Module 1: Introduction to Zoonoses, Emerging Infectious Diseases, and One Health PDF

A Lecture Series in VPH33 by LGM Ramirez Learning Outcomes ◦ Develop an in-depth comprehension of Veterinary Public Health and its importance to zoonoses and one health ◦ Determine the role of public health veterinarian ◦ Define terminologies that applies in understanding the principle of zoon...

A Lecture Series in VPH33 by LGM Ramirez Learning Outcomes ◦ Develop an in-depth comprehension of Veterinary Public Health and its importance to zoonoses and one health ◦ Determine the role of public health veterinarian ◦ Define terminologies that applies in understanding the principle of zoonoses and one health ◦ Classify the different types of zoonoses ◦ Determine the impact of zoonoses to animal and public health  OVERVIEW OF PUBLIC HEALTH Aims, Scope, Veterinarians Role Public Health … ◦ The WHO Expert Committee on Public Health Administration (1952) has defined public health as “the science and art of preventing disease, prolonging life, and promoting health and efficiency through organized community efforts.” ◦ The section of human medicine that deals with individual patients (like chronic cough or tumor patient) where the medical practitioner carries out clinical examination and investigates to find out the cause of the disease and prescribe accordingly to alleviate the disease is known as general medicine. Background of Veterinary Public Health ◦ Concept of Veterinary Public Health - evolved in the USA in late 1940s ◦ WHO established a Veterinary Public Health unit in 1949. ◦ In 1950 for the first time WHO and FAO expert group jointly formulated a definition as- “Veterinary Public Health comprises all the community efforts influencing and influenced by the Veterinary- Medical arts and sciences applied to the prevention of diseases, protection of life and promotion of the well-being and efficiency of mankind.” Background of Public Health ◦ In 1956 , FAO and WHO made a wide accepted definition of “Veterinary Public Health” as the field of activities which protects and advances the human well-being by utilizing the combined knowledge and resources of all those concerned with human and animal health and their interrelationships.” ◦ FAO & WHO again jointly redefined it in 1975 as - ‘Veterinary Public Health is a component of public health activities devoted to the application of professional veterinary skills, knowledges and resources to the protection and improvement of human health.” Background of Veterinary Public Health ◦ Finally, in 1999 the joint WHO/FAO expert group defined Veterinary Public Health as- “The contribution to the complete physical, mental and social well-being of human through an understanding and application of veterinary medical sciences.” Scopes of VPH/Domains of VPH 1. Zoonoses i. Diagnosis ii. Surveillance iii. Epidemiology iv. Control v. Prevention vi. Elimination 2. Food Protection (mainly animal origin) – to protect the food from any kind of contamination 3. Management of Health Aspects of Laboratory Animals Facilities of Diagnostic Laboratory 4. Biomedical Research Scopes of VPH/Domains of VPH 5. Health Education & Extension 6. Production and Control of Biological Products and Medical Devices 7. Management of Domestic & Wild Animal Population 8. Protection of Drinking Water and the Environment 9. Management of Public Health Emergency (Flood, Earthquake, Disease Outbreaks etc.). Functions of Qualified Public Health Vet ◦ A joint FAO & WHO expert committee on Veterinary Public Health (1975) has categorized the principal functions of Veterinarians as: 1. Animal related functions i. The human health aspects of production, processing and marketing of foods of animal origin. ii. Health related problems of other animal industries including safe disposal of animal wastes. iii. Zoonoses, their diagnosis, surveillance and control iv. Technical consultations on human health matters related to animals and their diseases. Functions of Qualified Public Health Vet 1. Animal related functions v. Investigations of the dangers to man posed by biting, toxic, venomous and other hazardous or objectionable animals. vi. Supervision of experimental animal colonies maintained by Public Health Lab. vii. Comparative studies on the epidemiology of noninfectious diseases in animals and man influenced by environmental and other influences. viii. Interchange of research information between Veterinary Scientist and human health experts with a view to augment community health. Functions of Qualified Public Health Vet 2. Biomedical functions i. Epidemiology ii. Health Lab. Services iii. General environmental health, including radiological health and environmental physiology. iv. Protection of foods. v. Production and control of biological products vi. Drug evaluation and control. vii. Most aspects of Public Health research, including research in reproductive physiology and fertility control. Functions of Qualified Public Health Vet 3. Generalist ◦ Functions are beyond the mentioned potential areas of responsibility in public health. ◦ Public Health Veterinarians can also serve in General Public Health as administrator, planners and coordinators. ZOONOSES Definition, Classification, and Impact Zoonosis ◦ “zoonoses” – coined by Rudolf Virchow in 1885 ◦ Greek word “zoon” = animals and “nosos” = disease or illness ◦ Stating that “Between animal and human medicine, there is no dividing line, nor should there be. The object is different but the experience gained constitute Rudolf Virchow the basis of all medicine” Rudolf Virchow 1821-1905  ndvsu.org Zoonoses as “those diseases and infections which are naturally transmitted between vertebrate animals and man‘’ – (WHO and FAO, 1959) What are Zoonoses? ◦ Any disease or infection that can be transmitted naturally from animals to humans; it comprises a large percentage of new and existing diseases of humans (WHO, 2020) ◦ “an infectious disease with the potential to transmit from non- human animals to humans” ◦ According to the World Health Organization (WHO) ◦ 75% of new human diseases in the last decade are zoonotic in origin ◦ 1.7 million currently "undiscovered" viruses that exist in mammals and birds, and up to 827, 000 of these could still infect people ◦ The richness of the biodiversity makes it vulnerable to zoonotic diseases. ◦ The primary sources of zoonotic outbreaks in the past ◦ the Nipah Virus in 1998, Severe Acute Respiratory Syndrome (SARS) in 2003, the Avian Influenza AH5N1, and New Influenza AH1N1 pandemic in the 2000s, and the Ebola Reston virus in the 1990s.  Why Zoonotic Diseases are important? 61% (868 / 1415) of human pathogens are shared by animals (Zoonoses) (Woolhouse et al., 2005) 64% (14/ 22) infectious agents identified from1973-1994 are zoonoses (Chomel, 2003) 73% (130/177) of emerging infectious diseases are zoonotic in origin (Woolhouse et al., 2005) Transmitters of Zoonoses Slide 1 (ndvsu.org)  ◦ Scientists believed that modern The Origin of Human Pathogens human infectious diseases arose during the Neolithic period or afterwards ◦ With technological advances (e.g. molecular clock analysis, single nucleotide polymorphisms and phylogeography) ◦ concludes that modern human infectious diseases did not arise from domestic animals during Neolithic period but point to a much older Paleolithic origin (2.5 million to 10,000 years ago) ◦ some may have co-evolved with hominids whereas others may have originated Probable origins of human-specific infectious diseases. Arrows indicate suggested https://www.researchgate.net/ in wild animals direction of the original transmission Zoonoses throughout the years Zoonoses on the Recent Centuries Who are at risk in human? ◦Population at risk ◦Most susceptible groups ◦ Infants ◦ Farmers, livestock owners, and ◦ Children