Pork supply chain failures identified in 2014 E. coli outbreak

During July–October 2014, 119 cases of E. coli O157:H7 infections associated with exposure to contaminated pork occurred in Alberta, Canada.

Twenty-three (19%) patients were hospitalized, six developed hemolytic uremic syndrome (HUS) but no deaths were reported.

Multiple contamination and mishandling findings​

E. coli O157:H7-contaminated pork and production environments and mishandling of products was identified at all key points in the distribution chain, including slaughter, processor, retail and restaurant facilities.

The pulsed-field gel electrophoresis (PFGE) cluster pattern was found in clinical and pork E. coli O157:H7 isolates.

Eighteen E. coli O157:H7-positive samples were obtained including from the pork production environment (1); pork production equipment (5); pork carcass (1); raw fresh pork (4); raw frozen pork (1); raw marinated pork (3); and a delivery vehicle (1) in a slaughter facility, two processing/distribution facilities, one restaurant and two private dwellings.

The outbreak represented the second largest foodborne E. coli O157:H7 outbreak in Canadian history after one associated with salami produced in British Columbia in 1999.

However, the originating source of the contamination was not confirmed.

Control measures included recalls, destruction of products, temporary facility closures, interventions to mitigate improper pork-handling practices, and prosecution of a facility operator.

Regulatory agencies inspected 201 food facilities to inform the investigation.

The local health department ordered one slaughter/retail facility, two processor/distributor/retailers and one restaurant to temporarily close.

At the slaughter facility, inconsistent personnel hygiene practices and poor knowledge of food safety were identified.

Link to pork​

Informed by case interviews, seven potential food sources (mung bean sprouts, beef, carrots, cucumbers, green onions, lettuce and pork) were identified and investigated.

The majority of patients reported having meals containing pork at Asian-style restaurants in multiple geographic Alberta cities during the exposure period.

Exposure to food at Alberta Asian-style restaurants (36 facilities across the province) was reported by 85 (74%) of the 115 primary outbreak patients.

Cross-contamination was an important contributing factor as seen by absence of known pork exposure in 35% of cases.

Such opportunities related to sharing of animal pens, inadequate cleaning and sanitation of knives or equipment between carcasses and close proximity of carcasses during slaughter.

“Based on the findings of this investigation, pork should be considered a potential source in public health E. coli​​ O157:H7 investigations and prevention messaging, and pork handling and cooking practices should be carefully assessed during regulatory food facility inspections​,” said the researchers.

Four cases were associated with chicken sausage from one facility; analysis identified E. coli O157:H7, detected pork and did not detect poultry.

Investigation revealed the chicken producer had purchased pork fraudulently labeled as chicken by an illegal distributor linked to a facility in the Alberta pork supplier network.

The distributor was issued court orders to close the business and appear for questioning. The operator failed to appear and an arrest warrant was issued.

Botulism in alcohol​

Meanwhile, an outbreak of botulism that sickened 31 people linked to prison-made illicit alcohol in June last year shows the spectrum of illness, according to researchers.

The botulism outbreak, the largest in the US since 1978, highlighted the variety of illness type, ranging from total paralysis requiring intensive care and mechanical ventilation to cranial nerve complaints not requiring hospitalization.

Prison staff suspected that an alcoholic beverage, illicitly made by inmates and known as “hooch” or “pruno,” was the source.

Although they confiscated >20 gallons of hooch during the investigation, the number of circulating batches before the outbreak and ingredients and preparation method of the batch responsible, are unknown.

One patient said honey, potatoes, apples, and tomato paste from a bulging can were combined, hidden and fermented in a sealed plastic bag at room temperature for three to five days.

Thirty-one cases were identified, including 19 confirmed (18 in Mississippi and one in Oklahoma), 10 probable (nine in Mississippi and one in Texas), and two suspected in Mississippi.

By the end of the outbreak, 24 inmates were hospitalized, including 15 admitted to an intensive care unit and nine who required intubation and mechanical ventilation; none died.

Twenty received botulinum antitoxin and 11 with mild illness did not receive antitoxin.

Source: Can Comm Dis Rep. 2017:43(1):21-4

“Escherichia coli​ O157:H7 Infections associated with contaminated pork products - Alberta, Canada, July‑October 2014”​

Authors: Honish L, Punja N, Nunn S, Nelson D, Hislop N, Gosselin G, Stashko N, Dittrich

Source: MMWR Morb Mortal Wkly Rep 2017; 65:1491–1492

“Notes from the Field: Botulism Outbreak from Drinking Prison-Made Illicit Alcohol in a Federal Correctional Facility - Mississippi, June 2016”​

Authors: McCrickard L, Marlow M, Self JL, et al