Biomedical Engineering Reference
In-Depth Information
2010
). People whose jobs require animal contact should be
assigned other duties until all diagnostic tests are
completed and they are considered free of infection that
could shed tubercle bacilli.
Animals with overwhelming infection may be anergic
and give a negative tuberculin skin test (
Corcoran and Jaax,
1991
), so necropsy of all animals that die during quarantine
should be performed with tuberculosis in mind and with not
less than Biosafety Level 2 precautions and containment
equipment. Biosafety Level 3 practices and facilities are
recommended for animal studies using nonhuman primates
that are naturally or experimentally infected with M.
tuberculosis and M. bovis (
Centers for Disease Control/
National Institutes of Health, 2009
). Therefore, animals
that are tuberculin positive should be euthanized if this
level of containment is not available. Multidrug treatment
may be considered but only if appropriate isolation and
containment facilities can be provided and accurate
detection of infection is possible (
Ward et al., 1985; Wolf
et al., 1988
). All animals that have been housed in the same
air supply areas as infected animals should begin a new 90-
day quarantine period with biweekly tuberculin testing
every time a new reactor is identified. All previously
negative contact personnel should be tuberculin tested
again and access personnel kept to a minimum.
caution should be employed when using sharp instruments,
especially needles, when working with infected animals.
Salmonellosis
Salmonellosis is a systemic infection, and infectious Gram
negative rods can be found in feces, blood, and urine. The
asymptomatic carrier state exists in nonhuman as well as
human primates, so apparently healthy animals can shed
the bacteria and stress may precipitate the recurrence of
active disease (
Whitney, 1976
). It is important to remember
that animals with Salmonella-associated diarrhea, with or
without fever, may have infectious organisms present in
other body fluids. In addition, the ability of most Salmo-
nella species not only to survive but also to multiply for
considerable periods in moist organic material is an
important epidemiological feature. Where animals are held
in outdoor corrals or bedding is used, this potential for
contamination of soil and vegetation should be an impor-
tant consideration.
Prevention
Biosafety Level 2 practices, containment, and
facilities with enteric precautions are recommended. The
licensed typhoid vaccine provides only partial protection,
but may be useful for people who regularly work with
cultures or materials known to contain S. typhi (
Blaser
et al., 1980a,b
). However, it is not currently recommended
for individuals working with nonhuman primates since
studies have shown that there is little risk of Salmonella
infection to laboratory personnel and animal handlers
exposed to nonhuman primates (
Gerone, 1983
).
Leprosy
Spontaneously occurring infection with Mycobacterium
leprae, the etiological agent of human disease leprosy
(Hansen's disease), has been seen in chimpanzees (
Gormus
et al., 1991; Meyers et al., 1991
), armadillos (Dasypus spp.)
(
Walsh et al., 1975
), a mangabey (Cercocebus)(
Meyers
et al., 1980
), and a cynomolgus macaque (
Valverde et al.,
1998
). This agent cannot be grown satisfactorily in artificial
media and attempts to develop an animal model have
shown that armadillos are overwhelmed by the organism so
they are not suitable for efficient investigation of epide-
miology, immunology, and therapy. However, mangabeys,
rhesus monkeys, and African green monkeys (C. aethiops)
appear to be acceptable animal models for leprosy.
Human-to-human transmission of leprosy has been
reported following an accidental needlestick in a surgeon
(
Marchoux, 1934
) and the use of a presumably contami-
nated tattoo needle (
Parritt and Olsen, 1947
). The infec-
tious organisms can be found in tissues and exudates from
lesions of infected individuals. Therefore, infected animals
can pose a risk to their human handlers and failure to
sterilize instruments between animals could spread infec-
tion among them.
Tetanus
Clostridium tetani is an anaerobic, gram-positive, spore-
forming bacillus that causes tetanus by producing a potent
exotoxin that is intensely toxic to humans and animals
when it is formed in tissues or when injected. The organism
is found in soil and in the intestinal tracts of humans and
other animals. Tetanus was a major cause of death in the
free-ranging rhesus monkey colony on Cayo Santiago in
Puerto Rico before an immunization program was insti-
tuted (
Kessler et al., 2006
).
Prevention
Tetanus organisms are ubiquitous, so it is
recommended that all persons should be vaccinated. Since
the potential for receiving contaminated puncture wounds
from bites and scratches is greater when working with
primate animals than in many other occupations, personnel
records should show that all employees have received
a primary tetanus immunization course of three doses fol-
lowed by a booster every 10 years. Up to date records
should be available and provided to healthcare profes-
sionals treating work-related wounds so that appropriate
tetanus coverage can be given.
Prevention
Biosafety Level 2 practices, containment, and
facilities are recommended. Special care should be taken to
avoid accidental transmission by the exposure of skin and
mucous membranes to infectious materials, and extreme
