Animal and Plant Pathogens and Their Effect on Agriculture

1. Animal and Plant Pathogens and Their Effect on Agriculture

2. Terminal Learning Objective: At the conclusion of this session, participants will recognize animal and plant pathogens of concern to agriculture in Georgia, recognize BUDDIES - unusual signs in animals that may indicate serious disease, recognize the 5 D’s that may indicate a serious or foreign plant disease, and describe protocol for handling and reporting serious animal incidents and potential foreign plant diseases. Enabling Learning Objectives: 1.1 Recognize animal and plant pathogens of concern to agriculture in Georgia 1.2 Recognize BUDDIES - unusual signs in animals that may indicate serious disease. 1.3 Recognize the 5 D’s that may indicate a serious or foreign plant disease. 1.4 Describe protocol for handling and reporting serious animal incidents and potential foreign plant diseases.

3. Objectives for Participants: • To become familiar with animal and plant pathogens of concern to agriculture in Georgia. • To recognize BUDDIES, unusual signs in animals that may indicate serious disease or agroterrorism. • To recognize the 5 D’s that may indicate a serious or foreign plant disease. • To become familiar with the protocol for handling and reporting serious animal incidents and potential foreign plant diseases.

4. For Activity 2

5. Animal Industry in Georgia • Strong animal industry vital to economy • Close to states with strong animal industries • Many companion animals with close contact with humans • Could be target for animal diseases • Know diseases that are most likely threat • Know how they spread in order to control

6. Disease and Host - disruption of normal physiology, causing a negative effect on survival or fitness Disease - any biologic agent that causes disease - an infected animal or plant Host Pathogen

7. Endemic vs. Exotic Pathogens Endemic - a pathogen or pest permanently established in a defined area e.g. a country or a state - pathogen or pest not native to an area Exotic pathogens or pests are subject to regulation and quarantines. If introduced to an area with a susceptible host, they can cause a great amount of damage. Exotic

8. Classes of biologic agents • Viruses • Bacteria • Fungi • Protozoa • Parasites • Prions All biologic agents are not pathogens!

9. Viruses – the basics • Smallest infectious thing – “non-living” • Composed only of a string of DNA or RNA and some protein • Can’t reproduce on their own – only increase in number inside living cells • Sometimes cause rupture of host cell, dissemination to other cells Examples of viral diseases: the flu, common cold, measles, foot-and-mouth disease, SARS, AIDS, plum pox virus

10. Bacteria – the basics • Microscopic, single-celled organisms • Smallest “living” thing • Also most numerous • Can survive on their own, can survive in soil Slide 18

11. How bacteria cause disease • Interfere with normal functioning • Produce toxins • Form clumps that inhibit normal circulation Example of bacterial disease: plague

12. Fungi – the basics • Plant-like organisms, but without chlorophyll • Live in dead or decaying organic matter – nature’s recyclers • Many plant diseases are caused by fungus diseases Examples of fungal diseases: rusts, mildews, smuts, athlete’s foot, thrush

13. Protozoa – the basics • Free-living single-celled organisms • Protozoa-contaminated food • Cyclospora – fecal contamination of food • Protozoa-contaminated water • Cryptosporidium in water supplies Example of protozoal disease: stage of trypanosomes in the blood

14. Parasites – the basics • Parasites and hosts – parasite benefits, host is harmed • Parasites can be internal or external • “worms”, ticks, mites on animals • Insects that feed on plants and animals • boll weevil and screwworm Examples of pests: Examples of parasitic diseases:

15. Prions – the basics • The most unusual infectious agent • Consists of PROTEIN ONLY • Resistant to usual forms of sterilization such as chlorine, autoclaving, etc. • Cause specific brain diseases (Examples: scrapie, Mad Cow Disease, Chronic Wasting Disease, Human CJD)

16. “Infectious” and “Contagious” – any disease caused by a pathogen – can spread directly from one human, animal or plant host to another – can spread from animals to humans Infectious Contagious Zoonotic

17. TRANSMISSION of pathogens • Aerosol – spread through air • Direct Contact – spread by rubbing, biting, contact with fluids • Fomite – spread by contact with contaminated objects • Vector – spread by other organisms (biological vs. mechanical)

18. Incubation period • Time between infection and presence of clinical signs • Dangerous time when disease could spread without noticing it • Daily biosecurity practices are best prevention

19. How diseases could enter the U.S. • Smuggled animals • Wild birds • Importation from a country where disease is not yet recognized • On people

20. Swine fever, Netherlands 8M hogs killed $3.4B in losses Entry via contaminated vehicle Exotic Newcastle Disease, Calif. More than 4M birds depopulated 4 states affected 15,000 premises quarantined 1,600 person task force >$100M in containment costs Avian Influenza Disease Outbreak Examples

21. Fourth International Conference on Emerging Infectious Diseases Atlanta, March 2004 "Three-fourths of the new diseases that have menaced mankind over the past 20 years, and 11 of the 12 most dangerous bioterrorism agents, are animal diseases that have gained the ability to infect humans.”

22. Agricultural vulnerablities • Some agricultural commodities are more geographically concentrated than others and therefore may be more vulnerable to a localized attack. Examples include the following: • Cattle (16% in Texas) • Hogs (22% in Iowa) • Grapes (92% in California) • Oranges (66% in Florida) • Cotton (23% in Texas) • Lettuce (78% in California) • Broiler chickens (16% in Georgia)

23. Livestock Pathogens as Bioterrorism Agents • Primary goal of an attack • Food shortages • Economic disruption • Mistrust in food supply • All of the above • Good agricultural practices aid in control

24. Pathogen lists and international controls • CDC (Centers for Disease Control and Prevention) list • World Organisation for Animal Health (a.k.a. OIE) list • USDA Agricultural Select Agent list -http://www.aphis.usda.gov/programs/ag_selectagent/ag_bioterr_toxinslist.html

25. High Consequence Livestock Pathogens • Foot-and-mouth disease • Classical swine fever • Rift Valley fever • Highly pathogenic avian influenza • Exotic Newcastle disease

26. Foot-and-mouth disease • Caused by a virus • EXTREMELY contagious • SHORT incubation period • Salivation, lesions, lameness • LOST PRODUCTION

27. Classical swine fever • Caused by a virus • VERY contagious • Depression, diarrhea • Neurologic signs

28. Rift Valley fever • Caused by a virus • Spread by mosquitoes as vectors • Results in liver failure and abortions • Zoonotic - INFECTS HUMANS ALSO!

29. Highly pathogenic avian influenza • Caused by a virus • Spread by contact, aerosol • Swollen, hemorrhagic combs • Rapid death – approaching 100% death loss • Can be zoonotic – Some strains infect humans • H5N1 strain not in the U.S.

30. Exotic Newcastle disease • Caused by a virus • Spread by contact, aerosol • Depression, diarrhea, death

31. It pays to remember your BUDDIES! “BUDDIES” are unusual clinical signs in animals that may indicate serious disease: • Blisters – mouth, nose, teats or hooves • Unusual ticks or maggots • Deaths/Downers – unusually high number of deaths or animals that can not rise and walk • Diarrhea • Illness (high number sick, high number of abortions) • Eating abnormally (will not eat) • Staggering – strange neurological signs, including spasms Be aware of situations when both owners and animals are ill!

32. If you spot any of these clinical signs: Notify your local veterinarian! If you cannot reach your local veterinarian or believe that any of these diseases exist, contact: • 404-656-3667 or 800-282-5852 (State Veterinarian) • 800-TRY–GEMA (Nights & Weekends) • 770-922-7860 (USDA Area Veterinarian in Charge -24/7)

33. Crop Production • Crop types • Food Crops • Feed Crops • Ornamental Horticulture • Fiber Crops • Top crops in GA • - Peanuts • - Pecans

34. Plant Pathogens • Fungi • Bacteria • Viruses • Nematodes Soybean Cyst Nematode

35. Major Groups of Plant Pathogens Nematodes Plant Cell Viruses Fungi Bacteria George Agrios, Plant Pathology, 3rd ed.

36. Examples of Crop Diseases Soybean Rust Fungi Rhizoctonia Limb Rot of Peanut (fungal disease) Joe Hennen, Botanical Research Institute, Ft. Worth, TX Watermelon Fruit Blotch (Bacterial disease) Karnal Bunt Fungus on Wheat Images courtesy of UGA Extension Plant Pathology

37. Examples of Crop Diseases Plum Pox Virus on Peach The Plant Disease Diagnostic Clinic, Cornell University Bacterial Wilt in Tomatoes plantpathology.tamu.edu/Texlab

38. Plant Pathogens as Bioterrorism Agents • May be more difficult to detect • As with livestock, goals of an attack, • Food shortages • Economic disruption • Mistrust in food supply • All of the above • Good agricultural practices important

39. Exotic Plant Pathogens of Concern If They Were to Find Their Way Into Georgia Crops

40. USDA Select Agent Plant Pathogens AGRO SECURITY • USDA Select Agent Plant Pathogens • Available at USDA web site Want more info?

41. Plant pathogens and toxins • Foreign plant diseases including fungi, bacteria, viruses, nematodes, insects • Mycotoxins - harmful chemicals (toxins) produced by pathogenic, plant-associated fungi • Among the most toxic compounds known • Toxic to animals and humans • Aflatoxin and trichothecenes (T-2)

42. Foreign Plant Disease Pathogens • Exotic (non-indigenous) organisms • Impact of deliberate introduction • increased control costs for local agriculture • export barriers • economic disruption • Example: • Xanthomonas axonopodis pv. citri – citrus canker citrus greening, caused by Liberobacter asiaticum Courtesy Tim R. Gottwald and Steve M. Garnsey.

43. Mycotoxin Producers • Advantages: • Major direct economic losses • Peanut (GA) $25 million • Wheat (ND, SD, MN) $1 billion • Mycotoxin contamination invisible = immediate • fear factor, mistrust in national food supply • Limited control options • Production of pure mycotoxin by fermentation • Disadvantage: • Large-scale deployment necessary

44. To protect agriculture: We must learn two things: • To recognize symptoms that might signal hostile entry of pathogens or serious plant disease • Who to contact if we suspect a serious plant problem exists 1 2

45. Plant Disease Symptoms – The 5 D’s The 5 D's of Plant Disease • Discolored • Deformed • Defoliated • Dying • Deficient These can be symptoms of foreign plant disease. Report them!

46. If you see evidence of plant disease of concern: Notify your local UGA Cooperative Extension Office! 1-800-ASK UGA1 or enter your Zip Code at: http://www.caes.uga.edu/extension/ If you are unable to contact the Extension Office, call the Georgia Department of Agriculture at: (800) 282-5852 (ask for Plant Protection) or, Area Animal & Plant Health Inspection Service Plant Protection and Quarantine office at: (770) 922-9894 Slide 9

47. Questions to ask when a problem occurs What is it? What is the risk? How did it get here? What is the response?

48. For Activity 3

49. Case Study: • What is it? • What is the response? Dean Gabriel, UFL

50. Citrus Canker in Florida 1910- Canker first identified in Florida 1933- Canker eradicated 1986- Detected in Manatee County 1994- Canker eradicated 1995- Found third time near Miami Airport 1995- Present. Various attempts to eradicate combined with interjection of legal system. Citrus canker has been found in 24 Florida counties. Trees destroyed Residential = almost 900,000 Commercial = over 15,000,000 Total = over 16,000,000