How to Switch to Environmental Health Monitoring

It takes time and dedicated effort to switch an entire institution to environmental health monitoring (EHM) from a traditional soiled bedding sentinel (SBS) program. Below are the steps we recommend taking for the best success. If you have further questions after exploring these steps and our FAQs above, please apply to our EHM Mentorship Program. Our environmental health monitoring initiative members are here to support you in the process of making the switch.


1. Collect reference material from the 3RsC website. 

2. Gather information on your facility’s rack and caging system to determine and decide your EHM options.

3. Reach out to vendors and diagnostic laboratories, as necessary. 

  • Contact your diagnostic laboratory to confirm their ability to perform testing on EHM submissions. Note that Charles River Laboratories, IDEXX, and VRL can all test EHM submissions.
  • If you plan to use EDT, contact rack manufacturers to price any necessary media holders. 

4. Gather a small internal advocacy group & get initial buy-in.

  • It’s easier to make progress with a team of people.
  • Get any necessary buy-in from Senior Management (e.g., vivarium director). 
  • Conduct and share results from a cost analysis as desired.
  • Evaluate your current sanitation methods and determine if any changes are needed. See our resource for more info.
  • Provide education to your staff with resources on the website and our editable slide deck.

5. Decide whether a small pilot program is necessary or desired at your institution.

  • Although there is strong literature support for the effectiveness of EHM as compared to SBS, some institutions may still want to conduct temporary hybrid testing either as a small scale pilot or across the facility to determine best practices and proof of concept.
  • We recommend this occur across one testing period (typically a quarter).
  • If the room is positive for specific agents and there is no current data on those in the literature, consider designing and publishing a case study on your results.
  • If the room is clean for all agents on the panel, you could choose to add Astrovirus or the rodent housekeeping gene (ex: ApoR) to the panel as a positive control for your internal study.
  • Once the pilot is complete, present the background, rationale, and pilot program to a larger audience (editable slide deck).

6. Develop materials and a timeline for implementing EHM across your facility and replacing soiled bedding sentinels.

  • Develop SOP and/or study outline and review with staff – SOPs available on 3RsC website. 
  • Train staff on the EHM technique selected.
  • Report any pilot results to all stakeholders.
  • Generate enthusiasm around the technology – departmental websites, newsletters, e-mail communication. 
  • Start small with a few rooms and then gradually expand the program to additional rooms.
  • You may choose to switch an entire sector over at a specific time or conveniently wait until the planned euthanasia of existing live animals before starting EHM across the next year.
  • Communicate with investigators and technical staff. 
  • If unexpected pathogens are discovered, develop a standardized way confirm results prior to taking additional action.

Successful Case Studies

Below is detailed information about how two large animal facilities replaced their soiled bedding information with environmental health monitoring techniques. We’ve included a PDF of each presentation for you to view and a high-level summary of their processes.

Case Study #1: The Centre for Phenogenomics (Toronto, Canada)

A slide titled

Overview:


The Center for Phenogenomics (TCP) began trials for Environmental Dust Testing in 2017, began implementation in 2018, and by 2023 had transitioned any remaining sentinels to sentinel-free soiled bedding (SFSB). The program continues to evolve with ongoing refinements to SFSB technique.


Facility features:


2 floors of ~13,000 SPF mouse cages, 300 racks, 9 racks per room 


Considerations:


  • A unique central ventilation system that required specialized attachment for EDT
  • Functional areas with unique health monitoring requirements


Steps to implementation: 


  • Added 1 sentinel-free soiled bedding (SFSB) cage per IVC rack
  • Transfer soiled bedding in a similar way to soiled bedded sentinel cages 
  • A dedicated vet tech performs media exposure/submissions 
  • Use the dredge method to expose media quarterly 
  • Pool 2 media in 1 submission and a combination of large and small PCR panels 
  • Each rack tested 4x per year


Challenges: 


  • Time: for documentation and training
  • Money: switching from serology to PCR 
  • Scheduling: aligning testing + pooling schedules for all 300 racks


Successes: 


  • Eliminated sentinels 
  • Saved tech time because no serology needed
  • Hybrid results (EDT + SFSB) allow flexibility
  • Demonstrated approximately 12% decrease in health monitoring costs per cage 


Updates and lessons learned:


  • Due to budget constraints, plans to expand EDT across the full facility are currently on hold; the program is being maintained primarily on SFSB cages, as the cost of purchasing media holders for additional racks remains a barrier 
  • SFSB is being used in the quarantine area and to confirm or narrow down positive findings on racks, with good results 


Future: 


  • Continue refining SFSB techniques 
  • Reassess expansion to EDT when budget allows 


Case Study #2: The University of Colorado, Anschutz Neducak Campus (Aurora, Colorado)

Title slide for an academic presentation on caging types by Dr. Chris Manuel at the University of Colorado Anschutz.

Overview:


Started the switch in 2022 and completed the transition in 11 months. Overall, 2200 rodents saved/year and $41,500 saved/year.


Facility features:


98% EDT (~23,000 cages) and 2% Sentinel-free Soiled Bedding (~400 cages) 


Considerations: 


  • Which transition model to use: gradual transition, EHM and SBS in parallel, or cold turkey elimination of SBS 
  • Dismantling a 50-year old program: how to insert, move, and collect media; starting, removing, and moving a new rack
  • Translation of SOPs to English, Spanish and Amharic 
  • Aim: transition 551 racks to EDT/SFSB 


Steps to implementation: : 


  1. Decided on the cold turkey transition model 
  2. Purchased sentinel media holders to maximize staff efficiency and decrease sampling variability 
  3. Staggered facility starts by 1 month 
  4. January to March 2022: vet techs focused on ending the SBS program, vets focused on starting EDT program
  5. Conducted EDT Training: used SOPs in both English and Spanish, hands on training with 8 animal care techs and 2 veterinary techs 
  6. Add reminders to racks: rack sanitation every 6 months, 2-3 racks changed out per day, move media as well 
  7. No parallel period to transition 
  8. SFSB sampling: dredge filter media, swirl 3-flocked swabs, single media exposure at 3 months 


Challenges: 


  • Need detail-oriented people designated as the Sentinel Program Coordinator 
  • Hard to implement not knowing the entire program 
  • Need to build in room for mistakes 
  • Communication can always be better 
  • People don’t always read emails, so hands-on training is important 


Successes: 


  • Anticipated a 15% media loss in the 1st quarter: actually a <2% loss 
  • Fully implemented for primary facility by March 1st, 2022, secondary facilities by April 1st, 2022
  • MNV detected at the same rate, no new agents detected 
  • Program benefits have been judged to outweigh any marginal cost differences 


Updates and lessons learned: 


  • A formal financial and time comparison has not been pursued, as the program’s benefits were considered to outweigh any marginal cost differences 
  • Sanitation evaluation is currently underway 


Future: 


  • Continue evaluation of sanitation practices in the context of EHM 
  • Refine SFSB techniques in line with updated guidance 

Interested in Sharing Your Institution’s Experience? 

If your institution has successfully implemented environmental health monitoring and you are interested in presenting your experience as a case study, we would love to hear from you. Case studies help the broader research community learn from real-world implementation experiences and are a valuable resource for institutions considering making the switch. 


Please reach out to aleezastephens@3rc.org to express your interest or learn more about how to get involved.