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The parasite plays a fundamental role in the
genesis and development of organs lesions by sequentially
inducing an inflammatory response, cellular lesions,
and fibrosis. Such pathological processes may
occur in many organs but appear more frequently
and more intensively in the heart, esophagus,
and colon.
The inflammatory response results from the rupture
of infected cells releasing trypomastigotes ,
potent proinflammatory parasitic molecules, and
cellular debris. It is intense in the acute phase,
during which multiple cycles of intracellular
parasite multiplication occur (leading to high
parasitemia), but it is less intense in the chronic
phase, when infection is partially controlled
by the immune response.
The cellular lesions mainly affect the myocytes
(myocytolysis) and the nervous cells (leading
to an autonomic denervation). They result from
direct destruction due to intracellular parasitism,
necrosis related to inflammation, and other cytotoxic
mechanisms involving CD8 T cells and, less frequently,
CD4 T cells.
The fibrosis appears slowly and gradually (healing
process) and regresses in the same manner. The
fibrosis associated with chronic chagasic myocardiopathy
is more intense than the fibrosis associated with
any other cardiopathy.
The heart is frequently affected in chronic.
Chagas disease, with significant destruction of
the conduction system, myocytes, and parasympathetic
cardiac nerves. This and the appearance of arrhythmogenic
electric foci in the inflammatory areas are at
the origin of the arrhythmic syndrome. The hypertrophy
of the remaining myocytes and the intense fibrosis
replacing the destroyed myocytes predispose to
cardiac dilatation and failure. The left ventricular
wall becomes thinner , allowing the formation
of an apical aneurysm, a feature of chagas disease.
Thrombi are often present in such aneurysm, easily
explaining the common occurrence of systemic and
pulmonary thromboembolism.
At the digestive level , the lesions (para sympathetic
intramural denervation) are dispersed irregularly
and mainly affect the esophagus and the colon
(more frequently, the sigmoid colon). The affected
segment may have a normal macroscopic appearance
with only functional peristaltic alteration, it
may be dilated (megaesophagus or megacolon). Volvulus
of the sigmoid colon is a complication appearing
in advanced cases is associated with a high risk
of necrosis.
Source of Information
• Yves Carlier, MD, MSc.
Chagas Disease (American Trypanosomiasis)
eMedicine.com, Inc.
http://www.emedicine.com/med/topic327.htm
Used with permission from eMedicine.com,
Inc., 2004. Carlier Y, Luquetti AO, Dias JCP, Truyens
C, et al. Chagas Disease (American Trypanosomiasis).
eMedicine Journal [serial online]. 2004. Available
at: http://www.emedicine.com/med/topic327.htm. Accessed
Date (i.e., January 19, 2004).
More Information
• The Chagas Disease
• Historical Review
• Dr.
Carlos Justiniano Riveiro Chagas (1879-1934)
• Dr.
Salvador Mazza (1886 -1946)
• Dr.
Mario Fatala Chabén (1936-1962)
• Dr.
Oswaldo Cruz (1872-1917)
• Medical
Information
• Epidemiology
• Mortality
• Race,
sex and age.
• Modes
of Transmission
• Pathophysiology
• Clinical
Information
• Diagnostic
• Other
Medical Information
• Prevention
and Control
• Frequently Asked Questions
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