Zoonotic Diseases: Connections between Animal and Human Health

1. Zoonotic Diseases: Connections between Animal and Human Health Glenda Dvorak DVM, MS, MPH, DACVPM Center for Food Security and Public Health Iowa State University, College of Veterinary Medicine

2. Zoonoses: What are they?

3. Definitions • Zoonosis • Greek: zoon=animal; noson=disease • Diseases and infections naturally transmitted between vertebrate animals and man (WHO) • Anthropozoonoses • Animal to man infections • Rabies, Brucellosis • Zooanthroponoses • Human to animal • Tuberculosis to elephants • Influenza to ferrets Center for Food Security and Public Health Iowa State University 2005

4. Definitions • Reservoir • Where the agent persists in nature • A host or carrier • Harbors pathogenic organisms • Without injury to itself (asymptomatic) • Serves as a source for infection Center for Food Security and Public Health Iowa State University 2005

5. Classification • Infectious Agent • Bacteria, viruses, fungi,protozoa, other parasites • Routes of transmission • Direct contact, fomites, aerosol, oral, vector • Life cycle/Epidemiology • Direct, cyclozoonosis,metazoonosis, saprozoonosis • Animal species Center for Food Security and Public Health Iowa State University 2005

6. Infectious Agents • Bacteria • Anthrax, Brucellosis, Cat-scratch disease, Leptospirosis, Plague, Q fever • Viruses • Equine encephalitides, Influenza, Monkeypox, Rabies, West Nile fever • Fungi • Aspergillosis, Blastomycosis, Cryptococcosis, Dermatophytosis, Histoplasmosis Center for Food Security and Public Health Iowa State University 2005

7. Infectious Agents • Parasites • Protozoa • Cryptosporidiosis, Giardiasis, Toxoplasmosis • Helminths • Baylisascariasis, Toxocariasis, Trichinosis • Arthropods • Scabies (mange) Center for Food Security and Public Health Iowa State University 2005

8. Ingestion (Oral) Contaminated meat Contaminatedfood or water Fecal matter Soil Vector Mosquitoes Fleas Ticks Rodents Birds Routes of Transmission • Direct contact • Tissue • Body fluids • Lesions • Excretions • Urine, feces • Secretions • Saliva, milk, semen • Fomites • Aerosol • Coughing, sneezing • Dust, bedding Center for Food Security and Public Health Iowa State University 2005

9. Life Cycle: Direct Zoonosis • Perpetuated in nature by single vertebrate species • Anthrax, Brucellosis, Q Fever, Rabies Center for Food Security and Public Health Iowa State University 2005

10. Life Cycle: Cyclo-zoonosis • Requires more than one vertebrate • Most are cestodes (tapeworms) • Hydatid disease, Taeniasis Center for Food Security and Public Health Iowa State University 2005

11. Life Cycle: Meta-zoonosis • Requires both vertebrates and invertebrates • Arboviral infections: West Nile virus,St. Louis encephalitis • Leishmaniasis, Trypanosomiasis Center for Food Security and Public Health Iowa State University 2005

12. Life Cycle: Sapro-zoonosis • Depends upon inanimate reservoir or development site AND vertebrate host • Many fungal and parasitic agents • Histoplasmosis, Toxocariasis, Toxoplasmosis • Food-borne illnesses • Salmonellosis, E. coli O157:H7 Center for Food Security and Public Health Iowa State University 2005

13. Animal Species • Dogs and Cats • Rabies, Roundworms, Ringworm • Lyme disease (dogs only) • Cat scratch disease (cats only) • Livestock • Salmonella, E. coli • Brucellosis, Q Fever Center for Food Security and Public Health Iowa State University 2005

14. Animal Species • Birds and Poultry • Avian Influenza, Psittacosis, Cryptococcus • Reptiles, Fish, Amphibians • Salmonella, Mycobacterium • Wild Animals • Rabies, Hantavirus, Plague, Tularemia Center for Food Security and Public Health Iowa State University 2005

15. Importance

16. Importance of Zoonoses • Over 250 zoonotic disease • 25 notifiable at a national level (2005) • Of new and emerging infectious diseases,75% zoonotic • Reported cases (2003) • Salmonellosis 43,657 • Lyme disease 21,273 • Cryptosporidiosis 3,506 • West Nile fever 2,866 • Tularemia 129 • Q fever 71 • Hantavirus 26 • Rabies 2 Center for Food Security and Public Health Iowa State University 2005

17. Emerging and Re-emerging Diseases Center for Food Security and Public Health Iowa State University 2005

18. Category A Anthrax Botulism Smallpox Tularemia Plague VHF Ebola, Marburg, Machupo, Lassa Category C Nipah Hantavirus CDC Category ABC AgentsZoonotic Category B • Brucellosis • Glanders • Melioidosis • Psittacosis • Q Fever • Typhus • Viral encephalitis • Toxins • Food Safety • Salmonella, E. coli • Water Safety • Cholera, Cryptosporidium Center for Food Security and Public Health Iowa State University 2005

19. Category A Anthrax Botulism Smallpox Tularemia Plague VHF Ebola, Marburg, Machupo, Lassa Category C Nipah Hantavirus CDC Category ABC AgentsNatural occurrence in the U.S. Category B • Brucellosis • Glanders • Melioidosis • Psittacosis • Q Fever • Typhus • Viral encephalitis • Toxins • Food Safety • Salmonella, E. coli • Water Safety • Cholera, Cryptosporidium Center for Food Security and Public Health Iowa State University 2005

20. Factors That Promote Transmission of Zoonoses • Globalization • Frequent contact • Environmental • Animal husbandryand health • Personal hygiene Center for Food Security and Public Health Iowa State University 2005

21. Global Travel and Commerce References: CDC and APHIS Center for Food Security and Public Health Iowa State University 2005

22. Frequent Contact • Domestic Animals (Pets) • Companion, member of the family • 60% have at least 1 pet • Livestock • Livelihood • Wildlife/Exotics • Recreation, pets Center for Food Security and Public Health Iowa State University 2005

23. Environmental • Habitat destruction • Baylisascariasis • Habitat expansion • West Nile virus • Overlap with wildlife habitat • Rabies • Change in weather conditions • Anthrax, Hantavirus Center for Food Security and Public Health Iowa State University 2005

24. Animal Husbandry • Intensive livestock production • Health and vaccination • Brucellosis, Tuberculosis • Prevention Center for Food Security and Public Health Iowa State University 2005

25. Personal Hygiene • Hand washing • Cleaning up fecal matter Center for Food Security and Public Health Iowa State University 2005

26. Susceptible Populations • Occupation • Livestock producers/stockmen, veterinarians, zoo keepers, laboratorians • Immunocompromised • HIV/AIDS, Chemotherapy,Chronic disease • Elderly • Pregnant women • Children • Travelers Center for Food Security and Public Health Iowa State University 2005

27. Livestock

28. Anthrax • Bacillus anthracis • Spores • Resistant, in soil for decades • Natural foci of infection • Cattle, sheep, goats, horses, deer • Sudden death • “Downer” – unable to rise • Blood from orifices • No cutaneous lesions Center for Food Security and Public Health Iowa State University 2005

29. High Risk Groups • Occupational • Livestock producers, farmers, ranchers • Tanneries, woolsorters, textile mills, slaughterhouse workers • Bone processors • Veterinarians and technicians • Laboratory workers • 2001-North Dakota • 1st case since 1992 • 2002-South Dakota • Veterinarian performing necropsy Center for Food Security and Public Health Iowa State University 2005

30. Anthrax: Cutaneous • Most common – 95% • Spores through break in skin • Incubation period: 3-5 days • Pruritus  papule  vesicle  breaks and ulcerates  eschar  surrounding edema  heals in 1-2 weeks • Fever, muscle aches, and vomiting • Spread to regional lymph nodes and septicemia • 5-20% case-fatality Center for Food Security and Public Health Iowa State University 2005

31. Anthrax • Inhalation • Dust from contaminated animal products • Severe respiratory distress, shock, death • Case-fatality (untreated): 75-90% • Gastrointestinal • Consumption of contaminated meat • Symptoms similar to food poisoning • Death possible in 2-5 days if untreated • Mortality >50% • Treatment: Ciprofloxacin, doxycycline Center for Food Security and Public Health Iowa State University 2005

32. Brucellosis Undulant Fever

33. Brucellosis Center for Food Security and Public Health Iowa State University 2005

34. Brucellosis • 100-200 cases/year • California, Florida, Texas, Virginia • Transmission • Direct contact (breaks in skin) • Vaginal or uterine discharge • Placenta, blood, urine • Ingestion • Unpasteurized milk or dairy • Aerosol • Self-inoculation with vaccine • Person-to-person rare Center for Food Security and Public Health Iowa State University 2005

35. Brucellosis • High risk groups • Livestock producers, dairy farmers, veterinarians, slaughterhouse workers, laboratory • Humans • Cyclic fever and flu-like symptoms • Muscle aches, headache, weight loss • Chronic • Osteoarticular (20-60% of cases) • Chronic fatigue, depression • Genitourinary (2-20% of cases) • Treatment: Long term antibiotics Center for Food Security and Public Health Iowa State University 2005

36. Q Fever • Coxiella burnetii • Rickettsia, intracellular • Resistant • 2000-2001: 48 cases • 2003: 71 cases • Animals • Sheep, cattle and goats • Cats, dogs, deer, rodents, rabbits • Most asymptomatic • Abortions or stillbirths Center for Food Security and Public Health Iowa State University 2005

37. Q Fever: Transmission • Direct/Indirect • Parturition • Uterine and placenta material heavily infected • Urine, feces, tissues • Contaminated bedding, clothing, wool • Aerosol • Dust contaminated (up to 1/2 mile) • Necropsy or meat processing Center for Food Security and Public Health Iowa State University 2005

38. Q Fever • High Risk Groups • Occupational, Pregnant women, Laboratory • Incubation • Range 2-5 wks; mean ~20 d • Acute • Self-limiting flu-like (50%) • Fever, myalgia, headache, fatigue • Non-productive cough • Chills, severe sweats • Cutaneous rash (10%) • Pneumonia Center for Food Security and Public Health Iowa State University 2005

39. Q Fever • Chronic (Immunocompromised) • In 1-5% infected • Endocarditis, osteomyelitis, hepatitis or cirrhosis • Mortality: 40-65% • Pregnant Women • Congenital transfer • Fetal death • Treatment • Antibiotics – long duration Center for Food Security and Public Health Iowa State University 2005

40. Center for Food Security and Public Health Iowa State University 2005

41. Companion Animals

42. Toxocariasis • Roundworms • Toxocara canis, T. cati • 10,000 cases per year • Transmission • Feces of dogs and cats • Esp. puppies and kittens • Egg ingested  hatches  migrates within body • High risk groups • Children – play in or eat dirt Center for Food Security and Public Health Iowa State University 2005

43. Toxocariasis • OLM – Ocular Larva Migrans • Aberrant migration of worm to retina • Can cause blindness • Permanent partial loss of vision • 700 cases each year • VLM – Visceral Larva Migrans • Rare • Repeat or heavy infections • Migration to brain, liver, lung Center for Food Security and Public Health Iowa State University 2005

44. Toxoplasmosis

45. Toxoplasmosis • Toxoplasma gondii (protozoan) • Annually in US • 225,000 cases • 5,000 hospitalizations - 750 deaths • 6 out of 1,000 pregnant women • 3,300 congenitally infected infants • HIV/AIDS patients • 40% clinical toxoplasmosis • 10% reactivation of latent infection Center for Food Security and Public Health Iowa State University 2005

46. Toxoplasmosis • Transmission • Ingestion of infected tissue (50%) • Undercooked or raw meat • 3rd most prevalent food-borne illness • Ingestion of oocysts • Food or water contaminated by cat feces • Raw unwashed vegetables • Soil or feces on unwashed hands • Transplacental (congenital) infection • High risk groups • Pregnant women, immunocompromised, children Center for Food Security and Public Health Iowa State University 2005

47. Intermittent Rodents, Marine mammals Center for Food Security and Public Health Iowa State University 2005

48. Human Disease • Asymptomatic or mild flu-like signs • Chronic: dormant cyst • Reactivates with weak immune system • Congential • Abortion; malformation; blindness; mental retardation; epilepsy • Toxoplasmic encephalitis • HIV patients • Antibiotics – several weeks to months • Stops active multiplication • Will not remove tissue cysts Center for Food Security and Public Health Iowa State University 2005

49. Psittacosis

50. Psittacosis • Chlamydophila psittaci • Persistent (weeks to months) • 50-100 cases per year • Pet birds, pigeons, poultry, ducks • Transmission • Inhalation of contaminated dust from feathers or bird droppings • Mouth-to-beak contact • Person-to-person rare (coughing) Center for Food Security and Public Health Iowa State University 2005