Dr. Chris Oura - African Swine Fever – a real and present global threat
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This document discusses African swine fever virus (ASFV), a large DNA virus that causes a hemorrhagic disease in pigs. The speaker outlines the current global situation of ASFV, noting its spread through parts of Europe, Russia, China, and Africa. Controlling ASFV is challenging due to its resistance, complex genotypes, wildlife reservoirs, potential carrier animals, and lack of vaccines. The United States should be concerned about ASFV spreading given transportation links and wild pig populations. Increased biosecurity is advised on US farms to prevent introduction of the virus.
Dr. Chris Oura - African Swine Fever – a real and present global threat
- 1. Chris Oura Professor of Veterinary Virology School of Veterinary Medicine Faculty of Medical Sciences The University of the West Indies Trinidad and Tobago [email protected] Allen D. Leman Swine Conference, 17th Sept 2018 University of the West Indies African Swine fever – a real and present global threat Should the USA be worried?
- 2. Today’s Presentation • The virus and the disease • Current global situation • Why are we struggling to control it? • Prospects for a vaccine? • Future risks for the USA • What next?
- 3. Main global exporters of pork - 2017: 1.Germany: US$4.8 billion (15.8% of total exported pork) 2.United States: $4.6 billion (15.2%) 3.Spain: $4.1 billion (13.5%) 4.Denmark: $2.7 billion (9.1%) 5.Canada: $2.5 billion (8.4%) 6.Netherlands: $2.2 billion (7.2%) 7.Brazil: $1.5 billion (4.9%) 8.Belgium: $1.4 billion (4.8%) 9.Poland: $1.1 billion (3.5%) 10.France: $932.9 million (3.1%) 11.Mexico: $527.6 million (1.7%) 12.Ireland: $502.6 million (1.7%) 13.Austria: $433.5 million (1.4%) 14.Hong Kong: $427.2 million (1.4%) 15.Chile: $396.5 million (1.3%) First of all – why the fuss? China produces over half of the worlds pork
- 4. • Large! • Complicated! ……….and very tough! Introducing the virus KP177R MGF100-1R X69R MGF505-1R L60L MGF110-3L MGF110-7L MGF110-11L MGF110-13L MGF360-1L L83L MGF110-1L MGF110-4L MGF110-8L MGF110-14L MGF360-4L MGF360-6L MGF300-1L MGF300-4L MGF360-9L MGF360-11L MGF360-12L MGF360-2L MGF360-3L MGF110-2L MGF110-5L-6L MGF110-9L MGF110-12L MGF360-8L MGF360-10L MGF360-13L A151R MGF505-3R MGF505-5R A118R MGF505-2R MGF505-4R MGF505-6R MGF505-7R MGF505-8R MGF505-10R MGF360-15RA104R A137R F778R F165R MGF360-14L A224L A240L A238L A859L A179L F317L F334L F1055L K78R K145R EP402R K196R EP424R EP153R C122R K205R K421R EP84R EP152R EP364R M448RC129R C717R C315R C962R C475L C62L EP1242L M1249L C84L C257L C147L B962L B318L B169L B119L B438L B407L B475L B354L B602L B646L B117L B175L B66L G1340L CP123L CP2475L CP204L B385R B125R B263R G1211R CP503R D79L S183L CP80R H108R H124R H223R CP312R O61R NP868R D250R S273RD205R P1192R H171R H339R H240R O174L NP1450L NP419L D129L D339L D1133L D117L D345L H359L R298L Q706L QP383R E423R E301R E165R E120R E111R I226R I73R MGF360-16R MGF360-18R MGF360-21R I177L QP509L E183L E199L I267L I196L MGF100-1L L8L L10L DP63R L9R E184L E146L E66L I243L I329L I215L DP238L MGF505-11L L7L L11L DP71L 31.6 63.2 94.8 126.4 158.0 189.3 DP96R
- 5. Lis /57 Zim 1/92 MOZ 1/03 MOZ 2/02 MOZ 1/05 Georgia /2007 Mad 1/98 Lus1/93 MOZ 1/02 Bot 1/99 RSA 2/96 RSA 1/95 RSA 1/99 RSA 1/98 Spec 245 Ten /60 Moz 1/94 RSA 1/96 Nam 1/95 Uga 1/95 Uga 3/95 Moz 1/01 Kab /62 MFUE 6/1 Sum 14/11 TAN 1/01 TAN 1/03 NYA 1/2 100 50 57 72 98 88 76 57 68 64 67 I XXVII II III XIX XX IV VII XXII V VI XXI XVIII VIII XI XII XIII XV XVI XIV IX African Swine Fever virus lots of different (geno)types
- 6. The disease – African Swine Fever
- 9. Recognising African swine fever Clinical signs: Loss of appetite, recumbancy (won’t get up), fever, vomiting, diarrhoea (bloody), joint swelling, skin haemorrhages Postmortem signs: Haemorrhages in many organs including lymph nodes and under the skin eg ears Enlarged, haemorrhagic, friable spleen
- 13. Haemorrhagic Lymph nodes and Kidney
- 14. Enlarged friable dark Spleen
- 16. Haemorrhagic lesions in gut
- 19. 2011-2017 2017
- 20. African swine fever - 2018 140,000 pigs on one farm slaughtered in Romania
- 21. Situation in China now Introduced into China in March / April???
- 22. The amount of live pigs sold by these six provinces reached 174,175,000, occupying 25.3 percent of the nationally sold live pigs in 2017.
- 23. And last Thursday / Saturday……… 5 wild boar found to be infected so far…………..
- 24. How is the virus being transmitted? In Africa Ticks not confined to Africa
- 25. How is the virus being transmitted? Transmission associated with blood
- 26. Key Risk factors – why is control proving so challenging? Contact between Wild Boar and backyard / feral pigs Human behavior – poor practices • Lack of knowledge / information • Money constraints • Lack of compensation Virus entering the Catering cycle Cured, smoked, raw hams Surviving swine becoming carriers? Long distance movement of wild boar – hunting? Ticks? Lack of Biosecurity Wild / domestic pigs eat anything! Movement of humans / migrant workers with pork products
- 27. Key Risk factors – why is control proving so challenging? 1. Role of Wild Boar – is ASFV now endemic in wild boar? Contact between wild and domestic pigs Modelled wild boar population density in Europe (source: FAO/ASFORCE, May 2015)
- 28. Densities of domestic pigs in the low biosecurity sector in Europe. Data: various statistical data 2008- 2011, FAO/EMPRES. Key Risk factors – why is control proving so challenging? 2. Role of low biosecurity (backyard and feral pigs) No movement controls in low biosecurity sectors
- 29. • Different forms of the virus are circulating: high – low virulence • Carrier status in recovered pigs / wild boar Key Risk factors – why is control proving so challenging? 3. Role for recovered ‘carrier’ pigs (domestic and wild)?
- 30. Source: Empress Watch, 2013. Key Risk factors – why is control proving so challenging? 4. Role of humans • Disposal of dead pigs – rivers • Selling pigs in the face of an outbreak • Movement of sick pigs to market • Swill feeding • Vehicle contamination • Vets, farm workers and hunters • Poor levels of biosecurity • Carcase disposal - flies Low levels of compensation Farmers / hunters - Lack of information
- 31. Ornithodorus tick distributions Key Risk factors – why is control proving so challenging? 5. Role of ticks – are they present and contributing ?
- 32. African swine fever – main challenges we face Very resistant virus Complex – multiple genotypes Present in domestic and wild swine Signs and symptoms confused with other diseases Reservoirs of infection (vectors / wildlife) Carrier animals present? Lack of effective vaccines Rapid uncontrolled spread in developing countries
- 33. Why NO vaccine for ASFV? • Large complex virus with many proteins (60-185 encoded) • Inactivated / passaged virus does not protect • Vaccine candidate antigens (viral proteins) do not protect • Vaccine trials require high containment facilities - expensive • Largely African problem (in past) - lack of commercial market. • Few groups involved in research – USA example
- 34. The six million dollar question: Should you worry about African Swine Fever in the USA? • Spreading around the world (EU / Russia / China /Africa) • High levels of mortality in pigs (domestic and wild) • Evidence that the virus may be attenuating in the field • Very tough and resistant virus – in processed meat • Many people coming from infected regions of the world (sandwich effect) • Vaccine still not in sight
- 35. Risk factors to assess - USA • Wild boar and feral pig populations in the USA • Backyard / outdoor / wild pigs - biosecurity • Ornithodorus ticks – contact with pigs • Levels of biosecurity on domestic pig farms • Border security – illegal / legal imports of pigs and pig products (and possibly feed) from abroad • Rapid accurate laboratory diagnosis essential Virus is only a short flight / boat ride away!
- 36. Advise to pig farmers in the USA Biosecurity, Biosecurity, Biosecurity • Review and increase existing levels of Biosecurity on the farm • Ensure pigs (and wild boar / feral pigs) are not fed catering waste, kitchen scraps or pork products, • Do not allow pig-meat products onto farms, eg in workers’ lunches. • Ensure that visitors have not had recent contact with affected regions. • Anybody returning from an affected country should avoid contact with domestic pigs, whether commercial holdings or smallholdings, areas with feral pigs or wild boar, until they are confident they have no contaminated clothing, footwear or equipment. • Familiarise yourself with the clinical signs of ASF and report any suspicious illnesses to your vet immediately.
- 37. Thanks very much! Any Questions? EU Reference Laboratory for ASFV, Madrid, Spain Carmina, Marisa and Jose Manuel University of the West Indies
Editor's Notes
- #5: Survivability outside the host is heavily related to temperature. The infectious half-life in urine and feces can range from 3 to 15 days and 4 to 8 days at 37°C and 4°C, respectively Can survive in carcasses for up to 6 months Persists for several weeks or months in frozen, fresh, or uncooked pork, as well as in salted dried / cured pork products. and survives in contaminated feed………..
- #10: African swine fever virus causes a haemorrhagic fever with high mortality in domestic pigs. These images show examples of haemorrages seen under the skin of the ear, in lymph nodes and the tongue and a greatly enlarged spleen characteristic of ASFV infection. The natural hosts of ASFV – warthogs, bushpigs and soft ticks remain persistently infected and show no signs of disease, acting as a reservior for infection. ASFV in endemic in many African countries and in Sardinia and was introduced to the Caucasus region in 2007 where it is still spreading. It was first identified in Georgia and has now spread into many parts of Russia.