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!]


Wake-up call: an alarming TV program about sleeping sickness spurred a group of students into action
From Current Science, 9/23/05 by Stephen Fraser

Kay Kobbe's third-grade students at Chatsworth Avenue School in Larchmont, N.Y., could not believe what they had seen. Kobbe had shown them a tape of an episode of the CBS-TV news program 60 Minutes, brought to school by classmate Sam Gruppo. The episode was about the 500,000 Africans who are suffering from human African trypanosomiasis, or sleeping sickness. The disease is 100 percent fatal if left untreated but 100 percent curable with the right drug treatment. According to Micheleen Richer, a U.S. doctor interviewed for the program, most people suffering from the disease could not get access to the drug.

When the students learned that so many people were suffering and dying unnecessarily, they took action. They formed the organization Kids for World Health (KFWH) to raise funds to purchase the drug and spread awareness of sleeping sickness and other neglected diseases.

Five years later, the organization has raised $30,000 and has chapters in a dozen U.S. schools. In an emotional ceremony held in Larchmont in March, the 15 original members of KFWH, all of them in seventh grade, presented a check to visiting scientists and doctors from the international medical community. "It's wonderful to hear a message of hope when you usually hear a message of despair," said one of the scientists, Chris Schofield, of the London School of Hygiene and Tropical Diseases.

TOXIC: TREATMENT

African trypanosomiasis is called sleeping sickness because one of its main symptoms is drowsiness. The disease is caused by a protozoan called Trypanosoma brucei. A protozoan is a one-celled organism that belongs to the protist kingdom. T. brucei attacks the human central nervous system--the brain and the spinal cord. (See "Tsetse Transmitter".)

For many years, the standard treatment for sleeping sickness was melarsoprol, a 50-year-old drug that contains antifreeze and arsenic. However, melarsoprol is highly caustic; it causes extreme pain and kills one in 20 patients. Understandably, many people refuse to take it.

Watching the 60 Minutes program, Kobbe's students learned that a cure for sleeping sickness was found years ago. In 1975, the drug company Merrell Dow synthesized a compound called eflornithine. The compound excited the medical community because it killed cells without causing poisonous side effects. Many researchers hoped that it would prove to be a safe treatment for cancer, the uncontrolled growth of cells in the body. Alas, it did not.

However, in 1980, an American parasite biologist named Cy Bacchi found that eflornithine destroyed T. brucei and was an effective, nontoxic cure for sleeping sickness. Its only side effects were some hair loss and mild anemia (a deficiency in red blood cells). Merrell Dow donated small amounts of eflornithine to clinics in Africa, and the compound's effectiveness proved to be so remarkable that it was dubbed the "resurrection drug." It lifted patients off their deathbeds.

Eflornithine was never developed and marketed as a drug, however. No profit could be made from something that would be valuable only to people who couldn't afford it. Eflornithine cost more to make than many victims of sleeping sickness earned in a lifetime.

Between 1975 and 1999, of the 1,393 new drugs approved for human use around the world, only 1 percent were for tropical diseases, according to the humanitarian organization Doctors Without Borders. Every year, millions of people contract such diseases, but most of the victims are too poor to afford modern medicines.

LIFESTYLE DRUG

Today, pharmaceutical companies invest millions of dollars in "lifestyle" drugs that erase cosmetic flaws and signs of aging. In 2000, the Gillette and Bristol-Myers Squibb companies took note of one side effect of eflornithine and restarted production of the compound as a treatment for unwanted facial hair in women. When the World Health Organization (WHO) and Doctors Without Borders learned about that, they persuaded Bristol-Myers and several other companies to donate eflornithine to tens of thousands of sleeping sickness patients in Africa.

At about the same time, Kids for World Health was kicking into gear. "I was appalled that people were dying without medicine," says Emily Wharton, one of the students in Kobbe's class. "We saw pictures of people like us with the disease."

The kids wrote to drug companies. They visited Sen. Hillary Clinton in Washington, D.C. They held bake sales and car washes and sold bracelets. They gave fund-raising talks in churches and temples.

The money they continue to raise is spent on diagnosis and treatment of sleeping sickness; some of it is also earmarked for books that teach African children about the disease. Finally, some of the money goes to the construction of the Kids for World Health pediatric wing and an attached school at a clinic in Tambura County, Sudan, run by Richer.

HEALTH EXPO

More than 500 people attended the first KFWH health fair last March. Among the attendees was Jean Janin, chief medical officer for the elimination of sleeping sickness at the WHO. "I remember when you first contacted me," he said, addressing the 15 founding members of KFWH. "You were very small; now you are big."

Janin continued, "Of course, we need money, but what we need more importantly is awareness. These young people have said it is not acceptable that children are dying of curable diseases. You are the future. Maybe one day some of you can take my seat."

Multiple Choice

Choose the response that best completes the statement or answers the question. Write the letter of the response in the blank provided.

-- 1. Sleeping sickness is caused by a (A) virus. (B) protozoan. (C) bacterium.

-- 2. An organism that transmits a disease-causing agent from one animal to another is called a (A) carrier. (B) transmitter. (C) vector.

-- 3. The medical term for sleeping sickness is (A) trypanosomiasis. (B) melarsoprol. (C) eflornithine.

-- 4. The fly that transmits the disease-causing agent for sleeping sickness is the (A) fruit fly. (B) housefly. (C) tsetse fly.

-- 5. Anemia is a deficiency in (A) calcium. (B) vitamin D. (C) red blood cells.

-- 6. The central nervous system includes the (A) brain. (B) spinal cord. (C) both A and B.

-- 7. The number of people in Africa who have sleeping sickness is (A) 5,000. (B) 50,000. (C) 500,000.

-- 8. Encephalitis is an inflammation of the (A) stomach. (B) brain. (C) salivary glands.

-- 9. One of the main symptoms of sleeping sickness is (A) drowsiness. (B) insomnia. (C) blindness.

-- 10. The uncontrolled growth of cells in the body leads to the disease (A) osteoporosis. (B) cancer. (C) rickets.

Answer

1. B, 2. C, 3. A, 4. C, 5. C, 6. C, 7. C, 8. B, 9. A, 10. B

TSETSE TRANSMITTER

Sleeping sickness is caused by the protozoan Trypanosoma brucei, But the tsetse fly is the vector for sleeping sickness. A vector is an organism, often an insect, that transmits a disease-causing agent from one animal to another.

When a tsetse fly bites a cow infected by T. brucei, it ingests some of the protozoa along with the blood meal. The protozoa multiply over a period of weeks within the fly's gut and then travel to the salivary glands of the fly.

When the same fly bites a human, it injects the protozoa into the person's bloodstream, infecting the person. The protozoa multiply in the blood and the lymphatic system, causing symptoms such as drowsiness, fever, rash, and wasting. Eventually the protozoa reach the brain and the spinal cord. Encephalitis (inflammation of the brain), coma, and death result.

The injectable drug eflornithine kills T. brucei and cures sleeping sickness. The cost of one two-week treatment with eflornithine is about $70.

COPYRIGHT 2005 Weekly Reader Corp.
COPYRIGHT 2005 Gale Group

Return to American trypanosomiasis
Home Contact Resources Exchange Links ebay