Transcript Preventive Veterinary Medicine VM544

Preventive Veterinary Medicine
VM544
Lecture 1
Introduction
Part II
Preventive Medicine
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
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.
The Role of Infectious Disease
and Preventive Medicine in our
Society
The impact was Major!
Historical View of Preventive Medicine
Rats, Lice and History
by Hans Zinsser
Three main points:
1. The history of mankind has been dominated by epidemic
disease - not great armies.
2. Preventive medicine has freed us from the devastation of
epidemic disease.
3. Veterinarians should be proud of our historic contributions
in preventive medicine and should expand our involvement
on the human preventive medicine team.
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
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
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
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
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???
The Great Plaques of History
Military 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.
The Great Plaques of History
The 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
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.
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)
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
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.
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.
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
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.
The History of Preventive Medicine
(as measured by the “success” of
the human species)
Graph of the Human Population
Two inflection points
Over Time
Agricultural revolution
Industrial revolution
Estimated Global Population
Due to improvements
in sanitation
(preventive medicine,
disease control
practices) and nutrition
7
Pop in Billions
6
5
4
3
2
1
0
-10,000
-2000
Years ago
-500
0
Both of which are key
elements of preventive
medicine
Antibiotics
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.
Theodoric of York
Curative Medicine was still in the “Dark
Ages” when preventive medicine was
increasing the life span of the human
population.
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.
High Infant Mortality Rate
Suicide
Wisconsin
Death Trip
Insanity
Religious dementia
Poverty
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”
Preventive Medicine
Hand washing - one of most important
means of preventing infection.
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.
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.
Veterinary Preventive Medicine
Three motivations
“…men go into this branch of work from a
number of motives, the last of which is a selfconscious 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
Veterinary Preventive Medicine
3 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
Veterinary Preventive Medicine
3 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)
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
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.
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.
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
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.