Biosecurity & Border control - Regional Representation OIE ... · 1.12.2019 · • Follow OIE Code for legal imports ... can help to inform assessment of risk • Useful for persuading

Prof Trevor W Drew OBE Director, Australian Animal Health Laboratory Geelong, AustraliaVisiting Professor, Jilin University, PR ChinaGuest Professor, University of Nottingham, UKGF-TADS SGE-ASF-ASIA, JULY-AUG 2019

Biosecurity & Border control: Where the virus can be found - What to look for - What to test

“there is little doubt ASF will continue its geographic expansion…” (FAO EMPRES, 2012)

• Potential for serious impact on global trade and food security

• Pork considered a priority protein source for meeting future global dietary needs

• Significant investment area for small holder subsistence farmers (‘backyard sector’) in the developing world

• Food security = regional stability

• Major world players are committed to ongoing research to solve the problem

ASF: a global threat

African swine fever | Trevor Drew | Page 2

Implications for the region are significant

Robinson (2014)


Definition of contagiousness

percentage of animals which get infected after contact with an infectious agent.

i.e. the probability that an animal picks up an infection after contact with a pathogen

Dependent on whether transmission is directly via an infected animal by the parenteral route, or via ingesting infected meat

How contagious is ASF?


(30%)

Thanks to Klaus Depner, FLI, Germany

ASF Contagiousness

Within a group (within a pig barn)

Requires high virus dose (>1000

HAU) for parenteral transmission

between groups (open system…e.g. forest)

Requires low virus dose (<100 HAU) for oral transmission

HIGH

LOW

How contagious is ASF?



ASF virus is a relatively stable virus

ASFV survives the process of

putrefaction and carcasses

may remain infectious for weeks –

longer in cold climates

ASFV therefore presents a high

risk to free countries

• frozen meat: indefinitely

• dry meat and fat: almost one year

• blood, salted meat and offal: more than 3 months

• faeces: over one week

Temperature plays an important role in decreasing the survival

duration of ASF virus in any matrix.



Two main elements:

a) Preventing the virus from entering the country

• Pre-border activities

• Activities at the border

• Illegal/incidental breaches

b) Preventing the virus from infecting a pig• Farm biosecurity

• Including activities of the veterinary authority

• Wild & feral pigs

• Behaviours – all sectors

In BOTH cases, identifying risk pathways and employing robust mitigation steps are key

Keeping your country free


Risk factors for spread of ASFDirect

• Infected domestic pigs

– Live cover

• Wild boar, carcases, abortions

• Pig products (swill feeding, spray-dried blood)

• Shared needles for vaccination, non-licensed preparations (eg autogenous vaccines)

• Germplasm, semen(?)

Indirect• Infected pens

• Contaminated feed, water

• Transport - lorries

• Personnel, veterinary visits

– Clothing, boots, instruments

– Part-used vaccines


Ticks ???

Unlikely

Greatest risk

Illegal movement of pigs => legal movement of pigs

Illegal import of pig products => legal imports

Accidental introduction <=> accidental release

• Carcases in rivers, wild boar migration, release from laboratories

Solution:

• Follow OIE Code for legal imports

• Prevent illegal introduction of animals and products

• Identify and mitigate risks of accidental introduction or release

Preventing the virus from entering the country


ASF is mainly introduced by HUMANS!

Pigs and products - OIE Code Chapter 15.1

• ONLY canned meat and gelatine are considered “safe” commodities• Specified conditions for heat inactivation – F0 of =>3 (3’ @ 121°C equivalent)

• ALL other commodities should follow the guidelines for import • 25 Clauses provide details

• Dependent on commodity

• Consider source country status

• Whether from domestic, or wild & feral pigs

• Involve quarantine and testing

Key issues in preventing introduction (1)


• Movement of wild and feral pigs from infected countries• Metapopulations – move around

• Natural barriers may prevent movement

• Hunting with dogs can drive wild & feral pigs to new areas

• Good communication with neighbouring countries is key

• “Amber” response when risk is considered greater?

• Increased passive surveillance

• Testing for exclusion

• Establishment of a Protection Zone

• High risk area – eg adjacent to an infected country

• Different rules – eg no pigs allowed to be kept, or no commercial piggeries

• Increased clinical surveillance

• Removal of wild boar from the area?





• Prevent passengers from bringing meat products into your country

• Also for other diseases

• Clear messaging

• Random/targeted inspections

• Fines/other punishment – more messaging

• Random testing of seized products can help to inform assessment of risk

• Useful for persuading government of the need for change in protocols

• Can generate additional publicity

Preventing infection of your wild & feral pigs:

• Access to infected waste food

• Travel across borders to an infected country

• Contact with wild boar from an infected country

• Hunters sometimes like to “supplement” local populations• Illegally bringing in wild boar

• Supplementary feeding during winter months

Encourage reporting of “found dead” wild & feral pigs• Engage with hunters

• They can play an important role in surveillance

• Inform them of the risks

• Test dead animals and remove the carcases

Key issues in preventing infection (1)


Preventing infection of domestic pigs:

• Swill feeding

• Difficult to prevent in backyard systems

• MUST be boiled – 30 min minimum

• Scavenging - discourage

• Food dumps

• Roadside/village scavenging

• Disposal of airline waste & seized products

• Germplasm from overseas (unless it follows OIE Code)

• Semen should be regarded as a source of infection, though evidence is scant

• Imported feed – especially those containing “growth additives”

• Unlicensed vaccines/autogenous vaccines

Good husbandry – quarantine/all-in:all-out, disinfection; restricted access

THESE MEASURES ARE UNLIKELY TO BE ACHIEVEABLE IN VILLAGE SYSTEMS

Key issues in preventing infection (2)


• Pigs in pens• Not allowed to roam/scavenge/mingle with pigs from other premises

• Pens with solid walls are best

• Replacement stock – trusted sources, healthy. AVOID live cover!

• Fencing• Pig-proof outer boundary – some distance from pens

• Visitors/workers• Essential only. Disinfectant foot dips. Dedicated clothing.

• Workers should NOT keep pigs or work on multiple farms.

• Veterinarians should wear disposable PPE and disinfect between visits

• Equipment• Don’t share, or disinfect thoroughly

• Waste – feed, urine, faeces and dead piglets• Avoid access of wild boar or other pigs. Rivers are good at spreading ASF!

Farm biosecurity


• Behaviours can be the biggest threat

• Insufficient resources for authorities - priorities

• especially surge capacity

• Poor knowledge can greatly aid its spread

• how the disease is transmitted

• What products may pose a hazard and how they may be made safe

• What steps are critical to preventing further spread

Reasons for active non-compliance are many

– Financial

• Desire to make profit or avoid loss

• Poor resources

– Cultural

• Traditional gifting/festivals

• Bad luck, fear of consequence

• Habitual?!

Behavioural traits – authorities and farmers


• What are the illegal trading routes in the region?

• Routes the same – products and direction may change

• Is outbreak driving attempts to smuggle?• Even more likely with changing meat prices

• Meat from pigs in infected premises???

Behavioural traits – pigs and pork


• Live animals don’t need refrigeration – only

water• Greater transmission risk than meat!

• Travellers – MUST change their behaviours• Total irresponsibility – but why? How do we change

behaviours?

• Penalties for non-compliance – how do we reward good

behaviour?

• Something for the SGE? A survey?

How to test? What to test?


• Detect the virus by PCR – validated & accredited• Serology is of little, if any value

• almost all pigs are dead before they seroconvert!

• At your border/in quarantine• Imported pigs – all?

• Semen (random sampling)

• Whole carcases – random sampling

• Other testing (eg seizures) may inform risk and identify need for additional measures

• Testing of imported cut meat or meat product is generally ineffective,

• Is the sample representative?

• Is the batch homogeneous?

• A negative result doesn’t mean the whole container or batch is safe

• But is of value if it gives a positive result!

Take-home messages - epi & control


• ASF is spread mainly spread by people via infected pigs and meat/products

• BEHAVIOURS of travellers

• Pig movements, live boar cover

• Waste food - swill feeding (spray-dried blood in the past)

• Fomites – lorries, vets, visitors,

• Passive surveillance (testing dead animals) is best/only strategy for early detection of ASF

• Awareness of animal owners, hunters, rangers, private vets is ESSENTIAL

• Outbreak management is culling & compensation

• Control in wild boar is reliant on their management• Culling adult females, carcase collection and disposal

• In countries with severe winters, may be a real challenge

• Lab diagnosis of suspect disease, by virus detection, is relatively easy, fast and reliable• But samples MUST be submitted!

• PCR is very specific & reliable

• Validated method – accredited lab and test?

• Serology is of limited help – of value mainly in demonstrating freedom

• MUST NOT wait for high mortalities

• Laboratory MUST be biosecure

• BSL2 minimum – ideally BSL3

• Lab workers should NOT keep pigs!

Take-home messages – lab testing for ASF


Trevor W. Drew

Director. CSIRO-AAHL, Geelong, AUSTRALIA

CSIRO AUSTRALIAN ANIMAL HEALTH LABORATORY

Thank you

For more information on ASF research or diagnosis, please contact:

David Williams

Group Leader – Emergency Disease Laboratory Diagnosis

Diagnosis, Surveillance & Response unit

t +61 3 5227 5364e [email protected] www.csiro.au/places/aahl.html

With acknowledgements to Klaus Depner, FLI, Germany

AAHL plays a key role in assuring Australia’s biosecurityAn advanced BSL4 high containment laboratory

OIE Collaborating Centre for:

- Laboratory Capacity Building

- New & Emerging Diseases

- Diagnostic Test Validation Science in the Asia-Pacific Region

Latest official ASF situation (FAO):

http://www.fao.org/ag/againfo/programmes/en/empres/ASF/Situation_update.html

Predicted impacts on meat markets:

https://www.rabobank.com.au/media-releases/2018/181128-african-swine-fever-reshaping-global-beef-markets/

https://research.rabobank.com/far/en/sectors/animal-protein/rising-african-swine-fever-losses-to-lift-all-protein.html

OIE Standing Group of Experts – Asia:

http://www.rr-asia.oie.int/disease-info/african-swine-fever/african-swine-fever-in-asia/standing-group-of-experts/201904-launch-mtg/

Animal traceability – US system:

https://www.feedstuffs.com/news/interactive-map-advances-animal-disease-traceability-program

Useful online resources


Documents

Biosecurity & Border control - Regional Representation OIE ... · 1.12.2019 · • Follow OIE Code for legal imports ... can help to inform assessment of risk • Useful for persuading