Examining the Differences Between Pathogen Control Programs and Hygiene Monitoring

Additionally, swabs/sponges should be taken whenever a pathogen is recovered from a sample or when proficiency check samples are run in the lab. Segregated rooms (areas) where pathogen isolates are handled will require sponges/swabs to be taken whenever the room is in use—often on a daily basis, and especially after cleaning and sanitation.

Setting specifications. Zone 1 post-sanitation specifications should be set at <10 cfu/sponge for hygiene assays and negative for pathogens. Zone 2 and 3 specifications may be set initially and then change depending on the baseline data. Six to 12 months of baseline data will be needed to create specifications that are achievable and provide insight throughout high and low sample volumes, seasonal changes, and varying technician scheduling.

After baseline collection, lab management should reassess and revise specifications as needed. Table 2 provides examples of specifications for each zone.

Data collection and review. Each month, the site list and results are to be reviewed by laboratory management, ensuring that sampling is conducted as per the SOP, that OOS results have been addressed, and that corrective/preventive actions were effective by verification sampling. This review also allows identification of developing trends and assurance that the program is working as intended. All data should also be reviewed in a historical context (e.g., comparison of present data to the last 30 days, last several months, previous year’s results).

If any pathogen result is positive, Salmonella serological testing or identifications to the species level is to be performed. The information can be compared to the positive strains used in the lab for quality control (QC) to determine if there was a cross-contamination. If the strain is not from the QC program, this may point to a routine lab sample that was run in the near past that tested positive or to a harborage point within the laboratory that will need to be isolated and removed. Without species-level identifications, corrective/preventive actions are difficult to conduct.

Some of the examples of trends to note:

• Increasing counts over several weeks;
• Increasing OOS results;
• Multiple OOS results on similar sites, within a zone, or across several zones;
• Identifications that point to QC or sample cross-contamination; and
• Multiple identifications of the same organism that may point to a harborage site within the lab.

Corrective/Preventive Actions

Corrective actions. When presumptive and/or OOS results are returned, corrective actions are conducted immediately to minimize/contain the risk. This usually involves intensive cleaning/sanitizing that may also require equipment disassembly if appropriate. It is important to note that prior to initiation of any corrective actions, a review of the laboratory area must be conducted noting hygienic state, activity and equipment in the area. Investigative swabbing must be conducted prior to any cleaning/sanitizing activity to preserve “evidence.”

Investigative process. Investigative samples are taken with the objective of identifying the cause of the OOS result. Investigations are conducted after a corrective action and will lead to appropriate preventive actions. Samples are taken in a vectoring manner (in 360-degree radius, if possible, surrounding the site). Vector samples should include locations adjacent, under, and above the initial site. In addition to vector sampling, the investigative team should observe the sample site and lab operations nearby. The team is looking at the process, lab environment, equipment, and utensils and identifying circumstances that led to the results.

Preventive actions. As opposed to corrective actions, preventive actions are performed only after the cause of the OOS has been identified. Actions are preventive in nature, such as making repairs, sealing against water incursions, or increasing equipment disassembly.

An effective laboratory EMP verifies that good laboratory practices are in place and that pathogen cross-contamination is prevented within the laboratory. Both a quantitative hygiene monitoring and a qualitative pathogen monitoring program are essential to providing the evidence that the laboratory environment is in control. Having a documented system and trained staff in place is an essential component of effective and efficient laboratory operations.