Screening of at‐risk blood donors for Chagas disease in non‐endemic countries: Lessons from a 2‐year experience in Tuscany, Italy

Abstract

Background Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi and is transmitted by blood‐sucking triatomine insects in endemic areas of Latin America. Transmission can also occur via blood transfusion and is a major cause of CD in non‐endemic areas. Objectives The aim of the study was to assess the prevalence of anti‐T. cruzi antibodies in blood donors at risk of infection in Tuscany, Italy, following the introduction of blood safety Italian legislation. Material and methods Donors (N = 1985) were tested in 2016 to 2018 for anti‐T. cruzi IgG using an immunochromatographic test (ICT). Chemiluminescent immunoassay (CLIA) was performed on ICT‐positive donors to exclude CD, whereas enzyme‐linked immunosorbent assay and western blot were performed in case of discordant results. All assays were performed on CD patients (N = 10) for validation. Results Ten blood donors had a positive ICT result, with a resulting T. cruzi seroprevalence of 0.5% but demonstrated negative results to CLIA, as well as to the other serological assays. The comparison of serological assays suggested a lower relative sensitivity of ICT. Conclusion The results of this study confirm the significance of serological testing in the screening strategy for CD. However, they provide evidence for discontinuing the use of ICT as a screening test and suggest that a sensitive, specific and multi‐sample format assay should be used at the national level for uniformity of results.

Seroprevalencia de infecciones hemotransmisibles en donantes de sangre

“…Ecuador es un país endémico para la enfermedad de Chagas y se determinó una prevalencia de 0,21 % para este estudio. Mangano y colaboradores [11] en Italia, reportaron una frecuencia de 0,50 % de donantes con riesgo de infección por Chagas, esta frecuencia es elevada en comparación con la detectada en el presente estudio. En contraste, en Brasil, Rebouças y colaboradores [4] determinaron una prevalencia menor (0,10 %), en tanto que en algunos centros de salud se encontró una frecuencia de 0,20 %, concluyendo que los datos indicaban que debía mantenerse medidas de prevención continuas, una de ellas con la tamización serológica obligatoria en los bancos de sangre para apoyar al control de la enfermedad.…”

Chagas Disease in Europe

“…The seroprevalence of CD among blood donors has a high variability between countries and regions with studies screening high-risk donors ranging from no detected cases to as high as a 3.9% seropositivity in an Italian study [ 64 , 70 , 71 , 72 , 73 , 74 , 75 ]. The asymptomatic and chronic nature of CD, together with the lack of awareness of patients and health care professionals, might contribute to transfusion transmitted cases being undetected [ 9 ].…”