Top 5 Takeaways

  1. Widespread Outbreak: Early 2021 witnessed a multistate outbreak of listeriosis with 13 cases across four states, predominantly affecting Hispanic populations, leading to 12 hospitalizations and one death.
  2. Source Identified Quickly: The outbreak was traced to queso fresco made with pasteurized milk, identified within 19 days of cluster detection through rapid food testing and record collection.
  3. Risk Communication Needs: Public health communications need enhancement to better reach Hispanic communities and emphasize the risks of consuming queso fresco and similar fresh, soft cheeses, even those made from pasteurized milk.
  4. Statistical Findings: Statistical analysis indicated significantly higher odds of listeriosis from consuming queso fresco compared to other foods, highlighting its high risk as a vector for the disease.
  5. Prevention and Response: The recall of the implicated cheese and rapid public health response potentially prevented further cases, demonstrating the effectiveness of prompt outbreak management protocols.

Original Article Author and Citation

Corresponding Author

Alexandra Palacios,

Suggested Citation

Palacios A, Otto M, Flaherty E, et al. Multistate Outbreak of Listeria monocytogenes Infections Linked to Queso Fresco — United States, 2021. MMWR Morb Mortal Wkly Rep 2022;71:709–712. DOI:


This MMWR report documents a multistate outbreak of listeriosis linked to queso fresco, a fresh cheese popular among Hispanic communities. The outbreak resulted in significant morbidity, emphasizing the importance of stringent food safety practices and targeted public health messaging.


The investigation was conducted using the national molecular subtyping surveillance network PulseNet, comprehensive food testing, and interviews via the Listeria Initiative questionnaire, which helped quickly pinpoint the source of the outbreak.


The analysis revealed a strong statistical link between consuming queso fresco and contracting listeriosis, underscoring the need for improved food safety protocols and public health communication strategies, particularly within Hispanic communities that traditionally consume fresh cheeses.


Effective public health surveillance, rapid outbreak response, and clear communication can significantly mitigate the impact of foodborne illness outbreaks. This incident also highlights the ongoing risk posed by even pasteurized fresh cheeses if not properly handled.

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