Chagas Disease
- Chagas disease is a parasitic infection
that occurs in Central and South America.
- Chagas disease is usually spread by the
feces of the reduviid bug, an insect that
infests mud, adobe, or thatch houses. People
get infected when they unknowingly rub bug
feces into their eyes or mouth or into a bite
wound. Infection can be also be transmitted
by blood transfusions or organ transplants.
An infected woman can pass the infection to
her baby during pregnancy, at delivery, or
while breastfeeding.
- Chagas disease can cause symptoms soon after
infection, but many people do not become ill
until many years later. Persons with weakened
immune systems are at greatest risk of severe
infections and complications.
- Most travelers to Central and South America
are not at risk for Chagas disease. To prevent
getting Chagas disease: 1) avoid sleeping
in thatch, mud, or adobe houses, 2) use insecticides,
and 3) be aware of the risk of blood transfusions.
What is Chagas disease?
Chagas disease is a parasitic disease that
is an important health problem in Central and
South America. Chagas disease is also called
American trypanosomiasis [tri-PAN-o-so-MY-a-sis].
What is the infectious agent that causes
Chagas disease?
Chagas disease is caused by the parasite Trypanosoma
cruzi.
Where is Chagas disease found?
Chagas disease is confined to South and Central
America.
How do people get Chagas disease?
- Chagas disease is usually spread by the
feces of reduviid bugs, insects that live
in cracks and holes of poorly constructed
houses and outbuildings in South and Central
America. The bugs become infected after biting
an infected animal or person. Once infected,
the bugs pass Trypanosoma parasites
in their feces. People get infected when they
unknowingly rub bug feces into their eyes
or mouth or into a skin wound or bite. People
can also become infected by eating uncooked
food contaminated with infected bug feces.
- Chagas disease can be transmitted by contaminated
blood transfusions or by organ transplants.
- Infected women can pass the infection to
their babies during pregnancy, at delivery,
or while breastfeeding.
What are the signs and symptoms of Chagas
disease?
Some people can be infected and never develop
symptoms. For those who do, Chagas disease has
three stages, each with different symptoms.
- Acute infection -- A few people (about 1%
of cases) have symptoms soon after infection.
The most recognized acute symptom is swelling
of the eye on one side of the face, usually
at the bite wound or where feces were rubbed
into the eye. Other symptoms are tiredness,
fever, enlarged liver or spleen, swollen lymph
glands, and sometimes a rash, loss of appetite,
diarrhea, and vomiting. Infants and very young
children can get an often-fatal swelling of
the brain.
- Indeterminate stage: During the indeterminate
stage, about 8 to 10 weeks after infection,
infected persons have no symptoms.
- Chronic infection: Some people develop serious,
irreversible damage to the heart or intestinal
tract that appears 10 to 20 years after infection.
Heart-related problems include an enlarged
heart, altered heart rate or rhythm, heart
failure, or cardiac arrest. Enlargement of
parts of the digestive tract can result in
severe constipation or problems with swallowing.
How soon after exposure do symptoms appear?
Acute symptoms can occur within a few days
to weeks. Most people do not have symptoms until
the chronic stage of infection, 10 to 20 years
after first being infected.
How is Chagas disease diagnosed?
Chagas disease is diagnosed by a blood test.
Who is at risk for Chagas disease?
Chagas disease primarily affects low-income
people living in poorly constructed homes in
rural areas in South and Central America. People
who sleep in houses made from mud, adobe, or
thatch are at greatest risk. The acute disease
generally occurs in children, whereas chronic
symptoms usually appear later in life. Persons
with weakened immune systems are at risk of
severe infections and complications.
Travelers who stay in hotels, resorts, or other
well-constructed housing facilities are not
at risk for getting Chagas disease.
What is the treatment for Chagas disease?
Medicine given during the acute stage of infection
is usually effective. Once the disease has progressed
to the later stages, there is no effective cure.
How common is Chagas disease?
Worldwide, an estimated 16 million to 18 million
people are infected with Chagas disease. Of
those infected, an estimated 50,000 die each
year.
How can Chagas disease be prevented?
- There is no vaccine or drug to prevent Chagas
disease. When traveling to areas where Chagas
disease occurs, follow these precautions:
- Avoid sleeping in poorly constructed thatch,
mud, or adobe houses. If that is not possible,
use a bednet.
- Use insecticides to kill insects and reduce
the risk of transmission.
- Be aware of the risk of contracting Chagas
disease through blood transfusions. In many
countries, the blood supply is not well screened.
This fact sheet is for information only and
is not meant to be used for self-diagnosis or
as a substitute for consultation with a health-care
provider. If you have any questions about the
disease described above, consult a health-care
provider.