Clinical Pearls & Morning Reports
Published March 4, 2020
It is necessary to consider the possibility of donor-derived infections or reactivation of chronic infection in any patient who has undergone transplantation and has a fever. With suspected donor-derived infection, the organ procurement organization should be contacted for additional donor information, including the donor’s medical, travel, and exposure history and whether illness has been reported in other organ recipients. Read the NEJM Clinical Problem-Solving article here.
Q: What causes Chagas’ disease?
A: Chagas’ disease is a vectorborne disease caused by the protozoan parasite Trypanosoma cruzi and spread through contact with the contaminated feces or urine of triatomine bugs. It is a major public health issue in Latin America, where more than 5.7 million persons are infected, resulting in substantial morbidity and mortality. Infection with T. cruzi has increasingly been reported in the United States. Infected triatomine bugs are also present in the United States; the range is projected to expand with climate change, although there are currently few reports of infection acquired domestically.
Q: What are some of the features of acute and chronic Chagas’ disease?
A: Acute Chagas’ disease is subclinical in most immunocompetent patients but can manifest as a nonspecific febrile illness. Eight to 12 weeks after acute infection develops, patients enter the chronic phase. They may have no evidence of disease for many years (a so-called “indeterminate form” of Chagas’ disease). However, in approximately 30% of affected patients, cardiac disease (e.g., dilated cardiomyopathy, arrhythmias, or sudden cardiac death) or gastrointestinal disease (e.g., achalasia or megacolon) or both will develop. In patients who have undergone transplantation and have acute infection, initial symptoms are often nonspecific and include persistent fever, malaise, and poor appetite.
A: Known Chagas’ disease in the donor is an absolute contraindication to transplantation of the heart, owing to the high burden of parasites latent in cardiac tissue, which results in poor outcomes in recipients, as evidenced by data derived from case reports and small case series. Transplantation of organs that confer a lower risk of transmission from the donor, such as kidneys and livers, may be acceptable if informed consent is obtained from recipients after they have been given information about the risk of infection and if close follow-up, including regular PCR testing for T. cruzi, is provided. Studies suggest favorable outcomes in patients who have had early detection and treatment of infection. In one series of 19 persons who received solid-organ transplants from seropositive donors and whose post-transplantation care included prospective monitoring for T. cruzi infection, no deaths were attributed to Chagas’ disease, although only one of these patients was a heart transplant recipient. In contrast, in cases in which an infected donor either was not screened or was positive but the recipient did not undergo prospective monitoring, diagnosis and treatment were delayed and outcomes were poor, particularly in cases of cardiac transplantation.
A: When infection with T. cruzi is confirmed by a positive PCR assay, antibody seroconversion, or direct visualization of the parasite, immediate initiation of antiparasitic therapy is recommended. Benznidazole is recommended as first-line therapy and is the only FDA-approved drug for the treatment of Chagas’ disease. The most common adverse effects of benznidazole include rash, peripheral neuropathy, bone marrow suppression, and angioedema.