SalmonellaSalmonella and and E E colicoli O157:H7 in O157:H7 in

Livestock at Livestock at Agricultural FairsAgricultural Fairs

Thomas E. Wittum, PhDThomas E. Wittum, PhD

Veterinary Preventive Veterinary Preventive MedicineMedicine

The Ohio State UniversityThe Ohio State University

Salmonella Salmonella sppspp

Multiple host speciesMultiple host species

Fecal-oral transmissionFecal-oral transmission

Important zoonotic food-borne Important zoonotic food-borne

pathogenpathogen

Can persist in the environmentCan persist in the environment

Frequently shed by healthy Frequently shed by healthy

animalsanimals

Ubiquitous in the environmentUbiquitous in the environment

Human illness caused by Human illness caused by SalmonellaSalmonella

Incubation 6-72 hoursIncubation 6-72 hours

Diarrhea/bloody diarrheaDiarrhea/bloody diarrhea

Abdominal crampsAbdominal cramps

FeverFever

Self-limiting except for Self-limiting except for

immunosuppressedimmunosuppressed

Escherichia coliEscherichia coli O157:H7 O157:H7

Multiple host speciesMultiple host species

Fecal-oral transmissionFecal-oral transmission

Important zoonotic food-borne Important zoonotic food-borne

pathogenpathogen

Can persist in the environmentCan persist in the environment

Frequently shed by healthy Frequently shed by healthy

animalsanimals

Seasonality of sheddingSeasonality of shedding

Human illness caused by Human illness caused by O157:H7O157:H7

Incubation 1-10 daysIncubation 1-10 days

Abdominal cramps and diarrheaAbdominal cramps and diarrhea

Bloody diarrheaBloody diarrhea

Hemolytic uremic syndrome (HUS)Hemolytic uremic syndrome (HUS)

Antimicrobial therapy is Antimicrobial therapy is

contraindicatedcontraindicated

Zoonotic transmissionZoonotic transmission

Primarily food-bornePrimarily food-borne Direct animal to human transmission Direct animal to human transmission

can and does occur easily in can and does occur easily in environments conducive to interactionenvironments conducive to interaction Not an efficient mode of transmissionNot an efficient mode of transmission

Some environments provide the Some environments provide the opportunity for high-level exposure of opportunity for high-level exposure of high-risk individualshigh-risk individuals Animal exhibitsAnimal exhibits Agricultural fairsAgricultural fairs

Outbreaks at Animal Outbreaks at Animal ExibitsExibits

SalmonellaSalmonella 1991 Seattle Pacific Science Center1991 Seattle Pacific Science Center 1996 Denver Zoological Gardens1996 Denver Zoological Gardens

E coliE coli O157:H7 O157:H7 2000 Washington petting zoo2000 Washington petting zoo 2000 Pennsylvania petting zoo2000 Pennsylvania petting zoo

The ~3500 US State Fairs (large, regional) & County Fairs (small, local) attract ~150 million visitors annually Fairs provide opportunity for direct & sometimes intimate human contact with livestock, including children

Several European & N American human STEC O157 outbreaks linked w/ visits to farms & fairs exhibiting livestock

US Agricultural Fairs

Risk for outbreaks at Risk for outbreaks at fairsfairs

Most fairs held in summer or early fallMost fairs held in summer or early fall warm weatherwarm weather

Mix urban/suburban children with farm Mix urban/suburban children with farm livestocklivestock

Multiple US county fair outbreaks since 1998Multiple US county fair outbreaks since 1998 Most US fair outbreaks linked to:

contaminated water supplies direct contact w/ ruminants (cattle, sheep, goats) airborne transmission (dust?) from livestock barns

E coliE coli O157:H7 fair O157:H7 fair outbreaksoutbreaks

19991999 New York, Washington Co FairNew York, Washington Co Fair 610 (171) 610 (171) WaterWater Ontario, Canada FairOntario, Canada Fair 159 (7) 159 (7) Petting zooPetting zoo

20002000 Ohio, Medina Co FairOhio, Medina Co Fair 39 39 WaterWater

20012001 Wisconsin, Ozaukee Co FairWisconsin, Ozaukee Co Fair 56 56 Animal contactAnimal contact Ohio, Lorain Co FairOhio, Lorain Co Fair 40 40 Show barnShow barn Ohio, Wyandot Co FairOhio, Wyandot Co Fair 20 20 Hand washingHand washing

E coliE coli O157:H7 fair O157:H7 fair outbreaksoutbreaks

20022002 Oregon, Lane Co Fair Oregon, Lane Co Fair 8686 Sheep/goat Sheep/goat

barnbarn 20032003

Texas, Fort Bend Co FairTexas, Fort Bend Co Fair 77 Animal Animal contactcontact

20042004 North Carolina State FairNorth Carolina State Fair 112112 Petting zooPetting zoo

20052005 Florida, multiple fairs/festivalsFlorida, multiple fairs/festivals 7272 Petting Petting

zoo zoo

Agricultural Fair Agricultural Fair LivestockLivestock

Husbandry & management very different than Husbandry & management very different than “commercial” livestock“commercial” livestock Anti-thesis of “factory farming”Anti-thesis of “factory farming” Meticulously groomed, cleaned & bathed Meticulously groomed, cleaned & bathed

before/during fairsbefore/during fairs Typically extremely well-cared for and well-fedTypically extremely well-cared for and well-fed Exhibitors work to impress judges with the good Exhibitors work to impress judges with the good

condition of their livestock and hygiene of their condition of their livestock and hygiene of their pens (competitions)pens (competitions)

Usually reared individually or in small groupsUsually reared individually or in small groups Market weight animals typically sold at end of fairMarket weight animals typically sold at end of fair Often very tame & friendly towards peopleOften very tame & friendly towards people

“Fairs represent particularly intense episodes of close contact between large numbers of humans, farm animals, and food/beverage vendors in the presence of unregulated water systems” Jay Varma, CDC, Sept 2002

ObjectiveObjective

To estimate fecal To estimate fecal SalmonellaSalmonella and and E E colicoli O157:H7 prevalence in livestock O157:H7 prevalence in livestock on display at US agricultural fairson display at US agricultural fairs

SamplingSampling

County fairs (n=29)County fairs (n=29) 22 fairs visited in State A (July-Oct 2002)22 fairs visited in State A (July-Oct 2002) 7 fairs visited in State B (July-Aug 2002)7 fairs visited in State B (July-Aug 2002) 25 cattle, 25 pigs, other species & flies as available25 cattle, 25 pigs, other species & flies as available

State Fairs (n=3)State Fairs (n=3) 3 State Fairs: A, B, and C; visited Aug, Sept, & Oct, 3 State Fairs: A, B, and C; visited Aug, Sept, & Oct,

20022002 60-70 market & breeding beef, swine, & dairy 60-70 market & breeding beef, swine, & dairy

cattlecattle Other species (sheep, goats, flies) as availableOther species (sheep, goats, flies) as available

SamplingSampling

Bacterial cultureBacterial culture Availability sampling of individualsAvailability sampling of individuals Fair, owner, & animal anonymity Fair, owner, & animal anonymity

requiredrequired All samples cultured for All samples cultured for SalmonellaSalmonella spp spp

and and E coliE coli O157:H7 O157:H7 Other non-O157 STECOther non-O157 STEC

Samples CollectedSamples Collected

2919 freshly ground-deposited livestock feces2919 freshly ground-deposited livestock feces one sample per animal or pen (pigs, sheep, goats)one sample per animal or pen (pigs, sheep, goats)

154 fly pools 154 fly pools ~8,000 blow flies, stable flies, & house flies~8,000 blow flies, stable flies, & house flies live trapped or netted from dumpsters, garbage live trapped or netted from dumpsters, garbage

cans, wash stations, livestock buildings, etccans, wash stations, livestock buildings, etc

Salmonella fecal prevalence in fair livestock

Beef cattle4.7%

Dairy cattle4.7%

Sheep5.2%

Goats4.9%

Swine39.3%

Other livestock4.6%

E coli O157 fecal prevalence in fair livestock

Beef cattle13.8%

Dairy cattle5.9%

Sheep5.2%

Goats2.8%

Swine3.6%

Other livestock0%

ResultsResults

Salmonella spp Isolated from livestock at most fairs (96%

fair prevalence) 16.4% prevalence in fly pools

E coli O157:H7 Isolated from livestock at all 29 county

fairs & all 3 State Fairs (100% fair prevalence)

7.1% prevalence in fly pools 1 human STEC O157 hemorrhagic colitis

case linked with visit to one of the sampled county fairs

Demonstration Milk Demonstration Milk CowsCows

One cow was shedding E coli O157:H7 Second cow had Salmonella hide

contamination Contact with hundred of children per day

Hand Sanitizing StationsHand Sanitizing Stations

17 located in animal 17 located in animal barns at State Fair Abarns at State Fair A First check 5/17 First check 5/17

usableusable Second check 6/17 Second check 6/17

usableusable No stations observed No stations observed

at State Fair Bat State Fair B

Follow-up testingFollow-up testing

Fair environmental samples Fair environmental samples collected prior to summer 2003 faircollected prior to summer 2003 fair Both Both SalmonellaSalmonella spp and spp and E coliE coli

recovered from fair environmentsrecovered from fair environments Environmental persistence of isolatesEnvironmental persistence of isolates

ConclusiConclusionsons

Salmonella sppcommon at US fairs, esp in swine

fecal prevalence similar to summer prevalence in commercial livestock

present in swine & ruminants

frequent in/on pest flies (vector?)

common at US fairs, esp in cattle

fecal prevalence similar to summer prevalence in commercial livestock

present in swine & ruminants

frequent in/on pest flies (vector?)

ConclusiConclusionsonsE coli

O157:H7

Recommendations ??Recommendations ??

CDCCDC Provide information about riskProvide information about risk Design venue to minimize riskDesign venue to minimize risk Adequate hand-washing facilitiesAdequate hand-washing facilities Prohibit hand-to-mouth activities in Prohibit hand-to-mouth activities in

animal interaction areasanimal interaction areas Heightened precautions for high-risk Heightened precautions for high-risk

individualsindividuals

Additional Possibilities??Additional Possibilities??

Test animals prior to fair entryTest animals prior to fair entry Limitations of testsLimitations of tests

Disinfection of fair environmentDisinfection of fair environment Nearly impossible to disinfect Nearly impossible to disinfect

agricultural environmentagricultural environment Treatment of animals prior to fair Treatment of animals prior to fair

entryentry Oral neomycinOral neomycin