The Listeria Hysteria: Risk assessment methods for foodborne listeriosis


Tanu K. Altomare, Kristina D. Mena*
*Corresponding author
University of Texas Health Science Center School of Public Health
Houston, Texas, USA


Listeria monocytogenes is an environmental microbe capable of causing severe infection in humans and other animals. Its persistence in food products and processing facilities presents unique challenges for food safety and disease control in the United States. Given the increasing number of documented and wide-ranging food-related contamination events with Listeria, this paper will provide an overview of selected Listeria outbreaks in the United States since 1981 and describes how quantitative microbial risk assessment (QMRA) can be applied to address this public health problem. QMRAs have been conducted for Listeria based on available data, including Listeria prevalence in cheeses. Through exposure scenario-building, QMRA can be applied to identify best management practices that minimize health risks associated with Listeria.


In the last three decades, the United States food industry has contended with microbial contamination of consumer products from a variety of causative agents.
A study conducted by the Centers for Disease Control and Prevention found that among all product recalls between 1993 and 1998 that were reported to the Food and Drug Administration for microbe-related contamination, the highest proportion were due to Listeria monocytogenes (1). Among these recalls, a majority were dairy products, salads, sandwiches, and pastries (1). Between 2008 and 2014, all documented outbreaks of Listeria in produce originated in the United States, and a majority of total Listeria outbreaks involved cases in multiple states (2). Listeria outbreaks continue to be associated with foods originally deemed unlikely vehicles for contamination, as seen in the 2014 outbreak concerning stone fruit (2). New epidemiological approaches are necessary to completely characterize health risks associated with foodborne Listeria (2).

Quantitative microbial risk assessment (QMRA) is a framework that translates field and l ...