Final Investigation Summary
of Dee Creek Farm

The final report is a summary of the field investigation conducted by the Washington State Department of Agriculture (WSDA) Food Safety Program (FSP) of the Southwest Washington E. coli outbreak linked to Dee Creek Farm and the sample test results.

Investigation
Foodborne Pathogens and Dairy Operations
Farm conditions
Sample Testing
Sample Results
Conclusions

The WSDA FSP on-farm investigation and laboratory testing of samples collected from the Dee Creek Farm confirms the Clark County Health Department conclusion that the E. coli 0157:H7 that sickened at least 18 people in Washington and Oregon originated from raw milk that sold illegally by Dee Creek Farm.

• E. coli 0157:H7 has been conformed in two milk samples provided to WSDA by Dee Creek Farm through the Clark County Health Department as well as five environmental samples taken from Dee Creek Farm milk barn areas.
   
• Milk, water and environmental samples were collected and sent to WSDA's microbiology lab in Olympia, the Washington State University College of Veterinary Medicine's field disease investigation unit lab at Pullman and the U.S. Food and Drug Administration lab in Bothell.
   
• The samples testing positive for E. coli 0157:H7 were then Pulsed-Field Gel Electrophoresis (PFGE) DNA fingerprint cross-matched with the human illness case samples at the Washington State Public Health Lab and determined to be the same pattern strain of E. coli 0157:H7 with no discernable differences.
   
• Based on this testing, epidemiologic work from the county health department as well as the on-farm investigation findings, the WSDA Food Safety Program has conclusively determined that Dee Creek Farm is the source of the outbreak.
   
• Dee Creek Farm illegally sold raw milk without required WSDA Milk Producer and Milk Processor licenses and sanitary public health inspections.
   
• Raw Milk bought and distributed from Dee Creek Farm, was consumed by all affected people prior to their becoming ill.
   
•  Public health officials in Washington and Oregon identified eighteen (18) people who developed symptoms consistent with E, coli infection.  Five (5) Clark County children were hospitalized with two (2) children needing critical care and life support during the incident.

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Investigation:

On December 12, 2005, the WSDA FSP was notified by the Washington State Department of Health (WDOH) of E. coli 0157:H7 illnesses in the Vancouver, Washington area.

WSDA FSP Manager Claudia G. Coles was contacted by WDOH Public Health Advisor, Janet Anderberg and informed that the Clark County Health Department had linked E.coli 0157:H7 illness cases to the consumption of raw milk obtained from Dee Creek Farm located in Woodland, Washington, which is in Cowlitz County.

Clark and Cowlitz county health officials and WSDA coordinated efforts for an on-farm investigation and collection of samples that were received from either the farm or shareholders who provided milk product to the Clark County Health Department.  The farm was apparently providing raw milk through a cow-share program where “shares” of cows are sold to individuals or families in exchange for milk product.

During the summer of 2005, a Portland, Oregon area news article indicated that the farm operated as a cow-share dairy business where 45 parties own a share of 5 Jersey milking cows.  A WSDA letter was sent to the firm on August 11, 2005, ordering the farm to cease the dispensing, giving, trading or selling of milk, or to meet the requirements of a milk producer and retail raw milk processor.  On September 1, 2005, Dee Creek farm sent a response letter to WSDA stating that they were currently not selling milk but indicating they were planning on working towards meeting the requirements for licensing.

Since the farm was not licensed by WSDA as a legal dairy operation for milk production or milk processing, WSDA had no knowledge of farm milking and bottling practices.  On the evening of December 12, 2005, WSDA attempted to contact Dee Creek Farm representatives by telephone but only reached an answering machine where a message requesting a return call was left.  Cowlitz County Health Department officials were able to reach the farm on December 13, 2005 and made arrangements for both Cowlitz County and WSDA officials to visit the farm and interview the Dee Creek Farm owners.  An attempt was made to obtain the list of cow-share holders who received the raw milk product.  A Cowlitz County Department of Health cease and desist order was served, which also required the farm to immediately submit all records of sales or distribution of dairy products from November 1, 2005 to present, with name and contact information.  No list was provided.  Subsequently, Dee Creek Farm owners were ordered to appear in Cowlitz County Court where the distribution list was finally provided under an order of the court.

WSDA visited the farm three times during the week of December 12th to conduct a thorough investigation and sampling of milk, water, animals and the farm environment.  The first two visits were limited as the Dee Creek family members were being taken to their doctor, meeting with their attorney or appearing in Cowlitz County Court.  Consequently, a complete investigation was not made until four days after the outbreak was announced by Clark County Health officials.

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Foodborne Pathogens and Dairy Operations:

The on-farm investigation noted a number of factors that point to practices that may have contributed to the E.coli O157:H7 outbreak and support the reasons that raw milk for human consumption is a high risk and potentially hazardous product.

As noted in the recent article presented at the 2005 National Mastitis Council’s Annual meeting titled “Foodborne Pathogens, Mastitis, Milk Quality and Dairy Food Safety” published by S.P.Oliver, B.M. Jayarno and R.A. Almeida, the origin of foodborne pathogens can be from excretion from the udder of an infected animal, or through direct contact with infected sources in the environment.  Most foodborne pathogens inhabit the ruminant intestinal tract, and therefore, dairy cattle are considered a major reservoir of Salmonella, Campylobacter, and Shiga-toxin producing E. coli (STEC) of which E.coli O157:H7 is a sub serotype.  E.coli O157:H7 is characterized by low infectious doses (1-100 colony-forming units) and they are highly pathogenic in humans where they cause serious acute and long-term illness, and can be fatal. 

Numerous studies and illness outbreak data have documented that foodborne pathogens of public health significance have been isolated from bulk tank milk and are capable of causing disease in humans.  The authors also reviewed studies that indicate that fecal and foodborne pathogen contamination occurs during the harvest of raw milk (i.e., milking, collection, and storage) and the farm environment likely plays a major role in the presence of foodborne pathogens in bulk tank milk.  They point out that reducing the potential for contamination during the harvesting of milk should result in the reduction (but not elimination) of foodborne pathogens in raw milk.

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Farm conditions:

WSDA inspectors noted a number if issues that are of concern and demonstrate that the farm would not meet public health requirements if license applications for Milk Producer and Milk Processor were submitted.

Some of the significant items noted in the field investigation report and documented by WSDA are:

• No animal health testing documentation for brucellosis and tuberculosis or health permits; large herd of wild elk in contact with Dee Creek Farm beef cattle.
   

• No water or waste water system available at milk barn for milking operations or cleaning; no hand wash or equipment sinks available for cleaning and sanitizing; no bacteriological test results were provided for the well water system used by the farm.
   

• Entrance to the milk barn parlor had approximately 12 inches of deep mud/manure with standing water that the cows walked through as they entered the barn; dirt flooring with rubber mats had mud/manure and debris and the milking bucket unit was in direct contact with these unclean surfaces during milk production.
   

• Although udder washing and teat pre-milking and post-milking was conducted whereby the udders appeared clean, cross-contamination was observed during the milk preparation process such as when during the udder preparation of the third cow, the cloth towel was exposed to contamination when it was placed on top of the milking unit and then used to dry the just washed udders.
   

• Cross-contamination of the milk bucket system occurred during the milking process such as when the inflation was soiled as it was being attached to the udders because it came into contact with the muddy leg of the cow and then inside of the milk inflation lip was wiped with a cloth towel that had been used to dry the udder of the cow being prepped for milking; chickens were present in the milk barn during milking next to the milking unit and actually flew over the milking unit at the start of milking; inflations are left dangling and unprotected when 3-teated cow milked; no cleaning/sanitizing (backflush system) of the inflation units available prior to milking the next cow.
   

• Milk transferred into stainless steel containers that are stored and transported in a vehicle that contained dirt and hay debris directly under the containers; no separate milk processing area from domestic kitchen available; no raw milk-warning label provided on the containers.

Specific observations made by WSDA inspectors during the farm visits regarding the milk production and milk processing operations are detailed in the final field investigative report.  A photo documentation and description of the photos is attached to this summary showing Dee Creek Farm surroundings, milk production and the area where bottling is conducted.

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Sample testing:

Milk samples were provided to WSDA through the Clark County Health Department who received product either from Dee Creek Farm representative Summer Steenbarger or other shareholders who provided product.  The five (5) milk products that were obtained by Clark County and submitted to WSDA for testing were analyzed for E.coli O157:H7, Listeria monocytogenes and Salmonella pathogenic bacteria.  All other samples were analyzed for E.coli O157:H7.

 A total of five (5) milk products were obtained from either Dee Creek or shareholders and provided to Clark County and submitted to WSDA for testing.

• One (1) partial filled gallon container of milk provided to Clark County via Dee Creek Farm after being returned to Dee Creek from a shareholder was received by WSDA on the morning of 12-14-05.  (WSDA Lab #05F-756)
   
• Two (2) milk products were received by WSDA in the late afternoon of 12-14-05 from Clark County health Department.  A skimmed cream milk product and a whey sample from making buttermilk were provided to the county via Dee Creek Farm and were reported to have come from a shareholder.  (WSDA Lab # 05F-762 -skimmed cream) and (WSDA Lab #05F-763 -Whey)
   
• Two (2) one-gallon milk products were received by WSDA on 12-19-05 from Clark County Health Department.  The samples were provided to the county directly from a shareholder.  The products were received in a frozen state and one container was dated 11-28 (WSDA Lab # 05F-788) and the other was dated 12-5 (WSDA Lab #05F-789)

 A total of five (5) water samples were collected from the farm. 

• Four (4) water samples were collected on 12-15-05

1)      Residential kitchen processing area sink. (WSDA Lab #05F-776)

2)      Cow water tank located in winter mudpack/pasture. (WSDA Lab #05F-777)

3)      Outside faucet between greenhouses. (WSDA Lab #05F-778)

4)      Lower pond at bottom of pasture. (WSDA Lab #05F-779)

•  One (1) water sample was collected on 12-16-05

1)      Belted Galloway beef cattle water trough (WSDA Lab #05F-782 and WSU tested)

 A total of thirty–two (32) environmental swab samples were collected at the farm.

• Twelve (12) environmental swab samples were collected on 12-15- 05.  (WSDA Lab # 05F-764 –05F-775)
   
• Twenty (20) environmental samples were collected on 12-16-05.  (These samples were analyzed at WSU and FDA labs.)

 Two sets of individual cow milk samples were tested.

• Five (5) individual cow milk samples were provided to WSDA by Dee Creek Farm through Clark County Health Department on 12-14-05.

The WSDA Lab sample numbers are:

#05F-757 –Sorrell
#05F-758 – Daisy
#05F-759 – Glory
#05F-760 – Pepper
#05F-761 - Lilly

• Five (5) individual cow milk samples were collected by WSDA after each milking on 12-16-05.

The WSDA Lab sample numbers are:

#05F-783 – Glory
#05F-784 – Lilly
#05F-785 – Sorrell
#05F-786 – Pepper
#05F-787 - Daisy

 Five (5) rectum anal mucosa samples were collected from each cow after milking was observed and collected on 12-16-05 by WSDA Animal Services Veterinarian Dr. Mark Kinsel.  These samples were tested at the WSU lab.

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Sample Results:

Positive E. coli O157:H7 test results occurred with the following seven (7) samples: 

1. One (1) partial filled gallon container of milk provided to Clark County via Dee Creek Farm after being return to Dee Creek from a shareholder was received by WSDA on the morning of 12-14-05.  (WSDA Lab #05F-756)
    
2. One (1) of the five (5) individual cow milk samples that were provided to WSDA by Dee Creek Farm through Clark County Health Department on 12-14-05.  (WSDA Lab #05F-757 – Sorrell)
    
3. One (1) of the twelve (12) environmental swab samples that were collected on 12-15- 05. 
   • Swab #2 - Topside of rubber mat in milking area, beneath where cows are milked. (WSDA Lab # 05F-765)
      
4. Three (3) of the twenty (20) environmental swab samples that were collected on 12-16- 05 and tested at the WSU Lab in Pullman, WA

• Swab #2 - Holding pen mud-pack/pasture at entrance to milking area.  (WSU #E11607)

• Swab #9 - Topside of rubber mat in milking area.  (WSU # E11608)

• Swab #10 - Mud on the ground just inside the door to the milking area.  (WSU # E11609)

5. One (1) of the twenty (20) environmental swab samples that were collected on 12-16- 05 and tested at the FDA Lab in Bothell, WA. 

• Swab #1 - Topside of rubber mat in milking area. (no FDA sample number available at the time of the report)

 These seven E.coli O157:H7 positive sample isolate results were then cross matched with human illness cases at the WDOH Public Health Lab located in Shoreline, WA.  All isolates were designated with the same Pulsed-field Gel electrophoresis (PFGE) pattern name as the outbreak pattern and are indistinguishable from the outbreak strain.  The WDOH Public Health Lab used standardized PulseNet methods.  Test results were provided to WSDA showing individual DNA fingerprint patterns for each isolate using two different restriction enzymes.  Both enzyme test results demonstrated that the WSDA samples matched the human case samples in this outbreak. 

 The WDOH Public Health laboratory reports show the matching DNA fingerprint patterns.

The results are identified by the following lab sample numbers: WDOH PHL # 9415, 9416, 9417, 9422, 9448, 9449 and 9469 are all human isolates and #9432-9435, 9450, 9451, 9470-9475, 9510 and 9511 are all samples collected from Dee Creek Farm.

Copies of the WDOH lab reports are attached to this summary [PDF 599KB]

Conclusions:

This WSDA FSP investigation along with the epidemiological work by the County Health Departments demonstrates that the illegal raw milk provided by Dee Creek Farms was the source of the E. coli O157:H7 that sickened at least 18 people in Washington and Oregon.

Report prepared and submitted by:

Claudia G. Coles
Food Safety Program Manager
Washington State Department of Agriculture

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