Ryan Marlow's Listeria: A Case That Exposed Gaps in Food Safety and Public Awareness

The case of Ryan Marlow, a North Carolina man who died in September 2023 after contracting Listeria monocytogenes, has brought renewed scrutiny to food safety protocols, public awareness of Listeria risks, and the challenges of tracking outbreaks. While the Marlow case itself garnered significant local attention, its connection to a larger, multistate outbreak linked to contaminated cheese products remained largely unnoticed by the broader public for several months. This explainer breaks down the "who, what, when, where, and why" of the Marlow case and its wider implications.

Who was Ryan Marlow?

Ryan Marlow was a 37-year-old father of five from Maiden, North Carolina. He contracted Listeria in August 2023 and suffered severe neurological damage. After a lengthy hospital stay and facing a grim prognosis, Marlow was removed from life support and died on September 27, 2023. His family's ordeal brought the devastating consequences of Listeria infection into sharp focus.

What is Listeria monocytogenes?

*Listeria monocytogenes* is a bacterium that can cause a serious infection called listeriosis. According to the Centers for Disease Control and Prevention (CDC), an estimated 1,600 people get listeriosis each year in the U.S., and about 260 die. The infection is most dangerous for pregnant women, newborns, older adults, and people with weakened immune systems. Symptoms can include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions. In pregnant women, listeriosis can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn.

When and Where did the outbreak occur?

The Listeria outbreak linked to the Marlow case began in 2017 and continued intermittently through early 2024. The CDC initially identified infections in multiple states, including Maryland, California, Colorado, Connecticut, New York, Ohio, Pennsylvania, South Dakota, Texas, Virginia, Washington, and Wisconsin. The Marlow case in North Carolina, while tragic, was only one data point in a larger, slowly unfolding public health investigation. The outbreak’s source was ultimately traced back to cheeses produced by Rizo-López Foods, Inc., of Modesto, California.

Why did it take so long to identify the source?

Identifying the source of Listeria outbreaks can be a complex and time-consuming process. Several factors contributed to the delay in pinpointing Rizo-López Foods as the culprit:

• Long incubation period: Listeria can have a long incubation period, ranging from a few days to several weeks. This makes it difficult for infected individuals to recall what they ate before becoming ill.


• Sporadic nature of cases: The cases were geographically dispersed and occurred over a long period, making it harder to identify a common source.


• Data limitations: Early investigations may not have collected sufficient information about specific food consumption patterns to link the cases to a single product.


• Whole Genome Sequencing (WGS): While WGS technology allows for highly accurate identification of bacterial strains and their relationships, it requires time to analyze and compare samples from different cases. WGS helped link the illnesses to a common strain of Listeria.


• Restaurant Association: The early tracebacks focused on the restaurants where people reported eating contaminated products.

Historical Context: Listeria and Food Safety Regulations

Listeria has been a recognized food safety hazard for decades. In the 1980s, several high-profile outbreaks linked to contaminated dairy products and ready-to-eat meats led to increased awareness and regulatory efforts to control Listeria contamination.

The Food Safety Modernization Act (FSMA), signed into law in 2011, aimed to shift the focus from responding to foodborne illnesses to preventing them in the first place. FSMA includes provisions for stricter food safety standards, increased inspections, and mandatory recalls. However, challenges remain in effectively implementing and enforcing these regulations, particularly for smaller food producers.

Current Developments: The Rizo-López Foods Recall

In February 2024, following years of investigation and a renewed push after additional illnesses were reported, Rizo-López Foods initiated a voluntary recall of all its cheese and dairy products. The recall included over 60 brands of cheeses, yogurts, and sour creams sold nationwide. The FDA also issued a warning advising consumers to discard any potentially contaminated products.

The CDC reported that, as of February 2024, the outbreak had resulted in 26 illnesses, 23 hospitalizations, and two deaths (including Ryan Marlow). The true number of cases may be higher, as some people may have been infected but not diagnosed or reported.

Likely Next Steps

Following the recall, several actions are likely to occur:

• FDA Investigation: The FDA will conduct a thorough investigation of Rizo-López Foods' production facilities to determine the source of the Listeria contamination and identify any deficiencies in their food safety practices. This will likely involve environmental sampling, review of production records, and interviews with employees.


• Legal Action: Individuals and families affected by the outbreak may pursue legal action against Rizo-López Foods for damages related to their illnesses.


• Regulatory Review: The FDA may review its regulations and guidelines for Listeria control in cheese production to identify areas for improvement. This could include stricter testing requirements, enhanced sanitation protocols, and improved traceability measures.


• Industry Response: The dairy industry may implement additional voluntary measures to enhance Listeria control, such as increased testing, improved sanitation practices, and employee training programs.


• Public Education: Public health agencies will likely ramp up efforts to educate consumers about Listeria risks and safe food handling practices. This could include public service announcements, educational materials, and outreach to vulnerable populations.


• Continued Surveillance: The CDC will continue to monitor for new cases of listeriosis and investigate any potential links to contaminated food products. This will involve analyzing data from state and local health departments and using WGS technology to identify clusters of related illnesses.

The Broader Implications

The Ryan Marlow case and the associated Listeria outbreak highlight several important issues:

• The vulnerability of the food supply: Despite advances in food safety regulations and technology, the food supply remains vulnerable to contamination.


• The importance of effective surveillance and outbreak response: Rapid and accurate detection and investigation of foodborne illness outbreaks are crucial to prevent further illnesses and deaths.


• The need for greater public awareness: Many consumers are unaware of the risks associated with Listeria and other foodborne pathogens.


• The role of personal responsibility: Consumers can play a role in preventing foodborne illness by following safe food handling practices, such as washing hands, cooking food thoroughly, and avoiding cross-contamination.


• Impact of social media: While the initial news coverage was local, the family's use of social media to document Marlow's illness and advocate for awareness highlighted the severity of Listeria and eventually contributed to broader public attention.

The Marlow case served as a tragic reminder of the devastating consequences of foodborne illness and the importance of vigilance in protecting the food supply. While the recall of Rizo-López Foods products is a significant step, ongoing efforts are needed to prevent future outbreaks and ensure the safety of the food we eat. The delayed recognition of the multistate outbreak shows that even with advanced technology like WGS, challenges remain in quickly connecting seemingly disparate cases and identifying the source of contamination, underscoring the need for constant improvements in surveillance, investigation, and public communication.