Eleven months after the FDA found Listeria contamination at an Almark Foods hard-boiled egg production plant, the CDC is announcing an ongoing outbreak linked to the eggs. Illnesses began in 2017.

As of today, seven people in five states have been confirmed infected with the outbreak strain of Listeria monocytogenes, according to the announcement from the Centers for Disease Control and Prevention. One of the patients died and four had to be admitted to hospitals.

“Epidemiologic and laboratory evidence indicates that bulk hard-boiled eggs produced by Almark Foods of Gainesville, GA, are a likely source of this outbreak,” the CDC reported. “Three of these people reported eating hard-boiled eggs in deli salads purchased from grocery stores and in salads eaten at restaurants.

“. . . Retailers and foodservice operators should know who supplies their bulk hard-boiled eggs. Consumers will not be able to tell if products they’ve purchased from stores contain these eggs, so it is important that people at higher risk for Listeria infections follow the advice listed below.”

The implicated eggs were packaged in plastic pails for use nationwide by food service operators, according to the CDC.

In the outbreak announcement the CDC referenced a February inspection at the production plant that was conducted by the Food and Drug Administration. That inspection is described in an FDA warning letter sent to the company in July. 

The FDA found the outbreak strain of Listeria in two locations at the plant. One was from a food contact surface and the other was from the floor in another room.

“. . . two isolates, collected from two different zone locations are genetically identical to each other, which suggests possible cross-contamination between the locations. Further, the WGS (whole genome sequencing) analysis of the strain also showed that the isolates are genetically identical to two cases of human illness dating back to 2017,” according to the FDA’s warning letter to Almark Foods.

Today’s outbreak announcement from the CDC reports that the agency discovered the outbreak illnesses when it found that two Listeria samples that had been uploaded by the FDA to the PulseNet database were the same as Listeria samples that had previously been collected from sick people. 

“These results provide additional evidence that people in this outbreak got sick from eating hard-boiled eggs produced by Almark Foods,” according to the CDC announcement.  

So far the CDC has found three people from 2017 and four people from this year who have been infected with the outbreak strain of the pathogen.

“Listeria specimens from ill people were collected from April 10, 2017, to Nov. 12, 2019,” the CDC reported. “Ill people range in age from less than 1 to 82 years, with a median age of 75. . . One illness was reported in a newborn who was infected with Listeria while the mother was pregnant, but the newborn survived.”

There is uncertainty about whether the implicated eggs are still in the supply chain. Almark recalled some products, according to the FDA warning letter, but a search of the agency’s recall database did not return any results for a recall by the company.

The FDA’s practice is to wait for companies to publicly post recall notices elsewhere before posting them on the agency website. It is not uncommon for business-to-business recalls to not be posted by FDA because recalling firms do not release the information to the general public.

The outbreak investigation is ongoing, according to the CDC. Investigators are collecting records from grocery stores and restaurants where outbreak patients reported eating hard-boiled eggs. 

“Investigations are ongoing to determine and document the distribution and production chain, as well as the source of hard-boiled eggs to the locations reported by ill people,” the CDC reported.

With the most recent patient having been discovered in November, there is a good chance that more will be identified because it can take up to 70 days after exposure for symptom of Listeria infection to develop.

FDA’s inspection findings
Inspectors from the FDA were at the Almark hard-boiled egg production plant from Feb. 5 through 13 this year, according to the agency’s warning letter dated July 22. They collected environmental swab samples from various locations and equipment in the facility. 

Two swabs were positive for the outbreak strain of Listeria monocytogenes. Inspectors collected those samples from a floor drain in the peeling room and from “the egg counter entrance and stainless-steel area at the end of the conveyor belt.  This location is a food contact surface,” according to the warning letter.

“The presence of L. monocytogenes in your facility is significant in that it demonstrates your sanitation efforts are inadequate to effectively control pathogens on your processing equipment to prevent contamination of food.

“We are aware that you have recalled products and initiated a study by the (redacted by FDA) to validate your use of a (redacted by FDA).  We will verify the implementation of your corrective actions and their adequacy during the next FDA inspection.”

Additional points included in the FDA’s warning included:

  • Prior to packaging, pails of cooked, peeled (redacted by FDA) eggs were removed from the cooler storage, the (redacted by FDA), and poured into stainless steel troughs, where the eggs are exposed to the environment prior to manual packaging.
  • Investigators observed buckets of salad eggs being stored unattended at ambient temperatures in the peeling room for at least three hours each day.

The agency also questioned a preservative used by Almark, saying that research provided by company officials was inadequate.

“After the inspection, you provided us with a preservative study intended to show that the preservative is lethal to the (redacted by FDA), with the preservative showing “elimination of pathogens in an (redacted by FDA) time period.” We note that this study is not adequate to validate the use of this treatment on eggs to eliminate pathogens because it does not address use of the treatment under your processing conditions.”

 About Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell spoiled but can still cause serious and sometimes life-threatening infections. Anyone who has eaten any of the implicated eggs and developed symptoms of Listeria infection should seek medical treatment and tell their doctors about the possible Listeria exposure.

Also, anyone who has eaten any of the eggs should monitor themselves for symptoms during the coming weeks because it can take up to 70 days after exposure to Listeria for symptoms of listeriosis to develop.

Symptoms of Listeria infection can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses.

Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are particularly at risk of serious illnesses, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature delivery, infection of the newborn, or even stillbirth.

(To sign up for a free subscription to Food Safety News, click here.)