Recommendations for Screening and Diagnosis of Chagas Disease in the United States

Abstract

Background: Chagas disease affects an estimated 326 000-347 000 people in the United States and is severely underdiagnosed. Lack of awareness and clarity regarding screening and diagnosis is a key barrier. This article provides straightforward recommendations, with the goal of simplifying identification and testing of people at risk for US healthcare providers.

Methods: A multidisciplinary working group of clinicians and researchers with expertise in Chagas disease agreed on 6 main questions, and developed recommendations based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, after reviewing the relevant literature on Chagas disease in the United States.

Results: Individuals who were born or resided for prolonged time periods in endemic countries of Mexico and Central and South America should be tested for Trypanosoma cruzi infection, and family members of people who test positive should be screened. Women of childbearing age with risk factors and infants born to seropositive mothers deserve special consideration due to the risk of vertical transmission. Diagnostic testing for chronic T. cruzi infection should be conducted using 2 distinct assays.

Conclusions: Increasing provider-directed screening for T. cruzi infection is key to addressing this neglected public health challenge in the United States.

Keywords: Trypanosoma cruzi; Chagas disease; diagnosis; neglected diseases.

Figure 1.

Algorithm for evaluation of congenital Chagas disease for infants ≤ 3 months of age born to a mother with suspected or confirmed Chagas disease, or infant with symptoms of congenital Chagas disease born to an at-risk mother with serological status unknown. Source: Centers for Disease Control and Prevention (https://www.cdc.gov/parasites/chagas/health_professionals/congenital_chagas.html) [36]. Abbreviations: CCD, congenital Chagas disease; PCR, polymerase chain reaction.

Figure 2.

Algorithm for evaluation of congenital Chagas disease (CCD) for infants ≥ 3 months of age. Source: Centers for Disease Control and Prevention (https://www.cdc.gov/parasites/chagas/health_professionals/congenital_chagas.html) [36].

Figure 3.

Algorithm for screening and diagnostic confirmation of Trypanosoma cruzi infection in the United States. ∗There could be rare exceptions, but infection is unlikely in individuals without 1 of these risk factors. ∗∗Not all commercial laboratories run a second serological test at this time. Samples should be sent for confirmation to CDC. ∗∗∗Confirmatory testing for discordant results is available at CDC. Abbreviations: CD, Chagas disease; CDC, Centers for Disease Control and Prevention; Dx, diagnosis.