5 Meet the Hudsons !LindaFredMarySusan JohnJeffDave
6 The Hudson Dairy Farm History Employees 1920 - Established UpgradedNew structures & equipmentEmployeesJeff Hudson, owner1 farm worker1 milkerDave, Linda, FredSusan & John feed the calvesJeff HudsonOwner Since 1982
13 Milk cow barn Feed barn Calf barn Milking parlor Tool shed Hudson home M&SMilk cow barnDry cow& heiferbarnFeedbarnHoldingareaCalfbarnBTRMilkingparlorToolshedHudsonhomeGrazing areaThere’s no one to tell him where to put the calves, so he leaves them in the calf barn !!!!!!
14 October 4 5.00 am 8.00 am 3 new calves, and 2 other calves have high temp. and bloody diarrhea …!8.00 amThe Vet examines the herd.He also takes a swab sample for lab testing.He then treats the calves, and then tellsJeff …”You might have a serious problem”
15 October 4 8.00 p.m. 11.00 PM This has not been a good day for Jeff ! A total 7 out of 15 calves are now sick. He treats the sick calves.PMJeff, has to take both and to the County Hospitalemergency room --- abdominal cramps and high temperature.This has not been a good day for Jeff !
16 October 5 4.00 am 5.00 am 6.00 am Children admitted. Dave volunteers to help5.00 am8 dead calvesDave loads the dead calves on the UNI-LOADERand takes them to the pit.6.00 amThe cows have just returned from milking,he quickly TURNS AROUND hoses downthe uniloader, and picks up feed for feeding the cows
17 October 8 October 10 Nothing much happening on the farm. The remaining sick calves nursed back to health.On October 8th, the children return home Diagnosis: Salmonellosis.October 10The veterinarian calls to tell that Salmonella from his calvesis a new type of Salmonella called DT104.
18 October 12 4.00 am 18 cows in milk are scouring ! 9.00 am Sick cows are moved from the milk barn to the maternity /sick pen.11.00 amThe Vet examines the cows.Verdict: Salmonellosis.12.00 noonMr. Smith a neighbor, who buys raw milk tells Jeff that they are going to host 24 Boy Scouts over the weekend on his game farm.
19 October 149.00 amJeff learns, 18 of 24 boy scouts are hospitalized & 2 in serious condition.11.00 amThe County Health Officer, the State Regulatory Veterinarian, The Milk Agent, his Veterinarian, FDA and USDA officials come to the farm.11.30 amHerd is to be quarantined, till further notice.
20 All newspapers carry the outbreak story ! Milk makes kids sick ………Salmonella outbreak traced to DAIRY farm ……..Milk contains bugs that makes people sick ……….Scientists say …….. Dairy farmingDairy cows ….. All infected with dangerous bugsKiller bug on the loose …… dairy cows responsible
21 How did Salmonella typhimurium DT104 get into raw milk ?
22 Date Event October 1 Apparently healthy calves brought Apparently clean lookingtruckNew calves mixed withother calves
23 Date Event October 1- 3 Incubation period for Salmonella (Children probablyinfected)October Clinical symptomsin calves & children
24 October 5 Dead calves loaded onto uniloader Date EventOctober 5 Dead calves loaded onto uniloaderUNI- LOADER IS CONTAMINATED WITH SALMONELLA !Uni-loader hosed down with water !!!!!Picks up feed FEED IS CONTAMINATED WITH SALMONELLA !SALMONELLA
25 Date Event October 5 Cows infected with Salmonella Typhimurium DT104 October Salmonella Typhimurium DT Multiple antibiotic resistance: AmpicillinChloramphenicolStreptomycinSulfonamidesTetracyclineIncidence increasing in the US3 human outbreaks reported !
26 Date EventOctober Cows infected with Salmonella
27 Date EventOctober Infected cows contaminate milking stall, parlor and milk in bulk tank
29 PART TWO What should you know about Salmonella ?
30 What’s Salmonella ? Salmonella is a bacteria Rod shaped Appears pink to red when stained with Gram’s stain (Gram-negative)Belongs to a family; Enterobacteriaceae (intestinal bacteria)Salmonella (genus)enterica ( species)serovar ( over 2200 serovars)Example: Salmonella enterica serovar Dublin S. DublinLight MicroscopeElectron Microscope
31 Historical Perspective One of the first veterinary students from Cornell University, and holder of the first D.V. M. degree (1876)DANIEL ELMER SALMON, D.V.M. ( ) Father of disease eradication Pioneer in public health practice and medical research Discoverer of salmonellae Experimental Immunologist, Epidemiologist, Administrator Bureau of Animal Health [ Veterinary Medicine and Human Health, C. W. Schwabe, 1969]
32 Where does Salmonella come from ? Inhabitant of intestinal tract ofanimalsbirdsreptilesinsectsHost adaptedHuman: S. TyphiCattle: S. DublinPoultry: S. PullorumPigs: S. CholeraesuisNon host adaptedS. Typhimurium
33 YES ! What’s Salmonellosis ? When Salmonella causes a physical illness in animals or human beings it is termed as SalmonellosisIs Salmonella communicable between animals and humans ?YES !Human outbreaks of Salmonellosis in the United States are frequently associated with food products of animal origin including eggs, meat, milk and milk products38 Outbreaks, 14 (37%) traced to products of bovine origin !
34 Bovine Salmonellosis Magnitude of the problem National survey 2.1% fecal samples from 7.4% of farmsCull dairy cows4.6% of cull cows (Washington State)Neonatal calvesOhio- 4.8% farms; California- 16 % farmsMissing informationEstimates of economic lossescalf and adult cattlemilk productioncontaminated raw bulk tank milkSalmonella inraw milkWisconsin %Tennessee %South Dakota - 6.1%
35 Bovine SalmonellosisCommon serotypes isolated from cattle in the United StatesS. Dublin - ( group ‘D’) MostS. Typhimurium - ( group ‘B’) commonS. NewportS. MuensterS. SaintpaulS. AnatumS. KentuckyS. Montevideo
36 How does Salmonella gain access to a farm ? Mostimportantsources ofinfectionReplacement calves trucksheifer/ cowsbirds /pests feed water visitors
38 Salmonella & host interaction Contaminatedfeedwaterfecescolostrum / milkSalmonella & host interactionAnimalIntestineOUTCOME ?SalmonellaEnvironmentMicroscopic picture of small intestine
39 Outcome of an Salmonella infection …. No Salmonella in feces and milkNo clinical signsSalmonella infrequentlypresent feces and or milkSYMPTOMLESS CARRIERSalmonella present in the body but not excretedrecoverLATENT CARRIERFever, diarrhea, bloody stool,dehydration, anorexia/ emaciationrapid breathing, sloughing ofskin from extremitiesClinical symptomsSalmonella infeces and or milkACTIVE CARRIERdeath
40 Salmonella carriers ? diagnosis prevention and control Animals with Salmonella infection that appear healthy and show no signs of disease makedetectiondiagnosisprevention and controlone of the most difficult tasks to achieve and provide the greatest challenges to the animal health industry.ACTIVE CARRIERLATENT CARRIERSYMPTOMLESS CARRIER
41 How do healthy animals become infected ? FECES AND DISCHARGESickContamination of:1. Barn/ manure2. Water troughs3. Feed4. Run off waste5. Uni-loader6. Other equipmentSick but apparentlylook healthyFecesOn farm newly purchasedMilkFecesDirectcolostrumIndirectHealthy calvesHealthy cows
42 “Characteristics of Salmonella and Salmonellosis --- points to remember”* ONE : Infection on a farm is maintained primarily by transmission of Salmonella from feces of infected animalsACTION: Break the links in the chain by minimizing opportunity for fecal contamination of feedstuffs, feeding surfaces, water troughs and equipment* Partly taken from: John M. Gay, Bovine Herd Salmonellosiswsu.edu / courses-jmgay/ fdiuherdsalmonella.htm
43 TWO: Salmonella infection & subsequent clinical disease is a result of : ACTION: Maximize host resistance by paying careful attention to the transition of susceptible animals (periparturient cows newborn calves).Organism Animal* serotype * age* virulence * immunity* No. of organisms * nutrition* prior exposure* stress
44 THREE: Salmonella infects anything in the livestock environment that has an intestinal tract: ACTION: Initiate control programs1. Rodent proof and bird proof feed storage2. Remove nesting and roosting opportunities
45 ICEBERG EFFECTFOUR: Majority of Salmonella infections in a herd over a period of time are symptomless Clinical infections are only the tip of the iceberg, even during clinical outbreaks of diseaseACTION: in an outbreak handle all animals as if they were shedding not just the sick ones. Reduce water and feed contamination.ClinicalNormalSubclinical
46 FIVE : Some symptomless animals shed Salmonella through saliva, nasal secretions, urine, milk and fecesSuch animals POSE THE GREATEST PROBLEM in controlling spread of Salmonella infection as they contaminatewater bowlsnipplesoral treatment equipment (balling guns, esophageal feeders)human handsACTION: Clean all equipment with Chlorhexidine ( 3 oz. / gal) and other items such as boots and mats with orthophenylphenol.
47 1. Normal Dry Matter Intake 2. Normal VFA level3. No Growth of Salmonella in rumen1. Lowered Dry Matter Intake2. Lowered VFA level3. Increase in number of Salmonella in rumen1. Don’t have regular access to feed2. During transport3. Parturition4. Subclinical ketosis5. Hypocalcemia6. Sudden ration changes7. Ration maladaptation8. Inadequate bunk space and pen space9. Mixing submissive heifers with dominant cows at parturitionSIX: Salmonella are usually killed by exposure to the volatile fatty acids of fully functional normal rumensACTION: Maximize rumen function by maximizinga consistent dry matter intake in periparturient andearly fresh cows
48 SEVEN: Salmonella survives for long periods under conditions common on the livestock farm Colostrum30 C, 2 to 5 weeks.5 C to 11 C, for ~ 10 days, low pH will reduce the number of SalmonellaPasture and soil daysGarden soil daysLiquid manure days ( S. Dublin), days ( S. Anatum)Slurry to 250 daysInfected feces stored in cans days ( S. Dublin)
49 EIGHT: People who are at risk of illness Farm workersExpectant mothers handling sick animalsWorking with sick calves and cowsPoor personal hygieneConsuming raw bulk tank milkPublicConsuming raw milk, fresh cheese made of raw milk.
50 NINE: Personal hygiene practices on farm Wash hands with soap and waterA must before and after:1. Attending sick calves and animals2. Milking cows ( also wear gloves)3. Manure handlingDress and boots1. Change into farm boots on the farm2. Wash farm boots regularly3. Leave farm boots on the farm4. Wash and disinfect farm clothesIF available: shower before leaving the farmAvoid drinking raw milk
51 Salmonella Typhimurium DT 104 Emerging foodborne pathogenDetected in several countriesWhy is DT 104 of concern ?Multiple antibiotic resistanceAmpicillinChloramphenicolStreptomycinSulfonamidesTetracyclineDT 104 has been isolated from;poultry, swine, cattle and wild animals
52 Outbreaks ( human) in the US: United StatesHumansS. Typhimurium: (1990) (1996)S. Typhimurium DT 104: (1990) (1996)Cattle ( Northwest)DT 104: No isolations till 198613% to 199164% to 1996Outbreaks ( human) in the US:4 ( 3 - west coast, 1- east coast)ALL 4 OUTBREAKS LINKED TO UNPASTEURIZED DAIRY PRODUCTSSOURCE OF DT 104 IN TWO OUTBREAKS, TRACED TO DAIRY FARMS
53 No unique control methods available for S No unique control methods available for S. Typhimurium DT 104 in animals.Control measures that are effective against other types of Salmonella will reduce the likelihood of transmission of S. Typhimurium DT 104.
54 Risk factors for Salmonella Typhimurium DT 104 Cattle in dealer premises were at increased risk of disease (Odds ratio 14.25)Introduction of newly purchased cattle ( 4 weeks after purchase) to the farm increases the risk of disease (OR 2.51)Purchase via dealers was at high risk as compared with purchasing stock directly from other farms (OR 3.90)Evans S., and R. Davies Case control study of multiple - resistant Salmonella typhimurium DT 104 infection of cattle in Great Britian. Vet. Rec. 139 :557:558.
55 Risk factors for Salmonella Typhimurium DT 104 Persistently contaminated buildings may be a source of infection (OR 2.48)Lack of isolation facilities for ill animals was associated with an increased risk of diseaseIn particular; if cows calved in buildings that previously housed diseased stock (OR 1.51)A high population density of cats around the farm increased the risk of infection (OR 1.35)Evidence of access to cattle feed stores by wild birds was associated with an increased risk of disease (OR 1.67)
56 Risk factors for Salmonella Typhimurium DT 104 Risk factors over which the dairy producer can exert control:1. Purchasing replacement stock from direct sources rather than a dealer2. Quarantine of purchased cattle for a 4 week period3. Housing sick animals in dedicated isolation areas4. Preventing wild bird access to cattle feed stores5. Vaccination
57 Typical Scenario-1 OUTBREAK No ofanimalsweeksOUTBREAKNewly assembled herd, animals from unknown source, or from a dealerHigh morbidity ( at least % in the herd infected)Drop in milk production, ~ 10 %, high risk of bulk tank milk contaminationTypically observed with S. Typhimurium, last 2-4 weeksSamples taken during outbreak show extensive herd contaminationSamples collected 4-6 weeks later, most of which test negativeSubsequent outbreaks or infections may be sporadic, or may go unnoticed
58 Typical Scenario-2 Recurrent Salmonella infection in calves and cows Cycling of Salmonella in a herdTypically seen with Salmonella group D and group EPresence of animal reservoir or extensive environmental contaminationHot spots: Maternity area, calf housing areas, watering troughsIdentify carriers, massive environmental cleanup, put in place appropriate management practices.
59 Other Scenarios... Salmonella detected in milk filters and bulk tank milkPre-fresh and orfresh cows sickFamily memberdiagnosed withSalmonellosis afterdrinking raw milkCalves and cows you recently sold caused SalmonellosisRecurrent diarrhea andloss of calves
60 PART THREE Strategies for Prevention and Control of Salmonellosis
61 Principles of Salmonella Control on Dairy Farms Herd risk factorsLarger herd sizeFreestallsRecycled-water flush system“Open” herdsLack of quarantine facilitiesRendered-product useConcurrent diseasesInadequate calf-feeding utensil cleaning
62 Principles of Salmonella Control on Dairy Farms -2 Individual animal risk factorsAge ( 3 to 6 week-old calves)Starvation/ nutritional deficienciesConcurrent diseasesPoor immunoglobulin levelsTransport and other stressesManure access
63 Principles of Salmonella Control on Dairy Farms -3 Sources of Salmonella bacteriaContaminated feedCarrier animalsVectors (birds, wild animals, pet animals, rodents)
64 Principles of Salmonella Control on Dairy Farms -4 Control measures during a Salmonella outbreakIdentify sick animalsIsolate sick animalsIdentify source of bacteria, and if possible eliminatePrevent reintroduction of the bacteriaInstitute hygiene measures (fecal-oral spread)Vaccination ?Treatment of infected animals ?
65 Control measures during a Salmonella outbreak -2 Human health precautions during a Salmonella outbreakAvoid exposure of young, old, or immune compromised peopleLimit number of people handling sick animalsAvoid having same people handle sick and well animalsHygienic measuresfoot bathhandwashseparate clothes/footwear for sick animal handlingPrevent pet animal exposure to cattleDON’T DRINK RAW MILK FROM AFFECTED FARM
67 Whole herd outbreak 1 General A Make sure all farm personnel are made aware of the outbreakB Discourage all farm visitations and visitorsC Disinfect1 All soiled work clothes in PPM of chlorine solution, rinse, wash and dry.2 Boots, rinse with high pressure hose and soak overnight in orthophenylphenol.
68 Whole herd outbreak 2 Secure the milking facility A Milker(s) clothes and bootsB Disinfect boots before entering the milking facilityC Do not milk cows with diarrheaD EXTRA PRECUATION DURING CLEANING OF UDDER AND TEATSE No visitors or other farm personnel
69 Whole herd outbreak 3 Restrict movement of animals A Minimize movement B Retain animals within the same barn/ unittill laboratory tests tests are negativeC No visitors
70 Whole herd outbreak 4 Equipment 5 Feed areas clean Clean equipment Between operations; one unit to anotherSame equipment is used for different tasks5 Feed areasRemove feed in the feeding alleys at the time of outbreakDisinfect the feeding alleyReplenish with fresh feed
71 Whole herd outbreak Calving area and Calf house Remove manure Scrap off dry manure and top soilClean wall with sodium triphosphate (1 oz. / gal)Spray the floor with sameTransfer all refuse to a marked area on the farm