Introduction to African

swine fever

Dr. Marius Masiulis

Emergency Responce Department State Food and Veterinary Service of Lithuania

African Swine Fever Virus

“Highly” contagious viral disease of swine Asfarviridae

Enveloped DNA virus Transmitted by arthropods

Isolates vary in virulence High virulence: up to 100% mortality Low virulence: seroconversion

ASF is defined as: “a highly contagious hemorrhagic disease of suids…”

Reality:

-> ASF is not a very highly contagious disease

Defining ASF as “highly contagious” leads to false expectations and underestimation of the problem…

Expectation

+3d

African Swine Fever Virus

• Highly resistant;

• Killed by high temps and some disinfectants;

• Affects domestic and wild pigs.

bush pig

warthog

collared peccary

European susceptible species: • Domestic pigs and European wild boar

• All age categories (no age dependency)

• Without gender predilection

(African wild swine – warthog - are unapparent infected and act as reservoir hosts for ASFV in Africa) It is not a zoonosis

Environmental Persistence

• Stable at pH 4-13…

• Survives at least:

- 11 days in feces (room temp)

- 1 month in soiled pig pens

- 70 days in blood on wooden boards

- 15 weeks in putrefied blood

- 18 months in blood at 4oC

• 140 days in Iberian and Serrano hams

• 399 days in Parma ham

• 112 days in Iberian pork loins. • 18 months in pig blood at 4°C

• 11 days in faeces at 20°C

• Stable in carcases (dead animals) which decompose

However, no infectious ASFV has been found in cooked or canned hams when processed at 70°C.

ASF VIRUS IS VERY STABLE

Carcasses: 3 – 5 weeks infectious

ASF genotype circulation

African Swine Fever

• First reported in 1921 in Kenya

• Acute to chronic disease

• characterized by high fever

• Cutaneous hyperemia

• Edema

• Hemorrhagic internal organs

• Abortions

• Can see bloody diarrhea

• Distribution – Sub-Saharan Africa

• Europe, Dominican Republic, Haiti, Cuba and Brazil

• Endemic in Africa and southern Europe

ASF spread

ASF spread

ITALY

ASF present since 1978

EASTERN EUROPE

9 countries affected since 2007

ASF in Baltic countries and Poland 2015 2014 2016

2014 - 45 places (hunted 22, dead 54)

2015- 111 places (hunted 73, dead 59)

2016- 303 places (hunted 99, dead

379)

1328 places with 2456

cases in wild boar

(310 hunted and 2146

found dead)

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2014- 6 outbreaks: 1 in commercial

farm and 5 - in non-commercial farms;

2015- 13 outbreaks in non-commercial

farms;

2016- 19 outbreaks in non-commercial

farm.

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2017 – 28 outbreaks in non-commercial farms, 2 - in commercial farms

2/6/2018 22

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2014 2015 2016 2017

January

June

July

August

September

October

• Eradication of the outbreaks - in accordance

with the Directive 2002/60/EC;

• Trade restrictions in accordance with

Commission Implementing Decision

2014/709/EC and national legal acts;

• Surveillance programme for ASF;

• Preventive slaughter of pigs in back yard farms

non complying with biosafety control;

• Biosafety control in pig farms;

• Ban of all live pig markets in the entire country.

General considerations when managing an

outbreak Eliminating the pathogen

• Killing or slaughter of animals, safe disposal of dead animals

and potentially contaminated products

• Cleaning, disinfection, disinsection

Stopping the spread of the infection • Movement restrictions (animals, vehicles and equipments)

• Biosecurity

• Investigations

• Vaccination, when available

• Communication and public awareness

ZONING

Specific post-control surveillance

SU

RVEIL

LAN

CE

EU strategy for ASF control and

eradication

Animal Identification and Registration (CD 2008/71/EC, 2000/678/CE)

Surveillance + (CD 2003/422/EC)

Animal movement control

Zoning and regionalization + (CD 2014/709/EU)

Stamping out policy (domestic pigs)

Cleansing and disinfection and farm bio-security

Prohibiting swill feeding (Regulation (EC No 1069/2009)

CD 2002/60/EC

Main Legislation in force on ASF

• Council Directive 2002/60/EC of 27 June 2002 laying down

specific provisions for the control of African swine fever and

amending Directive 92/119/EEC as regards Teschen disease and

African swine fever

Commission Decision 2003/422/EC of 26 May 2003

approving an African swine fever diagnostic manual

Commission Decision 2014/709/EU of 9 October 2014

concerning animal health control measures relating to ASF in

certain Member States and repealing Implementing Decision

2014/178/EU

Commission Decision 2013/426/EU of 5 August 2013 on

measures to prevent the introduction into the Union of ASF from

certain third countries or parts of the territory of third countries in

which the presence of that disease is confirmed and repealing

Decision 2011/78/EU

EU Guidelines

SANCO/7138/2013 - Guidelines on

surveillance and control of African swine fever in

feral pigs and preventive measures for pig

holdings

SANCO/7112/2015 – Principles and criteria for

geographically defining ASF regionalisation

SANCO/7113/2015 – ASF Strategy for Eastern

Part of the EU

African swine fever: risks

• backyard farming

• wild boar habitats

• free-ranging pigs

• movement of contaminated vehicles

• illegal movement of animals/animal products

• poor on-farm biosecurity

• particular species of ticks

• and etc.

How does a pig get infected? ONLY by direct contact with infected material or sick animals!

• Feeding on garbage containing infected pig meat and/or pork products;

• Contaminated fomites (premises, vehicles, clothes,…);

• Iatrogenic (needles, syringes, instruments…). Infected blood (blood cells) most risky material!!!! Aerosol infection is unlikely… There is no report indicating the occurrence of Ornithodoros spp. in the affected Member States.

http://www.efsa.europa.eu/efsajournal

Clinical presentation

• Incubation period: 3-19 days;

• Pigs of all ages and gender;

• ASF is not so infectious, so some animals within the herd may not get affected;

• The spread of the disease within the herd varies;

• Some indigenous resistant breeds observed in Africa;

• Wild boar = domestic pigs.

Clinical presentation

• Clinical signs highly variable

• Depending on virus virulence, breed, route of exposure, infectious dose;

• Sometimes only fever and death, or unspecific signs;

• Presentation in the field not identical to experimental cases;

• Sometimes only death is observed;

• Clinical course may vary from 20% to 100%.

ASF in Eastern Europe (acute form)

• Fever of 40-42°C;

• Lack of appetite;

• Animals are weak, lying down and huddling;

• Increased respiratory rate;

• Death within 3-15 days;

• Mortality rates 90-100% ;

• Acute forms are easily confused with other diseases (differential diagnosis);

• Animals usually in good body condition.

Acute form of ASF

• One or several of the following: • Bluish-purple areas and hemorrhages (spot like or extended) on the

ears, abdomen, and/or hind legs;

• Ocular and nasal discharges;

• Reddening of the skin of the chest, abdomen, perineum, tail, and legs;

• Constipation or diarrhea, which may progress to bloody;

• Vomiting;

• Abortion of pregnant sows at all stages of pregnancy;

• Bloody froth from the nose/mouth and a discharge from the eyes;

• The area around the tail may be soiled with bloody faeces.

• Note: The color changes and hemorrhages in the skin are easily missed in wild boar and dark-skinned/hairy pig breeds

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Restictive Measures in case of ASF confirmation

CD 2002/60/EC Protection & Surveillance Zones

CD 2014/709/EU

Regionalization

3 km radious

10 km radious

CD 2014/709/EU

“concerning animal health control measures relating to ASF in

certain Member States and repealing Implementing Decision

2014/178/EU”

• At risk commodities and level of risk:

1. Live pigs, Pig semen, ova and embryos

and Animal by-products of porcine

species

2. Pig meat, meat preparations and meat

products

CD 2014/709/EU

“concerning animal health control measures relating to ASF

in certain Member States and repealing Implementing

Decision 2014/178/EU”

Based on the epidemiological situation

Affected territories of affected member countries are listed:

Annex: Part I (at risk)

Annex: Part II

(feral pigs)

Annex: Part III (feral & domestic

pigs)

Annex: Part IV (endemic situation)

1 2 3 4 5

Incu- bation

Days post infection

ANTIBODIES

VIRAEMIA

Acute course of ASF

FEVER

'typical' symptoms

mortality up to 100%

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ASF laboratory diagnosis Virological and serological tests are largely available; ASF diagnosis is not a problem. MAIN AIM: virus detection with PCR from blood and / or organs – early detection! Antibodies are important for surveillance, when disease is longer time present in the infected country.

Test results can also be used for indicating the duration of infection

PCR Ab-Test duration of infection (estimates) pos neg <12d (or the animal died/sampled before 12d) pos pos >12d (or the animal died/sampled after 12d) neg pos >24d (or the animals was sampled after 24d

Samples needed by the lab for ASF diagnosis • Blood in EDTA (0,5%) for PCR

Plus (diagnostic manual; CD 2003/422/EC)

• Organ samples (spleen, lymph nodes, tonsil, kidney) PCR • Bone marrow in case of old wild boar carcasses • Serum for Abs detection

BLOOD only could give false negative tests….always test

ORGANS together with blood

Differential diagnosis

Classical Swine Fever (CSF); Erysipelas; Porcine Reproductive and Respiratory Syndrome (PRRS); Salmonellosis; Pasteurellosis; Streptococal infection; Leptospirosis; Circovirus infection (Pocine Deramatitis and Nephropathy Syndrome – PDNS); Circovirus infection (Postweaning Multisystemic Wasting Syndrome – PMWS); Coumarin poisoning.

Objectives of controlling ASF in feral pigs: (SANCO/7138/2013)

PREVENTION

Surveillance in the Infected Area

Feral pigs

• Animals sick or found dead

• Serological monitoring of

shot animals (evolution of

the disease)

• Inspection of places at high

risk (WB collection points)

Domestic pigs

• Strict health monitoring

programme (all pigs

sick/dead examined and

tested for ASF - CD

2003/422/EC)

• Vet inspection on pig

slaughtering for own

consumption

Passive Surveillance Key role in early detection

given the characteristics of ASF: Morbidity, Lethality (SANCO/7138/2013)

SANCO/7113/2015 ASF Strategy for Eastern Part of the EU

OBJECTIVE: is to establish a common strategy, regarding

• Pig farm categorization;

• Biosecurity requirements;

• Inspection and investigation regime;

• Sampling and laboratory investigations;

• Laboratory tests;

• Measures to apply in wild boar;

• Wild boar sampling; • Removal of wild boar carcasses.

Preventive Measures to be applied in pig holdings of the Infected Area and in the Infected Area

• Pigs: standstill and movement control (under official control, census,

biosecurity to avoid contacts with wild boar, SURVEILLANCE)

• Live pigs markets: when ASF suspected under control (surveillance),

closed when confirmed

• Carcasses disposal: all animals (DP, WB) tested and properly disposed

(category I, Regulation 1069/2009)

• Swill feeding (prohibition should be ensured, system for gathering waste..)

• Home slaughtering only under veterinary supervision

• Biosecurity (animals, personnel, vehicles, fence, feed, carcasses disposal,

equipment..)

• Tick control

• Awareness campaign (Owners, Vets, Hunters…)

Thank you for your attention! Any questions?