Chagas Disease

By Tim Taylor

Rarity in U.S.

Chagas disease is a rarity in the U.S., but an estimated 8 million people in South America, Central America and Mexico are infected with this inflammatory disease which, if left untreated, can cause serious heart and digestive problems. Chagas disease can infect anyone, but is diagnosed most often in children. Chagas disease is not spread by person-to-person contact but through an insect known as the triatomine bug, or “kissing bug,” because it often bites the face. The infection has gained attention in recent weeks after the Centers for Disease Control and Prevention announced that cases had been reported in Arkansas, Arizona, Massachusetts, Tennessee and Texas. Infected with the parasite Trypanosoma cruzi, the insects defecate after feeding, leaving the parasites on the skin. People will usually scratch the bite, causing a small amount of the bug’s feces, along with the germs, to enter the bloodstream.

Contaminated food

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Chagas disease is named after the Brazilian physician Carlo Chagas who discovered the disease in 1909. It can be spread by eating food contaminated with feces from insects infected with the parasite that causes the disease. It can also be spread by receiving a blood transfusion or organ transplant. Rare cases of Chagas disease have been found in the southern United States. Fortunately, it’s uncommon for travelers to the at-risk areas to contract Chagas disease because they tend to stay in well-constructed buildings, such as hotels. Triatomine bugs are usually found in structures built with mud or adobe or thatch. The disease can also be spread from a mother to a child at birth. It is generally considered safe to breastfeed even if the mother has Chagas disease. However, if the mother has cracked nipples or blood in the breast milk, she should pump and discard the milk until the nipples heal and the bleeding resolves.

Romaña’s sign

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Chagas disease, which can cause serious heart or stomach illnesses, is caused by contact with an infected triatomine bug, also known as the kissing bug. A few weeks or months after being bitten, the patient may display mild symptoms such as a fever and body aches, a rash, diarrhea and vomiting. This is called the acute phase of the disease. The most recognized marker of acute Chagas disease is called Romaña’s sign, which includes swelling of the eyelids on the side of the face near the bite wound or where the bug feces were deposited or accidentally rubbed into the eye. Even if symptoms develop during the acute phase, they usually fade away on their own, within a few weeks or months. If left untreated, the infection can persist and, in some cases, advance to the chronic phase. During this phase, symptoms such as an irregular heartbeat or difficulties with digestion may occur 10 to 20 years after the initial infection or they may never occur.

Killing the parasite

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Treatment for Chagas disease focuses on killing the parasite and managing the disease’s symptoms. During the acute phase of Chagas disease, the prescription medications benznidazole and nifurtimox may be of benefit. Both drugs are available in the regions most affected by Chagas disease. In the United States, however, the drugs can be obtained only through the Centers for Disease Control and Prevention. Once Chagas disease reaches the chronic phase, medications won’t cure the disease. But, the drugs may be offered to people under 50 because they may help slow the progression of the disease and its most serious complications. Additional treatment may be required based on the patient’s specific symptoms.  This may include a pacemaker or other devices to regulate the patient’s heart rhythm. As far as digestive-related complications, treatment may include diet modification, corticosteroids or, in severe cases, surgery.

A recognized risk

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If you have ever donated blood, you have been asked about the possibility of you having Chagas disease, which is common in Latin America. The disease is rare in the U.S., but transmission through a blood transfusion remains a recognized risk. That is why screening tests approved by the Food and Drug Administration are used to make our country’s blood supply even safer for everyone. The blood screening test allows blood banks to destroy potentially infectious blood before it is given to anyone. Screening will prevent those who are found to have the disease from donating blood again. Unfortunately, no test is perfect. Some false-positive results may occur with these very sensitive tests. A “false-positive result” occurs when an initial test indicates a person has Chagas disease, but further testing indicates the person does not have the disease after all. That’s why it’s a good idea to discuss your test results with your health care provider.These programs were first broadcast the week of December 7, 2015.

T. Glenn Pait, M.D., of UAMS is the host of the program.