Screening and treatment of chagas disease in organ transplant recipients in the United States: recommendations from the chagas in transplant working group

Update on donor-derived infections in liver transplantation

Advances in surgical techniques, immunosuppressive medications, and robust infectious disease prophylaxis have resulted in liver transplantation becoming the treatment of choice for patients with end-stage liver disease and unresectable hepatocellular carcinoma. Nonetheless, organ transplantation is not without risk. Unexpected donor-derived disease transmission is a newly recognized risk that complicates approximately 0.2% of all organ transplants. We review the epidemiology of donor-derived infectious diseases and methods of risk mitigation with a focus on liver transplantation.

Results of lookback for Chagas disease since the inception of donor screening at New York Blood Center

BACKGROUND

Chagas disease is a parasitic infection by Trypanosoma cruzi, typically transmitted via infected triatomine bug fecal contamination of bite sites. Other routes of infection include congenital, oral, organ transplantation, and blood product transmission.

STUDY DESIGN AND METHODS

From 2007 until 2011, New York Blood Center screened donations for the presence of T. cruzi antibodies using a Food and Drug Administration-approved test. Confirmatory testing was performed and recipients of units donated by confirmed-positive donors were investigated via lookback.

RESULTS

A total of 204 donors were T. cruzi antibody positive representing 0.019% of all donors during this time period (1,066,516 unique donors screened). Of the enzyme-linked immunosorbent assay-reactive donors, 77 were confirmed positive by radioimmunoprecipitation assay (0.007%). At least 154 units from 29 of the confirmed-positive donors had been transfused to 141 recipients. At the time of lookback, 48 of the 141 recipients were alive and seven underwent T. cruzi screening. Two recipients were found to be immunofluorescence assay (IFA) positive. Both IFA-positive recipients received a leukoreduced apheresis platelet unit (two separate donations) from the same confirmed positive donor, a 72-year-old immigrant from Argentina.

CONCLUSIONS

Lookback analysis was able to identify the first two cases of probable transfusion-transmitted T. cruzi infection since implementation of the national screening program, which increases the total number of reported cases in the United States to 8.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Donor-derived infection: epidemiology and outcomes

Over the past decade, the solid organ transplant community has focused increased attention on unexpected transmission of infectious pathogens from organ donor to recipient. While unexpected donor-derived infections are relatively uncommon, recent cases of transmission of human immunodeficiency virus (HIV) and hepatitis C to multiple recipients, as well as transmission of HIV from a living donor, have further increased interest in improving the safety of solid organ transplantation. This article will review the epidemiology and outcomes associated with unexpected donor-derived infection. Furthermore, the reporting and patient safety process will be discussed, as will preventative measures that can reduce the burden of donor-derived infection.

Chagas disease in non-endemic countries: epidemiology, clinical presentation and treatment

Imported Chagas disease (Trypanosoma cruzi infection) is increasingly recognized as an emerging problem in the USA and Europe due to immigration from Latin America. Most migrants from endemic countries will have been infected during childhood. Based on the natural history of the disease, up to 35 % of those infected may develop cardiac and/or gastrointestinal manifestations during the third or fourth decade of life. This disease was described more than 100 years ago, yet many challenges still remain such as the identification of risk factors for visceral involvement, effective treatment for chronic cases, and reliable markers of cure following treatment. Transmission of the infection may occur even in non-endemic areas through non-vectorial routes and many countries are therefore currently facing the challenge of this emerging public health problem.

Liver transplantation using Chagas-infected donors in uninfected recipients: a single-center experience without prophylactic therapy

Organ shortage is the first cause of death on liver transplant waiting lists. As a consequence, we recently decided to expand liver acceptance to those organs that could potentially transmit infectious diseases to their recipients. On January 2010, we initiated a prospective protocol using livers from Chagas-infected donors for transplanting uninfected recipients without using prophylactic therapy. During a 13-month period, 9 of 37 (24%) liver transplants were performed within this protocol. After transplant, each recipient was sequentially and strictly monitored for infection transmission using the Strout method and promptly treated with benznidazole if this occurs. During follow-up, two patients died without Chagas infection and only two (donor-derived T. cruzi transmission rate: 2/9; 22%) patients developed donor-derived Chagas transmission without clinical symptoms. The median follow-up time of the seven live patients was 15 months (range: 13-20). At present, all are symptoms-free with excellent allograft function and without evidence of Chagas disease. In conclusion, we consider that Chagas-infected donors are a promising source of liver grafts that could reduce the growing mortality on liver waiting lists in America. Relevant data from larger prospective studies are required to confirm these preliminary excellent results.

Is it safe to use a liver graft from a Chagas disease-seropositive donor in a human immunodeficiency virus-positive recipient? A case report addressing a novel challenge in liver transplantation

This is the first report presenting a human immunodeficiency virus (HIV)-positive patient with fulminant hepatic failure receiving a liver graft from a Chagas disease-seropositive deceased donor. We describe the history of a 38-year-old HIV-positive female patient who developed fulminant hepatic failure of an autoimmune etiology with rapid deterioration of her clinical status and secondary multiorgan failure and, therefore, needed emergency liver transplantation (LT) as a lifesaving procedure. Because of the scarcity of organs and the high mortality rate for emergency status patients on the LT waiting list, we decided to accept a Chagas disease-seropositive deceased donor liver graft for this immunocompromised Chagas disease-seronegative patient. The recipient had a rapid postoperative recovery and was discharged on postoperative day 9 without prophylactic treatment for Chagas disease. Fifteen months after LT, she was still alive and had never experienced seroconversion on periodic screening tests for Chagas detection. Although there is an inherent risk of acute Chagas disease developing in seronegative recipients, our report suggests that these infected organs can be safely used as a lifesaving strategy for HIV patients with a high need for LT.

Transplant-associated and blood transfusion-associated tropical and parasitic infections

Blood transfusion and transplantation may represent efficient mechanisms of spreading infectious agents to naive populations. In the developed countries, as a consequence of globalization, several factors such as international commerce, tourism, and immigration have acted as important features for the emergence or reemergence of infectious diseases previously referred to as tropical. This article reviews the relevant bacterial, protozoan and viral infections that are more frequently associated with blood transfusion and/or solid organ or marrow transplantation and may affect susceptible populations worldwide.

Chagas heart disease: report on recent developments

Chagas disease, caused by the parasite Trypanosoma cruzi, is an important cause of cardiac disease in endemic areas of Latin America. It is now being diagnosed in nonendemic areas because of immigration. Typical cardiac manifestations of Chagas disease include dilated cardiomyopathy, congestive heart failure, arrhythmias, cardioembolism, and stroke. Clinical and laboratory-based research to define the pathology resulting from T. cruzi infection has shed light on many of the cellular and molecular mechanisms leading to these manifestations. Antiparasitic treatment may not be appropriate for patients with advanced cardiac disease. Clinical management of Chagas heart disease is similar to that used for cardiomyopathies caused by other processes. Cardiac transplantation has been successfully performed in a small number of patients with Chagas heart disease.

Donor scoring system for heart transplantation and the impact on patient survival

BACKGROUND

The aim of this study was to design and validate a heart donor score that reflects experts' perceived risk of allograft failure.

METHODS

All heart donors reported to Eurotransplant between January 1, 2005 and December 31, 2008 (N = 4,110) were used to create a donor score. Based on observed discard rates and using multivariate regression, points were assigned for the following donor factors: age; cause of death; body mass index (BMI); diabetes mellitus (DM); duration of ICU stay; compromised history (drug, abuse, sepsis, meningitis, malignancy, HBsAg(+) or anti-HCV(+)); hypertension; cardiac arrest; echocardiography; coronary angiogram; serum sodium; and noradrenaline and dopamine/dobutamine doses. The donor score was obtained by adding all points. All heart donors reported to Eurotransplant in 2009 were included to validate the score (N = 885).

RESULTS

All donor factors, except BMI, DM and duration of ICU stay, significantly predicted discard. Based on the median value of the score, donors were classified into low-risk donors (LRDs: ≤16 points) and high-risk donors (HRDs: ≥17 points). In the validation set, discard rates were significantly different when comparing HRDs (35%) and LRDs (7%) (p < 0.0001). In addition, the heart donor score was significantly associated with 3-year survival: LRD 81.5% vs HRD 70.0% (p = 0.004).

CONCLUSIONS

The heart donor score accurately reflects the likelihood of organ acceptance and predicts long-term patient mortality. Application of this score at time of donor reporting may facilitate donor risk assessment and allow for more appropriate matching of extended criteria donor hearts.

Acute and congenital Chagas disease

The acute phase of Chagas disease lasts 4-8 weeks and is characterized by microscopically detectable parasitaemia. Symptoms are usually mild with severe acute disease occurring in less than 1% of patients. Orally transmitted Trypanosoma cruzi outbreaks can have more severe acute morbidity and higher mortality than vector-borne infection. Congenital T. cruzi infection occurs in 1-10% of infants of infected mothers. Most congenital infections are asymptomatic or cause non-specific signs, requiring laboratory screening for detection. A small proportion of congenital infections cause severe morbidity with hepatosplenomegaly, anaemia, meningoencephalitis and/or respiratory insufficiency, with an associated high mortality. Infected infants are presumed to carry the same 20-30% lifetime risk of cardiac or gastrointestinal disease as other infected individuals. Most control programs in Latin America employ prenatal serological screening followed by microscopic examination of cord blood from infants of seropositive mothers. Recent data confirm that polymerase chain reaction (PCR) is more sensitive and detects congenital infections earlier than conventional techniques. For infants not diagnosed at birth, conventional serology is recommended at at 6 to 9 months of age. In programs that have been evaluated, less than 20% of at risk infants completed all steps of the screening algorithm. A sensitive, specific and practical screening test for newborns is needed to enable Chagas disease to be added to newborn screening programs.

Safety of liver transplantation with Chagas disease-seropositive donors for seronegative recipients

The shortage of organs for transplantation has prompted the investigation of extended criteria donors, such as donors with transmissible infectious diseases. Here we report our recent experience with liver transplantation using organs from donors who were serologically positive for Chagas disease. We also provide a review of the literature and emphasize donor screening and preventive measures.

Trypanosoma cruzi and Chagas' Disease in the United States

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and causes potentially life-threatening disease of the heart and gastrointestinal tract. The southern half of the United States contains enzootic cycles of T. cruzi, involving 11 recognized triatomine vector species. The greatest vector diversity and density occur in the western United States, where woodrats are the most common reservoir; other rodents, raccoons, skunks, and coyotes are also infected with T. cruzi. In the eastern United States, the prevalence of T. cruzi is highest in raccoons, opossums, armadillos, and skunks. A total of 7 autochthonous vector-borne human infections have been reported in Texas, California, Tennessee, and Louisiana; many others are thought to go unrecognized. Nevertheless, most T. cruzi-infected individuals in the United States are immigrants from areas of endemicity in Latin America. Seven transfusion-associated and 6 organ donor-derived T. cruzi infections have been documented in the United States and Canada. As improved control of vector- and blood-borne T. cruzi transmission decreases the burden in countries where the disease is historically endemic and imported Chagas' disease is increasingly recognized outside Latin America, the United States can play an important role in addressing the altered epidemiology of Chagas' disease in the 21st century.