US Food Safety Hazard: Cantaloupe Caused Listeria Food Poisoning
On October 19, 2011 the US Food and Drug Administration (FDA) confirmed the presence of strains of listeria in cantaloupe samples taken from Jensen Farms. Currently, there are 33 additional illnesses and 29 deaths reported to be linked to the ongoing outbreak of listeria food poisoning from Colorado-grown cantaloupes.
The bacterium that causes listeriosis, L. monocytogenes, produces varying symptoms depending on a person’s risk factors. Listeriosis normally starts with diarrhea followed by fever and muscle aches, similar to the symptoms of flu. If pregnant women develop the flu-like symptoms they may also endure complications including miscarriage, stillbirth, premature delivery or a fatal infection of the newborn infant. Elderly people with defective immune systems and young children can develop headaches, stiff neck, mental confusion, loss of balance and convulsions and can result in fatal meningitis or encephalitis. The onset of symptoms can occur anytime between three days to two months after infection occurs.
The Colorado Department of Public Health and Environment reported it had nine cases of listeriosis including two deaths on September 2, 2011 prompting the US Food and Drug Administration and US Centers for Disease Control to commence an urgent investigation of the multiple state outbreak in which cantaloupe was the suspected infection vehicle.
On September 10, 2011 the FDA and Colorado state officials visited cantaloupe producer Jensen Farms to collect multiple samples. Of the 30 swabs taken, 13 were confirmed positive for L. monocytogenes with pulsed-field gel electrophoresis (PFGE) pattern combinations matching three of the four outbreak strains. In addition, cantaloupes from the firm’s cold storage area confirmed positive for the bacteria with PFGE pattern combinations matching two of the four outbreak strains.
The FDA identified several factors that most likely caused the introduction, spread and growth of L. monocytogenes at Jensen Farms. The problem may have been stemmed from bacteria in the field where the cantaloupes were grown or through contamination of the packing facility by a truck that hauled reject cantaloupes to a cattle operation. The bacteria may also have spread in water near the machinery and employee walkways, hard-to-clean floors and/or machinery in the packing facility, or from equipment previously used for other agricultural products. Bacteria growth is likely promoted by condensation, due to a missing pre-cooling step prior to cold storage.
The FDA concluded that if the facility had followed the non-binding recommendations for minimizing microbial food safety hazards in melons, as published by the FDA in July 2009, these problems might have been avoided. Obligatory standards will soon be enforced under the Food Safety Modernization Act of 2010, providing new authorities for the FDA.
In all, four outbreak strains of L. monocytogenes were found in 26 US states, leading to 29 deaths and 33 additional illnesses. Settlements to the families may cost $150 million.
SGS Food Safety Services
SGS, the global leader in third-party testing, provides food safety services to the whole food supply chain, from farm to fork, to help assure that your products are fit for consumption. SGS has testing labs throughout the world that can test food products for L. monocytogenes. For more information on food safety and testing for L. monocytogenes, contact SGS Consumer Testing Services at email cts.media@sgs.com or visit www.foodsafety.sgs.com.
