Acta Veterinaria Brno, 2000,
69: 69-80
(Amendments on 7 June 2008)
BOOK REVIEW
Dictionary of Veterinary Epidemiology.
Iowa State University Press, Ames, 1999, XVI and 284 pages. ISBN 0-8138-2639-X
"Dictionary of Veterinary
Epidemiology" was published by Iowa State University Press,Ames in 1999 as
English edition of the French publication of Toma, Benet, Dufour, Eloit, Moutou
and Sanaa: "Glossaire d'épidémiologie animale", Editions du Point
Veterinaire, Maisons-Alfort, 1991. The Office International des Epizooties
(OIE) provided financial assistance.
The book contains a list of 57 contributors
(all but one from North America, France and United Kingdom), 5 pages of
Foreword and Preface, 270 pages of term definitions and 4 pages of References.
The Foreword stresses that the book
presents the "French and the North American perspectives on
definitions of terms".
The publication contains definitions of 961
terms of which only a half are epidemiological terms. The rest belongs to
general statistics (36 %) and economics (10 %). Unfortunately, many definitions
from the French original having 1014 terms were deleted and some new terms were
added. A lot of space is allocated to examples (486) and comments (1318).
Original French title is not translated
exactly. The terms "animal" and "veterinary" are not of the
same meaning. The definitions of these key terms as well of "veterinary
epidemiology" used in title (normally indicating publication scope) are
missing.
The term "epidemiology" is defined
on p. 88 as the "Study of the health status of population." If we
compare this definition with the classical "Dictionary of
Epidemiology", edited by J.M. Last and published by Oxford University
Press in 1995, then we can see a great difference: “epidemiology” is defined as
"the study of the distribution and determinants of health-related states
or events in specific populations, and the application of this study to control
of health problems." This definition stresses dynamics and “makes explicit
the aim of epidemiology - to promote, protect, and restore health."
Last's publication contains 1399 term definitions (i.e. more by 43 %). One
would expect in the "Dictionary of Veterinary Epidemiology" the
definitions of much more terms than in human epidemiology due to a large number
of animal species, more etiological agents, more environmental and other
influencing factors, and more control methods.
Definitions of hundreds of important
epidemiological terms currently used in modern human and veterinary literature,
documents of international organizations such as OIE, WHO, FAO etc. as well as
in veterinary practice are not included. Some of them are only mentioned (however, without definitions) in the comments.
Definitions of the most terms of epidemiologically important characteristics of
populations, etiological agents and environment and their interactions,
representing the basis of population health/disease processes, are missing.
Definitions of the majority of indicators used for measuring distribution and
determinants of population health-related states and events are missing as
well.
The most alarming information about the
concept of "new scientific discipline" (p.XIII) which in fact is
degrading the epidemiology, is on pp. 110 and 111: epidemiological problems
solution belongs to so called "health managers" and not to
"epidemiologists" ! This clarifies the relatively low practical
importance of this kind of restricted "epidemiology" (less than a
"semi-epidemiology") which is being imposed upon international
organizations, many countries, undergraduate education and postgraduate
training. This clarifies the fact that many so called "veterinary
epidemiologists" are not involved in field control programmes with
professional responsibility for their results. (What a difference in comparison
with clinicians who after case diagnosis solve the problems !) This is
obviously the reason why the majority of veterinary faculties have not
"veterinary epidemiology" in the list of undergraduate curriculum
subjects (in spite of several FAO/WHO recommendations). Epidemiological
problems and their solution start and end in the field (usually supported by
laboratory investigations) and not in offices. Key output of any animal health
activity is a final practical result and not papers. Unfortunately, this
dictionary represents a narrow concept based mainly on data collecting,
processing and analyzing. The book title should be adjusted to the contents.
One could get the impression that the main
concern of this dictionary is to avoid using terms such as
"epizootic" (p. 89), "enzootic" (p. 84), etc. and replace
them by "epidemic", "endemic", etc. in direct contrast with
the French original which accepts these terms without any doubts ! It is
strange that this demand is in a publication of the International Office
of E p i z o o t i c s which has been
using these terms from its foundation in 1924 followed by the member countries.
In Last's "Dictionary of Epidemiology" the above mentioned terms are
accepted and correctly defined without any polemic. Normal dictionaries first
define the terms and then eventually comment on them which is not the case in
this book. The contributor instead of defining "veterinary
epidemiology" and "epizootiology" tries to impose his view using
false, contradictory, unjustified and not convincing arguments without
respecting the scientific nomenclature, ethymology and opinion of the others.
If we apply his "logic", then does why the book title use the
adjective "veterinary" ? He probably doesn't know what
"epizootiology" (identifying exactly by one word specific biological
science ) means. American Professor Calvin Schwabe wrote: "While the terms
epizootic and enzootic are in common usage and are generally understood, the
terms epizootiology and epizootiologists are heard less frequently. Strictly
speaking epizootiology is a more inclusive term than epidemiology."
The contributor who wrote about these terms
has obviously not a good idea about veterinary practice in the world. The terms
such as epizootic, enzootic, epizootiology, etc. are long established and
widely used in veterinary literature, documents of international organizations,
legislation (e.g. Mexican Animal Health Law, 1993), etc. The science of epizootiology
was introduced in many veterinary faculties as separate subject (with state
examination) supported by textbooks and research. Epizootiology covers not only
analytic methods but also methods for promotion, protection and restoration of
animal population health (including zoonoses control). The syllabus can be
found e.g., in the Report on Consultation on Undergraduate and Postgraduate
Teaching in Veterinary Public Health, World Health Organization, 1983. This
discipline has educated action-oriented veterinarians able to investigate the
situation and apply practical measures at field and managerial levels and not
"paper epidemiologists" for comfortable and attractive bureaucratic
work in offices only who can also "work" without investigating or
even seeing the animals. Aim and contents of any discipline are much more
important than its given name !
The key term "Animal health" on p.
10 is defined as: "State of well-being applied to animals." This is
very superficial definition not respecting the epidemiological aspects required
for practical application (e.g., for trade purposes). Several examples are from
human instead from animal medicine (e.g., alcoholism on p. 7). On p. 12, there
is a sentence with no biological logic: "In this example, the apparent
prevalence would be over seven times greater than the true
prevalence." One page example of
"Balance sheet" on p. 17 is dedicated to financial position of a
business instead to animal population health. Other example having nothing to
do with epidemiology is on p. 177 comparing annual profit of self-employed
small animal veterinarians being $45000 with pet food company veterinarian
making $65000.
On p. 111 the term "Healthy
carrier" is contradictory; from the epidemiological point of view the
carrier without clinical symptoms cannot be declared as healthy. On p. 120, the
text regarding the "incidence", the most used population disease
indicator, is very confusing: there are two quite different "incidence
rates" - new cases once per time unit and once per number of individuals;
difference between "incidence proportion" and "incidence
rate" is not clear; difference of reproduction periods (speed) between human and animal populations,
influencing denominator values, is not considered (second Comment 2).
Example on p. 147 merits mentioning:
"It is assumed that, for every case of salmonellosis recorded in humans in
the United States, at least nine are not reported." What about animal
diseases data processed by "statistical epidemiologists"; exact
calculation of data not corresponding with the reality ?!
On p. 162, there is a calculation mistake.
On p. 176 "Operational epidemiology" is explained as "the
epidemiology of intervention as opposed to the epidemiology of knowledge."
Operational epidemiology is not epidemiology of knowledge ? This reflects the underestimation
of field practice work which is decisive in epidemiology. Definition of
"Population medicine" on p. 189 cannot be restricted to animal
populations only.
There are many other definitions which
cannot be generally accepted. There are definitions which differ from French
original and create confusions in understanding the terms. I fully agree with
the Foreword that "the publication of this dictionary will not end the
debates over these terms" (p. XII).
In this context it should be mentioned the alibi statement (p. IX) about
the list of contributors: "Because they have not reviewed the entire work,
their inclusion in this list should not be interpreted as their endorsement of
all the definitions." !?.
In spite of the above comments, the effort
of all who contributed to this not easy work providing definitions of many useful
terms which are not available in other dictionaries, should be appreciated. The
publication can serve as one of different sources for a future international
dictionary that should cover the f u l l
spectrum of animal population health/disease terms respecting the needs,
experience and use in the w h o l e world.
Prof.MVDr Vaclav K o u b a, DrSc.
----------------------------------
P.S.
Additional comments (not included in ACTA VETERINARIA BRNO):
a) The “paper veterinary epidemiology” is
obviously addressed to the officers of public services working mainly
administratively in the offices isolated from
daily animal population health problems which solution depends on field practical work where is the decisive
stratum of the epidemiology - very
complex b i o l o g i c a l science.
b) The
degradation of veterinary epidemiology as biological science into something
else can be demonstrated by the WHO Consultation on Development and Training in
Veterinary Epidemiology, Hanover, Germany, 9-11 October 1990: “The meeting demonstrated
the gap between theory based on sometimes excessive use of mathematics and
computer modelling without orientation to action and the need for
cost-effective practical application in the field. The relative isolation of
the sophisticated methodology represent one of the major obstacles for the wide
use of epidemiological methodology in veterinary medicine, particularly in the
developing world.” Among participating “teachers” of veterinary epidemiology
were from several veterinary faculties the mathematicians
(!?).
c) False
concept of the above described purely theoretical “paper veterinary
epidemiology” confused with statistics and economics represents de facto a gravedigger of extremely useful animal population
health/disease science as a component of biological sciences.
d) If
practical results represent the main criteria of any biological science, then
catastrophic occurrence of the
foot-and-mouth disease in United Kingdom in 2001, causing the highest losses in
modern history - 4 million farm animals, has proved a total failure of the “paper veterinary epidemiology” isolated from the reality and
needs. R.P. Kitching, M.V. Thrustfield
and N.M. Taylor wrote in “Use and abuse
of mathematical models: an illustration from the 2001 foot and mouth disease
epidemic in the United Kingdom”, Rev.sci.tech.Off.int.Epiz., 2006, 25(1),
293-311 about much higher numbers: “The
official figure for the number of animals slaughtered was approximately 6.5
million, but when the total number of still-sucking lambs, calves and pigs that
were slaughtered is included, the total could be as high as ten million. The
financial cost of the FMD epidemic in the UK was over 12 billion, including US
dollar 4.5 billion in losses sustained by the leisure and tourist industry.
However, the social cost could not be quantified”. They supported the very critical opinion of the author of this book review
when stating: “During the 2001 epidemic of FMD in the
united Kingdom (UK), the traditional approach was supplemented by a culling policy
driven by unvalidated predictive models. The epidemic and its control
resulted in the death of approximately ten million animals (!!!),
public disgust with the magnitude of the slaughter, and political resolve to
adopt alternative options, notable including vaccination, to control any future
epidemics. The UK experience provides a salutary warning of how models
can be abused in the interests of scientific opportunism.” They
criticized the mathematical modellers: “Their
idea was to control the disease by culling in contiguous farms. That is fine
if you are sitting in front of a computer screen in London. However, it is different on the ground !” “The consequences following the
recommendations of these models were severe: economically, in terms of cost to the country; socially, in terms of
misery and even suicides among those involved in the slaughter
programme; and scientifically, in the abuse of predictive models, and their
possible ultimate adverse effect on disease control policy in the future.” “The
utility of predictive models as tactical decision support tools is limited by
the innate unpredictability of disease spread..” “..it was carnage by
computer !” This
graphically exemplifies the isolation and abstraction of ‘armchair
epidemiology’ !”
“Approximately three million healthy animals were slaughtered to control the epidemic.” The
paper is warning over the use of ever-more-detailed models as policy guides.
This example demonstrated very dangerous
harmfulness of the “paper
veterinary epidemiology” deviating the strategy and
measures from the field reality and ignoring biological character of the
epizootics and thus causing
enormous losses.
e) The
“paper veterinary epidemiology” international education/training centres (e.g.
Reading, Davis, Teramo, Fort Collins, Maisons-Alfort, etc.) have trained
thousands of participants mainly from developing countries. The effect has
consisted in theoretical knowledge and data processing skills (using the
computers), however, without ability to investigate at field level and analyse
animal population health/disease situation identifying and solving the main
problems of preventive, control and eradication measures at home.
f)
Examples of the “paper veterinary epidemiology” conducing to the “strategy of
doing nothing” at field practice level, i.e. admitting animal infection
spreading, see also in the paragraph 3.3 of
www.cbox.cz/vetmanpower.htm and
in the paragraph 2.10 of www.cbox.cz/vaclavkouba/orgglobalization.htm.
g) Authors’ letter to Prof. Dr Toma :
Prague, 20
December 1995
Mr.
Prof.Dr Bernard T o m a
Chef du Service des Maladies
contagieuses
Ecole National Veterinaire d'Alfort
94700 Maisons-Alfort
F R A N C E
-----------------------------------------
Dear Professor Toma,
I am writing you regarding the definition
of "epizootiology" in your excellent dictionary "Glossaire
d'epidemiologie animale", Editions du Point Veterinaire, 1991 which I
bought in Paris last year. On page 104 after a short definition of
"epizootiology" there is a three-line-note with following
sentence: "Ce terme, encore parfois utilise, est a eviter."
I would like to ask you to delete this
negative note in the next French issue and in the English version being
prepared.
The introduction and use of the term
"epizootiology" was influenced by the example of the policy and
documents of the "International Office of Epizootics" (OIE) in Paris
in the past (e.g. see "OIE
Resolutions and Recommendations on Epizootiology and Prophylaxis of the
Main Epizootic and Enzootic Diseases: 1924-1974", OIE, Paris, 1974 !). It
would be not fair to ask for avoiding the term "epizootiology" today
when it is relatively widely used.
The one-word-term "epizootiology"
reflects precisely the biological contents respecting scientific language
(Greek origin) covering all species of animal kingdom. This term is widely used
instead of "veterinary epidemiology" in veterinary theory and practice, legislation,
education (undergraduate curriculum, postgraduate programmes, school
structure), research and literature (including textbooks) of many countries.
Further examples:
a) Many documents of
international organizations use words "epizootiology" and
"epizootiological" such as:
- FAO/OIE/WHO World Animal
Health Information System
- FAO/OIE/WHO Animal Health
Yearbook
- OIE World Animal Health.
- In OIE International Animal
Health Code, 1992 on page 17 is the Section 1.2. called "Notification and
Epizootiological Information".
- In the Report on WHO
Consultation on Undergraduate and Postgraduate Teaching in Veterinary Public
Health, Brno,1983 the term "epizootiology" is often used (e.g. in
Annexes 10 and 11 are undergraduate syllabi for General Epizootiology).
- FAO Seminaire sur
l'epizootiologie et les aspects economiques de la sante animale, Niamey, Niger,
1983.
- Seminario regional de la FAO
sobre la epizootiologia y economia de sanidad animal, Lima, Peru, 1984.
b) Many Latin American countries
use this term instead of "veterinary epidemiology" (e.g. new Mexican
Animal Health Law adopted by Mexican parliament in 1993 for the new conditions of
NAFTA uses only terms "epizootiological" and no one word "epidemiological").
c) In the majority of Central
and Eastern Europe as well as Central Asia countries "epizootiology"
is used in legislation, research, literature, undergraduate and postgraduate
education with strong separated action-oriented "Epizootiology"
subject in undergraduate curricula (e.g. in Brno and Kosice Veterinary
Universities a 240 hours including laboratory and field practicals) supported
by university textbooks entitled "General Epizootiology" and
"Special Epizootiology" and by University Institutes or Departments
of Epizootiology. The terms "epizootiology" and
"epizootiological" are used in these countries veterinary practice (incl. networks of specialists called
"epizootiologists" - provincial and regional) where
"epizootiological" methods have been successfully applied in the
field at national and local levels.
d) Also in Western Europe this term is not
avoided (e.g. Institute of Bacteriology and Epizootiology in Swedish Veterinary
Faculty in Uppsala - Prof.Dr I.Mansson). The paper presented by Foot-and-Mouth
Disease World Reference Center in Pirbright at the Session of the Research
Group of European Commission for the Control of Foot-and-Mouth Disease in
Vienna, September 1994 is entitled "Molecular Epizootiology of FMD type
Asia 1"(Report, p.56-60).
e) In "Illustrated Manual
for the Recognition and Diagnosis of Certain Animal Diseases", vol. 2,
1988 prepared by top level specialists of Plum Island Animal Disease Center, USA
and Mexican-US Commission for the Prevention of Foot-and-Mouth Disease and
other Exotic Diseases the heading "Epizootiology" of particular
paragraphs is used on pages 7, 17, 20, 25, 30, 64, 71 and 79.
f) In the most important African
country - Nigeria the veterinary faculties curricula are using the subject
called "Epizootiology" as the component of preventive veterinary
medicine education ( see World Veterinary Congress 1995 Abstracts, FC5.4, p.
101 presented by Prof. Dr. Esuruoso).
g) Prof.Dr C. Schwabe in his
Veterinary Medicine and Human Health, 1969 on page 163 correctly explains and
comments on the term "epizootiology". He also writes: "Strictly
speaking epizootiology is a more inclusive term than epidemiology."
Name of "International Office of
Epizootics" as well as general use of the term "epizootic" do
not support avoiding the use of term "epizootiology".
Epizootiology has had major importance in
many countries with prevailing large scale animal production units giving
priority to population and preventive medicine aiming to increase animal
production and protect human health. Therefore, in these countries General and
Special Epizootiology was included in veterinary faculties undergraduate
curricula as a separated subject with particular examination (incl. final state
exams).
In many of above mentioned countries where
so called "new policy" consists in debilitating state veterinary
services, population and preventive
medicine (under the false monetary arguments) and strengthening curative
medicine veterinary is extremely
difficult to defend modern animal population health policy and activities
against financially attractive pet animals curative practice. At the
universities there are powerful clinicians pressing "epizootiology"
to be changed in "veterinary epidemiology" and thus, referring to examples of faculties of
some developed Anglo-Saxon countries, to be reduced or to disappear from the
curricula subjects. "Saved" teaching hours to be added to curative
medicine. They use as the arguments, without respecting different national
conditions, needs and traditions, the
examples e.g. from USA where in none vet. faculty is veterinary epidemiology as
separated subject of undergraduate curriculum and is only included in limited size
into some other subjects such as veterinary public health (with minimum field
practicals components). You can see how the problem of terminology can be
abused with very negative impact.
Let the international organizations,
countries, veterinary services, schools, institutes and specialists to use the
terms which they want and which are locally traditional and proved to be useful
under particular country conditions. Avoid imposing from abroad unnecessary
changes which create unnecessary problems with negative consequences.
I hope that you have understood correctly
my concern particularly now when the English version will be globally
distributed and used. Therefore, once again, I would like to ask you to
delete the above mentioned note in next issues of your dictionary ! Thanks in advance !
As far as our discussion in Yokohama on
the next Symposium of the Association for Veterinary Epidemiology and Economics
to be held next year in Paris is concerned, I will send you my proposals soon.
Yours sincerely,
Prof.Dr Vaclav K o u b a , DrSc.
P.B.516 , 17000
Praha 7
Czech Republic,
tel.0042-2-374584