Trypanosoma cruzi (Chagas' disease)
X0010 - Ultrasensitive qualitative detection of
by real time polymerase chain reaction
a protozoan parasite, causes Chagas' disease (“American
trypanosomiasis”). It is transmitted through parasitic
blood-feeding arthropod vectors of the family Reduviidae, particularly
Triatoma spp. (assassin bugs or "kissing bugs"), which occur naturally in
Central and South America. These insects normally transmit the infectious
stages of the protozoa to mammals through contamination of the
insect's bite by its feces, although vertical
transmission of T. cruzi
has also been shown to occur (Azogue et al., 1985; Miles, 1972).
Various mammals, including human beings, are the natural hosts
of Triatoma spp.
as well as T. cruzi.
Wild-caught New World monkeys from Central or South America are
often infected with
Trypanosoma species, including
T. cruzi. Old World
monkeys, including some macaques (eg
Macaca nigra) and
lemurs (eg Lemur catta),
are also susceptible when translocated into the geographic range
of reduviids or when experimentally infected.
Infected primates may remain subclinical for years
or may infrequently produce a variety of clinical effects such
as anorexia, dyspnea, fever, leukocytosis, lymphadenopathy and
myocarditis. During remission, the parasite may remain
undetectable in the blood for long periods, then return to
detectable levels periodically, often triggered by stress or
immune system challenge. In humans, reactivation of Chagas' disease in
patients infected with the human immunodeficiency virus (HIV)
has been reported since the early 1990s. The clinical
manifestations of reactivated Chagas' disease are severe central
nervous system (CNS) alterations and cardiomyopathy.
Trypomastigotes of T. cruzi,
observed by direct microscopic examination of blood smears,
characterize the acute phase of infection and confirm Chagas'
disease reactivation. Reactivation of
T. cruzi has also
been reported in rhesus monkeys experimentally infected with
colonies, T. cruzi
can be propagated between animals by blood-to-blood exposure, sexual
activity, and transplacental transmission. Animal handlers and
laboratory staff who handle blood and tissue from infected New
World monkeys are at risk for acquiring Chagas' disease via
laboratory diagnosis of T.
cruzi relies on blood smear observation or
serological detection. Unfortunately, these methods lack
sensitivity and specificity. PCR detection of this parasite
offers significant advantages over traditional methods in terms
of both specificity and sensitivity (Ndao et al., 2000;
Gutierrez et al., 2004).
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
diagnosis of T. cruzi
Help ensure that animal colonies are free of
Early prevention of spread of this parasite among a
Minimize personnel exposure to this parasite
Safety monitoring of biological products and vaccines
that derive from primates
Azogue, E., La Fuente, C. and Darras, C. (1985) Congenital
Chagas' disease in Bolivia: epidemiological aspects and
pathological findings. Trans R Soc Trop Med Hyg 79:176-180.
Gutierrez, R., Angulo, V.M., Tarazona, Z., Britto, C. and
Fernandes, O. (2004) Comparison of four serological tests for
the diagnosis of Chagas disease in a Colombian endemic area.
Miles, M.A. (1972) Trypanosoma
cruzi-milk transmission of infection and immunity from mother to
young. Parasitology 65:1-9.
Ndao, M., Kelly, N., Normandin,
D., Maclean, J.D., Whiteman, A., Kokoskin, E., Arevalo, I. and
Ward, B.J. (2000) Trypanosoma cruzi infection of squirrel
monkeys: comparison of blood smear examination, commercial
enzyme-linked immunosorbent assay, and polymerase chain reaction
analysis as screening tests for evaluation of monkey-related
injuries. Comp. Med. 50:658-665.
Specimen requirement: 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
tube, or 0.2 ml plasma, serum or CSF.
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
real time PCR