perspectives on zoonotic diseases dave van metre, dvm
TRANSCRIPT
Perspectives on Zoonotic DiseasesPerspectives on Zoonotic Diseases
Dave Van Metre, DVM, DACVIMDave Van Metre, DVM, DACVIM College of Veterinary Medicine & Biomedical SciencesCollege of Veterinary Medicine & Biomedical Sciences
Colorado State UniversityColorado State University
ObjectivesObjectivesWhy are zoonotic diseases of greatest Why are zoonotic diseases of greatest
consequence today?consequence today?Risk factorsRisk factorsBenefits of animalsBenefits of animalsPreventative measuresPreventative measuresWhat roles can we play in educating the What roles can we play in educating the
public?public?
What is a zoonotic disease?
A disease shared by humans
and vertebrate animals
There are 1,407 known human There are 1,407 known human disease pathogens of whichdisease pathogens of which816 are zoonotic diseases816 are zoonotic diseases
Woolhouse, J Emerging Infectious Diseases11:2005Woolhouse, J Emerging Infectious Diseases11:2005
75% of human emerging 75% of human emerging infectious diseases are caused infectious diseases are caused
by zoonotic pathogensby zoonotic pathogens
J Emerging & Infectious Diseases J Emerging & Infectious Diseases volvol 11, 200511, 2005
Transmission of Zoonotic DiseaseTransmission of Zoonotic Disease
Who is at risk?Who is at risk?Veterinarians & veterinary techniciansVeterinarians & veterinary techniciansAnimal Emergency RespondersAnimal Emergency RespondersGeneral Public When Visiting:General Public When Visiting:
Petting zoosPetting zoosDog parksDog parksAnimal SheltersAnimal Shelters
Pet owners Pet owners New petNew petOutdoor catOutdoor catReptiles and birdsReptiles and birds
Animal shelter personnelAnimal shelter personnelAnimal control officersAnimal control officersPet retail facility personnelPet retail facility personnelLivestock producersLivestock producers44--H program participantsH program participantsSalebarn personnelSalebarn personnel
Society has changed!Society has changed!•• More people have contact with animals today More people have contact with animals today
than they did a century ago!than they did a century ago!•• Early 19Early 19thth century: 40% of the population were century: 40% of the population were
involved with agricultureinvolved with agriculture•• Today <2% are involved with agriculture, butToday <2% are involved with agriculture, but……
60% households have at least 60% households have at least one kind of pet one kind of pet --
An ever growing diversity of petsAn ever growing diversity of pets
A disease shared by A disease shared by humans humans
and animalsand animals
Marshfield index case, 5/26/03disseminated lesions
Wisconsin 2003Wisconsin 20037 confirmed 7 confirmed 34 suspect human cases34 suspect human cases
Gambian RatGambian Rat
Monkeypox VirusMonkeypox Virus•• Orthopox familyOrthopox family•• Spread animalSpread animal--toto--
human via blood or human via blood or bitebite
•• HumanHuman--toto--human human spread possiblespread possible
•• Clinical presentation Clinical presentation similar to smallpox similar to smallpox but milder but milder
SmallpoxSmallpox
What are the risksWhat are the risks for acquiring a zoonotic disease for acquiring a zoonotic disease
in Colorado?in Colorado?
Some Behaviors Are Clearly RiskySome Behaviors Are Clearly Risky
Those at greatest riskThose at greatest risk
•• Children less than 5 years old. Children less than 5 years old. •• Elderly. Elderly. •• Pregnant women. Pregnant women. •• People undergoing treatments for People undergoing treatments for
cancer. cancer. •• People who have received organ People who have received organ
transplants. transplants. •• People with HIV/AIDS. People with HIV/AIDS.
Risk RecognitionRisk Recognition
Sick outdoor / hunter cat Sick outdoor / hunter cat
High fever, depressionHigh fever, depressionLymph node enlargement Lymph node enlargement
or abscessor abscess(+/(+/--) respiratory signs) respiratory signs
PlaguePlague•• YersiniaYersinia pestispestis
gram(gram(--), non), non--motile, motile, nonnon--spore forming spore forming bacillusbacillus
•• Fleas living on infected Fleas living on infected rodents spread rodents spread infection to humans, infection to humans, cats, deer, rabbitscats, deer, rabbits
•• Recovery offers Recovery offers temporary immunitytemporary immunity
Endemic Plague in the USEndemic Plague in the US
Counties with Plague-Positive Samples
1970 - 1994
Common reservoirs of Common reservoirs of YersiniaYersinia pestispestis
AerosolAerosol
Bubonic or Bubonic or SepticemicSepticemicPlaguePlague
PneumoniaPneumonia Contact
OropharyngealOropharyngeal &&Secondary pneumoniaSecondary pneumonia
Photographs: Ken Gage, Ph.D., Centers for Disease Control and Prevention, Fort Collins, CO
Bubonic PlagueBubonic Plague
‘‘BuboBubo’’ formation formation regional lymph nodesregional lymph nodes
Plague in catsPlague in cats
•• LymphadenopathyLymphadenopathy –– ‘‘BubonicBubonic’’ 53%53% MandibularMandibular area abscessesarea abscesses
•• SepticemicSepticemic•• PneumonicPneumonic
Most dangerous to peopleMost dangerous to people
•• Dogs frequently infected Dogs frequently infected but are rarely clinicalbut are rarely clinical
TularemiaTularemia•• Gram Negative bacillus: Gram Negative bacillus:
FrancisellaFrancisella tularensistularensis•• One of the most infectious One of the most infectious
bacteria knownbacteria known–– 10 or fewer bacteria will 10 or fewer bacteria will
result in infectionresult in infection
TransmissionTransmission
•• VectorsVectors–– HARD TICKSHARD TICKS
•• Human transmissionHuman transmission•• DermacenterDermacenter variabilisvariabilis
–– BITING FLIESBITING FLIES•• ChrysopsChrysops•• TabanusTabanus•• Mechanical transmissionMechanical transmission•• Infective for 14 daysInfective for 14 days
•• Direct contactDirect contact–– Skinning infected Skinning infected
animalsanimals
•• IngestionIngestion–– Infected tissuesInfected tissues–– Water Water –– Voles (Voles (MicrotusMicrotus spp)spp)
•• InhalationInhalation
Tularemia Cases 1990Tularemia Cases 1990--20002000
Clinical presentationsClinical presentations
Ulceroglandular (75Ulceroglandular (75--85%)85%)Ulcer and regional lymph Ulcer and regional lymph
node enlargementnode enlargementGlandular (5Glandular (5--10%)10%)OculoglandularOculoglandular
Conjunctivitis, cervical Conjunctivitis, cervical lymphadenopathylymphadenopathy
TularemiaTularemiaFluFlu--like illness with fever, headache, like illness with fever, headache,
generalized body aches and productive generalized body aches and productive or nonor non--productive coughproductive cough
Pneumonia (85%) Pneumonia (85%) pleural effusion (15%)pleural effusion (15%)
•• Untreated caseUntreated case--fatality rate fatality rate -- 3535--60%60%•• Culture diagnosis quite difficultCulture diagnosis quite difficult•• PersonPerson--toto--person spread not seenperson spread not seen
Kosovo
•• Nov 2001 Nov 2001 –– Feb 2002Feb 2002–– 715715 human caseshuman cases–– Ages Ages 1616--4444
•• Oropharyngeal formOropharyngeal form–– Rodent Rodent
contamination of contamination of food and waterfood and water
MMWR 2:2005
Cryptosporidium Cryptosporidium parvumparvum
•• Most common causes of waterborne Most common causes of waterborne disease within humans in the United disease within humans in the United States. States.
•• Serological surveys indicate that 80% Serological surveys indicate that 80% of the population has had of the population has had cryptosporidiosis.cryptosporidiosis.
•• Incubation period 2Incubation period 2--10 days10 days
CryptosporidiosisCryptosporidiosisTransmissionTransmission
FecalFecal--oraloralHuman to humanHuman to humanAnimal to humanAnimal to humanFood borneFood borneWaterborneWaterborne
Most common Most common outbreak source:outbreak source:Failures in solid waste Failures in solid waste
managementmanagement
EtiologyEtiologyCryptosporidium Cryptosporidium
parvumparvumReservoirsReservoirs
HumanHumanLivestockLivestockBirdsBirds
CryptosporidialCryptosporidial genotypesgenotypes
GENOTYPE IGENOTYPE IHumanHuman--human transmission onlyhuman transmission onlyNotNot infective for cattleinfective for cattleIsolated from major human outbreaksIsolated from major human outbreaks
GENOTYPE IIGENOTYPE IIAnimalAnimal--animal and animalanimal and animal--human human
transmission (zoonotic)transmission (zoonotic)Associated with animal waste contactAssociated with animal waste contact
Human CryptosporidiosisHuman Cryptosporidiosis
Incubation: 1Incubation: 1--12 days12 daysSelfSelf--limiting in limiting in immunocompetentimmunocompetentNausea and abdominal painNausea and abdominal painWatery diarrhea: 3Watery diarrhea: 3--4 days duration4 days durationImmunosuppressedImmunosuppressed patientspatients
Persistent diarrheaPersistent diarrheaPersistent sheddingPersistent shedding1010--20% of AIDS patients affected20% of AIDS patients affected
Human outbreaksHuman outbreaks
Solid Waste FailuresSolid Waste FailuresGeorgia, 1987Georgia, 1987
13,000 people affected13,000 people affectedMilwaukee, WI, 1993Milwaukee, WI, 1993
403,000 people affected403,000 people affectedDairy farms along 2 rivers upstream ??Dairy farms along 2 rivers upstream ??
Austin, TX, 1998Austin, TX, 1998150 people affected150 people affected170,000 gallons of raw sewage into local creek170,000 gallons of raw sewage into local creek
Human outbreaksHuman outbreaksPublic Water Parks & Swimming PoolsPublic Water Parks & Swimming Pools
Georgia, 1995Georgia, 1995Louisiana 1988Louisiana 1988Wisconsin 1993 Wisconsin 1993
Food Service RelatedFood Service RelatedGeorgia Day Care, 1995Georgia Day Care, 1995
Food worker shedding Food worker shedding oocystsoocystsSpokane WA Banquet, December 1997Spokane WA Banquet, December 1997
Infected food service workers: Green onionsInfected food service workers: Green onions
Control and preventionControl and prevention
Personal hygienePersonal hygienePublic educationPublic educationIsolation of affected people from food Isolation of affected people from food
handling or child care jobshandling or child care jobsProper fecal waste managementProper fecal waste management
Q FeverQ FeverCoxiellaCoxiella burnettiiburnettiiOne organism may cause infectionOne organism may cause infectionOften symptomatic in animalsOften symptomatic in animalsRare cause of abortion in sheep & Rare cause of abortion in sheep &
goatsgoatsInhalationInhalation most common way to most common way to
get infectedget infectedObstetrical assistance to sheep or Obstetrical assistance to sheep or
goatsgoatsUnpasteurized milk, soft cheesesUnpasteurized milk, soft cheeses
Q Fever in HumansQ Fever in HumansIn untreated patients, case fatality rate is 1%; In untreated patients, case fatality rate is 1%;
-- death is rare in treated patientsdeath is rare in treated patientsFever accompanied by chills, headache, weaknessFever accompanied by chills, headache, weakness
About half of patients present with pneumoniaAbout half of patients present with pneumoniaNo personNo person--toto--person transmissionperson transmission
Chronic form (65% mortality)Chronic form (65% mortality)((ValvularValvular endocarditisendocarditis))
Heart disease Heart disease
3 Key messages 3 Key messages Living happier, healthier lives with animalsLiving happier, healthier lives with animals
Three stepThree step--processprocess1.1. PreventionPrevention
•• Vaccination, parasite controlVaccination, parasite control•• Basic biosecurityBasic biosecurity
Three steps (continued)Three steps (continued)
2.2. Appropriate sanitation / hygiene practicesAppropriate sanitation / hygiene practices• Cleaning and disinfecting animal
areas as needed• Hand washing!• Don’t eat or drink in animal facilities
3.3. Early diagnosis and treatmentEarly diagnosis and treatment• Both people and animals!
Tell your doctor that you work with animals!
Animals are important part of Animals are important part of our cultureour culture
•• Agriculture Agriculture •• CompanionsCompanions•• Service and working Service and working
animalsanimals•• WildlifeWildlife
Benefits of contact with animals outweigh the risks!
Rocky Mountain Regional Center of ExcellenceRocky Mountain Regional Center of ExcellenceFor Biodefense & Emerging Infectious DiseasesFor Biodefense & Emerging Infectious Diseases