Vol. 1, Issue 7  ‣ October 2024

Table of Contents

The Centers for Disease Control and Prevention (CDC) estimates that each year, approximately one in six Americans get sick from foodborne illnesses, resulting in 128,000 hospitalizations and 3,000 deaths.¹ One of the most serious pathogens associated with these illnesses is Listeria monocytogenes.

This environmental pathogen can contaminate a variety of foods, survive and multiply at refrigeration temperatures, and can cause severe illness known as listeriosis. Listeriosis symptoms include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and seizures, often preceded by gastrointestinal issues. 

An invasive infection extends beyond the gastrointestinal tract, posing a serious risk, especially to vulnerable groups such as the elderly and those with weakened immune systems. In pregnant women, listeriosis can lead to miscarriages, stillbirths, premature delivery, or severe infections in newborns.²

In early July 2024, the CDC launched an investigation into a multistate outbreak of L. monocytogenes infections, which led to at least ten deaths and 59 hospitalizations across 19 states, making it the largest Listeria outbreak in over a decade.(7) To trace the outbreak’s source, public health officials interviewed the affected individuals about their food consumption in the month prior to getting sick. Of the 44 people able to be interviewed, 39 (89%) reported eating deli-sliced meats, 25 (57%) specifically consumed deli-sliced liverwurst, and 19 (43%) identified Boar's Head brand liverwurst. Subsequently, the Maryland Department of Health tested an unopened package of Boar's Head liverwurst and identified the presence of L. monocytogenes. Whole genome sequencing confirmed that the strain from the liverwurst sample was highly related to the strain linked to the outbreak.³

On July 25, 2024, Boar’s Head Provision Company voluntarily recalled approximately seven million pounds of ready-to-eat meat and poultry products. An internal investigation at their Jarratt, Virginia facility identified a specific production process used exclusively for liverwurst as the source of the contamination.⁴ At the beginning of September, Boar's Head closed their Jarratt plant causing the layoff of over 500 workers, as the company now faces numerous lawsuits.⁷

The Federal Meat Inspection Act (FMIA) mandates USDA inspections of all commercially sold meat to ensure that they meet U.S. food safety standards.⁵ After the outbreak became public, the USDA released two years' worth of inspection reports revealing unsanitary conditions at the Jarratt plant, including rusted equipment, meat build-up, live insects, and mold. This situation has led food safety experts to advocate that the problems found at the Boar’s Head facility warranted stronger enforcement actions.⁶

This outbreak highlights the need for improved monitoring systems, more stringent testing protocols, and enhanced consumer education in order to prevent similar outbreaks in the future. 

When detecting Listeria, precision and efficiency are critical. These products offer advanced solutions for identification, differentiation, and environmental monitoring, ensuring accurate results across diverse applications.

CompactDry™
Listeria spp (LS)

CompactDry™ LS offers a ready-to-use system for isolating, detecting, and enumerating Listeria spp., with colonies turning blue due to chromogenic substances. It's ideal for food, cannabis, cosmetics, and raw material testing.

Buffered Listeria Enrichment Broth (BLEB) Base

A selective enrichment medium for Listeria monocytogenes in food samples.

HardyCHROM™ Listeria

This chromogenic medium selectively isolates and differentiates Listeria monocytogenes from food and environmental samples.
L. monocytogenes colonies appear turquoise with a white halo, offering results in as little as 24 hours.

CRITERION™ Fraser
Broth Base

Designed for the selective enrichment and detection of Listeria spp., this medium is ideal for rapid testing in food and environmental samples. Fraser Supplement, Cat. no. Z210, is required.

Buffered Listeria Enrichment Broth Selective Supplement, 3.4ml

Used in combination with Buffered Listeria Enrichment Broth Base, this supplement enhances selective enrichment of Listeria monocytogenes from food samples.

Sani-S'wipe Sampling Cloths, Blue

A non-destructive sampling cloth that allows for comprehensive microbiological testing across large surfaces, including food production areas and carcasses.

Microgen®
Listeria-ID 

Microgen® Listeria-ID has been designed to enable laboratories to properly identify and differentiate Listeria spp. species when sampled from a single colony isolated on selective agar plates. 

Thank you to everyone who attended AAFP 2024 in Fayetteville, AR! It was wonderful opportunity to connect with industry thought leaders and discuss Hardy's latest solutions for food safety professionals.

Hardy Diagnostics was the first company to introduce chromogenic media to America in 1996. Over the years, Hardy has developed the largest line of chromogenic media in the US.

The CompactDry™ plate line presents a variety of organism-specific or total count tests, packaged nicely in a sophisticated and sturdy cassette.

Mark Pruett

FOOD AND BEVERAGE PRODUCT MANAGER

Mark is the Food and Beverage Product Manager at Hardy Diagnostics, bringing a wealth of experience from his extensive background in microbiology and the food industry. Passionate about advancing food protection, Mark continues to drive excellence and innovation in his role at Hardy Diagnostics.

Do you have a suggestion, comment, or question? Please contact Mark here.

061224KZ