Return to Table of Contents: WVA Bulletin Vol. 19 Nr. 1 January
2002
History of Diseases
Spreading Through International Trade
Lessons for the Future
By V. Kouba, Formerly:
Chief, Animal Health Service, Food and Agriculture Organisation, of the United
Nations, Professor of Brno Univ. of Vet. Sciences, PB 516, 17000 Praha 7, Czech
Republic.
Introductory lecture
presented at the 32nd Congress of the World Association for the History of
Veterinary Medicine (WAHVM), 15-18 August 2001, Oslo, Norway.
Photo: Vaclav
Kouba
Prof.MVDr Vaclav Kouba, PhD,DrSc., born in Czech
Republic in 1929, graduated in 1953 at Brno University of Veterinary Medicine.
Formerly: Chief, Animal Health Service, Food and Agriculture Organization of
the United Nations (FAO), Rome; Veterinary Public Health Expert, World Health
Organization (WHO), Geneva;
Key criterion of veterinary medicine historical
mission is its practical impact on global animal population health. Its
usefulness depends on how far is able to protect healthy animals, to recover
health of sick animals and to reduce, eliminate and eradicate transmissible
diseases.
Unfortunately, historical facts document serious
discrepancy between rapidly increasing quantity and quality of scientific
knowledge and rapidly worsening of animal diseases global situation. Among main
causes belongs spreading of infectious and parasitic diseases through
international trade in animals, their products and objects which could be
contaminated by pathogens. Public health, economic, ecological and social
negative impacts of diseases spreading are enormous.
The purpose of this paper is historical analysis of
animal diseases introduction through international trade during last decades of
the 20th century, i.e. from 1980 when regular reporting of disease
"import" was started. Analyses of previous periods were published for
example by Blancou and Meslin (1). Import of animal commodities represented a
risk not only of diseases introduction but also of after-import spreading with multiplying
negative, often long-term or permanent, catastrophic consequences. Discovery in
time, control and eradication of introduced and spread diseases were usually
very difficult and costly. Not all "imported" diseases could be
blocked within quarantine to avoid secondary outbreaks. Most introduced
diseases couldn't be eradicated.
Material and methods
·
The analysis is based
upon country official data as reported annually to international organizations.
Data on international trade in animal commodities are from FAO Trade Yearbooks
(5). Data on diseases introduction related to international trade are from
FAO-WHO-OIE Animal Health Yearbooks (4) and OIE World Animal Health yearbooks
(Country Reports and Tables) (7). Data on cases reported during the year 2000
are from OIE Internet pages. The analysis was supported by OIE documents (6) as
well by authors' publications (2,3) and international experience.
·
The analysis of
reports on disease introduction related to international trade was subdivided
according to the OIE List A and List B diseases. Numbers of reports on diseases
recognition in country for the first time and reports on diseases reappearance
(reintroduced or reemerged) after more than 3 years were analyzed as well.
·
There were a lot of
cases of disease "import", some of them were discovered and reported
to international organizations (international information system covered only
about 1/10 of known species of transmissible diseases), some were discovered
and not reported (e.g., most diseases were not obligatory notifiable and not
controlled) and much more cases were not discovered at all (e.g., due to lack
of active investigations able to detect subclinical carriers, etc.). Emerging
diseases represented a new insidious threat.
Results
·
Diseases spread
through international trade was linked with increasing import of animal
commodities. (Graphs 1 and 2). During 1961-1999 international import in
monetary value of live animals increased 9 times, of meat and meat preparations
20 times and of dairy products 17 times! Analogically increased national trade
in these commodities. It was obvious that simultaneously increased disease
spreading risk. Unfortunately, protective measures instead to be strengthened
were not adjusted. Public veterinary services, responsible for protection of
country animal population health, were left more or less the same or even
reduced. The main "reason" was an economic one, in spite of the fact
that worldwide trade in livestock and meat rose up to US$ 51 billion in the
last year of evaluated period.
·
International trade in
animals and their products during 1980-2000 caused spread of many animal
diseases. Number of official annual reports on the OIE List A and List B
diseases introduction related to international trade reached 600 (20 % of the
List A and 80 % of the List B). More than hundred cases of introduction of
other animal diseases were reported as well.
·
From 120 annual
reports on OIE List A diseases introduction the major shares had foot-and-mouth
disease, rinderpest, contagious bovine pleuropneumonia and Newcastle disease.
Alarming are reports on increasing number of FMD introduction cases after the
"WTO Agreement on the Implementation of Sanitary and Phytosanitary
measures" came into force in 1995 (from 29 cases during 1980-2000 were 21
reported during 1995-2000 !).
·
From 90 reports on the
introduction of OIE List B multiple species diseases the major share had
paratuberculosis. From 191 annual reports on the introduction of cattle
diseases the major share had enzootic bovine leukosis. From 69 reports on the
introduction of sheep and goat diseases the major share had scrapie. From 34
reports on the introduction of equine diseases the major share had
piroplasmosis. From 20 reports on the introduction of swine diseases the major
share had atrophic rhinitis. From 76 reports on the introduction of avian
diseases the major share had chlamydiosis.
·
Number of reports on
animal diseases "recognized in country for the first time" reached
487.
·
Disease reappearance,
i.e. reintroduced or reemerged, was reported 338 times. The analysis includes
only reports of the reappearance when the interval between last previous and
new cases was 3 and more years. The reason was that the reappearance after less
than 3 years could be in some cases the result of a recidive due to surviving
subclinical carries of pathogens.
Example:
Foot-and-mouth diseases reintroduction in Japan after 92 years.
·
Among many factors
facilitating spread of animal diseases through international trade belonged for
example:
1.
Mono-etiological instead
of poly-etiological risk assessment based on theoretical mathematical
calculations without considering: characteristics of transmissible diseases and
their etiological agents ability to reproduce and propagate; true diseases
occurrence, trend and dynamics; ability of diagnostic methods to discover all
affected animals; veterinary services abilities; post-introduction efficiency;
human factors; etc..
Example: Taiwan had
been free of FMD (foot-and-mouth disease) over 68 years before 1997. FMD
occurred in March 1997 and stormed the whole island that led to tremendous
economic impact due to the loss of exportation market... During four-months a
total of 6,147 farms was infected ! (OIE)
Incorrect risk
assessment caused that among imported animals and their raw animal products
were sometimes also carriers of etiological agents species, types, subtypes and
strains which in importing countries were considered as exotic.
2.
In the middle of the
nineties certain international organizations started policy of
"facilitating trade" at the expense of animal and human health. For
the first time in the history was introduced legal framework conducing to
benevolent risky trade officially admitting and even supporting also diseases
spreading through international trade. Previous international recommendations
of minimal health requirements for protective import conditions were converted
in binding maximum limits. This changed the principle of "health
first" into "business first" !.
Simultaneously, reporting
on animal diseases status was significantly reduced instead to provide more
information needed for countries' decision about import conditions. Previous
reporting of disease occurrence grading and disease import cases was replaced
by only one uninterpretable symbol "+" !
3.
Benevolent
international regulations not respecting that the trade in animals and their
raw products was much more risky than in all other commodities. Profiting
traders didn't cover losses caused by diseases "import", which was
opposite situation in comparison with cases of defective industrial commodities
import.
Example: Eradication
of Cochliomyia hominivorax, horrible myiasis affecting all mammals, including
man, introduced through legal trade (accompanied by standard international
attests confirming disease free status !) from South America into North Africa
, cost 80 million US$ (losses not included); exporting country (traders)
contributed nothing ! (FAO)
4.
International
agreements unfavourable to importing country protection, i.e. without
sufficient quality guarantee of pathogen free animal commodities and without
fair reclamation procedure. Illegal import and almost uncontrollable re-export
made veterinary control much more difficult.
5.
Low self-sufficiency
in national production of food of animal origin which was requiring larger
imports; instable trade partnerships, too many and too distant origin and
destination places.
6.
Lack of ability to
apply effective preventive, control and eradication measures under more
complicated conditions than before and to control increasing trade; weak public
veterinary services being unable to monitor animal population health situation
at field level, to inspect on the spot rapidly increasing export/import ;
issuing veterinary export certificates by not always independent and reliable
non-government specialists; self-declaring specific "disease free
zones" for export in countries with instable situation (new cases) and
without adequate investigations and international inspection; unjustified
concessions due to traders' pressure to reduce protective measures against
diseases introduction.
7.
Controlling only
limited number of selected diseases and certifying their "free
status" for animals and products to be exported, ignoring not notifiable
and not controlled transmissible diseases and the possibility of test false
negative results.
8.
Absolutely
insufficient research, education and training in population medicine,
preventive and control measures at national and global levels (incomparable
with economically well supported flourishing individual curative medicine).
9.
Human factors:
exporting country not reporting true disease situation; risk underestimation;
inexperience, errors; irresponsibility, cheating, corruption, outside
"pressure"; falsification of identity and health certificates; low
discipline when applying laws, regulations, norms and measures; low authority
of veterinary services; not considering lessons from historical experience.
Discussion
The analysis proved alarming worsening of disease situation
in the world during recent decades.
It is obvious that the grade of disease spreading
through international trade was directly correlated with diseases occurrence
and control deficiency in exporting countries, trade size and frequency as well
as with the numbers of and distances between origin and destination places.
There were many cases when, in spite of favorable
risk assessment, risk reducing measures and standard veterinary certification,
specific diseases spread through import into countries free of these diseases.
Not all introduced diseases could be blocked in the
quarantine to avoid creating secondary outbreaks. Not all introduced diseases
could be eradicated or only after longer period requiring a lot of economic and
other inputs. The recovery, i.e. eradication, was feasible only in very limited
number of cases due to lack of necessary inputs, mainly in developing
countries.
Disease reintroduction represented serious impact due
to devaluation of eradication programmes which had been usually very demanding,
expensive and requiring long period. In one moment the result of many years of
intensive successful work was converted into zero.
Animal disease import risk was generally
underestimated giving priority to instantaneous profit of traders and ignoring
potential disease spread with often irreparable consequences.
"Import" of diseases represented for importing country the
"purchase of problems".
Too many cases of disease introduction through trade
proved that old traditional veterinary import conditions, certifications and
measures didn't correspond with historically changing situation, requiring much
better and more consistent protection measures than in the past.
Veterinary services were able to recover health and
save life of many sick animals, solving mostly local problems. However,
simultaneously many times more animals became sick due to diseases spreading
mainly through international and national trade. De facto, it was gradually
started trend towards the globalization of animal diseases, which is against
the historical mission of veterinary medicine to promote, protect and restore
animal population health in the whole world.
Conclusion
Increasing intensity of international trade in
animals and raw animal products caused increasing spread of diseases among
countries and continents. The situation was getting worse as never, in spite of
having much better scientific knowledge and practical experience as in previous
periods. Very few successfully finished national eradication programmes were unable
to compensate rapidly spreading diseases in the whole world. Too many results
in diseases control and eradication achieved by previous generations were
gradually devaluated.
The lesson for the future consists in avoiding
repetition of past mistakes and in supporting trade in pathogen free healthy
animals and wholesome animal products only. Historical analyses are necessary
for identifying factors facilitating diseases spreading through international
trade and for applying correcting actions.
In importing countries, increase of animal production
to be supported as much as possible and thus to reduce the need for risky
import. Country protection to be strengthened and factors increasing diseases
introduction risk to be avoided or reduced to acceptable minimum. In exporting
countries, improvement of animal health quality through diseases reduction and
eradication to be supported as the best way to facilitate fair trade in animals
and raw animal products and thus avoiding transmissible diseases "export".
Public veterinary services to be radically
strengthened to be able to cope with rapidly increasing trade. Wide gap in
research of animal population health and disease at national and global levels
to be filled, adequate methods to be developed and intensive education and
training in preventive population medicine to be introduced or extended.
The lesson for the future: to stop neglecting
historical experience and to apply consistently the principle of preventive
medicine - Primum non nocere. Nobody wants next generations to blame us for
letting animal diseases global situation worse than it was before.
Historia est magistra vitae!
Literature
(1) Blancou J, Meslin FX. International trade and
human or animal diseases: a historical review. Proceedings of the World
Veterinary Congress, Yokohama, 1995,p.4.
(2) Kouba V. Epizootiologia general, 2nd edit.
Havana, Edicion Pueblo y Educacion, Instituto del Libro, 1987, 867 pp.
(3) Kouba V. Analysis of diseases spreading through international
trade in animals in developing countries. Agricultura Tropica et Subtropica,
Prague Agriculture University, 2001, Vol. 33, 70-74.
(4) FAO-OIE-WHO Animal Health Yearbook. Rome, FAO,
1980-1996.
(5) FAO Trade Yearbook. Rome, FAO, 1966-1996.
(6) Risk analysis, animal health and trade.
Rev.sci.tech. Off.int.Epiz., 1993, 12(4), 1005-1362.
(7) World Animal Health. International Office of
Epizootics, Paris, 1991-2000.
List of Figures
Graph 1. International trade in animals, meat and
dairy products. World.
Graph 2. International trade in major animal
commodities. World.
Return to Table of Contents: WVA Bulletin Vol. 19 Nr. 1 January
2002