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 !