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Also called American trypanosomiasis, Chagas disease is an infection caused by the parasite Trypanosoma cruzi. It is estimated that 16-18 million people are infected with Chagas disease; of those infected, 50,000 will die each year. It is a serious disease.
Incidence; Causes & Development
Chagas disease primarily affects low income people living in rural areas and many people get the infection during childhood.
It is spread by reduviid bugs, or "kissing bugs", which live in cracks and holes of substandard housing primarily found in South and Central America. Insects become infected after biting an animal or person who already has Chagas disease. Infection is spread to humans when an infected bug deposits feces on a person's skin, usually while they are sleeping. If this person accidentally rubs the feces into the bite wound, an open cut, the eyes, or their mouth, then they can become infected. Animals can become infected the same way, and they can also contract the disease by eating an infected bug.
Infection can also be spread by infected mothers passing infection to their baby during pregnancy, at delivery, or while breastfeeding; by blood transfusion or organ transplant; by eating uncooked food contaminated with infective feces of these "kissing bugs."
Signs & Symptoms
The early stage of infection (acute Chagas disease) usually is not severe, but sometimes it can cause death, particularly in infants. In about one-third of those who get the infection, chronic symptoms develop after 10-20 years. For these persons who develop chronic symptoms, average life expectancy decreases by an average of 9 years.
Symptoms may occur within a few days to weeks. Most people do not have symptoms until the chronic stage of infection, 10-20 years after first being infected. There are three stages of infection with Chagas disease; each stage has different symptoms. Some persons may be infected and never develop symptoms.- Acute
Acute symptoms only occur in about 1% of cases. Most people infected do not seek medical attention. The most recognized symptom of acute Chagas infection is the Roma?a's sign, or 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 usually not specific for Chagas infection. These symptoms may include fatigue, fever, enlarged liver or spleen, and swollen lymph glands. Sometimes a rash, loss of appetite, diarrhea, and vomiting occur. Among infants and very young children with acute Chagas disease, swelling of the brain can develop and this can cause death. In general, symptoms last for 4-8 weeks and then they go away, even without treatment.
- Indeterminate
Eight to 10 weeks after infection, the indeterminate stage begins. During this stage, people do not have symptoms.
- Chronic
Ten to 20 years after infection, people may develop the most serious symptoms of Chagas disease. Cardiac problems, including an enlarged heart, altered heart rate or rhythm, heart failure, or cardiac arrest are symptoms of chronic disease. Chagas disease can also lead to enlargement of parts of the digestive tract, which result in severe constipation or problems with swallowing. In persons who are immune compromised, including persons with HIV/AIDS, Chagas disease can be severe. Not everyone will develop the chronic symptoms of Chagas disease.
Treatment & Prevention
Medication for Chagas disease is usually effective when given during the acute stage of infection. Once the disease has progressed to later stages, medication may be less effective. In the chronic stage, treatment involves managing symptoms associated with the disease.
Prevention and Avoidance of Chagas Disease
Chagas disease is locally transmitted in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. Those people who sleep in poorly-constructed houses found in the rural areas of these countries are at elevated risk of infection. Houses constructed from mud, adobe, or thatch present the greatest risk.
Travelers planning on staying in hotels, resorts, or other well-constructed housing facilities are NOT at high risk for contracting Chagas disease from reduviid bugs.- Avoid sleeping in thatch, mud, or adobe houses.
- Use insecticides to kill insects and reduce the risk of transmission.
- Be aware that, in some countries, the blood supply may not always be screened for Chagas disease, and blood transfusions may carry a risk of infection.
There is neither a preventive vaccine nor recommended drug against Chagas disease. If you think you might have this disease, see your health care provider who will order blood tests to look for the parasite or for antibodies in your blood.
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Risk factors for Chagas Disease:
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GLOSSARY
Acute
An illness or symptom of sudden onset, which generally has a short duration.
AIDS
Acquired Immune Deficiency Syndrome. An immune system deficiency disorder that suddenly alters the body's ability to defend itself. The AIDS virus invades the T4 helper/inducer lymphocytes and multiplies, causing a breakdown in the body's immune system, eventually leading to overwhelming infection and/or cancer, with ultimate death.
Antibody (Antibodies)
A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic (foreign substance) stimulus. Antibodies are complex substances formed to neutralize or destroy these antigens in the blood. Antibody activity normally fights infection but can be damaging in allergies and a group of diseases that are called autoimmune diseases.
Cardiac
Pertaining to the heart, also, pertaining to the stomach area adjacent to the esophagus.
Chronic (Chronicity)
Usually referring to chronic illness: Illness extending over a long period of time.
Constipation (Constipated)
Difficult, incomplete, or infrequent evacuation of dry, hardened feces from the bowels.
Diarrhea
Excessive discharge of contents of bowel.
Human Immunodeficiency Virus (HIV)
A retrovirus associated with onset of advanced immunodeficiency syndrome (AIDS).
Liver (Hepatic)
The largest and one of the most complex organs of the body, the liver is responsible for much of the metabolism of fats, proteins and carbohydrates. It is the site of much of the body's detoxification. It is connected very closely with digestion and the regulation of blood sugar, among many other functions. Found behind the ribs on the right side of the abdomen, it has many important functions such as removing harmful material from the blood, making enzymes and bile that help digest food, and converting food into substances needed for life and growth. Hepatic: Pertaining to the liver.
Lymph Nodes (Axillary Nodes, Inguinal Nodes, Lymph Gland, Lymph Glands, Lymph Node, Lymphatic)
Small, bean-shaped nodes at various points throughout the body that function to filter the lymph fluid and attempt to destroy the microorganisms and abnormal cells which collect there. The most common locations are the neck (both sides and front), armpit (axillary) and groin (inguinal), but also under the jaw and behind the ears. Swollen or painful lymph nodes generally result from localized or systemic infection, abscess formation, or malignancy. Other causes of enlarged lymph nodes are extremely rare. Physical examination for lymph nodes includes pressing on them to check for size, texture, warmth, tenderness and mobility. Most lymph nodes can not be felt until they become swollen, and then will only be tender when pressed or massaged. A lymph node that is painful even without touching indicates greater swelling. Lymph nodes can usually be distinguished from other growths because they generally feel small, smooth, round or oval-shaped and somewhat mobile when attempts are made to push them sideways. Because less fat covers the lymph nodes in children, they are easier to feel, even when they are not busy filtering germs or making antibodies. Childrens' nodes enlarge faster, get bigger in response to an infection and stay swollen longer than an adult's. Also known (incorrectly) as lymph glands.
Parasite (Parasites, Parasitic, Parasitical)
An organism living in or on another organism.
Spleen (Splenectomy)
The largest organ of the lymphatic system in the body, located between the stomach and the diaphragm (the muscle below the lungs which provides the motion for breathing). It destroys old red blood cells, produces lymphocytes and plasma cells, and stores blood. It also has other as yet unknown functions. A splenectomy is the surgical removal of the spleen.
Last updated: Sep 28, 2008
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