Zoonoses and You

1. Zoonoses and You Julia M. Murphy, DVM, MS, DACVPM Epidemiologist

2. Zoonosis • An infection or infestation shared in nature by humans and other animals • Stedman’s Medical Dictionary, 27th Edition

3. Zoonotic Skew • 1709 Human Pathogens 49% zoonotic • 156 emerging human pathogens 73% zoonotic • Emerging pathogens 3 times more likely to be zoonotic. • Taylor & Woodhouse, ICEID 2000

4. Zoonotic Agents of Concern • CDC has categorized biological agents of concern • All but one Class A agent is zoonotic: • Viral Hemorrhagic Fevers • Plague Tularemia Anthrax • Smallpox Botulism

5. Zoonotic transmission • Possible routes: • Fecal Oral – bacterial, parasitic • Inhalation • Direct Contact • Vector Borne – mosquitoes and ticks • Penetrating Wounds

6. Fecal-oral transmission • Salmonella Ancylostoma • Campylobacter Toxoplasma • E. coli O157:H7 Listeria • Giardia Trichinella • Cryptosporidia Toxocara

7. Salmonella • Bacteria • Frequently reported in Virginia (>1000 cases/year) • ~30,000 reported to CDC/year • Over 1 million cases suspected • ~2000 serotypes cause disease

8. Salmonella • Commonly associated w/meat, poultry, and dairy • Wide reservoir in animals and environment

9. Salmonella • Incubation 6-72 hours • Vomiting, stomach cramps, diarrhea • 15-20 bacteria to infect • Mostly self limiting

10. Salmonella-Prevention • Avoid temperature abuse and cross contamination • Avoid consumption of raw meats and raw dairy • Wash produce thoroughly • Hand washing

11. E. Coli O157:H7 • Reportable in VA since 1999 • ~70 cases reported/year in VA • CDC estimates 73,000 cases/year

12. E. Coli O157:H7 • E. coli found in intestines of all animals and humans • O157:H7 found in cattle and maybe deer • produces a toxin

13. E. Coli O157:H7 • Thought that 10 bacteria can infect • Incubation 3-4 days • Bloody diarrhea, stomach cramps • Potential kidney failure

14. E.Coli-Prevention • Avoid cross contamination • Thoroughly cooking all foods • Avoid consumption of raw meats and raw dairy • Wash produce thoroughly • Hand washing

15. Giardia • Protozoan parasite • ~400 cases reported in VA/year • ~20,000 cases reported in US/year • most common intestinal parasite IDed by PH labs in the US

16. Giardia • Found in soil, food, water, or surfaces that have been contaminated with infected feces • 1 organism can cause disease • Can be found in a wide variety of animals

17. Giardia • 7-10 day incubation • Variety of symptoms or may be asymptomatic • Frequent episodes of diarrhea • Bloating • Cramps

18. Giardia-Prevention • Carefully dispose of sewage wastes so as not to contaminate surface or groundwater • Avoid drinking improperly treated water • Hand washing

19. Cryptosporidium • Protozoan parasite • ~40 cases reported in VA/year • ~3000 cases reported in US/year

20. Cryptosporidium • Young cattle, pigs, horses and sheep can manifest clinical signs • Immunosuppressed animals • Hardy in the environment • Not species specific

21. Cryptosporidium • Incubation about 7 days • Clinical symptoms: • Diarrhea • Abdominal cramps • Asymptomatic carriers are common

22. Cryptosporidium-Prevention • Persons with diarrhea should not use public swimming facilities • Avoid water or food that may be contaminated • Hand washing

23. Inhalation Transmission • Psittacosis • Histoplasmosis • Hantavirus • Coxiella burnetii (Q Fever) • Tuberculosis

24. Psittacosis • Caused by Chlamydophila psittaci • Rarely reported in VA • <50 cases reported/year in US

25. Psittacosis • Birds shed intermittently in feces and respiratory secretions • Often no signs in infected birds • Stress initiates shedding/illness

26. Psittacosis • Inhaled from desiccated droppings/secretions, dust from feathers • Incubation 1-4 weeks • Fever, headache, rash, chills • Only rare instances of person to person spread

27. Psittacosis-Prevention • Diagnose and treat sick birds • Clean bird cages regularly • Use of protective clothing and equipment when working with birds

28. Hantavirus • A total of 396 cases of hantavirus pulmonary syndrome have been reported in the United States • Over 50% of cases from the Four Corners area • VA has reported 2 cases

29. Hantavirus • Infect rodents worldwide • Deer mouse is 1° reservoir in US • Aerosol transmission from rodent excreta • Person to person spread not been seen in US

30. Hantavirus • Early symptoms usually nonspecific: • Fever, chills, muscle aches • Within 24 hours most cases develop hypotension and pulmonary edema • 36% of reported cases have died

31. Hantavirus-Prevention • Rodent control in and around the home remains the primary strategy • Cleaning using a bleach solution or household disinfectant when cleaning rodent infestations

32. Direct Contact Transmission • Leptospirosis • Tularemia • Brucellosis • Monkeypox

33. Brucella • Bacteria that affects various species including sheep, goats, cattle, deer, elk, pigs, dogs • 100-200 cases per year in US • ~1 case/year in VA

34. Brucella • Incubation variable (1-2 mo. common) • Irregular fever, headache, sweats, chills • No evidence of person to person spread

35. Brucella • People become infected via direct contact with infected tissues, blood, urine, vaginal discharges, aborted material • Can cause infection if inhaled • Can cause infection if consumed

36. Brucella • Higher risk occupations for exposure • Veterinarians • Abattoir workers • Laboratory workers

37. Brucella-Prevention • Avoid raw dairy products, especially in foreign countries • Vaccinate livestock; test and slaughter • Use gloves and other personal protective equipment around afterbirth, aborted fetuses

38. Monkeypox • Virus related to smallpox • Mostly in west and central Africa • Isolated from monkeys and other species • Introduced into US and eliminated in 2003

39. Monkeypox • Introduced into US by prairie dogs infected by imported African rodents, most likely African Gambian rats.

40. Monkeypox • Transmitted by the bite of or contact with infected animal • Possible person to person transmission • Incubation period 7-14 days

41. Monkeypox • Rash, fever, chills/sweats, headache, back ache, swollen lymph nodes, sore throat, cough, shortness of breath.

42. Monkeypox • Importation rules and interstate transport and sale/trading of such animals not very stringent • 79 humans in 6 states infected by prairie dogs

43. Monkeypox-Prevention • In 6/2003, the CDC and FDA issued a legal order to stop the import of all rodents from Africa into the United States • In 10/2003, the order was replaced by an interim final rule which continues to enforce the order

44. Vector Borne Transmission • Arboviral encephalitis • Examples: West Nile virus (WNV) Eastern equine encephalitis (EEE) • Rocky Mountain spotted fever • Lyme disease • Ehrlichiosis

45. West Nile Virus • Mosquito borne • 1999- First identified in US • 2002- First identified in VA • Number of cases in US have ranged from 62-~3800/year • Number of cases in VA have ranged from 0-29

46. West Nile Virus Mosquito vector Incidental infections West Nile virus West Nile virus Incidental infections Bird reservoir hosts

47. West Nile Virus • Non-Neuroinvasive Disease • Mild, flu-like, self limiting • Resolves in ~1 week • Neuroinvasive Disease • ~1/150 people • Meningitis, encephalitis

48. West Nile Virus “Iceberg” <1%CNS Disease ~20% “West Nile Fever” ~80% Asymptomatic

49. WNV-Prevention • Long, loose, light clothing • Repellants - DEET (<50% adults; <30% children) • Screens on windows • Avoid environments/times of day when mosquitoes biting

50. WNV-Prevention • Mosquito Control • Eliminate breeding sites • proper drainage • remove or turn over water containers • change bird baths weekly • Larvicide • Adulticide – aerial spraying after Hurricane Isabel