Seroprevalence of trypanosoma cruzi infection among blood donors in the state of Bahia, Brazil

Abstract INTRODUCTION: Chagas disease (CD) affects 5.7-7.0 million individuals worldwide, and its prevalence reached 25.1% in the state of Bahia, Brazil. There is an association between the prevalence of CD, the socioeconomic status of the population, and the risk of re-emergence due to non-vectorial transmission, such as blood transfusion. This study determined the seroprevalence of T. cruzi infection among blood donors in the state of Bahia, located in northeastern Brazil, and their epidemiological profile during a 10-year period. METHODS: We performed a descriptive cross-sectional study involving a database review. Data were collected from patients with non-negative results for T. cruzi infection during a 10-year period. RESULTS: A total of 3,084 (0.62%) samples were non-negative for T. cruzi infection in an initial serological screening, and 810 (0.16%) samples were non-negative in the second screening. The correlation between infection and age (30 years or older) and between infection and lower educational level (12 years or less) in the first and second screening was statistically significant. The seroprevalence of T. cruzi infection was higher in men in the first screening. In addition, 99.52% of the municipalities of Bahia had at least one case of CD. Livramento de Nossa Senhora and Salvador presented the highest disease prevalence and recurrence, respectively. CONCLUSIONS: The seroprevalence of T. cruzi infection in these populations was lower than that found in other studies in Brazil but was comparatively higher in densely-populated areas. The demographic characteristics of our population agreed with previous studies.

Seroprevalence of Trypanosoma cruzi in blood donors at the National Blood Transfusion Services: Guyana / Seroprevalencia del Trypanosoma cruzi en los donantes de sangre en el Servicio Nacional de Transfusión de Sangre en Guyana

INTRODUCTION: Blood transfusion is an important transmission route of Trypanosoma cruzi (T cruzi), a major parasitic infection in Central and South America. The limited treatment options are most effective in acute Chagas' infection. At present, there is no current data on the prevalence of T cruzi in the blood donor population of Guyana. This information is necessary to protect the supply of the blood donation programme. This study sought to determine the prevalence of T cruzi in the blood supply at the National Blood Transfusion Services of Guyana with the hope of providing knowledge to the on-going surveillance for Chagas' disease worldwide and therefore address the risk of its spread by blood transfusion. METHODS: Two commercialized ELISAs utilizing crude or recombinant T cruzi antigens were used to study 2000 blood samples voluntarily donated for the purpose of altruistic or family replacement donation retrospectively. RESULTS: The results showed that approximately 1 in 286 donations tested positive for antibodies to T cruzi. CONCLUSION: These results indicate that T cruzi continues to be a risk in Guyana and there is a need to continue screening donated blood. Trypanosoma cruzi is a life-long infection and infected persons may be asymptomatic chronic carriers of the disease. Education, housing improvement, and controlled use of insecticides should be introduced to contain Chagas' disease.

INTRODUCCIÓN: La transfusión de Sangre es una vía de transmisión importante del Trypanosoma cruzi (T cruzi), una infección parasitaria mayor en América Central y América del Sur. Las opciones de tratamiento limitadas son más eficaces en los casos de la enfermedad de Chagas aguda. En el presente, no existen datos actualizados acerca de la prevalencia del T cruzi en la población de donantes de sangre en Guyana. Esta información es necesaria para proteger el suministro del programa de donación de sangre. Este estudio se propuso determinar la prevalencia de T cruzi en el suministro de sangre de los Servicios Nacionales de Transfusión de Sangre en Guyana, con la esperanza de aportar conocimientos a la vigilancia que tiene lugar en relación con la enfermedad de Chagas a nivel mundial, y por consiguiente aborda el riesgo de la difusión de esta última mediante la transfusión de sangre. MÉTODOS: Dos inmunoensayos ELISA con antígenos de T cruzi crudos o recombinantes, fueron utilizados a fin de estudiar 2000 muestras de sangre donadas voluntariamente a modo de donaciones altruistas o de reposición familiar, retrospectivamente. RESULTADOS: Los resultados mostraron que aproximadamente 1 de 286 donaciones daban positivo a anticuerpos frente al T cruzi. CONCLUSIÓN: Estos resultados indican que el T cruzi sigue siendo un riesgo en Guyana, y hay necesidad de continuar tamizando la sangre donada. El Trypanosoma cruzi es una infección crónica, y las personas infectadas pueden ser portadores asintomáticos crónicos de la enfermedad. Deben introducirse medidas en cuanto a educación, mejoramiento de las viviendas, y uso controlado de insecticidas, a fin de detener la enfermedad de Chagas.

Relationship between serum concetrations of type III procollagen, hyluronic acid and histopathological findings in the liver of HCV-positive blood donors

BACKGROUND: Serologic markers have been proposed for monitoring hepatic fibrosis in chronic liver disease. Among fibrosis markers, type III procollagen (PIIIP) and hyaluronic acid have been studied in these patients. AIM: To evaluate the association between these serum markers with histological findings. METHODS: A prospective cross-sectional study was carried out with HCV-positive blood donors. The studied population included men and women whose age ranged from 18 to 60 years, with elevated liver function tests [ALT levels > 1.5 times the normal value and alterations of two or more of the following: any changes in the levels of ALT, aspartate aminotransferase, conjugated bilirrubin, gammaglobulin, gammaglutamyltranspeptidase, albumin, platelet count; alkaline phosphatase levels >1.5 times the normal value, or prothrombin time below 70 percent and above 60 percent]. Fourty-nine patients were submitted to liver biopsy, blood analysis of PIIIP, hyaluronic acid, besides liver function tests. RESULTS: Liver function tests were not associated with tissular fibrosis, as assessed by ALT (>1.5 times above normal, fibrosis risk=18.8 percent; <1.5 times, 11.8 percent). Elevated PIIIP was correlated with 66.7 percent chance of fibrosis, whereas normal levels, 9.3 percent. Hyaluronic acid, when elevated, gave a chance of 33.3 percent of fibrosis; when normal, 12.5 percent. CONCLUSION: There was no association between liver function tests, hyaluronic acid and fibrosis. However, PIIIP was related with liver fibrosis. Maybe, this marker should be useful to assess fibrosis in patients with chronic hepatitis C.

RACIONAL: Marcadores sorológicos têm sido propostos para monitorar fibrose hepática em doença crônica do fígado. Dentre os marcadores de fibrose, ácido hialurônico e procolágeno tipo III têm sido estudados nestes pacientes. OBJETIVO: Avaliar a associação de marcadores séricos de fibrose com achados histológicos. MÉTODOS: Foi realizado estudo transversal prospectivo em doadores de sangue anti-HCV positivos. A população estudada incluiu homens e mulheres com idade entre 18-60 anos com provas de função hepática alteradas (níveis de alanina aminotransferase >1.5 vezes do normal e alterações de dois ou mais dos seguintes: qualquer alteração nos níveis de alanina aminotransferase, aspartato aminotransferase, bilirrubina conjugada, gamaglobulina, gamaglutamiltranspeptidase, albumina, plaquetas, níveis de fosfatase alcalina >1,5 vezes o valor normal, tempo de protrombina abaixo de 70 por cento e acima de 60 por cento). Quarenta e nove pacientes foram submetidos a biopsia hepática e coleta de sangue para análise de procolágeno tipo III, ácido hialurônico e provas funcionais hepáticas. RESULTADOS: Não houve relação entre elevação de provas de função hepática e a presença de fibrose - ALT (>1,5 vezes acima do normal, risco de fibrose = 18,8 por cento; <1,5 vezes, 11,8 por cento). Procolágeno tipo III elevado foi correlacionado com 66,7 por cento chances de fibrose, enquanto nível normal, 9,3 por cento. Ácido hialurônico, quando elevado, demonstrou chance de 33,3 por cento de fibrose; quando normal, 12.5 por cento. CONCLUSÕES: Não houve associação entre provas de função hepática, ácido hialurônico e fibrose, mas houve entre esta última e procolágeno tipo III. Talvez este marcador possa ser útil para avaliar fibrose em pacientes com hepatite crônica pelo vírus C.