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Pennsylvania Raw Milk

Outbreak: Pennsylvania Raw Milk Campylobacter 
Product: Raw MilkInvestigation Start Date: 01/24/2012
Location: Maryland, New Jersey, West VirginiaEtiology: Campylobacter jejuni
Earliest known case onset date: 01/14/2012Latest case onset date: 02/01/2012
Confirmed / Presumptive Case Count: 81 / 67Positive Samples: 2

While it is legal to sell unpasteurized raw milk in Pennsylvania and illegal to sell in neighboring Maryland, New Jersey and West Virginia, this outbreak included cases in residents from all of these states. While additional regulations by state officials could be considered, such as monthly pathogen testing, that could reduce the risks associated with consumption of raw milk, the only way to prevent unpasteurized milk–associated disease outbreaks is for consumers to refrain from consuming unpasteurized milk.


The following is the abstract from the published article found here. The full, free text can be found here.

This multistate outbreak of campylobacteriosis was among the largest (148 confirmed and probable cases) nationally in recent years associated with consumption of unpasteurized raw milk and was epidemiologically and molecularly linked to consumption of certified unpasteurized milk from a Pennsylvania dairy.
15 unpasteurized milk samples obtained directly from the dairy during the investigation (but after most of the onsets of the cases) were negative for Campylobacter. However, 2 unopened retail samples collected from Maryland consumers tested at Maryland’s state public health lab, yielded C. jejuni with an indistinguishable PFGE pattern to all clinical isolates. This highlights the importance of testing food and environmental samples linked to actual exposure dates whenever available.
This outbreak occurred despite a state program implemented to reduce the risk associated with raw milk consumption. Although the dairy had tested for Escherichia coli O157:H7 more frequently than required by state regulations, those regulations for testing for other pathogens, such as Campylobacter, was only performed biannually.


Wilson’s Leather Spray

Outbreak: Leather Spray & Respiratory Illness 
Product: Wilson's Leather SprayInvestigation Start Date: 12/27/1992
Location: OR, WAEtiology: Acute Respiratory Illness
Earliest known case onset date: 12/21/1992Latest case onset date: 12/31/1992
Presumptive Case Count: 84Positive Samples: 0


On December 27th, 1992, reports filtered in over the course of several days that people were becoming ill following the use of an aerosol leather conditioner. Symptoms reported included prolonged cough, shortness of breath, pleuritic chest pain, headaches, malaise, chills, and fever. In total, reports increased to 400 persons, involving approximately 550 persons. The product, Wilson’s Leather Protector, was recalled by mid-day on December 27th. Six people were hospitalized.

Click the following link to view the CDC outbreak page.

From the Annals of the IOM

Episode 7: Wilsons Leather Spray. Click the play button to view our informational video on this outbreak!

Wilsons Leather Spray can.
Oregonian piece partway through the outbreak.
Symptoms included prolonged cough, shortness of breath, and pleuritic chest pain. Many persons also reported headaches, malaise, chills, and fever as high as 104 degrees Fahrenheit!
Following the public recall, as of December 31st, the number of preliminary reports to the Oregon Health Division and Oregon Poison Center of illness associated with use of this spray, increased to 400 and involved approximatey 550 persons in at least 17 states.
The technology was different, but it got the job done!


Sally Jackson Cheese

Outbreak: Sally Jackson Cheese 
Product: Raw milk goat, sheep, & cow cheesesInvestigation Start Date: 12/06/2010
Location: Multi-stateEtiology: E. coli O157:NM
Earliest known case onset date: 09/09/2010Latest case onset date: 11/26/2010
Confirmed Case Count: 8Positive Samples (Food / Environmental): 0 / 0


Oddly, none of the cases in this outbreak ever recalled the cheese by the brand name, even after investigators deduced the brand of cheese and questioned the cases about it specifically. It was fortunate that investigators could make a compelling case with largely circumstantial evidence that was later bolstered by laboratory and environmental evidence. Following a recall, the Sally Jackson facility closed permanently.


E. coli O0157:NM Outbreak Associated with Artisan Cheese from Sally Jackson Cheese

On December 6, 2010, routine follow-up interviews, conducted by the Oregon Public Health Division, on 2 patients diagnosed with E. coli O157 infection with indistinguishable PFGE patterns, positive for both Shiga toxins stx-1 and stx-2, revealed that they had both patronized ClarkLewis a local farm to table-style restaurant in Portland, Oregon.

Menus were reviewed, and the only item in common to both cases was an unspecified selection of artisanal cheeses. As the chef was not able to identify which cheeses were served on cases’ meal days, Oregon Public Health Division staff reviewed their invoices from the past 2 weeks to determine which cheeses could have been served. Staff also queried the national laboratory network, PulseNet, to identify possible additional cases. Cases were defined as patients with PFGE-matching E. coli O157 isolates since July 2010. Investigators reviewed interview records; menus; sales records; and shipping invoices from restaurants, retailers, and food distributors; patients were reinterviewed as necessary. Food samples were assayed.

Eight cases were identified from Oregon (1); Washington (4); Vermont (1) and Minnesota (2). Median age was 39 (range, 22–69) years, and 5 were female. All patients had diarrhea with onset during September–November 2010. Two patients were hospitalized; none had HUS; none died.

One Washington State resident was lost to follow-up. The Oregon resident and one Washington resident reported cheese exposures at ClarkLewis on November 12 and November 13, 2010; 8 different artisanal cheeses were potentially served those days. One Washington resident reported consumption of cheeses at a wedding in northeastern Washington on September 5, 2010, where locally bought goat, sheep and cow cheeses where served; the Sally Jackson facility was located a few miles from the northeastern Washington wedding location. Another Washington resident tasted various artisanal cheeses at Calf & Kids cheese shop in Seattle on November 21. The Vermont resident had visited a relative in Washington State and partook of a cheese plate at Palace Kitchen restaurant in Seattle on October 23, 2010. The 2 Minnesota residents had onset dates of September 26 and October 8, 2010; one was a member of a cheese club, and the second recalled having eaten artisanal cheeses. Altogether, 7 cases reported consumption of artisanal cheeses, but none recalled specific varieties or brands. Invoices from ClarkLewis suggested 8 cheeses that could have been served, including Sally Jackson raw goat cheese.

Review of invoices from the distributor indicated that Sally Jackson cheeses were also sold at Calf & Kids in Seattle and at Palace Kitchen. Invoices from Palace Kitchen indicated that they could have carried Sally Jackson’s raw sheep cheese when the Vermont resident ate there. The Sally Jackson distributor also supplied ClarkLewis, and invoices indicated that the cheeses were sold to ClarkLewis on November 10 (and potentially served on November 12 and 13). Those cheeses had been received by the distributor on September 28, indicating that a single contaminated batch released for consumption in September could have accounted for all cases. Three additional restaurants (2 in Washington, 1 in Oregon) that received the same September batch were identified, and leftovers were collected for testing.

Based on this information, investigators decided to visit the cheese production site to assess whether any violations were occurring that might contribute to the contamination of the cheese. Officials of the Washington Department of Agriculture (WDA) and the U.S. Food and Drug Administration (FDA) visited the Sally Jackson facility on December 10, 2010. Sally Jackson was producing raw milk cheeses from its own goats, sheep and cows. Goat cheeses were wrapped in grape leaves, while sheep and cow cheeses were wrapped in chestnut leaves. Both types of leaves were from the trees surrounding the facility. Multiple hygiene violations were identified, including improper handwashing after contact with livestock (before making cheese); kitchen well-water source for food and food surfaces that was not in microbiological compliance; unsanitary non-food areas (e.g., manure on the floor, black mold deposits on the ceiling); suitable outer garments not worn (owner wore manure-soiled clothing during cheese production). Cheeses were unlabeled, and no lot or code numbers had been assigned. The owner was unable to identify the production dates of the cheeses but was able to identify those aged more than 60 days and those less. Employee food handling and hygiene practices were reviewed, potential source of contamination were assessed, and multiple cheese samples were collected for testing.

Despite the fact that no cases could name a specific cheese product and before any laboratory results were available, suspicion was sufficient to take public health actions. Sally Jackson had a limited but multi-state distribution and voluntarily recalled products nationwide on December 20, 2010; FDA released the information to the news media. PFGE-matching E. coli O157 was subsequently cultured on December 20 from raw cheeses collected at the Sally Jackson facility and restaurants.

The bride’s family confirmed that the cheeses served at the wedding had been bought from Sally Jackson, and invoices from the distributor in Minnesota indicated that the 2 Minnesota cases could have been exposed to Sally Jackson products.

Sally Jackson cheeses were the source of this outbreak of E. coli O157:NM.
Though the raw milk could have been contaminated at the timing of milking, direct raw milk contamination also could have occurred as multiple obvious hygiene violations were identified (i.e., improper handwashing, manure-soiled clothing). Additionally, the cheeses could also have been contaminated from the leaves in which they were wrapped. Following the recall, the Sally Jackson facility closed permanently.


Salmonella and backyard poultry

Outbreak: Salmonella and backyard poultry 
Product: Chicks, chickens, ducks, ducklingsInvestigation Start Date: 06/26/15
Location: Multi-stateEtiology: Salmonella Enteritidis, Salmonella Hadar, Salmonella Indiana, & Salmonella Muenchen
Earliest known case onset date: 01/03/2015Latest case onset date: 09/07/2015
Confirmed Case Count: 252Positive Samples: 0


In January 2015, a coast to coast outbreak infected 252 people with four different strains of Salmonella infections: Salmonella Enteritidis, Salmonella Hadar, Salmonella Indiana, and Salmonella Muenchen. By the end of the outbreak on September 6th, 2015, all but 7 U.S. states had at least one person ill. 63 people were hospitalized but thankfully no one died. Click the following link to view the CDC outbreak page.

From the Annals of the IOM

Episode 4: Salmonella and Backyard Poultry. Click the play button to view our informational video on this outbreak!

CDC outbreak map.
Epi curve for the outbreak.
The International Outbreak Museum exhibit, next to Bill Keene action figure.


Cold Stone

Outbreak: Cold Stone Cake Batter Ice Cream 
Product: Cake Batter Ice CreamInvestigation Start Date: 06/29/2005
Location: Multi-stateEtiology: Salmonella Typhimurium
Earliest known case onset date: 05/21/2005Latest case onset date: 07/04/2005
Confirmed / Presumptive Case Counts: 25 / 0Positive Samples (Food / Environmental): 2 / 0


The vehicle for this outbreak was ice cream made with a contaminated cake mix ingredient. Four patients reported eating cake batter flavor ice cream from two separate outlets of Cold Stone Creamery.


Salmonella Typhimurium Outbreak Associated with Cake Batter Ice Cream from Cold Stone Creamery

On June 29, 2005, the Minnesota Department of Health identified four Salmonella Typhimurium isolates with a pulsed-field gel electrophoresis (PFGE) subtype that was new to the PulseNet national database. Four patients reported eating cake batter flavor ice cream from two separate outlets of Cold Stone Creamery.

The PulseNet national database was queried to identify potential cases in other states. A case was defined as infection with an S. Typhimurium isolate that matched the outbreak PFGE pattern, and illness onset since May 2005. All cases were interviewed with a standard questionnaire. State and federal officials conducted a traceback of ice cream ingredients.

We identified 25 cases in nine states (MN, 5; OR, 5; WA, 5; VA, 3; OH, 2; CA, IL, MA, MI, PA, 1 each); 24 reported eating cake batter ice cream from Chain A. The median age of cases was 13years (range, 2–32 years). The median incubation was 4 days (range, 1–7 days). Illness onset dates ranged from May 21 to July 4; four cases were hospitalized. Cold Stone Creamery voluntarily recalled cake batter ice cream on July 1. This flavor’s ingredients included a pasteurized liquid sweet cream base and Gold Medal Super Moist yellow cake mix. The sweet cream base was used in numerous other ice cream flavors, but the cake mix was used only in cake batter ice cream. The cake mix comprised spray-dried egg whites, flour, and several low risk components. Tracebacks in Minnesota, Oregon, and Virginia implicated a single lot of cake mix produced on April 14, 2005. No manufacturing anomalies were identified for this lot; but two cake mix samples yielded the outbreak strain of S. Typhimurium. The Food and Drug Administration warned food retailers that cake mixes and flour are not considered “ready to eat” and should be heat processed before consumption.

The vehicle for this outbreak was ice cream made with a contaminated cake mix ingredient. While the ultimate source of contamination was not confirmed, we recommend a review of the efficacy of spray-drying egg whites as a kill step for Salmonella. Routine and rapid subtyping of bacterial isolates, coupled with a vigorous epidemiological response, is critical to identifying and abating multi-state outbreaks.