2011 Outbreak of Listeria in Cantaloupe

The 2011 Outbreak of Listeria in Cantaloupe caused a national outbreak that began in August and sickened 148 people, out of which 25 died. The source of the outbreak was cantaloupe from Jensen Farms in Holly, Colorado. The source of contamination was packaging equipment and cold storage facilities on the farm.

Recall Info

The recalled cantaloupes were shipped from July 28, 2011 through September 10, 2011. They were shipped to the following 21 states: Arizona, Arkansas, California, Colorado, Idaho, Illinois, Kansas, Minnesota, Missouri, Nebraska, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Utah and Wyoming.

The cantaloupe may be labeled: Colorado Grown, Distributed by Frontera Produce, USA, Pesticide Free, Jensenfarms.com, Sweet Rocky Fords. They are packed in cartons labeled: Frontera Produce, www.fronteraproduce.com or with Frontera Produce, Rocky Ford Cantaloupes. Both cartons also include: Grown and packed by Jensen Farms Granada, CO and Shipped by Frontera Produce LTD, Edinburg, Texas. Some of the cantaloupes are not labeled with a sticker.

Searching For the Outbreak Source

The outbreak was initially identified in late August 2011 by Colorado state epidemiologist Alicia Cronquist after four people fell sick from listeria. Colorado state microbiology Hugh Maguire analyzed bacteria from the patients' blood to determine the strain of listeria. By September 2, "the state food lab determined that two patients had matching strains and two other patients matched in a separate strain. With hundreds of strains of listeria, two or more can be on the same food." By checking CDC records of what listeria victims reported eating, Cronquist found that all of the patients had eaten cantaloupe.

"Health authorities purchased 15 cantaloupes at three grocery stores and tested the rind and flesh for listeria bacteria. They also were testing patients' leftover melon. Maguire's lab fast-tracked the genetic matching, setting aside some of the lab's other, more routine work...

"As more patient blood samples arrived at the state lab, they fell into three distinct strains. Cantaloupe taken from patients' refrigerators had the same strains but no sticker naming the farm. In interviews, though, patients volunteered that the cantaloupe said 'Rocky Ford' on it or was extra sweet.

"By tracking the melon purchases of patients back to the distribution trucks, investigators from the state and the Food and Drug Administration narrowed the focus to two farms and sampled soil and machinery."

The farm was Jensen Farms, which recalled its cantaloupes on September 14, 2011.

Sewage Sludge Investigation

Investigators then contacted Parker Ag Services, a company that sprays sewage sludge (sometimes referred to using its PR nickname "biosolids") on farmland to see if the sewage sludge may have been the cause of the contamination.

"Parker Ag Services vice president Mike Shearp told 7NEWS that government investigators have questioned him in recent days as to where those biosolids were applied. He said the substance was applied to a field directly across from a Jensen Farms field years ago."

The sewage sludge came from New York. Experts have confirmed that food-borne pathogenic disease outbreaks have occurred in other countries due to the use of sewage sludge and that it is possible for the sludge to dry, like dust, and become airborne. Jensen Farms says it does not use sewage sludge in its operation.

Resources and Articles

Other SourceWatch resources

• Foodborne Illness

External Articles

• Doug Powell, "Fridge raids help track listeria-in-cantaloupe outbreak; biosolids being investigated as possible source," Barfblog, September 23, 2011.
• Amanda Kost and Marc Stewart, "Exclusive: Biosolids Near Farm Examined For Listeria Link: Treated Human Waste Applied Across From Farm Years Ago," ABC News, September 22, 2011.