Tracy Stiles
Foodborne Disease Surveillance Laboratories
Massachusetts Department of Public Health
Listeria Outbreak in Massachusetts
y Only the third outbreak in 30 years where pasteurized milk was implicated in human infection with L.monocytogenes
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Home > Listeria, Outbreaks, Recalls, Whittier Farms Lawsuit > 16 Listeria Samples Found at the
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January 18, 2008 | Posted By Pritzker | Ruohonen | Comments |
16 Listeria Samples Found at the Whittier Farms Milk
Processing Plant
The Massachusetts Department of Public Health (MDPH) continues its
investigation into the Listeria outbreak linked to contaminated Whittier
Farms milk. According to the MDPH, additional samples of milk products
and several environmental samples taken at the Whittier Farms milk
processing plant have tested positive for Listeria monocytogenes.
The following is from a MDPH press release regarding this Listeria outbreak.
The processing plant, located in Shrewsbury, Massachusetts remains closed and will not re-open
until cleared to do so by the MDPH Food Protection Program and U.S. Food and Drug
Administration (FDA) Regional Milk Specialists.
Massachusetts public health officials also continue to work with other agencies, including U.S.
Food and Drug Administration and the Massachusetts Department of Agricultural Resources to
complete the investigation and review whether changes are needed in current state regulations or
in the federally mandated inspection and testing processes for dairy farms and plants.
Summary of Listeria Positive Laboratory Tests
Sample
Description
Listeria Strain
Coffee flavored milk
Glass, Quart
A*
Coffee flavored milk
Glass, Quart
A*
1% Chocolate flavored milk
Plastic, 8 oz.
A*
Chocolate flavored milk
Plastic, 8 oz.
A*
Chocolate flavored milk
Plastic, Pint
A*
Vanilla flavored milk
Glass, Quart
A*
Strawberry flavored milk
Plastic, 8 oz
A*
Skim milk
Glass, Quart
A*
1% Chocolate flavored milk
Glass, Quart
B**
Coffee flavored milk
Glass, Quart
B**
1% milk
Glass, Quart
B**
2% milk
Glass, Quart
C**
* Denotes Listeria strain consistent with outbreak strain
** Denotes Listeria strain not consistent with outbreak strain or known human cases
Environmental Samples
Description
Listeria Strain
Environmental Swab 1
Floor near homogenizer
A*
Environmental Swab 2
Drain in fill room
D**
Environmental Swab 3
Bottle washer washband
E**
Environmental Swab 4
Empty unwashed bottle
F**
* Denotes Listeria strain consistent with outbreak strain
** Denotes Listeria strain not consistent with outbreak strain or known human cases
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Email Address:
Listeria Statistics
Massachusetts
y MA sees ~30 cases of Listeriosis each year
y In 2007:
y
23 isolates were received at SLI
y
y
Several isolates not received at lab
19 different Asc I patterns
y Total Database (MA)
y
y
225 entries of Listeria
190 different Asc I patterns
Listeria 2007 All MA
Dice (Opt:1.50%) (Tol 1.5%-1.5%) (H>0.0% S>0.0%) [0.0%-100.0%]
100
PFGE-A PFGE-AscI
PFGE-ApaI
June 2007
Patient 1
Unique pattern
in MA
No action taken
October 2007
Patient 2
Match to
June
Patient
November 2007
Both match by PFGE
Per CDC—No other matches
Appears to be local cluster
Epi notified
Post to Webboard
CDC Response:
Isolates >120 days apart
No Cluster ID
Where did it come from?
y November 2007
Family of one patient implicated unpasteurized cider
y LBOH visited home y Collected cider (which had been pasteurized)
y Also took a bottle of flavored milk
y
y
Family reported patient drinks this milk regularly
L. mono isolated from milk
y PFGE match to 4 patients
y
y Did the milk contaminate the patient or did the patient contaminate the milk?
The Investigation begins…
y November 2007
y MA FPP visited local dairy where milk was processed
y Collected 11 milk samples (raw and sealed flavored and non‐flavored)
y Also collected environmental swabs
y L. mono isolated from one flavored milk sample
y
y
Same flavor as from patient’s home
PFGE match to all cases
MA Press Release 12/27/08
T HE COMMONW EALTH OF MASSACH USETTS
EXEC UTIVE O FFICE OF HEALTH AN D H UMAN S ERVICES
DEPARTMENT OF P UBLIC H EALTH
250 W ASH INGTON STREET, BOSTON, MA 02108-4619
DEVAL L. PATRICK
GOVERNOR
TIMOTHY P. MURRAY
LIEUTENANT GOVERNOR
JUDYANN BIGBY, M.D.
SECRETARY
JOHN AUERBACH
COMMISSIONER
FOR IMMEDIATE RELEASE:
December 27, 2007
CONTACT:
Donna Rheaume
617-624-5006
DPH ISSUES CONSUMER WARNING FOR MILK PRODUCTS SOLD AT WHITTIER FARMS IN
SHREWSBURY
DPH Issues Consumer Warning for Milk Products Sold at Whittier Farms in Shrewsbury
Boston — The Department of Public Health (DPH) is issuing a warning to consumers not to drink any milk
products from Whittier Farms in Shrewsbury because of listeria bacteria contamination.
Investigation
y December 2007
Plant voluntarily recalled all products and ceased operations
y Many conference calls held with Lab, Epidemiology, FPP, and DEP
y
y
y
y
y
Calls detailed lab reports to date, epi findings to date, and past inspections of the processing plant
Plant was compliant with all regulations
Plant in good repair
Dairy owners in full cooperation with investigators
History of the plant
y
y
y
y
Family owned farm and processing plant
Routinely inspected by MDAR
Compliant with FDA IMS Program
Milk comes from the families own cows
y 300 cow herd
y Supplemented with another dairy (also compliant with MDAR and IMS program)
y Milk is shipped from farm to plant via dedicated milk truck owned by the family
y Truck sanitized routinely with “clean in place” procedure
y
Compliant with all regulations
y Process ~3500lbs of milk 3 days/week
y Product is distributed to customers via home delivery and 2 retail stores at farm and plant
y Bulk cream is distributed out of state for use in baked goods
Inspection
y FPP visited plant for a full environmental inspection
y
y
Cooperation with FDA and LBOH
Inspection occurred over multiple days
Collected more than 100 samples of milk and environmental swabs
y Conducted review of all procedures, mandatory recording charts, inspection of facilities, and sanitizing process
y
Full Inspection
Day 1
y Focused on pasteurization charts and equipment April 1, 2007‐
December 27, 2007
y Observations included:
y
y
y
y
tools used to measure and mix flavored syrups on raw side of plant stored open and exposed to air
Condensation was observed on the ceiling in front of 2 raw mixing batching tanks
y Dripping to create pooled water on floor
Open‐ended milk bypass piping stored on a wall adjacent to raw milk separator unit
y Internal inspection showed sour odor and soil in gasket area
Floor mat in front of raw milk product pump showed residual milk and sour odor underneath
Day 2 of Inspection
y Inspected piping and processing downstream of processor
y Yellow‐brown deposit on internal surface of valve
y Rough, raised weld on interior surface of pipe to storage tank
y Rubber plug valve on a storage tank pitted in milk contact area
y Raised inner weld on discharge pipe from pump supplying milk to filler machine
y Floors uneven and cracked in several areas in front of 2 pumps used to transfer pasteurized product to filling machine
y Deteriorating floor by floor drain in front of homogenizer
Day 3 of Inspection
y FPP intended to evaluate bottle washer
y Found it to have been disassembled to initiate maintenance
y Instead inspected the pasteurizer while bottle washer was reassembled
y Continuous HTST milk pasteurizer
y
y
y
High temperature short time
Milk is held at 161°F for 15 sec
Any flavorings are added post‐pasteurization
y
Milk is then pasteurized again
y Equipment compliance testing is done every 90 days
y All pasteurization was found to be in compliance with PMO
Day 3 (Continued)
y Plant Inspection
y Condensate observed on day 1 had been repaired
y Closed sanitary lubricant for milk contact surfaces was stored in an y
y
y
y
unclean container
Cracked cement floor with mold on ceiling, upper walls, and plastic strip curtains in milk product cooler
y Lower walls in cooler showed wear
Deteriorating floor surface near floor drain next to a raw product tank
y Several feet away from pump that is used to transfer pasteurized
product to the filler
Deteriorating floor (raised and cracked) directly below glass bottle filler
Pointed wooden stick on cap applicator
y Used to unclog caps from cap chute on filler machine
Day 3 Plant Inspection (Continued)
y
Mold formation on walls of bottle washer room
y
y
Possibly due to inadequate ventilation
In raw milk room, a hose was observed hanging on the wall
y
y
y
y
Uncapped, unprotected, cracked
Connected to public water supply
Used for sanitizing equipment
Water sample was collected from hose
Day 4 of Inspection
y Majority of swabbing and sampling occurred
Dairy had private lab swab duplicate areas
y Observations
y Dripping water from ceiling
y
y
y
Observed in raw milk storage area
Observed in filling area adjacent to fill milk valves
Plastic milk cases were soiled
y Bottle washer had been reassembled
y
y
Conveyor “fingers” that move the bottles appeared unclean
Final Inspection Day
y Bottle washer documentation was reviewed
No violations to sanitizer concentrations or recording
y Additional Observations
y Bottle washer drains into pipe that terminates in the bottle filling room
y Milk cases are cleaned by hand by the bottle washer
y New glass bottles stored open in a trailer
y
y
y
Inside was damp with visible mold growth and evidence of rodent droppings
Bottles are all washed prior to use
The Commonwealth of Massachusetts
MDPH Press Release
Update
1/2/08
Executive Office of Health and Human Services
Department of Public Health
250 Washington Street, Boston, MA 02108-4619
FOR IMMEDIATE RELEASE:
January 2, 2008
DEVAL L. PATRICK
GOVERNOR
TIMOTHY P. MURRAY
LIEUTENANT GOVERNOR
FURTHER INFORMATION:
Tom Lyons (617) 624-5275, or
Donna Rheaume (617) 624-5006
JUDYANN BIGBY, MD
SECRETARY
JOHN AUERBACH
COMMISSIONER
**UPDATE**
MDPH CONTINUES LISTERIA INVESTIGATION
Whittier Farms Dairy Processing Plant remains closed while state and federal health officials
continue to investigate the source of contamination
BOSTON – The Massachusetts Department of Public Health (MDPH) is continuing its public
health investigation of listeria contamination in milk products from Whittier Farms Dairy.
Whittier Farms operates a dairy farm in West Sutton, Massachusetts, as well as a dairy
processing plant and retail outlets at the farm and in Shrewsbury, Massachusetts. A source of
contamination at the processing plant has not yet been identified.
Four cases of listeriosis infection have been identified by DPH. The cases occurred in June,
October and two in November. The four cases involved three elderly individuals and a pregnant
woman. Two elderly men have died as a result.
DNA fingerprinting conducted by the State Laboratory Institute showed that the bacteria causing
these infections came from a common source. Whittier Farms milk product samples collected
from a patient’s home and from Whittier Farms showed listeria contamination. The DNA
fingerprints of the listeria found in the milk samples and in the patients were the same.
There have been no new cases of listeriosis confirmed as linked to this outbreak.
“State and federal regulatory health officials have initiated an environmental investigation at the
facility that includes a thorough examination of the plant and its production equipment, as well
as their pasteurization, packaging, cleaning and sanitization procedures. The state will also be
conducting environmental and product testing for listeria before the dairy is allowed to begin
operations again.” said Suzanne Condon, Director of MDPH’s Environmental Health Bureau.
Whittier Farms has voluntarily suspended operations and distribution until the source of
contamination is identified and corrected. The company has contacted all known customers and
distributors of its products and informed them about the situation. A public health advisory was
released by MDPH on December 27 to warn non-home delivery customers who may have
purchased products in retail outlets and retained them at home to discard these products
immediately.
Results y L.mono grew out of 8 milks and one environmental swab
y
Positive swab was taken from floor drain near a homogenizer unit
y
y
y
Close proximity to where raw milk equipment was cleaned
Inspection showed floor surface around the drain was pitted and had pooled water
PFGE matched all cases
y An additional 4 milks and 2 swabs grew Listeria
(L.mono and other species) that did not match cases by PFGE
y
Positive swabs from shield in bottle washer and fill room floor drain
Enumeration Results
Code/date
Date of
initial
dilution
Most
probable
number,
organisms/
mL
plastic,
8 oz
1/6/2008
1/11/2008
460
JH
4929
chocolate
milk,
Whittier
Farm
plastic,
pint
12/31/2007
1/11/2008
>1100
08F030
JH
4930
vanilla
milk,
Whittier
Farm
glass,
quart
12/31/2007
1/11/2008
>1100
08F034
JH
4934
chocolate
milk
plastic,
8 oz
1/3/2008
1/11/2008
>1100
08F007
JH
4906
1%
chocolate
quart
glass
12/31/2007
1/11/2008
>1100
08F017
JH
4917
coffee milk
quart
glass
1/10/2008
1/11/2008
>1100
08F003
JH
4902
1% milk
quart
glass
1/3/2008
1/11/2008
>1100
08F004
JH
4903
2% milk
quart
glass
12/31/2007
1/11/2008
>1100
08F016
JH
4916
skim**
quart
glass
1/10/2008
1/15/2008
46,000
08F017
JH
4917
coffee milk
quart
glass
1/10/2008
1/15/2008
460,000
State
Lab ID
number
08F028
08F029
Inspect
or
number
Sample
description
Type of
contain
er
JH
4928
1%
chocolate,
Whittier
Farm
Dic e (Opt:1.50% ) (Tol 1.5%-1.5%) (H>0.0% S>0.0%) [0.0%-100. 0% ]
PFGE-AscI
100
50
PFGE-As cI
ENVIRONMENTAL SW AB
ENVIRONMENTAL SW AB
ENVIRONMENTAL SW AB--COOLER FAN
ENVIRONMENTAL SW AB--CENTRAL COOLER FAN#2
ENVIRONMENTAL SW AB-FLOOR DRAIN, RAW MILK TANK OF HTST PROCESSOR
ENVIRONMENTAL SW AB-FLOOR DRAIN, RAW MILK TANK OF HTST PROCESSOR
ENVIRONMENTAL SW AB
ENVIRONMENTAL SW AB-FLOOR DRAIN, RAW MILK TANK OF HTST PROCESSOR
ENVIRONMENTAL SW AB--BOTTLE WASHER
ENVIRONMENTAL SW AB--BOTTLE WASHER
ENVIRONMENTAL SW AB--POOLING WATER IN FRONT OF RAW TANK COFFEE
ENVIRONMENTAL SW AB--FILL ROOM FLOOR DRAIN
ENVIRONMENTAL SW AB--FILL ROOM FLOOR DRAIN
1% CHOCOLATE
CHOCOLATE MILK
VANILLA MI LK
CHOCOLATE MILK
ENVIRONMENTAL SW AB--FLOOR
ENVIRONMENTAL SW AB
SKIM MILK
SKIM MILK
SKIM MILK
SKIM MILK
STRAWBERRY MILK
STRAWBERRY MILK
STRAWBERRY MILK
STRAWBERRY MILK
STRAWBERRY MILK
1% CHOCOLATE
COFFEE MILK
2% MILK, QT. GLASS
2% MILK, QT. GLASS
1% MILK
STRAWBERRY MILK
MDPH Press Release
Update #3
1/17/08
THE COMMONWEALTH OF MASSACHUSETTS
EXECUTIVE OFFICE OF HEALTH AND HUMAN SERVICES
DEPARTMENT OF PUBLIC HEALTH
250 W ASHINGTON STREET, BOSTON, MA 02108-4619
DEVAL L. PATRICK
GOVERNOR
TIMOTHY P. MURRAY
LIEUTENANT GOVERNOR
JUDYANN BIGBY, M.D.
SECRETARY
JOHN AUERBACH
COMMISSIONER
FOR IMMEDIATE RELEASE:
January 17, 2008
CONTACT:
Donna Rheaume
617-624-5006
** UPDATE NO. 3** STATE RELEASES WHITTIER FARMS LABORATORY
SAMPLE RESULTS
Environmental and milk products test positive for Listeria. Milk processing plant will remain
closed until cleared by health officials.
BOSTON — As part of its on-going investigation of a Listeria monocytogenes (Listeria)
outbreak linked to contaminated milk, the Massachusetts Department of Public Health (MDPH)
said today that additional samples of milk products and several environmental samples taken at
the Whittier Farms milk processing plant have tested positive for Listeria.
The processing plant, located in Shrewsbury, Massachusetts remains closed and will not re-open
until cleared to do so by the MDPH Food Protection Program and U.S. Food and Drug
Administration (FDA) Regional Milk Specialists.
One environmental swab, one sample of skim milk and seven flavored milk samples tested
positive for the same strain of Listeria found in four of the five cases linked to this outbreak. No
sample was available to test in the fifth case linked to the outbreak — a 31 year-old pregnant
woman from Middlesex County who drank Whittier milk products and was diagnosed with Corrective Action
y Letter requesting corrective action was sent to the plant
y Outlined all observed violations
y February 1, 2008 y Dairy announced publicly it would not reopen the processing plant
y Attributed to the financial burden of making necessary corrections
Epidemiology y 4 lab confirmed cases June‐November
y Age range 31‐87 years
y 3 males, one female
June patient consumed skim milk from this dairy regularly
y October patient had no obvious exposure to milk
y 1 November patient regularly drank flavored milk from this dairy
y 1 November patient was unable to be interviewed (numerous attempts were made) y
Epidemiology
y Epidemiology Investigation identified one additional case in September
y Pregnant woman presented with listeriosis
y L. mono was isolated
y Isolate never sent to lab
y Patient reported milk consumption from this dairy y Epi‐linked not PFGE‐linked
Summary of Cases
y
y
y
y
y
Cases range June‐November
5 cases
3 adult deaths 1 late term miscarriage
1 premature c‐section resulting in healthy baby
Laboratory Strengths y MA PFGE Lab is Rock Solid!
y Diligent in finding match even though it was >120 days
y Followed all protocols including epi notification, posting to webboard
y Continued to monitor for this strain
y Great teamwork among all labs y PFGE, Food, Dairy, Enteric, Reference Labs
y All staff ready and willing to help out wherever needed
Laboratory Weaknesses y MA Food Lab needed help
The “forgotten lab” in Massachusetts
y Lab tested ~100 samples/year
y
y
y
y
y
Mainly extraneous materials, little pathogen testing
Protocols had been altered
Results improperly documented
More testing done for this outbreak than any of the previous years
After 1st set of samples, BT‐FERN staff was enlisted to assist (Assisted in the 100+ samples)
y Much potential for the future
y
Lessons Learned‐Epidemiology
y What about case in September?
y
If it had been sent to lab, would we have identified the outbreak sooner?
y
y
y
MA will begin focusing on re‐education of the local labs
MA Regulations now state all isolates of L.mono are to be forwarded to the state lab immediately (within 48 hours) MA Regulations are being updated to make all submissions required
Up to now, it is not mandatory y Still difficulty in getting interviews from this population
y
Lessons learned‐Inspection
y Several distinct strains of Listeria were found in product samples and environmental samples
y Suggests post‐pasteurization contamination can go undetected
y Facility design likely contributed to intermittent post‐pasteurization contamination from equipment and environment
y Equipment met FDA standards for time, temp, and flow for pasteurization
y Is this enough to ensure a safe milk supply?
y
y
y
y
Plant had no environmental monitoring program for L.monocytogenes
Not required, but should it be?
Often done at larger facilities
Special concern for ready‐to‐eat foods with a longer shelf life
y Listeria will multiply at refrigeration temperatures
y Is a physical inspection of the plant part of routine inspections?
Acknowledgments
y Massachusetts Lab Staff
PFGE Lab
y BT‐FERN Staff y Media Room Staff
y Reference Lab Staff
Massachusetts Epidemiologists
Massachusetts Food Protection Program
Massachusetts DEP
Massachusetts Hospital Labs
y If they had not submitted the isolates we would never have found
the outbreak!
y
y
y
y
y
y Local Board of Health