Preventive Veterinary Medicine VM544

1. Preventive Veterinary MedicineVM544 Lecture 1 Introduction Part II

2. Preventive not “preventative” medicine and there are no “preventative drugs” to give to animals so they won’t get sick. What is “preventive medicine”? -Objective of clinical medicine = “cure the sick” -Objective of preventive medicine “solve the problem” - The River Story Preventive Medicine

3. Preventive Medicine • The veterinarian’s role in human health is in preventive medicine for people. • We prevent animal diseases from affecting people. • We prevent diseases associated with animal usage from affecting people. • The emphasis on preventive medicine is seen in all the units of this course. • Perhaps the only string the connects the different units.

4. The Role of Infectious Disease and Preventive Medicine in our Society • The impact was Major!

5. Historical View of Preventive Medicine Rats, Lice and Historyby Hans Zinsser • Three main points: • The history of mankind has been dominated by epidemic disease - not great armies. • Preventive medicine has freed us from the devastation of epidemic disease. • Veterinarians should be proud of our historic contributions in preventive medicine and should expand our involvement on the human preventive medicine team.

6. History of Epidemic Disease “Swords and lances, arrows, machine guns, and even high explosives have had far less power over the fates of the nations than the typhus louse, the plague flea, and the yellow fever mosquito.” Zinsser, p 9-10

7. History of Epidemic Disease “Civilizations have retreated from the plasmodium of malaria, and armies have crumbled into rabbles under the onslaught of cholera spirilla, or of dysentery and typhoid bacilli. Huge areas have been devastated by the trypanosome that travels on the wings of the tsetse fly, and generations have been harassed by the syphilis of a courtier.”Zinsser, p 9-10

8. History of Epidemic Disease “War and conquest and that herd existence which is an accompaniment of what we call civilization have merely set the stage for these more powerful agents of human tragedy." Zinsser, p 9-10

9. Great Plaques of History • Black Death • “The Black Death…about one quarter of the entire population of Europe was destroyed by the disease - that is 25,000,000 people. It carried in its wake moral, religious, and political disintegration” The “fabric” of society unraveled. Zinsser, p. 88-98

10. Great Plaques of History • English Sweating Sickness • “In some towns, from a third to half of the population was wiped out. It is stated that in some places 80-90% of the population died.” • “…the most severe outbreak was that of 1529. This started in May in London and the terror it inspired was so great that society was disorganized, agriculture stopped, and famine resulted.” Zinsser, p.88-98 • Was it a Hanta Virus???

11. The Great Plaques of HistoryMilitary Campaigns –The Crusades • The 1st Crusade: • “The cavalry were rendered useless within a few months by the death of 5,000 of their 7,000 horses. When Jerusalem was taken, in 1099, only 60,000 of the original 300,000 were left, and these, by 1101 had melted to 20,000.” Zinsser, p.125-150 • The 2nd Crusade: • Of the ½ million men, only a handful reached Antioch. • The 4th Crusade: • Never reached Jerusalem due to a plague epidemic.

12. The Great Plaques of HistoryThe Fall of Rome • The fall of Rome appears to be (at least in part) due to epidemics, which included plague, dysentery, and meningitis. • The barrage of epidemics led to the abandonment of cities and villages, and a disruption of agriculture. • In the city of Constantinople, “5,000 to 10,000 persons died each day.” Zinsser p.128-149

13. The impact of disease in warfare • “…soldiers have rarely won wars. They often mop up after the barrage of epidemics.” Zinsser, p.132 • Desert Shield food borne illness • Early foodborne illness because only combat troops moved in at first. • Vets, environmental engineers, sanitarians, food inspectors, etc.

14. The impact of disease in warfare • American Civil War: Diseases like tuberculosis, dysentery and pneumonia produced 2x as many casualties than combat. Diseases of mobilization. • Diseases 6 times combat casualties for Spanish-Am. War. (Yellow Fever)

15. The impact of disease in warfare • The New World probably provides a more dramatic example of the impact of disease on civilization. • Conquest of South, Central and North America

16. Where are we at today? • 1980s – declared victory over infectious disease. • There may never be an end to epidemics as victory over infectious disease may never be achieved.  • We are part of the biosphere. • We live in “DNA soup” • We can’t pretend to be “above” or “separate” from nature • Preventive medicine will continue to be important.

17. Current Perspectives in the War Against the Microbes. • Joshua Lederberg: “Infectious Disease as an Evolutionary Paradigm” • Infectious agents are constantly changing, DNA exchange among microbes is rampant. • There are remnants of over 300 retroviruses in our genome. • Laurie Garrett- “The Coming Plague” • The war against microbes has not been won. • Most emerging human infections are zoonotic.

18. Global Role of Zoonotic Disease • Infectious disease is much more important in the developing world • Our life American life style is a historical aberration. • 70% of the world is illiterate • 50% suffer from malnutrition • 1% have a college education

19. Preventive Medicine • Epidemic disease is largely controlled through preventive medicine by: • Sanitation (food hygiene, pest control, etc.) • Good nutrition • Disease control measures (education, isolation, vaccination, eradication, control of disease in animals, etc.) • Major improvements were made before the advent of antibiotics or curative medicine.

20. The History of Preventive Medicine (as measured by the “success” of the human species)

21. Graph of the Human Population Over Time • Two inflection points • Agricultural revolution • Industrial revolution • Due to improvements in sanitation (preventive medicine, disease control practices) and nutrition • Both of which are key elements of preventive medicine

23. Antibiotics

24. Preventive Medicine • The increase in the human lifespan is mainly due to preventive medicine • Your garbage collector may contribute more to your health than your heart surgeon. • The natural state of mankind is disease and squalor • Epidemic disease will return if preventive medicine breaks down.

25. Theodoric of York • Curative Medicine was still in the “Dark Ages” when preventive medicine was increasing the life span of the human population.

26. Wisconsin Death Trip by Michael Lesy • The “Good Old Days” • Quarantine signs on doors. • Limited movement (public gatherings rare, meat purchased cautiously, restaurants rare) • The natural state of mankind is disease and squalor. • Last 100 years in US is a (Temporary?) aberration from the norm.

27. High Infant Mortality Rate Suicide Insanity Religious dementia Poverty Wisconsin Death Trip

28. Disease and Squalor • Epidemic disease will return when preventive medicine breaks down. • Sewers, clean water, garbage disposal, pest control, health department disease control, dairy and meat inspection, etc. are all part of preventive medicine. • Called “Public Health Infrastructure”

29. Preventive Medicine • Hand washing - one of most important means of preventing infection.

30. Career Pitch • Consider becoming a soldier in the ‘species versus species’ war between humans and pathogenic organisms. • WE NEED YOUR HELP! • Employment opportunities look excellent. • I believe that this is a worthwhile way to spend your career.

31. Veterinary Preventive Medicine VM 544 • This course regards the ways in which veterinarians participate in (human) preventive medicine. • Veterinarians work for human society through their work with animals • The field of public health is specifically mentioned in the veterinary oath.

32. Veterinary Preventive MedicineThree motivations “…men go into this branch of work from a number of motives, the last of which is a self-conscious desire to do good.”.…“About the only genuine sporting proposition that remains unimpaired by the relentless domestication of a once free-living human species is the war against these ferocious little fellow creatures, which lurk in dark corners and stalk us in the bodies of rats, mice and all kinds of domestic animals; which fly and crawl with the insects, and waylay us in our food and drink and even our love.” Zinsser, p13

33. Veterinary Preventive Medicine3 motivational points of view “This is the true joy in life, of being used for a purpose recognized by myself as a mighty one. Of being a force of nature, instead of a feverish, selfish little clog of ailments and grievances, complaining that the world will not devote itself to making you happy. I am of the opinion my life belongs to the whole community, and as long as I live it is my privilege to do for it whatever I can. I want to be thoroughly used up when I die! For the harder I work the more I live. I rejoice in life for its own sake. Life is no brief candle to me. It is a sort of splendid torch that I have got to hold up for the moment, and I want to make it burn as brightly as possible before handing it over to future generations.” George Bernard Shaw

34. Veterinary Preventive Medicine3 motivational view points “Is this a job, a mission, or a holy crusade?” Dr. Tina Smith (Spoken while bleeding sows for the pseudorabies eradication program)

35. Careers in Vet. Prev. Med. • 75% of veterinarians are employed in private practice • They will relate to the public practice veterinarians for disease control programs, regulations and disease reporting. • They prevent zoonotic disease among the general public. • 25% of veterinarians are in public practice and are not privately employed

36. Veterinary Preventive Medicine • Where public practice veterinarians are employed • 27% Federal • 37% University • 20% Industry • 9% State and Local Government • 7% Armed Forces • With the biggest growth areas in population medicine, preventive medicine and public practice predicted for the future.

37. Veterinary Preventive Medicine • In my opinion careers in public practice: • are not “alternative” careers. • often times have good working conditions with great benefits. • often are 40 hour a week jobs. • offer great job variety, are intellectually stimulating, and a offer a feeling of doing something important.

38. Veterinary Preventive Medicine • Career limitations for DVMs are largely self imposed: • the human medicine community welcomes us as part of the team. • Keep an open mind about public practice. • Never say “never” • Talk to guest speakers to develop contacts for later. • Plan to use your last 1 ½ years of vet school to prepare for public practice. • Emphasize food animal skills

39. Clerkship Opportunities • The Government and Corporate Veterinary Practice Clerkship • This is approximately 3 weeks long and meets with about fifty public practice vets. • Special problems courses at: • CDC, USDA, AFIP, MDA, MDCH, Dow Chemical, Pharmacia & Upjohn, zoos, military, AFIP, Sea World, laboratory animals, etc.