How Chagas Disease Is Treated

The treatment of Chagas disease depends on when the disease is diagnosed. People who are diagnosed during the acute phase of the disease are treated differently than those who are diagnosed during the chronic phase.

Acute-Phase Disease

The only good opportunity for curing Chagas disease—that is, of completely eradicating the Trypanosoma cruzi (T. cruzi) parasite from the body—is if treatment can be started early in the course of the disease, during the acute phase.

In any person diagnosed with acute T. cruzi infection, or if an infant is found to have a congenital infection, treatment should be given with antitrypanosomal drugs. The two drugs that have been shown to be effective against T. cruzi are benznidazole and nifurtimox. Women who are pregnant should not receive these drugs.

If a full course of treatment with either one of these drugs is completed, eradication of T. cruzi is accomplished up to 85 percent of the time.

Benznidazole

Benznidazole usually has fewer side effects and is most often the treatment of choice. This drug must be taken for 60 days. Its most common side effect is skin rash.

Nifurtimox

Nifurtimox (which is not approved in the United States) tends to cause gastrointestinal symptoms. It can also produce insomnia, disorientation, and peripheral neuropathy. These side effects limit its usefulness. This drug has to be taken for at least 90 days.

Chronic Infection

With chronic Chagas disease, eradicating the T. cruzi parasite with antitrypanosomal therapy is much more difficult than it is during the acute phase, and may be impossible.

Still, most experts recommend treating with benznidazole or nifurtimox if the infected person is in the indeterminate phase of chronic Chagas disease (that is, does not have cardiac or gastrointestinal manifestations of Chagas disease), and is under age 50. People over age 50 have a higher incidence of side effects from antitrypanosomal drugs, but therapy still may be considered.

Antitrypanosomal therapy is not recommended if Chagas heart disease is already present, if severe Chagas gastrointestinal disease is present (such as megacolon), or if significant liver or kidney disease is present. In these people the chances of eradicating the T. cruzi infection is very low, and the risk of side effects is high.

Chagas Cardiac Disease

Treatment with antitrypanosomal drugs is not beneficial for established Chagas heart disease. Instead, treatment should be specifically aimed at managing the heart disease itself.

Chagas heart disease is a form of dilated cardiomyopathy that often produces heart failure, and people with this disease ought to receive all the standard treatments for dilated cardiomyopathy.

Treating Heart Failure

Medical therapy usually includes treatment with beta blockersACE inhibitors, and spironolactone. Diuretic therapy is used to help reduce edema and dyspnea.

Cardiac resynchronization therapy (CRT) appears to be as useful in Chagas heart disease as in any other form of heart failure. However, the usefulness of CRT in treating heart failure is largely limited to people who have left bundle branch block, whether they have Chagas disease or any other form of dilated cardiomyopathy. And, unfortunately, in Chagas disease right bundle branch block is more common than left bundle branch block—so CRT is suitable for fewer people with Chagas heart failure than with other kinds of heart failure.

People with Chagas disease appear to do as well with cardiac transplantation as patients with other kinds of heart failure. One concern in performing transplant surgery in Chagas heart disease has been that the immunosuppressive therapy required after transplantation may cause the T. cruzi infection to reactivate. However, clinical studies have shown that reactivation of the infection after transplantation does not appear to be a common problem in Chagas heart disease.

The risk of thromboembolism (a condition that often produces deep venous thrombosispulmonary embolism, or stroke ) is increased in anyone with heart failure, but it appears to be a particular risk for people with Chagas heart disease. Most people with Chagas heart disease should be placed on either anticoagulant therapy (with Coumadin or a NOAC drug), or prophylactic aspirin to lower the high risk of thromboembolism.

Treating Cardiac Arrhythmias and Preventing Sudden Death

Therapy to prevent or treat serious cardiac arrhythmias is often necessary for people with Chagas heart disease because they are at increased risk for both bradycardias (slow heart rhythms) and tachycardias (fast heart rhythms).

Bradycardias occur with some frequency in people with Chagas disease. The bradycardias are caused both by disease of the sinus node and by heart block. If the slow heart rhythm is producing symptoms, or if it appears likely to produce severe symptoms such as syncope, therapy with a pacemaker is necessary.

The truly major concern related to cardiac arrhythmias in people with Chagas heart disease, however, is sudden death caused by ventricular tachycardia or ventricular fibrillation. The risk of having these life-threatening arrhythmias is related to the severity of the cardiac damage that has been done by Chagas.

If cardiac function is depressed to the point that these dangerous arrhythmias are particularly likely to occur, the insertion of an implantable defibrillator should be strongly considered. However, especially in Latin America, where implantable defibrillator therapy is often not readily available, patients with Chagas disease are very likely to be treated with the antiarrhythmic drug amiodarone instead, in an attempt to reduce their risk of sudden death.

Gastrointestinal Disease

Antitrypanosomal therapy does not improve the gastrointestinal disease caused by Chagas. Treatment is aimed at reducing symptoms by decreasing gastrointestinal reflux and controlling nausea and constipation with medications and diet. Surgical intervention may become necessary if megacolon or megaesophagus are present.

Prevention

In recent decades several Latin American countries have undertaken major efforts to eradicate or at least greatly reduce Chagas disease. 

Generally, these efforts have focused on getting rid of the vector of the disease—that is, the “kissing bugs” that transmit the T. cruzi parasite from human to human. Eradication of kissing bugs has been attempted by using long-term insecticides in peoples’ homes. These efforts have helped substantially but have not eliminated the problem—and Chagas disease remains endemic in many rural areas in Latin America.

Prenatal testing for T. cruzi has helped reduce congenital transmission of the disease. Women cannot be treated with antitrypanosomal drugs while pregnant, but treatment before pregnancy is often quite effective. Women currently infected with T. cruzi are also advised not to breastfeed, although transmission of the disease through breast milk has not been proven.

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View Article Sources
  • Andrade JP, Marin Neto JA, Paola AA, et al. I Latin American Guidelines For The Diagnosis And Treatment Of Chagas' Heart Disease: Executive Summary. Arq Bras Cardiol 2011; 96:434.
  • Bern C. Chagas' Disease. N Engl J Med 2015; 373:456.
  • Martí-Carvajal AJ, Kwong JS. Pharmacological Interventions For Treating Heart Failure In Patients With Chagas Cardiomyopathy. Cochrane Database Syst Rev 2016; 7:Cd009077.
  • Pinazo MJ, Cañas E, Elizalde JI, et al. Diagnosis, Management And Treatment Of Chronic Chagas' Gastrointestinal Disease In Areas Where Trypanosoma Cruzi Infection Is Not Endemic. Gastroenterol Hepatol 2010; 33:191.
  • Pinazo MJ, Muñoz J, Posada E, et al. Tolerance Of Benznidazole In Treatment Of Chagas' Disease In Adults. Antimicrob Agents Chemother 2010; 54:4896.