Sentinel Surveillance Procedures
including Soiled Bedding Transfer
Date Issued: April 17, 1999
Comparative Medicine Resources
Date Revised: September 1, 1999; September 23, 2002; January 22, 2003;August 26,
2008; January 16, 2012
Purpose:
To describe procedure for rodent sentinel orders, placement, soiled bedding transfer, and testing profiles.
Introduction:
Sentinel rodents are used to monitor the pathogen status in rodent colonies. Infectious agents or pathogens
may be transmitted by airborne particles or directly by fecal-oral exposure. In order to maximize exposure of
sentinels dirty bedding containing urine and feces from research rodents is placed in sentinel cages.
Sentinel animals’ blood is tested for antibodies that are produced in response to pathogens that may be
present in the research rodents. Skin and feces are screened for ecto- and endoparasites. Sentinels are
tested at least once every four months.
A. Procedure:
Sentinel rodents and identification
1. For routine surveillance order non-contact sentinel rodents quarterly so that there are always rodent
sentinels in the room. Sentinel evaluation months are January, May, and September (see final
page). Sentinels shall be distributed in each room so that there is a ratio of approximately 50
investigative animal cages per one pair of sentinel rodents; when multiple PIs are part of the ~50
cages, list them on the sentinel cage card. If there are no sentinels in the room, Caretaker must
promptly notify Vet Tech or Supervisor in charge of that room.
2. Age and strain of sentinel rodents.
Species
Mouse
Rat
Hamster
Guinea Pig
Woodchuck
Strain
Swiss-Webster
Sprague-Dawley
Syrian (golden)
None (sample PI rodents)
None (sample PI rodents)
Sex
F
F
F
F
F
Age
4-6 weeks
4-6 weeks
4-6 weeks
N/A
N/A
3. Sentinel rodents are identified on the cage card with a 1-inch x 3-inch colored sticker labeled as
“Sentinels”; the color of the sticker should vary between alternating groups of sentinels of each
quarterly period.
B. Soiled Bedding Transfer: responsibility and frequency of sampling
1. The Animal Caretaker (ACT) performs dirty bedding transfer when cages are regularly changed.
2. Soiled Bedding Change Amount and Frequency:
Cage Type
No. of Cages Sampled
per Change Cycle
Standard Non-ventilated
~25
~50
Standard Ventilated
ALL
Quarantine Ventilated
Minimal Frequency
of Cage Change
once weekly
once every 2 weeks
once every 2 weeks
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C. Sampling procedures
1. Select cages (see table above) per P.I. or group of PIs as listed on each sentinel card to collect soiled
bedding sample. When the first soiled bedding transfer is made to newly arrived sentinels, write the
date of the transfer on the cage card.
2. Place a purple round sticker on the corner of each cage card and write the date of the soiled bedding
transfer with a pen. If there already is a purple sticker on the cage card place the new dot slightly on
top of the old one. The decal sheets are located in a plastic sleeve on the rear of the door.
3. Choose cages that have not been sampled previously.
4. If all cages have already been sampled, begin another round of sampling on the same cage.
5. If there are only 5-10 cages in the room, sample all cages at the regular change interval.
.
D. Take a Get a clean cage to use for dirty bedding
1.
2.
Place a clean cage with clean bedding handy. In the barrier, place any open cage in the hood.
This will be the new sentinel cage.
E. Start changing cages for the research rodents
1.
After the selected cage to be sampled has been changed and the research rodents have been
moved to their clean cage, add the dated purple label and take a sample from the most fecalsoiled part of the bedding. Use a disposable plastic spoon and transfer one teaspoonful to
new sentinel cage without the sentinels in the cage.
2.
Discard the used spoon once each sentinel cage is completed.
3.
Change the sentinels last.
4.
Place the sentinels in the “clean” cage, which has been primed with dirty bedding.
F. When new sentinels arrive
When new sentinels, the ACT houses the animals in the appropriate cage system for the room. Remove
all previous purple dots from all the cages and start from scratch sampling and labeling the cages.
G. Sentinel evaluation
At three months the sentinels after the first bedding change, sentinels from the room are humanely
killed and sampled. Do not submit blood from sentinels that are greater than six months of age, and
do not pool serum samples.
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Rodent Sentinel Health Surveillance Program Description (TABLE 2)
January 2011
Soiled bedding transfer
Two 4-6 week old female Swiss Webster mice,
Sprague-Dawley rats, Syrian hamsters and/or gerbils
are placed in all rodent rooms every three months.
One teaspoon each of soiled bedding from the number
of cages per group (see table 1) are housed with the
sentinel rodents at the time of the cage change. All
cages are sampled each cage change except for nonventilated cages. At least two sentinels are placed for
approximately 50 colony cages. After at least six
weeks of exposure to soiled bedding at least one
animal is submitted for pathology. This includes gross
necropsy, serum collection and parasitology. Once a
room tests positive for a pathogen, three consecutive
monthly negative serology findings are required to
deem the room pathogen-free of any specific agent.
Serology timetable
Guinea Pig
Clinical
Basic
MAY Primary
Primary
Clinical
Basic
SEP Comprehensive
Comprehensive
Comprehensive Comprehensive
plus Hantaan virus
Serology profile panels
Mouse
Panels
Rat
Panels
Microbiology and Histology
Helicobacter species are examined via PCR in mouse
colonies only at the request of the researcher. Histologic
and bacteriologic samples are examined as indicated
based on observation of gross lesions and clinical signs.
Barrier Procedures
All cages, bedding, food and water are autoclaved;
All work with cages and animals are performed
in a BSL II Hood;. Complete PPE is mandatory for entry,
and when forceps are not used during animal handling,
gloves are used to handle rodents during between each
group of animals when there are different IACUC
protocol numbers. All surfaces are disinfected with
chlorine dioxide solution [MB-10 ® or Vimoba ®] before
and after each protocol/investigator and at the beginning
and end of the work period.
Hamster
Primary
Necropsy
Dissection and examination of thoracic and
abdominal organs are performed. Gross lesions
are reported to a veterinarian and stored in 10%
formalin.
Parasitology
Ectoparasitology: pelt exam by dissecting scope
Endoparasitology:
1) Microscopic exam of cecal contents
2) Fecal floatation
3) Cellophane tape exam of perineum
Rat
Mouse
JAN Primary
Hamster
Panels
Guinea Pig
Panels
Primary
Minute Virus of Mice (MMV)
Mouse Parvovirus (MPV1-3 and generic NS1)
Mouse Hepatitis Virus (MHV)
Theiler’s MeningoEncephalomyelitis Virus (TMEV)
Epizootic Diarrhea of Infant Mice (EDIM)
Mouse Norovirus (MNV)
Comprehensive: Primary Panel plus
Ectomelia Virus (ECTR)
Lymphocytic Choriomeningitis Virus (LCM)
Mouse Adenovirus (MAD1) (MAD2)
Pneumonia Virus of Mice (PVM)
Polyoma Virus (POLY)
Respiratory Enteric Orphanvirus III (REO3)
Sendai Virus (SEN)
Mycoplasma pulmonis (MYCO)
Hantaan virus (HAN)
Primary
NS1 (Generic Parvo)
Rat Parvovirus (RPV)
Kilham’s Rat Virus (KRV)
Rat Coronavirus (RCV)
Toolan’s Virus (H-1), a parvovirus
Rat Theilovirus (RTV)
Rat Minute Virus (RMV), a parvovirus
Comprehensive: Primary Panel plus
Sendai Virus (SEN)
Mycoplasma pulmonis (MYCO)
Pneumonia Virus of Mice (PVM)
C. piliformis (Tyzzer’s)
Respiratory Enteric Orphanvirus III (REO3)
Lymphocytic Choriomeningitis Virus (LCM)
Hantaan virus
Cilia Associated Respiratory Bacillus ( CARB)
Mouse adenovirus, strain 1 (MAD 1)
Clinical
C. pilofrmis (Tyzzer’s)
Sendai Virus (SEN)
Lymphocytic Choriomeningitis Virus (LCM)
Comprehensive: Clinical Panel plus
Simian virus 5 (SV5)
Respiratory Enteric Orphanvirus III (REO3)
Encephalitozoon cuniculi
Pneumonia Virus of Mice (PVM)
Basic
C. pilofrmis (Tyzzer’s)
Sendai Virus (SEN)
Encephalitozoon cuniculi
Pneumonia Virus of Mice (PVM)
Caviid parainfluenza virus 3 (PI3)
Lymphocytic Choriomeningitis Virus (LCM)
Comprehensive: Basic Panel plus
Guinea pig cytomegalovirus (GPCMV)
Simian virus 5 (SV5)
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