle: Rabies spreads primarily through the bite or saliva of infected animals such as dogs, bats, and foxes. The virus enters the body through wounds or mucous membranes. Pathogenesis: After entering the body, the rabies virus migrates along peripheral nerves toward the central nervous system, where it causes severe inflammation and neurological symptoms. Clinical Signs: Initial symptoms include fever, headache, and tingling at the bite site, progressing to hydrophobia, aggression, paralysis, and death once symptoms appear. Animal Hosts: Dogs are the main reservoir in Asia and Africa, while bats, raccoons, and skunks act as reservoirs in the Americas and Europe. Photo by CDC on Unsplash

10. Rabies Prevention and Control Eliminating a 100% Preventable Disease Mass Dog Vaccination: Vaccinating at least 70% of the dog population interrupts virus transmission and is the most effective long-term control measure. Post-Exposure Prophylaxis (PEP): Immediate wound washing, administration of rabies immunoglobulin, and a full vaccine course are life-saving interventions after exposure. Public Awareness and Education: Community programs teaching bite prevention, safe animal handling, and early reporting are vital in rural and high-risk areas. Global and National Efforts: The WHO, FAO, WOAH, and India’s National Rabies Control Programme aim for ‘Zero by 2030’—a world free of human rabies transmitted by dogs. Photo by Hasinirainy Rova on Unsplash

11. 11 Rabies Virion particles (magnified ~2 million times) Colorized transmission electron micrograph Rabies Virus

12. Human and Economic Impact of Zoonotic Outbreaks The Cost of Neglecting the Human–Animal Health Link Global Health Burden: Zoonotic diseases account for 2.5 billion human infections and 2.7 million deaths annually worldwide, disproportionately affecting low- and middle-income countries. Economic Losses: Livestock losses, trade restrictions, and healthcare costs from zoonotic outbreaks lead to an estimated $120 billion in global economic damage over the past two decades. Impact on Livelihoods: Farmers, animal handlers, and rural communities face direct income loss, reduced productivity, and social stigma during disease outbreaks. Beyond Numbers — The Human Toll: Behind every statistic are families affected by illness, food insecurity, and fear. Effective zoonotic control safeguards both economic resilience and human dignity. Photo by Annie Spratt on Unsplash

13. Biosecurity in Veterinary Practice Building the First Line of Defense Farm-Level Hygiene: Regular cleaning, disinfection of stalls and equipment, and controlled entry to animal facilities prevent pathogen buildup and cross-contamination. Movement Control & Quarantine: Isolating new or sick animals reduces transmission risk. Implementing quarantine protocols and visitor restrictions are vital steps in outbreak prevention. Protective Equipment & Waste Disposal: Use of gloves, masks, coveralls, and proper disposal of animal waste reduce exposure risk for veterinary workers and farm staff. Education and Compliance: Biosecurity succeeds when all stakeholders—farmers, handlers, and veterinarians—are trained and committed to consistent implementation. Photo by Jonathan Bean on Unsplash

14. Biosecurity in Research and Diagnostics Ensuring Safety in High-Risk Environments Biosafety Levels (BSL-1 to BSL-4): Laboratories are classified based on containment needs. BSL-1 handles minimal risk agents, while BSL-4 deals with deadly pathogens like Ebola, requiring airtight facilities and full-body suits. Containment and PPE: Proper ventilation, negative pressure rooms, and use of gloves, respirators, and face shields prevent pathogen escape and exposure during diagnostic work. Sample Handling and Waste Management: Strict protocols for receiving, labeling, transporting, and autoclaving samples minimize contamination and accidental release. Training and Culture of Safety: Continuous training, supervision, and adherence to standard operating procedures foster a culture of biosafety critical to preventing laboratory-acquired infections. Photo by Lucas Vasques on Unsplash

15. Public Health Collaboration — The One Health Approach Integrating Human, Animal, and Environmental Health Concept of One Health One Health recognizes the interconnectedness of humans, animals, and ecosystems. It promotes multidisciplinary collaboration to prevent and manage zoonotic diseases. Collaborative Framework Veterinarians, physicians, ecologists, and policymakers share surveillance data, coordinate response efforts, and implement joint vaccination and control programs. Case Successes Integrated approaches have controlled rabies through joint vaccination campaigns, reduced avian influenza spread, and improved antimicrobial resistance monitoring. Sustainable Future By addressing disease at the source—wildlife, livestock, and environment—One Health strengthens resilience against pandemics and supports global food security.

16. Technological Innovations in Zoonosis Surveillance Harnessing AI, Genomics, and Big Data for Early Detection AI-Powered Disease Prediction Machine learning algorithms analyze environmental, animal health, and trade data to predict outbreaks before they occur — improving response times and reducing spread. Genomic Surveillance Whole-genome sequencing of pathogens enables rapid identification of mutations, tracking of transmission routes, and development of targeted vaccines. Digital Epidemiology Mobile reporting apps and online dashboards integrate veterinary and human health data for real-time outbreak monitoring and coordinated response. Remote Sensing & IoT Satellite data and smart sensors track ecological shifts, wildlife migration, and farm health indicators — linking environmental change to disease emergence.

17. Global Preparedness and Policy Framework Coordinating International Action Against Zoonotic Threats Tripartite Collaboration (WHO, FAO, WOAH): The Tripartite Alliance leads global zoonotic disease control through joint surveillance, policy harmonization, and capacity building across sectors. International Health Regulations (IHR 2005): These legally binding regulations guide nations to detect, assess, report, and respond to public health events, including zoonotic and pandemic threats. National Action Plans: Countries implement preparedness plans integrating human, animal, and environmental health systems — India’s ‘National Action Plan on AMR’ is a model for coordination. Funding and Capacity Building: World Bank, WHO, and FAO invest in laboratory networks, emergency response systems, and training programs to strengthen global resilience. Photo by Davi Mendes on Unsplash

18. Conclusion & Call to Action Protecting Our Shared Future Through One Health and Biosecurity Shared Responsibility Zoonotic disease control is not confined to laboratories or clinics—it demands coordinated action across human, animal, and environmental health sectors. Prevention Over Reaction Investing in surveillance, biosecurity, and education costs far less than responding to global outbreaks. Preparedness saves both lives and livelihoods. Empowering Veterinary Leadership Veterinary professionals serve as the first sentinels against zoonoses. Their expertise bridges animal care, public health, and policy development. A Healthier Planet for All By embracing the One Health philosophy, we protect biodiversity, secure food systems, and ensure a safer future for generations to come.

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20. 20 THANK YOU DR AZHER MEHMOOD BVSc & AH