Seek and Destroy: Best Practices for Controlling Environmental Pathogens

Investigations can also be triggered by an indicator site positive. This becomes part of the aggressive sampling following an indicator out of control observation. These indicator sites are strategically located in close proximity to a known growth niche, barrier or hurdle. Movement of the organism from the indicator site through a verification site or area would be required before violation of food safety. These indicator sites over time measure the strength of the barrier or hurdle or the effectiveness of the management of growth niches.

In addition, a Seek and Destroy Investigation can be conducted on a new piece of equipment to develop sanitation methods and identify potential areas of risk and on a piece of equipment to define the normal and periodic deep level of disassembly.
Investigative sampling to identify optimal locations for placement of indicator sites in either Z3 or Z4, and measurement of risk in Z4 area are also acceptable.

Indicator sites. Indicator sites are the measurement system for a microbiological process control. They are “risk-based” indicators of special causes or process shifts in the environment.

Ideal indicator sites include locations close to the growth niche that can identify an active growth niche, locations that can identify suspect organisms before they become attached to or imbedded within the equipment, Z4 to Z3 Transfer areas, and Sanitary Facility & Equipment Design issues.

Post rinse. Post-rinse sampling is an indicator for potential risk. Positive post-rinse sampling is not an indicator of a food safety hazard, however. Typical sites are below the product line and in areas that tend to collect spatter from the rinsing process (e.g., machine sides, legs, support structure, floor wall juncture). Detection of the organism does not mean there is a harborage site within the scope of the sampled area. Positive post-rinse samples will typically trigger aggressive sampling or not-for-cause investigative sampling. Post rinse 10 days in a row.

Sample large areas that collect “spatter.” Composite sampling is acceptable. Positive results will direct investigation team to a line, pair of lines, or section on a line.

The S&D Process quick tips.

• Measurement system
  • APC to manage growth niches
  • APC at Preop to measure effectiveness of sanitation
    • Expect 99 percent large area swabs (Plant KPI) to be < 100 cfu (total area)
• Continuously seek indicator sites
• Increase percentage of indicator sites to verification sites by adding indicator sites as the process evolves and data is collected
• Reward finding positives
• Seek and Destroy Investigation on a piece of equipment that has been in operation without any linked verification positives to measure the effectiveness of sanitation methods below the normal level of disassembly

Maturity Models

Maturity models are used in the S&D Process to define the stages or levels of control attained. The stages include Awareness, Enlightenment, Preventive, and Predictive.

Awareness & Enlightenment are characterized by repeated positives in the same general areas: firefighting and a failure to find and eliminate or manage the harborage site(s). Failure to effectively use or deploy preventative practices keeps the establishment in a “firefighting state.” In this state, management promotes not getting to the root cause and rewards solving the same problem over and over again.

The S&D Process moves the establishment along the journey from the Awareness Stage to the Predictive Stage. The establishment transcends to the Preventive Stage when harborage sites are eliminated through redesign or managed with an intervention capable of eliminating the pathogen from the harborage site. The Predictive Stage evolves as data is used to predict when to apply interventions and other more aggressive preventive controls.

I see the elements of our maturity models changing as technological advances occur in metagenomics, rapid methods, and broader application of whole genome sequencing. These technologies are reducing the time for identification of outbreaks as well as detecting smaller events. Time compression is and will continue to occur at the processor level to identify, eliminate, or manage harborages.