Jeffrey T. McCollum, D.V.M., M.P.H., Alicia B. Cronquist, R.N., M.P.H., Benjamin J. Silk, Ph.D., M.P.H., Kelly A. Jackson, M.P.H., Katherine A. O’Connor, B.S.N., M.P.H., Shaun Cosgrove, M.S., Joe P. Gossack, B.S., Susan S. Parachini, B.A., Neena S. Jain, M.D., M.S.T.P.H., Paul Ettestad, D.V.M., Mam Ibraheem, M.D., M.P.H., Venessa Cantu, M.P.H., Manjiri Joshi, M.P.H., Tracy DuVernoy, D.V.M., M.P.H., Norman W. Fogg, Jr., M.P.S., James R. Gorny, Ph.D., Kathryn M. Mogen, M.P.H., Charlotte Spires, D.V.M., M.P.H., Paul Teitell, B.S., Lavin A. Joseph, M.S., Cheryl L. Tarr, Ph.D., Maho Imanishi, V.M.D., M.P.H., Karen P. Neil, M.D., M.S.P.H., Robert V. Tauxe, M.D., M.P.H., and Barbara E. Mahon, M.D., M.P.H.

N Engl J Med 2013; 369:944-953 September 5, 2013 DOI: 10.1056/NEJMoa1215837


Although new pathogen–vehicle combinations are increasingly being identified in produce-related disease outbreaks, fresh produce is a rarely recognized vehicle for listeriosis. We investigated a nationwide listeriosis outbreak that occurred in the United States during 2011.


We defined an outbreak-related case as a laboratory-confirmed infection with any of five outbreak-related subtypes of Listeria monocytogenes isolated during the period from August 1 through October 31, 2011. Multistate epidemiologic, trace-back, and environmental investigations were conducted, and outbreak-related cases were compared with sporadic cases reported previously to the Listeria Initiative, an enhanced surveillance system that routinely collects detailed information about U.S. cases of listeriosis.


We identified 147 outbreak-related cases in 28 states. The majority of patients (127 of 147, 86%) were 60 years of age or older. Seven infections among pregnant women and newborns and one related miscarriage were reported. Of 145 patients for whom information about hospitalization was available, 143 (99%) were hospitalized. Thirty-three of the 147 patients (22%) died. Patients with outbreak-related illness were significantly more likely to have eaten cantaloupe than were patients 60 years of age or older with sporadic illness (odds ratio, 8.5; 95% confidence interval, 1.3 to ∞). Cantaloupe and environmental samples collected during the investigation yielded isolates matching all five outbreak-related subtypes, confirming that whole cantaloupe produced by a single Colorado farm was the outbreak source. Unsanitary conditions identified in the processing facility operated by the farm probably resulted in contamination of cantaloupes with L. monocytogenes.


Raw produce, including cantaloupe, can serve as a vehicle for listeriosis. This outbreak highlights the importance of preventing produce contamination within farm and processing environments.

Listeria:  Marler Clark, The Food Safety Law Firm, is the nation’s leading law firm representing victims of Listeria outbreaks. The Listeria lawyers of Marler Clark have represented thousands of victims of Listeria and other foodborne illness outbreaks and have recovered over $600 million for clients.  Marler Clark is the only law firm in the nation with a practice focused exclusively on foodborne illness litigation.  Our Listeria lawyers have litigated Listeria cases stemming from outbreaks traced to a variety of foods, such as cantaloupe, cheese, celery and milk.   Marler Clark is presently representing 46 victims and their families in the 2011 Jensen Farms Listeria cantaloupe outbreak and 2 women, one who lost her child in the 2012 Marte brand Frescolina ricotta salata cheese Listeria outbreak.

If you or a family member became ill with a Listeria infection after consuming food and you’re interested in pursuing a legal claim, contact the Marler Clark Listeria attorneys for a free case evaluation.