Epidemiology and Control of Zoonotic Infections

1
Epidemiology and Control of Zoonotic Infections

• Center for Infectious Disease Preparedness
• University of California, Berkeley
• Spring 2005, Tuesdays 1030am-12pm

2
Instructors

• Ben Sun, DVM, MPVM
• bsun_at_dhs.ca.gov
• Gundula Dunne, DVM, MPVM
• gdunne_at_dhs.ca.gov
• Guest Lectures
• Jason Stull, DVM, MPVM
• Anne Kjemtrup, DVM, MPVM

3
Goals

• Importance of Zoonoses in
• Public Health
• Ecology and Natural History
• Prevention and Control

4
Organization

• 8 Weeks
• Presentation Lecture Questions
• Disease Coverage
• Multiple per lecture
• Examples
• Focus on animal aspects
• See references for additional reading

5
Requirements

• Weekly reading
• Case Report
• Paper
• Oral Presentation

6
Oral Presentation

• Given at beginning of class
• Relevant to the lecture
• 10-15 minutes
• Identify disease
• Background
• Case Investigation
• Discuss Zoonotic Aspects
• Confidentiality (remove identifiers)
• Limited number of spaces

7
Paper

• DUE MARCH 1
• Any zoonotic disease
• Double spaces, font size 12
• No more than 5 pages
• Background
• Case Investigation
• Discuss Zoonotic Aspects
• Need a topic? Ask us

8
Class Schedule

• Week 1 Zoonosis Intro TSE
• Week 2 Rabies
• Week 3 Classic Zoonoses
• Week 4 Bioterrorism
• Week 5 Vector-borne Diseases
• Week 6 Parasitic Zoonoses
• Week 7 Emerging Zoonoses
• Week 8 Foodborne Illnesses

9
Epidemiology and Control of Zoonotic Infections
Lecture 1

• January 18, 2005

10

• Part I Introduction to Zoonoses
• Part II Transmissible Spongiform
  Encephalopathies

11
Intro to Zoonoses

• Definition
• Importance
• Etiologies
• Animal Examples
• Transmission Routes
• Life Cycles

12
Zoonoses

• From the Greek
• Zoon Animal
• Noson Disease
• Diseases and infections which are naturally
  transmitted between vertebrate animals and humans
• - WHO 1959

13
Zoonoses

• Does NOT include
• Fish and reptile toxins
• Allergies to vertebrates
• Diseases in which animal-derived food serves as a
  vehicle (e.g. hepatitis A contaminated deli meat)
• Experimentally transmitted diseases

14
Zoonoses

• gt 250 zoonotic diseases
• 60 of US Household have 1 pet
• Multiple pets in the home
• Human-animal bond
• Exotic species as pets

15
Zoonoses Common Diseases

• Frequency (CDC, 2003)
• Salmonella 39,919
• Lyme disease 18,991
• West Nile (CNS) 2,862
• Trichinosis 4

16
Zoonoses

• Spectrum of Disease Severity
• Death rabies
• Severe illness plague
• Chronic illness Q-fever
• Mild illness psittacosis

17
Zoonoses Importance

• Economics
• Zoonotic disease are expensive
• Rabies post-exposure prophylaxis
• GI illness due to Salmonella or Campylobacter
  lost productivity, medical costs
• Import/Export
• BSE restriction on cattle
• Avian Influenza restriction on chicken
• Travel/Globalization
• Decreased transit time - SARS
• Remote area accessibility

18
(No Transcript)
19
Zoonoses Importance

• Surveillance
• Animals are sentinels
• Prevention and Control
• Animal key component
• Complications (e.g. Lyme disease)
• Unknown reservoirs (e.g. Ebola)

20
Zoonoses Etiologic Classification

• Viral
• Bacterial
• Parasitic
• Mycotic

21
Zoonoses Viral Examples
indicates covered in lectures
22
Zoonoses Bacterial Examples
indicates covered in lectures
23
Zoonoses Parasitic Examples
indicates covered in lectures
24
Zoonoses Mycotic Examples

• Aspergillosis
• Blastomycosis
• Cryptococcosis
• Dermatophytosis
• Histoplasmosis
• Sporotrichosis

indicates covered in lectures
25
Zoonoses Animal Species

• Dogs Cats
• Rabies
• Roundworm
• Ringworm
• Lyme Disease (dogs only)
• Cat Scratch Disease (cats only)
• Food Animals
• Salmonella
• E.coli
• Brucellosis

26
Zoonoses Animal Species

• Birds
• Psittacosis
• West Nile
• Cryptococcus
• Reptiles, Fish, Amphibians
• Salmonella
• Mycobacterium
• Wild Animals
• Hantavirus
• Plague
• Tularemia

27
Routes of Transmission

• Direct
• Droplet or Aerosol
• Oral
• Contact
• Indirect
• Foodborne
• Water-borne
• Fomite
• Vector-borne
• Environmental

28
Zoonoses - Life Cycle

• ORTHOZOONOSES
• May be perpetuated in nature by a single
  vertebrate species
• E.g. rabies, brucellosis, anthrax

29
Zoonosis Rabies Life Cycle
Virus inoculation (bite)
Salivary gland excretion
30
Zoonoses - Maintenance Cycle

• CYCLOZOONOSES
• Requires more than one vertebrate species but no
  invertebrate host
• Most are cestodiases (tapeworm diseases)
• Taenia saginata and T. solium require man to be
  one of vertebrate hosts
• Others, such as hydatidosis, man is accidentally
  involved

31
Life Cycle                                     
                                              
32
Zoonoses - Life Cycle

• METAZOONOSES
• Require both vertebrates and invertebrates to
  complete transmission
• All arboviral infections
• West Nile virus, Saint Louis encephalitis
• Some bacterial diseases
• Plague, many rickettsia
• Some parasitic diseases
• Leishmaniasis, schistosomiasis

33
Zoonoses Metazoonoses

• Invertebrate Host Mosquitoes
• Vertebrate Host Birds
• Incidental Hosts
• HUMANS, horses, amphibians, other mammals

34
Risk Factors

• Companion Animal
• Dogs roundworm
• Rats Rat Bite Fever
• Occupational
• Animal control workers rabies
• Wildlife biologists hantavirus
• Foodborne
• Raw meat E.coli
• Unpasteurized dairy Listeria

35
Risk Factors

• Recreational Activities
• Camping Lyme disease
• Farm Settings
• Sheep Q-fever
• Cattle Cryptosporidium
• Travel
• Maylasia Nipha
• Australia Hendra

36
Reportable Diseases of Animals

• By veterinarian or other individual
• Reported to CA Department of Health Services
• Plague
• Rabies
• Reportable to the CA Department of Food and
  Agriculture
• Anthrax
• Brucellosis
• Glanders
• Listeriosis
• Rabies in livestock
• Venezuelan equine encephalomyelitis
• West Nile
• And more

37
(No Transcript)
38
(No Transcript)
39
Zoonosis Take Home Points

• Transmitted between animals and humans
• Zoonoses are common
• Animals part of everyday life
• Recognize the risk factors

40
Acknowledgements

• Dr. Bruno Chomel
• Dr. Ben Sun