Biomedical Engineering Reference
In-Depth Information
Prevention
The insect vectors of Chagas disease are found
in the southwestern USA, where many nonhuman primates
are held in outdoor facilities and there are about 80 North
American species of Chrysops. Therefore, Biosafety Level
2 conditions with special attention to vector control are
recommended.
Prevention
Biosafety Level 2 is recommended, and
immunocompromised individuals should not work with
animals known to be infected with P. jiroveci.
Amebiasis
Entamoeba histolytica produces dysentery in both human
and nonhuman primates (
Haq et al., 1985
), but in monkeys
and apes an asymptomatic state may exist (
Whitney, 1976
).
Animals with this type of infection can be more dangerous
than those with overt symptoms. Although bloody dysen-
tery causes concern, formed stools do not. The trophozoite
forms found only in soft stools are fragile, but the infective
cysts that are found in normal feces are resistant to drying
and chemical actions. These cysts are readily transmitted in
or by food, water, insects, and fomites and pose a real
hazard to other animals and people in contact with them
(
Remfry, 1978
). E. histolytica and E. dispar have been
identified in captive macaques in the Philippines, empha-
sizing the need for screening imported animals (
Rivera
et al., 2010
).
Leishmaniasis
Leishmaniasis, caused by the protozoan flagellate Leish-
mania spp., is spread by sandflies of the genus Phlebotomus.
Human infection with L. tropica produces a nodular cuta-
neous lesion followed by local ulceration; it is self-healing
over a period of weeks to months. Recovery is associated
with immunity to infection. L. donovani produces kalaazar,
a chronic visceral infection in humans. Both are found in
monkeys, andM. mulatta have been experimentally infected
with L. tropica to study the humoral immune response
(
Wolf, 1976
). Laboratory-associated infections with these
organisms have been reported (
Centers for Disease Control/
National Institutes of Health, 2009
).
Prevention
Biosafety Level 2 with special attention to
vector control is recommended. Infective stages of all of these
bloodborne parasites may be present in blood, feces, lesion
exudates, and infected arthropods. Depending on the parasite,
accidental parenteral inoculation, transmission by arthropod
vectors, skin penetration, and ingestion are the primary
laboratory hazards. It is almost impossible to prevent all
mosquitoes and other arthropods from gaining access to
human and animal housing, and chemical insecticides should
not be used in animal quarters. However, electrified insect
traps with ultraviolet light attraction, advantageously placed
near doors in animal rooms, can minimize the risk of vectors
transmitting bloodborne parasites.
Prevention
Biosafety Level 2 with particular attention to
enteric precautions and good hygiene is recommended.
Enteric Flagellate Infections
Trichomonas spp. and Giardia spp. occur in large numbers
in the intestinal tracts of nonhuman primates (
Whitney,
1976
). Studies of G. lamblia among children of preschool
age showed that hand-to-mouth transmission by fecal
contamination of fingers, toys, and the environment is the
major source of infection in this setting. Infected children
serve as reservoirs of endemic infection from which
siblings, parents, day-care workers, and their friends are
infected (
Pickering et al., 1984
).
Pneumocystis
Pneumocystis jiroveci (previously P. carinii) appears to be
cosmopolitan; it infects many domestic and farm animals
as well as nonhuman primates and humans (
McClure and
Keeling, 1971; Poelma, 1975
). It was known to cause
pneumonia epidemics in premature or debilitated infants,
but came into the limelight as one of the major opportu-
nistic infections in patients with AIDS (
Durack, 1981
). It
has occasionally been observed in association with respi-
ratory disease in macaques and may cause pneumonia in
animals that are severely debilitated or immunosuppressed
(
Henrickson, 1984
) such as those infected with SIV (
Board
et al., 2003; Patil et al., 2003
).
Traditionally, the definitive diagnosis of P. jiroveci
infection requires demonstration of the organism in the
lung or lower respiratory tract by biopsy, but serological
diagnosis by antigen detection is also used (
Pifer et al.,
1978
) as is PCR (
Board et al., 2003; Jiancheng et al., 2009
).
Prevention
There is no known zoonotic transmission, but
the analogy between nursery school and primate housing
facilities is apparent, and the preventive measures of
Biosafety Level 2 and good hygiene are applicable to both.
Cryptosporidiosis
Cryptosporidium spp. are pathogenic agents of diarrhea in
both immunologically intact and immunosuppressed
humans and nonhuman primates. A reproducible experi-
mental model for studying this disease has been developed
in M. nemestrina (
Miller et al., 1990
). The disease is nor-
mally an acute, self-limited diarrhea, but it has severe
implications for immunocompromised individuals and has
become prominent as an opportunistic infection of AIDS
patients (
Wormser, 1985
) and SAIDS monkeys (
Baskin
et al., 1997; Kaup et al., 1998
).
