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CENTRO DE INVESTIGACION EN SANIDAD ANIMAL (CISA-INIA), Valdeolmos, Madrid, Spain
Control eradication models; the
Spanish experience
Dr. Carmina Gallardo (gallardo@inia.es)
I. Introduction
I- Introduction
Since no vaccine against ASF was available, the program was based on:
Detection of ASF sero+ and carriers
Enforcement of strict sanitary measures
Key components of the program:
1. Network of mobile vets field teams
2. Serological testing of animals
3. Improvements in sanitary infrastructures
4. Elimination of ASF outbreaks, identification & slaugther of carriers
5. Vet control of swine movements with individual identification of every animal
I- Introduction
History
ASF appeared in Spain in 1960
Spread within a undeveloped
livestock sector
60s: Spanish economy began
to take off
In a few years, from back yard
to intensive pig productions
systems
Epidemiology
Initially, ASF manifested acute clinical & hig
mortalitiy
Later, became to an endemic disease: mild-to-subclinical & mortality below 5% (lab confirmation was required)
Prof. Sanchez-Botija published in 1963 that ASFV could be transmitted to pigs by ticks (Ornithodoris erraticus)
O. erraticus was common in Southwestern regions where the disease was endemic and the outdoor production of Iberian pigs was located
Swine production sector in 80’s
In spite of ASF, strong development pork-producing sector
Swine production increased from 6m head (1960) to
16.7m head (1989)
200.000 employed
1.2m tons of meat (of which 50%
consumed as manufactured products)
Geographic distribution of Spanish pig population
Intensive
Extensive
Production systems:
Economic consequences due to ASF
Economics hardships on pig
producers
Barriers to trade in live pigs, fresh
meat & pigs products
Great cost on ASF control
measures (11.4 m euros in 1983)
In March 1985 the Government approved a “Coordinated Program
to eradicate ASF.”
Initial financial support of 43m euros by European Community
III
Key Actions
1. Network of mobile vets field teams (127 vets)
2. Serological surveillance of 100% of pig farms
3. Improvement in animal holding facilities
4. Elimination of all ASF outbreaks (stamping out)
III- Key Actions
III- Key Actions 1. Network of mobile vets field teams (127 vets)
Sanitary control of holdings
Animal identification
Epidemiological surveys
Samples collection
Serological control at abattoirs
Epidemiological investigations
Promotions of Sanitary Associations*
*ADS: Asociación de Defensa Sanitaria (Animal Health Protection Asociation)
III- Key Actions
2. Serological surveillance of 100% of pig farms Main needs:
A simple, fast, accurate & specific diagnostic test (Indirect ELISA)
A Reference Laboratory to harmonize the techniques (INIA)
A net of Regional Laboratories for serological surveillance (13 labs)
At the beginind: Indirect ELISA to screen samples IFA to confirm results
In the final stages: INIA developed and improved ELISA (new soluble Ag with all ASFV proteins)
INIA developed Immunoblotting assay as confirmatory instead of IFA
Consequences New ELISA: Better recognitions of carriers New Immunoblotting: Easier and more objective
interpretation New Immunoblotting: Better recognition of weak positives
III- Key Actions
3. Improvement in animal holding facilities
1st objective: to improve sanitary barriers to prevent de spread of the disease
Hygiene measures: fences, sanitary enclosures, safe disposal of manure…
Loans at low interest rate were offered
More than 2175 holdings were improved (1985-95)
For this purpose:
4. Elimination of all ASF outbreaks (stamping out)
All pigs in infected herds immediately slaughtered
Samples collection for virological & epidemiological investigations
Immediate and adequate compensation to the pig producers
STAMPING OUT is:
A resource-intensive method of eradication
The most cost-effective method
Allow countries to declare ASF free in the shortest
STAMPING OUT must be:
Applied for a period long enough to eradicate
Accompanied by public awareness campaigns
III- Key Actions
Procedures once outbreak identified (I):
Depopulation by slaugthering all pigs in the affected herd Cleaning and disinfection of all facilities during 1 month after depopulation Extermination of insects and rodents
Removal and destruction of all animal feed and animal products Cleansing of manure pits by 2% sodium hydroxide Incineration of straw bedding
III- Key Actions
Procedures once outbreak identified (II):
Sanitary zone of a few hundred km radius
Movement of animals, products, feed and waste into or
out the sanitary zone were restricted
Movement of people to and from
the area were restricted
After implementation measures were gradually lifted (although some specific were maintainedat least 3 months)
III- Key Actions
III- Key Actions
Procedures once outbreak identified (III):
After cleaning and disinfection, introduction
of sero- sentinels
Number of sentinels equivalent to 10-20% of
the population
If after 1 month don’t become sick:
serological test
If neg, authorities allow the repopulation of
farm (from status controlled farm)
Restocking procedures usually completed
within 3 months after entry of sentinels
III- Key Actions
Biosafety and sanitary measures to avoid transmission
between herds played an important role in the eradication
Epidemiological surveys
indicated that 84% in 1989 and
93% in 1990, neighbor contact as
the most likely source of the new
outbreaks
Transmission between herds Special Attention !
IV
Restricted Areas
3 Km
10 Km
IV- Restricted Areas
3 km radius All pigs of all herds serologicallly screened immediately after confirmation Movement prohibited for 30 days
Protection zone
Surveillance zone 10 km radius
Screening 30 days after cleaning & disinfection of infected holding
Movement prohibited for 30 days
3 Km
10 Km
V. Livestock Movement &
Animal Identification
V- Livestock Movement & Animal Identification
Movement of animals
Vehicles required to be washed and disinfected
Animals in transit previously identified & provided with veterinary certificate (stating origin & sanitary situation)
Abattoir
Vets checking the sanitary certificate (before slaughtering)
Life pigs inspected antemortem & tissues posmortem
Sanitary certificates retained at least 1 year
Manufacturers retained identification of meat origin
Register & Identification
Pig farmer census was improved & completed
Producers & manufacturers register was improved
Infected farms register was daily updated
Annual Report of the Program development issued
V- Livestock Movement & Animal Identification
Lidership role in the eradication program (voluntary)
Common approach against ASF
Serological surveillance of breeders
Correct sanitary infrastructures
Sanitary suitable program for ASF
Aids from Administration
1990: 1,000 HPG created grouping 41,500 farmers & 1m animals
A register was created classifying farms (health status & facilities)
Involvement and participation of farmers
Wide publicity campaign in the mass media
Encouraging the creation of Health Protection Group
V- Livestock Movement & Animal Identification
VI
Regionalization
The erradication programe evolves into regionalization
The erradication programe evolves into regionalization
Portugal
ASF Situation in 1985
Infected Area
Surveillance Area
Free Area
VI- Regionalization
As a result of the progress…
1989 ECC authorizes dividing Spain into 2 regions:
ASF-free region (largest part of the country & 70% of pig
population)
ASF-infected region
Consequently prohibition of trade was lifted (from ASF- free regions)
Portugal
ASF Situation in Dec 1989
Infected Area
Surveillance Area
Free Area
Since 1990:
Outbreaks continued in others areas until 1993 The virus persistence was due to:
Production facilites lack of sanitation and biosafety features
Presence of soft ticks (Ornitodorus erraticus)
Uncontrolled wild boar population
VI- Regionalization
No Outbreaks in certains parts of Infected Region (although some serological evidence observed in certain herds)
Portugal
ASF Situation in Feb 1991
Infected Area
Surveillance Area
Free Area
No Outbreaks since 1990
Free Area
Serological sampling of 5% sow herds (each year) Samples from adjacent areas to surveillance and infected zones
Surveillance Area
In each breeding herd: 30% of breeding animals tested (each year)
Serological sampling of 5% wild boar population (each year)
Wild boar killed during hunting season
In open/mixed production systems: 50% of breeding animals in all herd tested (each year)
In fattening herds: All pigs more than 40kg in all herd tested once
VI- Regionalization
Infected Area
In all breeding herd: 30% of breeding animals tested (twice per year)
In open/mixed production systems: 50% of breeding animals in all herds tested (twice per year)
In fattening herds: All pigs more than 40kg in all herds tested (once per year)
Wild boars: All killed during hunting season had to be virological &
serological examinated
VI- Regionalization
Special measures in Surveillance & Infected
Destruction of the unsanitary animal production facilities
Serological surveillance by ELISA of pig at risk of being bitten by ticks Construction of metal fences of 100 m radio around animal facilities
VI- Regionalization
Portugal
ASF Situation in July 1993
Infected Area
Surveillance Area
Free Area
ASF Situation in July 1994
Portugal
Infected Area
Surveillance Area
Free Area
VII. Final Phase:
International Coordination
VII- Final Phase
The epidemiological situation presented needed to join efforts with Portugal
The remaining infected areas in both countries were located around the border Spain/Portugal
Jul 94-Dec 96: Cost of serological testing, slaughter & destruction, cleaning & disinfection, 50% funded by EC (7.2 m euros)
Portugal
Portugal
ASF Situation in Nov 1994
Infected Area
Surveillance Area
Free Area
Portugal
ASF Situation in Dec 1994
Infected Area
Surveillance Area
Free Area
Portugal
ASF Situation in Jul 1995
Infected Area
Surveillance Area
Free Area
Portugal
ASF Situation in Dec 1995
Infected Area
Surveillance Area
Free Area
In Dec 1995: Spain was declared officially free
of ASF !!!
ASF Eradication:
Conclusions
Conclusions
Great effort on the Agriculture Ministry had to be done:
To create the necessary infrastructure
To train higly qualified personnel
To coordinate with Regional authorities
Since 1987, no new outbreaks in the areas producing confined systems
Since 1987, outbreaks appeared only in Southwest (extensive systems)
Since 1994, no new outbreak appeared anywhere in Spain
Consequently:
Vaccine was not essential for ASF eradication
Acknowledgments
Livestock Department of Ministry of Agriculture of Spain
Dr. Sánchez-Vizcaíno (Fac. Vet. UCM)
Dr. Marisa Arias (CISA-INIA)
Spanish pig population in 1995
The 2nd producer in Europe:
22.4 m pigs
2.5 m sows
Portugal
Spanish pig population in 2008
The 2nd producer in Europe:
25 m pigs
2.6 m sows
Portugal
Prevention strategies for ASF
QUARANTINE is the first line of defence,
”Prevention is better than
cure””
EDUCATION is the most important resource, in the prevention of ASF.
Thank you,
see you later !