Biomedical Engineering Reference
In-Depth Information
will not be detected unless brain tissue is specifically sub-
jected to fluorescent antibody or other definitive examina-
tion (
Richardson and Humphrey, 1971
).
Prevention
The accident just described reinforces the
recommendation for wearing goggles, glasses, or a face
shield when handling infectious agents. It also emphasizes
the importance of always having an alcohol sponge, sterile
cotton ball, or gauze around the tip of the needle on
a syringe of infectious material, even for tapping out the
bubbles, while exercising extreme caution to prevent
needlestick, the most common laboratory accident.
Prevention
The tissues and excretions of naturally or
experimentally infected animals are potential sources of
human exposure; the highest titers are in the central
nervous system, salivary glands, and saliva. Preexposure
vaccination should be offered to individuals working with
newly imported primates in quarantine and is recom-
mended for those working with rabies virus or known
infected animals. Accidental parenteral inoculation, cuts or
sticks with contaminated laboratory equipment, bites from
infected animals, and exposure of mucous membranes or
broken skin to infectious droplets of tissue or fluids are the
most likely means of exposure. Wounds should be thor-
oughly washed with soapy water and deep puncture
wounds flushed via catheter; cautery and suturing are not
recommended. Both human diploid cell vaccine and rabies
immune globulin (RIG) should be given immediately. If
RIG is not available, antirabies serum (equine origin) is
recommended (
Jackson, 2011
).
Although it may not be feasible to open the skull or
remove the brain within a biological safety cabinet, it is
pertinent to wear heavy protective gloves to minimize the
chance of injury from instruments or bone fragments and to
wear a face shield to protect the mucous membranes of the
eyes, nose, and mouth from exposure to droplets or tissue
fragments. If an oscillating saw is used to open the skull,
care should be taken to avoid striking the brain with the saw
blade (
Centers for Disease Control/National Institutes of
Health, 2009
). These recommendations apply to all
nonhuman primate necropsies.
Papovavirus Infection
Papovavirus-like particles were found in tissue taken from
an oral mucosal lesion of focal epithelial hyperplasia in
a chimpanzee. Striking nodular elevations were found
primarily on the mucosa of the lips but were also present on
the buccal mucosa and tongue. In the outbreak described,
lesions were found in 16 of 45 chimpanzees examined. At
the same time, several animal caretakers reported warts
(verucca vulgaris) on the knuckles of fingers that were
sometimes bitten by young chimpanzees. Since the papil-
lomavirus that causes human warts is a papillomavirus
from the family Papovaviridae, it was speculated that the
two were related, but this was not confirmed (
Hollander
and van Noord, 1972
). Papilloma viruses have been iso-
lated from rhesus monkeys and have a disease pattern
similar to human papilloma virus infections (
Kloster et al.,
1988
).
Prevention
If indeed the human warts were related to the
chimpanzee oral lesions, wearing gloves should have pre-
vented spread of the virus. If caretakers accustomed to
having chimpanzees bite their fingers suffered no more
serious consequence than warts, they were fortunate
because even small nonhuman primates such as squirrel
monkeys and marmosets can inflict serious bite wounds.
Adenovirus Infections
Simian adenoviruses have been associated with infections
of the respiratory tract (
Boyce et al., 1978
), eye, pancreas
(
Chandler et al., 1974
), and urinary tract (
Asher et al.,
1978
).
These viruses have not been of major zoonotic impor-
tance, but there is one report of human infection with
a simian adenovirus that illustrates a potential source of
accidental laboratory infection. A technician, attempting to
remove an obstruction that developed in the needle on
a syringe filled with SV23 during a series of animal inoc-
ulations, sprayed a drop of virus into the eye of one of the
operators. Severe conjunctivitis developed, spread to the
other eye, and persisted for 5 weeks, but recovery was
complete without sequelae (
Hull, 1969a
). The use of
adenoviruses and adeno-associated virus for gene transfer
studies is a more likely means of transmission and moni-
toring of active shedding of
Spongiform Encephalopathy Agents
The causative agents of the spongiform encephalopathies
known as Creutzfeldt
e
Jakob disease and Kuru in people,
scrapie in sheep, and others are in a class by themselves
(
Brown et al., 1984
). They have an extraordinarily long
incubation period that ranges from months to decades so
they have been known as “slow viruses” or “unconventional
viruses” and, most recently, as “prions.” This name was
derived from the “protein-like infectious particles” found in
brain tissue infected with scrapie (
Prusiner, 1982
). These
agents are extremely resistant to all standard means of
sterilization: acetone, alcohol, hypochlorite, iodine,
peroxide, permanganate, formaldehyde, glutaraldehyde,
ethylene oxide,
b
-propiolactone, nucleases, proteases,
detergents, ultraviolet radiation, ultrasonic energy, or even
steam autoclaving for less than an hour (
Chatigny and
Prusiner, 1980; Brown et al., 1982; Chatigny, 1989
).
these agents must be
performed.
