October 19, 2011.- FDA reported this morning that 13 out of 39 environmental samples taken during its initial outbreak “regulatory” investigation at Jensen Farms’ packing house were positive for Listeria monocytogenes. Five out of 10 cantaloupe samples tested by FDA also were positive for outbreak strains of Listeria monocytogenes. City water used to wash the cantaloupes was clean.
Among the 18 positive samples, FDA labs found three of the four different strains of Listeria monocytogenes that have been recovered from outbreak patients, in addition to another strain that has not been recovered from any patients.
FDA and state investigators conducted a “root cause” investigation of Jensen’s operations on September 22-23rd – after the company disassembled and cleaned their equipment and decontaminated the entire packing house. Environmental samples taken during the September 22-23rd investigation were all negative for Listeria monocytogenes, as were samples of cantaloupe taken in the growing fields.
The root cause investigation identified several factors that, according to FDA, “…likely contributed to the introduction, spread and growth of Listeria monocytogenes…”
- There could have been low level sporadic Listeria monocytogenes in the field where the cantaloupe were grown, which could have been introduced into the packing facility
- A truck used to haul culled cantaloupe to a cattle operation was parked adjacent to the packing facility and could have introduced contamination into the facility
- The packing facility’s design allowed water to pool on the floor near equipment and employee walkways;
- The packing facility floor was constructed in a manner that made it difficult to clean
- The packing equipment was not easily cleaned and sanitized; washing and drying equipment used for cantaloupe packing was previously used for postharvest handling of another raw agricultural commodity.
- There was no pre-cooling step to remove field heat from the cantaloupes before cold storage. As the cantaloupes cooled there may have been condensation that promoted the growth of Listeria monocytogenes.
During a morning media teleconference, FDA and Colorado officials were at pains to assure the public that the Jensen Farms packing house was an unusual situation. “There is no reason to believe,” said Sherri McGarry of FDA, “that these practices were representative of the industry.”
FDA has issued a Warning Letter to Jensen Farms, citing “…widespread contamination throughout …” and “…poor sanitary practices in the facility.” The agency has not yet released a copy of Form 483 inspection report, usually handed to the company at the close of an inspection where significant violations have been found.
Jensen Farms has fifteen working days to respond to the Warning Letter with specific steps it has taken to correct the violations.
Yesterday, CDC issued its latest Investigation Update, reporting that this outbreak has claimed 25 lives, caused one miscarriage, and sickened 123 people in 26 states. It will be at least another two weeks, according to CDC, before the agency feels comfortable declaring the outbreak to be at an end.
FDA believes that all of the Jensen Farms cantaloupes have been removed from the marketplace. Nevertheless, juice from cut cantaloupes could have contaminated refrigerator and food preparation surfaces. FDA recommends that consumers who may have purchased the recalled cantaloupes should clean and disinfect their refrigerators and work areas as follows:
- Wash the inside walls and shelves of the refrigerator, cutting boards and countertops;
- Sanitize the surfaces with a solution of one tablespoon of chlorine bleach to one gallon of hot water;
- Dry with a clean cloth or paper towel that has not been previously used; and
- Wash hands with warm water and soap following the cleaning and sanitizing procedure.