In reading the FDA’s Environmental Assessment: Factors Potentially Contributing to the Contamination of Fresh Whole Cantaloupe Implicated in a Multi-State Outbreak of Salmonellosis regarding the Chamberlain Farm’s Salmonella outbreak from last year over the weekend, I was struck by how complete the investigation was.  I was also struck by how it seemed that this farmer was clearly not paying attention when the Listeria Cantaloupe outbreak occurred a year earlier.  I would urge you to read the full Assessment.  Here are the high-lights – or, low-lights.

In August 2012, the Food and Drug Administration (FDA), in conjunction with the Centers for Disease Control and Prevention (CDC) and state health departments, began to investigate a multi-state outbreak of salmonellosis. According to the CDC, the final case count reported from 24 states was 261 persons infected with the outbreak strains of Salmonella Typhimurium (228 persons) and Salmonella Newport (33 persons). The number of infected persons identified in each state are as follows: Alabama (25), Arkansas (6), Florida (1), Georgia (13), Illinois (36), Indiana (30), Iowa (9), Kentucky (66), Maryland (1), Michigan (8), Minnesota (2), Mississippi (7), Missouri (17), Montana (1), New Jersey (2), North Carolina (5), Ohio (5), Oklahoma (1), Pennsylvania (2), South Carolina (4), Tennessee (8), Texas (2), Virginia (1), and Wisconsin (9).  Among 257 persons for whom information was available, illness onset dates ranged from July 6, 2012 to September 16, 2012. Ill persons ranged in age from less than one (1) year to 100 years, with a median age of 47 years. Fifty-five percent of ill persons were female. Among 163 persons with available information, 84 (51%) reported being hospitalized. Three deaths were reported in Kentucky.

Based on epidemiological and product traceback investigational evidence, cantaloupes from Chamberlain Farms in the southwest region of Indiana were implicated in the outbreak. Additionally a cantaloupe sample collected at a retail location by the Kentucky Department of Public Health tested positive for Salmonella Typhimurium (0324) that was indistinguishable by pulsed-field gel electrophoresis (PFGE) analysis from the outbreak clinical isolates from ill patients associated with this foodborne illness outbreak. This cantaloupe sample traced back to Chamberlain Farms. The cantaloupes implicated in the outbreak were harvested from June 20, 2012 through August 16, 2012 and packed at a single on-farm packinghouse.  The firm voluntarily stopped distribution of all cantaloupes and began removing all cantaloupes from the market on August 16, 2012. The firm also instituted a voluntary class I recall on August 24, 2012 for all cantaloupe distributed since harvest began on June 20, 2012 (total of 222,000 cantaloupes from 29 consignees in 8 states). The firm also began removing all watermelon from the market on September 6, 2012, based on a watermelon sample that tested positive for Salmonella Newport (0149). The positive watermelon sample was collected from a Chamberlain Farms field and analyzed by the Indiana State Department of Health (ISDH).

On August 14-31, 2012, FDA, along with ISDH officials, conducted a regulatory inspection at Chamberlain Farms during which FDA and ISDH observed growing, harvesting, and packing or holding of covered produce practices. FDA and ISDH also collected multiple samples, including whole cantaloupe and environmental (non-product) samples from within the packinghouse, for laboratory analysis to identify the presence or absence of Salmonella.  Of the 70 environmental and product sub-samples collected from within the packinghouse, six were confirmed positive for Salmonella Newport (0807) with (PFGE) pattern combinations that were indistinguishable from one of the outbreak strains. Cantaloupe collected from the firm’s fields during the inspection were confirmed positive for Salmonella Typhimurium (0324) and Salmonella Newport (0807) with PFGE pattern combinations that were indistinguishable from the two outbreak strains isolated from ill patients.

Environmental Assesment:

FDA’s findings regarding this particular outbreak highlight the importance for the industry to employ good agricultural and management practices in their packinghouses as well as in growing fields. Specifically, FDA recommends that firms take the following steps in the growing environment:

  • Assess produce growing practices and procedures to control, reduce or eliminate the introduction of Salmonella and other pathogens into the agricultural environment where fresh produce is grown.
  • Growers should follow good agricultural practices for handling animal manure to reduce the introduction of microbial hazards to produce. Such practices include processes such as composting that are designed to reduce possible levels of pathogens in manure. Good agricultural practices may also include minimizing direct or indirect manure-to-produce contact.
  • Growers may consider scheduling application of raw manure on adjacent fields to maximize the time between manure application to those fields and harvest of produce. Growers may also consider establishing field plans where the fields closest to produce crops are planted with crops that do not receive raw manure.
  • Consider barriers or physical containment to secure manure storage or treatment areas where contamination from runoff, leaching, or wind spread is a concern.

FDA recommends that firms take the following steps in the packing and holding environment:

  • Assess produce packinghouse and equipment design to ensure adequately cleanable surfaces and eliminate opportunities for introduction, growth, and spread of Salmonella and other pathogens.
  • Ensure that water is of sufficient microbial quality for its intended use. Using dump tank water with sufficient water disinfectant present and monitoring the levels to reduce the potential risk of cross-contamination. Note: The primary purpose of the water disinfectant is not to clean the melons but rather to prevent the water from becoming contaminated should pathogens be introduced into the water from melons. The contaminated water could then act as a source of contamination for incoming melons.
  • Assess and minimize opportunities for introduction of Salmonella and other pathogens in packinghouses.
  • Implement regular cleaning and sanitizing procedures.
  • Verify the efficacy of cleaning and sanitizing procedures.
  • Periodically evaluate the processes and equipment used in packing operations to assure they do not contribute to fresh produce contamination.
  • Implementing melon handling operations that minimize the incidence of melon surface moisture to reduce potential plant and human pathogen growth. Cooling and cold storing melons as soon as possible after harvest, if melons are to be air cooled.
  • Developing and maintaining written food safety plans and SOPs for areas such as handling and storage practices, field, facility and vehicle cleaning and sanitation, and employee training programs.
  • Maintaining records for significant activities performed, such as monitoring of water sources and use; testing water quality; treating water; monitoring for signs of animal intrusion; cleaning and sanitation of equipment, containers, and vehicles; employee training; and corrective actions taken.
  • Recording information such as the date and time, name of person(s) who completed the record, the location of the field and location in the field, if applicable, and the activity being monitored in the documentation.
  • Growers should further consider the recommendations put forth in FDA’s Guidance for Industry: Guide to Minimize Microbial Food Safety Hazards for Fresh Produce and Vegetables and FDA’s Draft Guidance for Industry: Guide to Minimizing Microbial Food Safety Hazards of Melons.