ASF: GLOBAL IMPACT AND CONTROL

Prof. José M. Sánchez- Vizcaínojmvizcaino@visavet.ucm.eswww.sanidadanimal.info

ASF REFERENCE LABORATORY

ASFV: A old friend 1978-

MAIN WORK:DIAGNOSIS TEST &

REAGENTS EPIDEMIOLOGY-CONTROL

and ERADICATIONASF REFERENCE LABORATORY

ASF. A REEMERGING DISEASE

AGENDA:

EPIDEMIOLOGICAL SITUATION

CRITICAL POINTS FOR CONTROL

ASF VACCINE

ASF FUTURE

CONCLUTIONS

INFECTED OR CARRIERS PIGS (D&W) play an important role in the dissemination of the disease

ONCE ESTABLISHED:

By direct contact between sick or carrier and healthy animals (exudates, wounds,...)

ASF. Routes of transmission

Contaminated transport, FOOD

slurry, insects, rats...

Ticks and back yard

By eating infected swill or garbages

FREE AREAS:

Lisbon 1957Malta, 1978Sardinia, 1978Georgia, 2007

Portugal, 1960Spain 1960Italy, 1983Belgium, 1985Russia, 2008-

1. Raw pork waste at airport/port:

2. Movement of pork or pig products:

3. Movements of infected wild boars:Russia, 2008-

2. Boar or pork meat of infected swine fed to pigs (movement of infected meat)

1. Movements of infected pigs or carriers from infected neighbouring countries

Nigeria, Togo, Benin, all in 1997-98; Zambia, 2001; Kenya 2001; Ghana 2002;Tanzania 2004;Burkina Faso 2007;Kenya 2007;Tanzania 2008

South Africa 1973; Sao Tome & Principe, 1979; Ivory Coast 1996; Namibia 2004; Kenya 2007

ASF EPIDEMIOLOGY:

Kenya1921

1957

Historical distribution I

Portugal, 1957Spain 1960Frane 1974Malta 1978Sardinia 1978Italy, 1983Belgium, 1985Russia, 2008-

ASF. Scenarios : Europe ISpain 1985-1995

IN DOOR

2004-2005 (38)

1993-2003 (37)

Source of info.: NRL for ASF meeting , 2006, D. Rutili

1993-2005 (20)

Backyard (16,031) : 90.34%

Intensive (320): 1,80%

Confined/Fr (899): 5.06%

Free ranging (494).: 2.78%

Pig population.: 248.356Epidemic weaves:94-96; 2004-2005.

NO SOFT TICKS in Sardinia

ASF. Scenarios : Europe II

Sardinia,Italy PARTICULAR FARMES

ASF EPIDEMIOLOGY:

1978

Historical distribution II

ASF.Scenarios :Central and S.America

• CUBA 1978• D. REPUBLIC 1978

•BRASIL 1980

BACKYARD

NO TICK

ASF EPIDEMIOLOGY:

1998 2001

2007

Historical distribution

ASF. A REMERGING DISEASE

ASF.Scenarios: South and East Africa

Sylvatic cycle 21 Genotypes

D + D + T

DOMESTIC INFECTED PIGS NO Ab ?

Positive Virus. No Abs. Tolerance pigs ????

ASF. Scenarios : West Africa

Role of Ticks ??

back yard

W to D

D to D

2007

ASF 2007-2011

Asfv, genotype IIMozambique, Madagascar, Zambia273 Outbreaks. More 78.000 Dead pigs

273 notified outbreaks

+78.000 dead pigs

4 affected countries

Source: OIE, own elaboration

ASF EPIDEMIOLOGY:

ASF in Russian Federation• April 2007ASFV p72 genotype II, compatible

with the virus circulating in Mozambique, Madagascar and Zambia (Rowlands et al., 2008)

• All the ASFV isolates identical p72, p54 and CVR sequences suggesting only one entry (Gallardo et al., 2009)

• No pathological changes Acute and hiperacuteforms of the disease (Blagodarsnosti, 2011) .

• No serological (Ab) surveillance has been made

ASF. Scenarios : Europe III

D to D

Back yard pigs

D + W + BY

Risk of EndemicityChronic form ?

WHY IS ASF MOVING?World globalization

Economic crisis Swill feeding

More ASF virus in Africa

IDENTIFICATION OF RISK FACTORSENTRANCE IN CAUCASUS REGION: Increase of the ASF V in Africa Economic crisis Swill feeding Lack of biosecurity

SPREAD: Swill feeding!! TRADITION Wild boars contact with domestic No biosecurity (ASF don’t need high biosecurity) Movement of animals and products WITHOUT CONTROL No a Coordinated National control program (Local Program

Krasnodar Region)ENDEMICITY: Wild boar affected Swill feeding Potential. Carriers and chronic infections NO COORDINATED NATIONAL PROGRAM. NO COMPESATION

FOR FARMES Vector (ticks)?

POSIBLE ENTRANCE: MODERATE Efsa,2010

http://www.efsa.europa.eu/en/scdocs/scdoc/1556.htm

CONCLUSIONS AND RECOMMENDATIONS

ASF in the Caucasus and Russian Federation• The ASFV circulating in the Caucasus and the Russian Federation

is a highly virulent virus. No reduction of virulence since the first outbreak in 2007 in Georgia.

• ASF has spread in the TCC and in the RF since 2007; measures put in place were not sufficient to control the spread

• The risk of maintaining ASF and its spread within the TCC and the RF in domestic pigs is HIGH

• The risk of ASF introduction into the EU is moderate• Risk of ASF become endemic in domestic pigs in EU is negligible

(High Biosecurity), low or moderate (free range)

EVALUATING THE RISK OF ASFV ENTRANCE IN THE EU

Development of a generic CUANTITATIVE risk assessment framework for the introduction of ASF in EU countries

ROUTES FOR ASFV INTRODUCTION IN THE UE

• Legal imports

• Illegal imports

• Wild animals

• Ticks: Ornithodorus spp.

• Fomits: vehicules, leftovers, people….

Live animals (domestic+wild)

Animal Products Meat Products

Semen and embryo

RA (stochastic) for the potential ASFV introduction into the UE

Mur et al., 2011

PathwayLive pigimports

PathwayWild boars

De la Torre et al., 2011

Suitableareas for WB

LEGAL IMPORTS OF LIVE SWINESThe overall mean (95% PI) annual probability of ASFV introduction into the EU by

legal import of live pigs was 5.22*10-3 (6.06*10-4, 1.84*10-2 ) ~ one outbreak in192 years.

69%

68%

FRESH30%

FROZEN67%

OTHER3%

LEGAL IMPORTS OF PIG PRODUCTS EXTRA EU

VEHICULES/ROADS

SEMIQUANTITATIVE MODEL

SOME ASF CHARACTERISTICS

AFRICAN SWINE FEVER IMPORTANCES POINTS

PROBLEMS FOR ASF CONTROL

No vaccine availableDomestic & Wild animals affected

Carrier animalsTicks

Very resistant in the environment

Clinical signs similar to other diseases

High variability

Laboratory diagnosis needed

Pigs &products

Freezer

No neutralizing Ab

ASF LABORATORY DIAGNOSIS

108 bp-

257 bp-

1 2 3 4 5 6 7 8 9 10 11 12 13 14 C M V

PPC-3/4 + PPA-1/2

GOOD HEALTH

• NO INACTIVATED VACCINE

• ATENUATED VACCINE. NO SAFE AND ONLY PARTIALPROTECTION in HOMOLOGOUS (CARRIERS & C. FORM)

• NO RECOMBINAT VACCINE: NO good candidates

•NO DNA:Some

Candidates

•NO SubUnit vaccines: very poor partial protection

ANTIBODIES ARE RELATED WITH SOMETYPE OF PROTECTION

AS WELL AS WITHCHRONIC AND ENDEMIC ASF INFECTION

ASF PROTECTION: NO VACCINE

Eradication without vaccine ispossible but not easy. Endemics:Portugal,Spain.

No Endemics countries: Brazil…

ASF. Spain: 1985-1995

IN DOOR

OUT DOOR

ASF IMMUNE RESPONSES INVOLVED IN PROTECTION

POOR UNDERSTOOD:

• PROTECTIVE IMMUNITY AGAINST HOMOLOGOUS VIRUS(VIRUS IN LINPHO NODES)

• THE MAIN DIFFICULTY. LACK OF NEUTRALIZING Ab andhigh genetic variability

• Ab PARTIAL PROTECTION. DELAY IN THE ONSET C. SIGNS

• IMPORTANCE ROLE OF NK AND CD 8. DESTROYED I. M

• SOME TYPE OF PROTECCION (Ab and CMI) OCCURS

PROBLEMS OF ATENUATED ASF VACCINE UNTIL NOW:

LIMITED FIELD STUDIES: PORTUGAL and SPAIN 60s-70sEXPERIMENTAL RESULTS: SEVERAL AUTHORS

A) Release of infected virus: Low virulence strains, Chronicforms ?. Carriers (Portugal, Spain 70s )

B) No sufficiently attenuated

C) Only Homologous virus protection.

PROSPECTS FOR ASF VACCINE:

Know more about Mechanism of Atenuated vaccine:

a)Pre Virus Entry (neutralizing Ab, Others)b)Post Virus Entry (Infections inhibition)

1) Low virulence isolates by passages in TC or from field2) Generation ASFV recombinant without some genes*3) Recombinat with several ASFV genes in DNA vector4) Others

* Several candidates look promesing

EARLY DETECTION

THE CHALLENGE

CONTROL AND ERADICATION

FIELD IS THE FIRST STEP:

COLLABORATION: ADMINISTRATION- FARMERS

RISK FACTORS for EARLY DETECTION I

• No perception of the risk for entrance:No good information to farmers and Vets– Legal and ilegal imports of live pigs and meat products– Commercial relations with affected countries– Other disases in the area (CSF, Erysipela…)

• Low education level, no information about thedisease to FAMERS and VetsNo information of ASF. How is ASF?

• Low biosecurity practices– Swill feeding– Backyard systems

• Late detection caused by:– Wrong surveillance program. No RBS– Late detection in field no formation of veterinary

services and farmers. Others diseases– Low veterinary service in the area inadequate

connection field-laboratory– Unknown of the risk

RISK FACTORS for EARLY DETECTION II

FIELD TRAINING: FARMERS and VETS

INFORMATION TO FARMERS:

TV

RADIO

JOURNALS

CAFE

http://rasve.mapa.es/Publica/Formacion/curso/index.html

DIGITAL SIMULATION

ASF EARLY DETECTION NEEDED:FIELD:• Risk information• ASF Information

LABs:• Good conection with field• Good test and procedure

TRAINING: FIELD AND LABORATORY

ASF CONTINGENCY PLANS. FAST RESPONCE:

ADMINISTRATIVE STRUCTURE: Veterinary ServiceLegislation, diagnosis methodology, etc.

LIVESTOCK PRODUCTION STRUCTURE: Census, farms Location, movements, wild live population….

ASF CHARACTERISTICS: Risks factors, susceptible animalsVectors, clinical sings, lesions, samples to labs, route ofentrance, diagnosis methods, desinfectans, …..

Coordinated program

1. A program of all for all

2. Important farmers

3. Medium

• Inadequate control program:– Movement of animals and products WITHOUT CONTROL– Swill feeding. Difficult to changes mentality– Not establish the control and surveillance area– Delayed compensation + lack of resources

• Pig production system:– Pig density– Farming practices (backyard, swill feeding!!)

• Presence of wild boars and contact with domestic pigs• Presence of ticks

RISK FACTORS for CONTROL

ASF. CONTROL AREA

MANUAL for a FAST RESPONCE

1. NOTIFICATION SYSTEM2. ZONING OF AFECTED AREAS3. BAN ON ANIMALS MOVEMENTS4. LABORATORY CONFIRMATION5. PROCEDURE FOR DESTRUCTIONS OF CARCASSES6. DEPOPULATION7. CLEANING AND DISINFECTION8. SEROLOGICAL CONTROLS9. STUDY WILD BOAR AND/OR VECTORS10.SENTINEL ANIMALS11.REPOPULATION

Possibility of became endemic in some countries

of Europe

Moderate-high risk for the EU countries

MORE TIME TO DETECTINFECTION MORE

DIFFICULTES TO ERADICATE

ARE WE AWARE ?

ARE WE READY ?

More ASFV in Africa and now in CC and RF

No vaccine available. Eradication without vaccine

not easy but possible

IN MEMORIAN OF ISABEL MINGUEZ TUDELA (08/05/1956- 16/04/2011)Passed Away in Brussels at age of 54

Sencientic Officer in the DG ResearchFor over 15 years, she acted as a majorbridge within the scientific communitylinking different European research teams and establishing connections with scientistsfrom America, Asia and Africa. Manage a greatnumber of EU research projects on animal health (ASFRisk)

Rest in Peace, dear friend.

A W0RLD FREE of ASFjmvizcaino@visavet.ucm.es