Rodent Health Monitoring Program

Overview | Excluded Agents | Sentinels | Importing Rodents | Incoming Quarantine | Shipping Rodents | Internal Rodent Transfers | Outbreaks | Biologicals Testing

OVERVIEW

Specific Pathogen Free (SPF) facilities are designed to maintain rodents in an environment free of infectious agents known to be pathogenic and/or capable of interfering with research objectives (see Excluded Agents). The Rodent Health Monitoring Program (RHMP) tracks the infectious agent status of individual rodent racks, room by room. This is accomplished via the sentinel monitoring system (see Sentinels.)

The RHMP generates room and facility health reports based on the findings of the sentinel monitoring system. These health reports are provided upon request to investigators wishing to ship rodents to other institutions (see Shipping Rodents.)

The RHMP reviews requests to receive rodents from other institutions (Non-Approved Vendors), and either approves or disapproves these requests based on the pathogen status of the sending institution (see Importing Rodents). Rodents from Non-Approved Vendors go through Incoming Quarantine before being housed. The length of stay in quarantine (usually 5-9 weeks) is determined by the RHMP, again depending primarily on the pathogen status of the sending institution.

Results of “biologicals” testing are also reviewed by the RHMP prior to the use of such materials of biological origin in UW and Harborview rodents (see Biologicals Testing.)

Requests to transfer rodents between facilities (and sometime rooms) within the UW system are routed through the RHMP for approval (see Internal Rodent Transfers.)

Should an infectious agent be detected, the RHMP is responsible for its elimination. The entire room is placed under quarantine until the infected rodents are identified and removed (or otherwise cleared of their infection) and successive rounds of sentinel testing demonstrate that the infectious agent is no longer present (see Outbreaks.)

EXCLUDED AGENTS

The following infectious agents are excluded from University of Washington specific pathogen free (SPF) rodent housing facilities:

• Mouse hepatitis virus (MHV)
• Mouse parvovirus (MPV)
• Minute virus of mice (MVM)
• Reovirus-3 (Reo-3)
• Pneumonia virus of mice (PVM)
• Epizootic diarrhea of infant mice (EDIM)
• Theiler’s murine encephalomyelitis virus (TMEV)
• Lymphocytic choriomeningitis virus (LCMV)
• Ectromelia (mouse pox)
• Sendai virus
• Sialodacryoadenitis virus (SDAV)
• Rat parvoviruses
• Mycoplasma pulmonis
• Pinworms
• Fur mites

Helicobacter spp. are excluded from selected animal rooms.

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SENTINELS

Roughly analogous to the “canary in the coal mine”, sentinel rodents monitor the pathogen status of investigators’ rodents. Every rack in a room is monitored. As you are facing a rack, the cage containing the two sentinels usually resides in the lower right-hand position.

Every time an investigator’s rodent cage is changed (usually weekly), about a tablespoon of soiled bedding from that cage is transferred to the sentinel cage. In this way, sentinels are exposed to whatever pathogens may be present in the urine, feces, fur, saliva, dander, etc. from 100% of the cages on the rack. Because of this, investigator personnel must not handle or move sentinels or sentinel cages.

At the end of the monitoring period (usually one quarter, or twelve weeks) the sentinels are sampled and tested for a battery of infectious agents. Sentinels may be tested more or less frequently for selected pathogens.

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IMPORTING RODENTS

Rodents may be imported into UW animal facilities from either of two general classes of animal vendors: Approved and Non-Approved Vendors.

Approved Vendors

Approved Vendors are generally the larger commercial companies, like Charles River, Jackson Laboratories and Taconic Farms, which perform frequent testing and guarantee that their rodents are free from a long list of potential pathogens, including zoonotic agents (pathogens transmissible to humans).

Rodents purchased from Approved Vendors may be housed directly in rodent housing rooms. To order rodents from an Approved Vendor, or to get a current list of Approved Vendors, contact Animal Purchasing in room T-150. Forms are available in Animal Purchasing or online (see Forms Online). Submit the completed request form to Animal Purchasing, T-150, fax 206-543-7706, animals@u.washington.edu. ***You do not need RHMP approval to order from an Approved Vendor.***

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Non-Approved Vendors

Examples of Non Approved Vendors (NAVs) include smaller commercial vendors, other educational institutions, biotechnology firms, and non-profit research organizations like Fred Hutchinson Cancer Research Center. The difference between an Approved and a Non-Approved Vendor designation has to do with frequency of pathogen testing, quality and security of facilities and transport methods, in-and-out traffic of animals (and people), history of outbreaks, etc. For example, the University of Washington would be considered a Non-Approved Vendor to another institution.

An NAV Request Packet may be obtained from Animal Purchasing in room T-150 or online (see Forms Online). The packet includes the NAV Request form, a blank request for health reports from the sending institution, and guide to ordering animals from non-approved vendors. The final step in the process is approval by the Rodent Health Monitoring Program (RHMP). For this, the RHMP must have the filled-out NAV request form from the UW investigator requesting the animals, and current (within the last three months) health reports from the sending institution.

Most NAV requests receive prompt approval, because health reports from the sending institution are complete, up-to-date, and indicate no evidence of infection. However, sending institutions are sometimes under quarantine for an outbreak themselves, and approval must be delayed until the institution has brought the infection under control. One of the functions of the RHMP is to work with the sending institution to resolve such issues.

Once a shipment is approved, the investigator will be notified of the shipping date. When the rodents arrive, they will be housed in Incoming Quarantine for a period of time (see Incoming Quarantine).

In rare instances, approval may be denied. This only happens when the sending institution is unable or unwilling to eradicate the infection(s). The investigator will be notified of the disapproval, and various options will be explained by the RHMP. Embryo rederivation, possibly by an Approved Vendor, is usually the most reliable way to eliminate an infection.

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INCOMING QUARANTINE

Rodents arriving from a Non Approved Vendor must go through a period of Incoming Quarantine before being released into the general animal facility population. The length of stay in Incoming Quarantine is determined by the RHMP, and depends primarily on the overall pathogen status and outbreak history of the sending institution. Most Incoming Quarantine stays last 5-9 weeks, including testing.

During quarantine, sentinels are assigned to monitor each shipment. At the end of the quarantine period, the pathogen status of the investigator’s rodents is assessed via testing these sentinels. The investigator will be notified when his or her rodents “pass” quarantine and are released by the RHMP to their final, pre-approved room destination.

Breeding is permitted in Incoming Quarantine two weeks prior to the scheduled release date. This is so pups aren’t born in quarantine. Please contact the RHMP if you want to set up breeders, or if delicate mice need to be bred earlier to avoid being unable to breed at all.

Rodents may be removed from Incoming Quarantine for terminal procedures. Please contact the RHMP if you wish to retrieve your rodents from quarantine for this purpose.

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SHIPPING RODENTS

Since the University of Washington is generally considered a Non-Approved Vendor by other institutions, investigators wishing to send their rodents to collaborators elsewhere will need to ask the Rodent Health Monitoring Program (RHMP) for a current Rodent Health Monitoring report. The RHMP will ask for information (such as where the rodents are located) and forward the appropriate health report to the sending institution. Please submit it to Rodent Health Monitoring, fax 206-221-4261, rhmp@u.washington.edu.

NOTE: It is entirely up to the receiving institution whether or not it will accept the rodents. The RHMP is not involved beyond providing health reports. However, the RHMP is happy to help clarify any issues the receiving institution may have regarding the pathogen status of the animals or our facilities in general.

Rodents destined for interstate or international travel must be accompanied by a health certificate. This is different from a rodent health monitoring report. Health certificates are available through Veterinary Services. Please allow three (3) days to obtain a health certificate, as the rodents must be physically examined by a veterinarian.

It is imperative that the investigator wait to ship until approval is granted (in writing) by the receiving institution. Once approval is granted, the investigator is responsible for packing the rodents safely for their journey, making the shipping arrangements with the appropriate commercial carrier, and actually delivering the rodents into the hands of the commercial carrier’s delivery person. The RHMP and Vet Services are pleased to offer advice on these matters, but they do not select, pack, or ship the animals themselves.

For more information on shipping please see the shipping section of the Veterinary Services page.

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INTERNAL RODENT TRANSFERS

To transfer rodents between UW facilities (K-wing, T-wing, 6 th floor, HR&T, Brotman, etc.), obtain an Inter-Facility Animal Transfer Request packet from the Animal Purchasing Office in room T-150 or online (see Forms Online) Complete the enclosed Animal Transfer Request form, and submit it to Rodent Health Monitoring, fax 206-221-4261, rhmp@u.washington.edu. Your request will first be reviewed by the facility supervisor for housing approval.

Once housing is approved, the Rodent Health Monitoring Program (RHMP) will check the health status of the sending and receiving institution. The RHMP coordinator will notify you by email when your transfer has been approved. Except for transfers between the UW, Harborview, and or Brotman, you are responsible for the physical transfer of your rodents. Please see your facility supervisor for instructions and supplies.

Rodent transfers between 6 th floor animal facility rooms also require housing and RHMP approval. Please fill out and submit an Animal Transfer Request form, as above. Rodent transfers within the K-wing, T-wing and HR&T barrier facilities do not require approval. Please ask the facility supervisor for instructions, however, and keep your own records of such transfers.

Rodent transfers from one UW investigator to another also require an Animal Transfer request form, even if the rodents don’t leave the room. This is so the appropriate adjustments may be made to the protocols of the respective investigators.

Approved transfers from modified SPF facilities to barrier SPF facilities will require a stay in quarantine (usually 5 weeks). The reverse, approved transfers from barrier facilities to modified SPF facilities, do not require quarantine. This simply reflects the higher level of SPF protection afforded by barrier versus modified SPF housing conditions.

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OUTBREAKS

What happens if a pathogen is detected? The entire room is placed under quarantine, and the investigators are notified by the Rodent Health Monitoring Program (RHMP).

What happens next depends on the type of pathogen that was detected. In the case of a parasite like pinworms or fur mites, treatment is begun by Veterinary Services. Treatment is generally effective, but can be lengthy and expensive. For example, pinworm treatment takes 3 months.

In the case of a virus like mouse hepatitis virus (MHV), or certain of the bacteria for which no effective treatment exists, infected rodents are identified through testing conducted by the RHMP. Usually, rodents found to be infected are euthanized. If an entire line of rodents is infected however, and cannot be found at another SPF facility, then there may be other options we can explore to save the line from extinction. Embryo rederivation is one of those options.

Once virus- or bacteria-infected rodents have been identified and removed, new sentinels are brought into the room and receive soiled bedding from the remaining animal cages. Successive rounds of sentinel testing are conducted until it is determined that the pathogen is no longer present in the room. Usually this takes four consecutive negative tests.

How long quarantine last depends on the pathogen involved, and how well its spread was contained before anyone knew it was there. This last statement can’t be overemphasized. As long as SPF procedures are rigorously followed by all workers, all of the time, it’s quite possible for a pathogen as infectious as MHV to be limited to a single cage!

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TESTING BIOLOGICALS

Materials of biological origin (biologicals) may harbor one or more of the infectious agents that are excluded from SPF rodent facilities. Examples of biologicals that can transmit infectious agents include serum, cell lines, transplantable tumors and tissues such as bone marrow.

Fortunately, biologicals can be tested for infectious agents, and this should be done before they are introduced into animals. (An exception can be made for biologicals developed de novo from our own SPF rodents.)

PCR (polymerase chain reaction) is currently recommended as a more rapid, cost-effective and, in some cases, more sensitive alternative to antibody production tests. Both Charles River Laboratories and RADIL (University of Missouri) do PCR testing on biological materials. Either service is acceptable. For pricing and sample submission instructions, please visit their websites:

http://www.radil.missouri.edu/info/DiagTesting/services/molecularbiology.asp

• Select IMPACT Profile III for mice
• Select IMPACT Profile V for rats

http://www.criver.com/products/diagnostics/dxinfectious1.html

Please forward your test results (and questions) to the Rodent Health Monitoring Program:

rhmp@u.washington.edu - Fax 206-543-7706

Updated May 14th, 2008