Photomicrograph of Giemsa-stained Trypanosoma cruzi crithidia (CDC)Chagas in Latin America (A:Endemic zones)This child from Panama is suffering from Chagas disease manifested as an acute infection with swelling of the right eye (Romaña's sign). Source: CDC.Life cycle of Trypanosima cruzi. Source: CDC
Find information on thousands of medical conditions and prescription drugs.

American trypanosomiasis

Chagas disease (also called American trypanosomiasis) is a human tropical parasitic disease which occurs in the Americas, particularly in South America. Its pathogenic agent is a flagellate protozoan named Trypanosoma cruzi, which is transmitted to humans and other mammals mostly by hematophagous insects of the subfamily Triatominae (Family Reduviidae). Those insects are known by numerous common names varying by country, including assassin bug, benchuca, vinchuca, kissing bug, chipo, barbeiro, et cetera. more...

Home
Diseases
A
Aagenaes syndrome
Aarskog Ose Pande syndrome
Aarskog syndrome
Aase Smith syndrome
Aase syndrome
ABCD syndrome
Abdallat Davis Farrage...
Abdominal aortic aneurysm
Abdominal cystic...
Abdominal defects
Ablutophobia
Absence of Gluteal muscle
Acalvaria
Acanthocheilonemiasis
Acanthocytosis
Acarophobia
Acatalasemia
Accessory pancreas
Achalasia
Achard syndrome
Achard-Thiers syndrome
Acheiropodia
Achondrogenesis
Achondrogenesis type 1A
Achondrogenesis type 1B
Achondroplasia
Achondroplastic dwarfism
Achromatopsia
Acid maltase deficiency
Ackerman syndrome
Acne
Acne rosacea
Acoustic neuroma
Acquired ichthyosis
Acquired syphilis
Acrofacial dysostosis,...
Acromegaly
Acrophobia
Acrospiroma
Actinomycosis
Activated protein C...
Acute febrile...
Acute intermittent porphyria
Acute lymphoblastic leukemia
Acute lymphocytic leukemia
Acute mountain sickness
Acute myelocytic leukemia
Acute myelogenous leukemia
Acute necrotizing...
Acute promyelocytic leukemia
Acute renal failure
Acute respiratory...
Acute tubular necrosis
Adams Nance syndrome
Adams-Oliver syndrome
Addison's disease
Adducted thumb syndrome...
Adenoid cystic carcinoma
Adenoma
Adenomyosis
Adenosine deaminase...
Adenosine monophosphate...
Adie syndrome
Adrenal incidentaloma
Adrenal insufficiency
Adrenocortical carcinoma
Adrenogenital syndrome
Adrenoleukodystrophy
Aerophobia
Agoraphobia
Agrizoophobia
Agyrophobia
Aicardi syndrome
Aichmophobia
AIDS
AIDS Dementia Complex
Ainhum
Albinism
Albright's hereditary...
Albuminurophobia
Alcaptonuria
Alcohol fetopathy
Alcoholic hepatitis
Alcoholic liver cirrhosis
Alektorophobia
Alexander disease
Alien hand syndrome
Alkaptonuria
Alliumphobia
Alopecia
Alopecia areata
Alopecia totalis
Alopecia universalis
Alpers disease
Alpha 1-antitrypsin...
Alpha-mannosidosis
Alport syndrome
Alternating hemiplegia
Alzheimer's disease
Amaurosis
Amblyopia
Ambras syndrome
Amelogenesis imperfecta
Amenorrhea
American trypanosomiasis
Amoebiasis
Amyloidosis
Amyotrophic lateral...
Anaphylaxis
Androgen insensitivity...
Anemia
Anemia, Diamond-Blackfan
Anemia, Pernicious
Anemia, Sideroblastic
Anemophobia
Anencephaly
Aneurysm
Aneurysm
Aneurysm of sinus of...
Angelman syndrome
Anguillulosis
Aniridia
Anisakiasis
Ankylosing spondylitis
Ankylostomiasis
Annular pancreas
Anorchidism
Anorexia nervosa
Anosmia
Anotia
Anthophobia
Anthrax disease
Antiphospholipid syndrome
Antisocial personality...
Antithrombin deficiency,...
Anton's syndrome
Aortic aneurysm
Aortic coarctation
Aortic dissection
Aortic valve stenosis
Apert syndrome
Aphthous stomatitis
Apiphobia
Aplastic anemia
Appendicitis
Apraxia
Arachnoiditis
Argininosuccinate...
Argininosuccinic aciduria
Argyria
Arnold-Chiari malformation
Arrhythmogenic right...
Arteriovenous malformation
Arteritis
Arthritis
Arthritis, Juvenile
Arthrogryposis
Arthrogryposis multiplex...
Asbestosis
Ascariasis
Aseptic meningitis
Asherman's syndrome
Aspartylglycosaminuria
Aspergillosis
Asphyxia neonatorum
Asthenia
Asthenia
Asthenophobia
Asthma
Astrocytoma
Ataxia telangiectasia
Atelectasis
Atelosteogenesis, type II
Atherosclerosis
Athetosis
Atopic Dermatitis
Atrial septal defect
Atrioventricular septal...
Atrophy
Attention Deficit...
Autoimmune hepatitis
Autoimmune...
Automysophobia
Autonomic dysfunction
Familial Alzheimer disease
Senescence
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Medicines

The most common insect species belong to the genera Triatoma, Rhodnius, and Panstrongylus. Other forms of transmission are possible, though, such as ingestion of food contaminated with parasites, blood transfusion and fetal transmission.

Trypanosoma cruzi is a member of the same genus as the infectious agent of African sleeping sickness, but its clinical manifestations, geographical distribution, life cycle and insect vectors are quite different.

History

The disease was named after the Brazilian physician and infectologist Carlos Chagas, who first described it in 1909, but the disease was not seen as a major public health problem in humans until the 1960s. He discovered that the intestines of Triatomidae harbored a flagellate protozoan, a new species of the Trypanosoma genus, and was able to prove experimentally that it could be transmitted to marmoset monkeys which were bitten by the infected bug.

Chagas named the pathogenic parasite that causes the disease Schizotrypanum cruzi (later renamed to Trypanosoma cruzi), after Oswaldo Cruz, the noted Brazilian physician and epidemiologist who fought successfully epidemics of yellow fever, smallpox, and bubonic plague in Rio de Janeiro and other cities in the beginning of the 20th century. Chagas’ work is unique in the history of medicine, because he was the only researcher so far to describe completely a new infectious disease: its pathogen, vector, host, clinical manifestations, and epidemiology. Nevertheless, he at least believed falsely until 1925, that the main infection route is by the sting of the insect and not by the feces, as it was proposed by his colleague Emile Brumpt 1915 and assured by Dias 1932, Cardoso 1938 and Brumpt himself 1939.

On another historical point of view, it has been hypothesized that Charles Darwin might have suffered from this disease as a result of a bite of the so-called Great Black Bug of the Pampas (vinchuca) (see Illness of Charles Darwin). The episode was reported by Darwin in his diaries of the Voyage of the Beagle as occurring in March 1835 to the east of the Andes near Mendoza. Darwin was young and in general good health though six months previously he had been ill for a month near Valparaiso, but in 1837, almost a year after he returned to England, he began to suffer intermittently from a strange group of symptoms, becoming very incapacitated for much of the rest of his life. Attempts to test Darwin's remains at the Westminster Abbey by using modern PCR techniques were met with a refusal by the Abbey's curator.

Epidemiology and geographical distribution

Chagas disease currently affects 16-18 million people, killing around 20,000 people annually and with some 100 million at risk of acquiring the disease. Chronic Chagas disease remains a major health problem in many Latin American countries, despite the effectiveness of hygienic and preventive measures, such as eliminating the transmitting insects, which have reduced to zero new infections in at least two countries of the region. With increased population movements, however, the possibility of transmission by blood transfusion has become more substantial in the United States . Also, T. cruzi has already been found infecting wild opossums and raccoons as far as North Carolina .

Read more at Wikipedia.org


[List your site here Free!]


Autonomic denervation in the experimental American trypanosomiasis in rats: Functional response to neurotoxins
From Revista do Instituto de Medicina Tropical de Sao Paulo, 5/1/02 by Junior, Antonio Lucio teixeira

SUMMARY OF THESIS*

A well documented feature of Chagas disease is an extensive reduction in number of neuronal cell bodies in cardiac parasympathethic ganglia, and oesophageal and colonic myenteric plexus. This autonomic denervation has been suggested to play a role in the development of the late manifestations of Cha-as disease, i.e. dilated cardiomyopathy, megacolon and megaoesophagus. Severe cardiac autonomic denervation also occurs in the acute experimental American trypanosomiasis in rats. The present study aims at verifying whether this denervation, as demonstrated histochemically, was accompanied by impairment of heart function, as assessed by the chronotropic response to the scorpionic (Tit)l,ts serrulatus) crude venom in the isolated rat heart preparation.

The venom extracted from the scorpion Tityus serrulatus contains potent neurotoxins that activate sodium channels in neuronal terminals leading to the release of the mediators acetylcholine and noradrenaline. We have shown that activation of isolated heart preparation (Langendorff's) with T serrulatus venom induces a marked rhythm alteration characterised by significant early bradycardia followed by tachycardia which were blocked by muscarinic and b,-adrenoceptor antagonists, respectively. Thus, T serrulatus venom is a useful tool to evaluate chronotropic response of adrenergic and cholinergic nerve terminals in isolated rat heart preparation.

In control hearts, the venom induced significant bradycardia (73% decrease in heart rate) followed by tachycardia (10% increase in heart rate). In infected animals, despite the severe (sympathetic) or moderate (parasympathetic) cardiac denervation, the venom provoked similar bradycardia (63% decrease), but the tachycardia was higher (50% increase). The basal heart rate of infected animals (164 15 bpm, beats per minute) was significantly lower compared to control rats (213 +/- 13 bpm). Atropine prevented this lower rate in infected animals. Our results demonstrated minor cardiac sympathetic dysfunction with sparing of the parasympathetic function.

Altogether, our present and previous studies in rats, and the evidence of progressive autonomic denervation in chronic chagasic cardiomyopathy favour the notion that autonomic denervation may be a consequence and not the cause of the chronic Chagas heart disease.

*This thesis is available at the Library of the Instituto de Medicina Tropical de Sio Paulo

TEIXEIRA Jr., Antonio Lucio - Desnervacao autonomica cardiaca na tripanosomfase americana experimental em ratos: resposta funcional a neurotoxinas. Belo Horizonte, 2000. (Dissertaqao de mestrado - Instituto de Ciencias Biol6gicas da Universidade Federal de Minas Gerais)

Antonio Lucio Teixeira Junior Rua Sdo Joao da Ponte 157/201 30310-650 Belo Horizonte - MG altexjr@hotmail.com

Copyright Instituto de Medicina Tropical de Sao Paulo May/Jun 2002
Provided by ProQuest Information and Learning Company. All rights Reserved

Return to American trypanosomiasis
Home Contact Resources Exchange Links ebay