Biomedical Engineering Reference
In-Depth Information
ensuring that the observations made by the animal techni-
cians result in timely veterinary intervention.
Following the 72-hour acclimation period, animals
should be chemically immobilized and examined by
a veterinarian. At this time a physical examination should
be performed to document the health of the animal and
animals should receive their first tuberculin skin test. If
necessary, they should be permanently identified at this
time with a tattoo or other identification method used by the
receiving facility. Correction of minor health problems
(e.g. dental tarter or minor hernias) should be delayed until
the end of quarantine, since treatment usually involves
extra personnel and equipment that increase the risk of
disease transmission.
The tuberculin skin tests should be evaluated at 24, 48,
and 72 hours by an individual competent in the interpre-
tation of the test and the results should be recorded in each
animal's medical record (see following sections). The
tuberculin test and body weight determination should be
repeated every 2 weeks for the duration of the quarantine
period, with a minimum of three consecutive negative
tuberculin tests (Roberts and Andrews, 2008).
Animals' weight histories should be carefully moni-
tored and animals that have lost more than 20% of their
body weight or young animals who are not gaining weight
after 45 days should be reexamined and evaluated. It can
sometimes take many months for animals to recover weight
lost during transport, but additional causes for weight loss
should be considered and ruled out as appropriate. If
a cause for the weight loss can be identified, then appro-
priate treatment options should be instituted immediately.
If no cause is identified or a disease without an adequate
treatment is identified, then a decision should be made as to
the value of that single animal compared to the rest of the
animals in that group and the overall colony health.
The risk of possibly introducing an infectious disease
should be considered against the value of that single
animal. Weight loss is a common clinical sign associated
with M. tuberculosis.
During the early part of quarantine, baseline clinical
pathology samples should be collected. This allows time
for repeat tests for equivocal results or for post-treatment
evaluation. Complete blood count, serum chemistry, thick
and thin blood smears, serum for storage and serological
testing, fecal sample for ova and parasite examination,
rectal swab for enteric pathogen culture, and an evaluation
for ectoparasites are among the tests usually performed.
Any tests with abnormal or equivocal results should be
performed a second time and any diseases identified should
be treated appropriately.
Appropriate immunizations can be administered during
the quarantine period but care should be taken that the
immunizations do not interfere with the diagnostic testing,
i.e. measles vaccine can interfere with tuberculin skin
testing. Administering prophylactic anthelminthics
is
generally performed while in quarantine.
Illness in Quarantine/Positive Tuberculin
Test
Nonhuman primates are susceptible to a host of disease
conditions, both infectious and noninfectious. The decision
to treat animals that have noninfectious diseases should be
based on the value of the animal because working in
quarantine involves additional equipment, labor, and time.
The decision to treat animals that have a potentially
contagious disease must be carefully evaluated on the basis
of the quarantine group, the potential risk to colony health,
and personnel health and safety. For new or young animals
(particularly wild caught) treatment of serious illness may
not be justified. For valuable animals or for those that are
transferring between institutions and have an extensive
research history, the risk may be justified.
Once the decision to treat is made, care must be taken to
protect other animals at risk. It is preferable to have dedi-
cated clinical equipment for the quarantine area. If this is
not possible, alternate policies and procedures should be
established to minimize disease transmission. Instruments
and supplies used should be either disposable or sterilized
with either steam or gas before use in other areas of the
facility. Treatments or procedures should be performed
after all other work is completed.
Because NHPs are extremely susceptible to tubercu-
losis, a positive TST should be immediately reported to the
quarantine veterinarian and decisive action taken. If any
animal in the group has a positive or suspicious TST
reaction, that animal should be removed and other animals
in the group should undergo five sequential negative TST
after removal of that animal before being cleared from
quarantine (Roberts and Andrews, 2008). In most cases of
an unequivocally positive tuberculin reaction, the decision
will be to euthanize the animal, perform a postmortem
exam, and submit tissue samples for histopathology, special
staining, and culture and sensitivity.
Laboratories such as the Mycobacterium branch of the
US Veterinary Resource Laboratory in Ames, Iowa, are
available for consultation (National Animal Disease
Center) as are state veterinary and human health labs. The
entire shipment of animals must begin a new quarantine
period following a positive TST in any single animal.
Animals that die in primary quarantine for unexplained
reasons should be handled cautiously. Animals should be
carefully double bagged, weighed, and submitted for
necropsy. The veterinarian should be notified immediately
and an immediate necropsy should be performed. It is
preferable for a veterinary pathologist with experience in
primate pathology to perform the necropsy, but
if
