Análise do perfil de Rh e Kell em doadores de sangue em Porto Alegre, Rio Grande do Sul / Phenotypic profile analysis of Rh and Kell blood group systems among donors in Porto Alegre, Rio Grande do Sul

Introdução: A hemoterapia é uma prática terapêutica pelo meio de transfusão sanguínea. Devido ao baixo estoque de bolsas de sangue e o aumento de pacientes crônicos e emergenciais, se faz necessária a realização de testes imuno-hematológicos para minimizar os riscos de reações transfusionais e aloimunizações em doadores e receptores de sangue. Deste modo, no estudo foi avaliada a prevalência dos antígenos dos sistemas Rh e Kell em doadores de sangue de Porto Alegre ­ RS.Métodos: Estudo quantitativo, transversal e retrospectivo que foi realizado através da análise das informações dos doadores de sangue contidas no banco de dados do Hemocentro do Estado do Rio Grande do Sul, nos anos de 2018 e 2019.Resultados: Das 6.479 amostras fenotipadas, quanto ao sistema Rh, 44,6% são Rh positivo e 55,4% são Rh negativo. As frequências dos antígenos encontradas foram de, CC 10,1%, Cc 27%, cc 62,9%, EE 1,2%, Ee 13,9%, ee 84,9%. E, para o sistema Kell, K1 positivo 7,1% e K1 negativo 92,9%.Conclusões: Antígenos do sistema Rh e Kell exibem um grande nível de imunogenicidade e uma forte ligação com a Doença Hemolítica do Recém-nascido, podendo ocorrer a sensibilização em pacientes caso não haja a compatibilidade sanguínea. Este estudo ressalta a importância da implementação da fenotipagem eritrocitária em doadores de sangue, sugere-se mais estudos com períodos distintos para a pesquisa de resultados satisfatórios.

Introduction: Hemotherapy is a therapeutic practice consisting of blood transfusion. Low blood supply and an increase in chronic and emergency patients have made it necessary to conduct immunohematology tests to minimize the risks of adverse reactions and alloimmunization in donors and recipients. Therefore, this study aimed to assess the prevalence of Rh and Kell blood group antigens among blood donors in Porto Alegre, Rio Grande do Sul, Brazil.Methods: We conducted a quantitative, cross-sectional, retrospective study. Information from blood donors included in the Rio Grande do Sul's Blood Center database from 2018 to 2019 were analyzed.Results: A total of 6,479 samples were phenotyped, of which 44.6% were Rh-positive and 55.4% were Rh-negative. Antigen prevalence was CC (10.1%), Cc (27%), cc (62.9%), EE (1.2%), Ee (13.9%), and ee (84.9%). As for the Kell group, 7.1% were K1-positive and 92.9% were K1-negative.Conclusions: The Rh and Kell antigens are highly immunogenic and have a strong link with the hemolytic disease of the newborn. Sensitization may occur in patients if there is no blood compatibility. This study highlights the importance of implementing erythrocyte phenotyping in blood donors. Further studies should be conducted in different time frames to achieve satisfactory results.

Significación de los marcadores infecciosos para identificar portadores de hepatitis B en donantes de sangre / Significance of hepatitis B surface antigen, IgM/IgG core antibody and hepatitis B virus DNA in blood donors

Resumen Introducción: La identificación de portadores del virus de la hepatitis B en donantes de sangre es imperativo para evitar la transmisión de la enfermedad a través de transfusiones sanguíneas. Objetivo: Determinar si los donantes de sangre con resultados positivos de los marcadores serológicos HbsAg y anti-HBc eran portadores de ADN del virus de la hepatitis B. Métodos: Se recolectaron 12 745 muestras de seis bancos de sangre ecuatorianos, las cuales fueron analizadas con pruebas serológicas para identificar los marcadores infecciosos HBsAg, anti-HBc, anti-HBs mediante prueba ELISA automatizada. Todas las muestras positivas para uno, dos o los tres marcadores fueron analizadas con técnica molecular para determinar la presencia de ADN viral. Resultados: Se identificó que 27.5 % de las muestras reactivas solo a anti-HBc y 100 % de las muestras con resultados positivos de HBsAg/anti-HBc-IgM/IgG presentaron ADN del virus de la hepatitis B (p = 0.001). Conclusiones: La elección de los marcadores de infección y los métodos de detección definen los resultados. Es importante la realización de dos pruebas serológicas y una molecular para identificar a los portadores del virus de la hepatitis B y evitar su transmisión.

Abstract Introduction: Identification of hepatitis B virus carriers in blood donors is imperative in order to avoid transmission of the disease via blood transfusion. Objective: To determine if blood donors with positive results for serological markers HBsAg and anti-HBc were hepatitis B virus DNA carriers. Methods: 12,745 samples were collected from six Ecuadorian blood banks and analyzed for HBsAg, anti-HBc and anti-HBs infectious markers by automated ELISA. All samples that tested positive for one, two or all three markers were analyzed with molecular techniques to determine the presence of viral DNA. Results: 27.5 % of the samples that were reactive for anti-HBc alone and 100 % of those with positive results for HbsAg and IgM/IgG anti-HBc were identified to contain hepatitis B virus DNA (p = 0.001). Conclusions: The selection of infection markers, as well as the detection methods define the results. Performing two serological and one molecular test is important in order to identify hepatitis B virus carriers and prevent its transmission.

Prevalência do descarte de bolsas de sangue por sífilis em um serviço de hemoterapia no estado de Sergipe, Brasil / Prevalence of disposal of blood units due to syphilis in a hemotherapy service in the state of Sergipe, Brazil

Introdução: A doação de sangue é um ato capaz de salvar vidas. Quando a triagem sorológica é positiva, a bolsa de sangue é descartada. Este trabalho teve como objetivo avaliar a prevalência de descarte de bolsas de sangue em razão da positividade dos testes de triagem para sífilis. Métodos: Foi realizado um estudo epidemiológico observacional, com avaliação transversal e da tendência temporal da positividade do VDRL de acordo com as variáveis epidemiológicas, a partir de dados coletados no banco de sangue do Hemocentro de Sergipe das doações ocorridas de 1 de janeiro de 2007 a 31 de dezembro de 2018. Resultados: Do total de 308.953 doações de sangue, 4.594 bolsas (1,48%) foram descartadas devido a positividade para sífilis. A positividade foi significativamente maior no sexo masculino (OR = 1,14). Houve aumento significativo da prevalência com o aumento da faixa etária, de 0,63% (IC95% 0,51-0,760 em menores de 20 anos até 4,54% (IC95% 3,88-5,30) em pessoas com 60 anos e mais. Entre o período de 2007-2011 foi identificada uma tendência de crescimento da soroprevalência para sífilis (APC = 31,4) seguida pela estabilização do número de descarte de bolsas nos últimos anos. Discussão: O estudo identifica que, apesar de ter havido um aumento significativo no período inicial, a tendência foi de estabilidade nos últimos anos avaliados. É importante destacar a falta de um exame que indique concretamente a presença ativa da sífilis, pois todos os testes podem permanecer como cicatrizes por longos períodos, mesmos em pessoas com o tratamento adequado. (AU)

Introduction: Blood donation is an act that can save lives. When serological screening is positive, the blood bag is discarded. This study aimed to assess the prevalence of blood bag disposal due to positive screening tests for syphilis. Methods: An observational epidemiological study was carried out, with cross-sectional temporal trend assessment of VDRL positivity according to epidemiological variables, based on data collected in the blood bank of the Sergipe Blood Center, from the donations that occurred from 1 st January, 2007 to December 31 st , 2018. Results: Of the total of 308,953 blood donations, 4,594 bags (1.48%) were discarded due to positive serology for syphilis. Positivity was significantly higher in males (odds ratio = 1.14). There was a significant increase in prevalence with age, from 0.63% (95% CI 0.51-0.76) in individuals under 20 years old to 4.54% (95% CI 3.88-5.30) in those with 60 years and over. Between 2007-2011, a trend of increase in seroprevalence for syphilis was identified (annual percent change = 31.4), followed by stabilization in the disposal of bags in recent years. Discussion: Despite the increase in syphilis reported in society, the study identified that, although there was a significant increase in the initial period, it has been followed by stability in the last years evaluated. What is important is the lack of a test that in fact indicates the active presence of syphilis, since all tests can identify serological scars that remain for long periods, even in people with proper treatment. (AU)

Frecuencias de grupos sanguíneos de interés clínico en donantes y pacientes de Costa Rica / The frequency of blood groups of interest in donors and patients from Costa Rica

Introducción: Los sistemas sanguíneos ABO, Rh y Kell son lo más relevantes desde el punto de vista clínico por su inmunogenicidad y ser los principales causantes de reacciones hemolíticas. Objetivo: Determinar las frecuencias de los grupos sanguíneos ABO y Rh, y la frecuencia del antígeno Kell en pacientes y donantes de Costa Rica. Métodos: Durante el periodo de 2009 al 2018 se obtuvo de las bases de datos de los bancos de sangre de tres hospitales de adultos de Costa Rica, las frecuencias de los grupos sanguíneos ABO, Rh y Kell en muestras de donantes y pacientes. Para contrastar las frecuencias de cada grupo sanguíneo se realizó una prueba de independencia de variables Chi cuadrado, con el 95 por ciento de confianza. Los datos se analizaron con el paquete estadístico SPSS versión 23. Resultados: Las frecuencias de los grupos ABO en las muestras de donantes y pacientes mostraron diferencias pequeñas pero significativas. La frecuencia del fenotipo Rh D negativo fue más alta en pacientes (8,0 por ciento) que en donantes (6,1 por ciento). Se estimaron las frecuencias de los antígenos C (67,8 por ciento), c (80,5 por ciento), E (41,4 por ciento), e (94,4 por ciento) y K (3,1 por ciento) a partir de las muestras de los donantes. Conclusiones: Las estrategias de reclutamiento de donantes de sangre aumentan la frecuencia del fenotipo Rh negativo en donantes con respecto a los pacientes. Las estadísticas recopiladas demuestran un aumento en la frecuencia del grupo O en comparación con los últimos estudios relacionados. Finalmente, los otros antígenos presentaron pocas variaciones en comparación a estudios previos(AU)

Introduction: The ABO, Rh and Kell blood systems are the most relevant from the clinical point of view, due to their immunogenicity and because they are the main causes of hemolytic reactions. Objective: To determine the frequencies of ABO and Rh blood groups, and the frequency of the Kell antigen in patients and donors from Costa Rica. Methods: During the period from 2009 to 2018, the frequencies of ABO, Rh and Kell blood groups in donor and patient samples were obtained from the blood bank databases of three adult hospitals in Costa Rica. To contrast the frequencies of each blood group, a chi-square test of independence of variables was performed, with 95 percent confidence interval. The data were analyzed with the statistical package SPSS version 23. Results: The frequencies of ABO groups in donor and patient samples showed small but significant differences. The frequency of the negative Rh D phenotype was higher in patients (8.0 percent) than in donors (6.1 percent). The frequencies of the antigens C (67.8 percent), c (80.5 percent), E (41.4 percent), e (94.4 percent), and K (3.1 percent) were estimated from donor samples. Conclusions: Blood donor recruitment strategies increase the frequency of negative Rh phenotype in donors compared to patients. The statistics collected demonstrate an increase in the frequency of the O group compared to recent related studies. Finally, the other antigens did not show as much variation compared to previous studies(AU)

Association of TLR3 single nucleotide polymorphisms with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors

Abstract INTRODUCTION: The human T-lymphotropic virus type 1 (HTLV-1) has a single-stranded RNA genome and expresses specific proteins that have oncogenic potential. Approximately 15 to 20 million people worldwide have been infected by this virus. Changes in protein or gene expression are the effects of single nucleotide polymorphisms (SNPs) within the Toll-like receptor 3 (TLR3) gene. The function and efficacy of signal transduction also lead to modified immune responses. The present study aimed to investigate the association of SNPs within TLR3 (rs3775291 and rs3775296) with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors. METHODS: This study was performed on 100 HTLV-1-infected asymptomatic blood donors and 118 healthy blood donors. Genomic DNA from all participants was purified and then amplified using specific PCR primers. SNPs within TLR3 were evaluated using the restriction fragmentation length polymorphism technique, and the results were analyzed using SPSS software (version 22). RESULTS: The frequencies of the TLR3 (rs3775296) CC, CA, AA genotypes were 70%, 24%, and 6% in the patient group, and 50.8%, 44.9%, and 4.2% in the control group, respectively. There was a significant difference in the frequency distribution of TLR3 (rs3775296) genotypes and alleles, but not in the frequency distribution of TLR3 (rs3775291) genotypes between the patient and control groups. CONCLUSIONS: The TLR3 SNP rs3775296 was significantly associated with HTLV-1 infection and may be a protective factor against this viral infection.

Seroprevalence of anti-SARS-CoV-2 among blood donors in Rio de Janeiro, Brazil

ABSTRACT OBJECTIVE To estimate the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the state of Rio de Janeiro, Brazil. METHODS Data were collected on 2,857 blood donors from April 14 to 27, 2020. This study reports crude prevalence of antibodies to SARS-CoV-2, population weighted prevalence for the state, and prevalence adjusted for test sensitivity and specificity. Logistic regression models were used to establish the correlates of SARS-CoV-2 prevalence. For the analysis, we considered collection period and site, sociodemographic characteristics, and place of residence. RESULTS The proportion of positive tests for SARS-Cov-2, without any adjustment, was 4.0% (95%CI 3.3-4.7%), and the weighted prevalence was 3.8% (95%CI 3.1-4.5%). We found lower estimates after adjusting for test sensitivity and specificity: 3.6% (95%CI 2.7-4.4%) for the non-weighted prevalence, and 3.3% (95%CI 2.6-4.1%) for the weighted prevalence. Collection period was the variable most significantly associated with crude prevalence: the later the period, the higher the prevalence. Regarding sociodemographic characteristics, the younger the blood donor, the higher the prevalence, and the lower the education level, the higher the odds of testing positive for SARS-Cov-2 antibody. We found similar results for weighted prevalence. CONCLUSIONS Our findings comply with some basic premises: the increasing trend over time, as the epidemic curve in the state is still on the rise; and the higher prevalence among both the youngest, for moving around more than older age groups, and the less educated, for encountering more difficulties in following social distancing recommendations. Despite the study limitations, we may infer that Rio de Janeiro is far from reaching the required levels of herd immunity against SARS-CoV-2.

High prevalence of blood donor test-seeking behavior among health sciences undergraduate students

Abstract INTRODUCTION This study investigated the prevalence of blood donors' test-seeking behavior and related factors among health sciences undergraduate students. METHODS A total of 750 students were invited. Data regarding sociodemographic and behavioral characteristics, blood donation practices, and test-seeking behavior were collected. RESULTS: Of the invited students, 341 (45.5%) agreed to participate and answered questions regarding test-seeking behavior. The sample comprised 83.1% females, 96.8% singles, 87.2% heterosexuals, and 32.6% of them had previously donated blood. A high prevalence of blood donor test-seeking behavior (14.4%; 95% CI: 10.8%-18.5%) was observed and associated with blood donation practices. CONCLUSIONS: Test-seeking behavior was common among the interviewed students, thereby highlighting the importance of developing a better understanding of its determinants to prevent this behavior in key populations.

Decrease in blood donation rates in Japan: a time series analysis / Redução na taxa de doadores de sangue no Japão: uma análise de série temporal

ABSTRACT: Objective: To clarify that one of the causes for the decrease in blood donation (BD) rates was the introduction of the 400 ml BD program in 1986. Method: BP rates were monitored over 48 years (1965-2012) and were divided into pre- and post-intervention periods prior to analysis. An interrupted time series analysis was performed using annual data on BD rates, and the impact of the 400 ml BD program was investigated. Results: In a raw series, autoregressive integrated moving average analysis revealed a significant change in slope between the pre- and post-intervention periods in which the intervention factor was the 400 ml BD program. The parameters were as follows: intercept (initial value) = 0.315, confidence interval (CI) = (0.029, 0.601); slope (pre-intervention) = 0.316, CI = (0.293, 0.340); slope difference = -0.435, CI = (-0.462, -0.408); slope (post-intervention) = -0.119, CI = (-0.135, -0.103); all, p = 0.000; goodness-of-fit, R2 = 0.963. After adjusting for stationarity and autocorrelation, the parameters were as follows: intercept (initial value) = -0.699, CI = (-0.838, -0.560); slope (pre-intervention) = 0.136, CI = (0.085, 0.187); slope difference = -0.165, CI = (-0.247, -0.083); slope (post-intervention) = -0.029, CI = (-0.070, 0.012); all, p = 0.000 (except for slope (post-intervention), p = 0.170); goodness-of-fit, R2 = 0.930. Conclusion: One of the causes for decrease in BD rates may be due to the introduction of the 400 ml BD program in Japan.

RESUMO: Objetivo: Esclarecer que uma das causas para a diminuição das taxas de doação de sangue (BP) foi a introdução do programa de doação de sangue BP de 400 mL em 1986. Método: As taxas de BP foram monitoradas ao longo de 48 anos (1965-2012) e divididas em períodos pré e pós-intervenção antes da análise. Uma análise de séries temporais interrompidas foi realizada usando dados anuais sobre as taxas de BP, e investigamos o impacto do programa de BP de 400 mL. Resultados: Em uma série bruta, a análise integrada autorregressiva de médias móveis revelou uma mudança significativa na inclinação entre os períodos pré e pós-intervenção em que o fator de intervenção foi o programa de 400 mL da BP. Os parâmetros foram os seguintes: intercepto (valor inicial) = 0,315, intervalo de confiança (IC) = (0,029, 0,601); inclinação (pré-intervenção) = 0,316, IC = (0,293, 0,340); diferença de inclinação = -0,435, IC = (- 0,462, -0,408); inclinação (pós-intervenção) = -0,119, IC = (-0,135, -0,103); todos, p = 0,000; poder explicativo do modelo, R2 = 0.963. Após o ajuste para estacionariedade e autocorrelação, os parâmetros foram os seguintes: intercepto (valor inicial) = -0,699, CI = (-0,838, -0,560); inclinação (pré-intervenção) = 0,136, IC = (0,085, 0,187); diferença de inclinação = -0,165, IC = (-0,247, -0,083); inclinação (pós-intervenção) = -0,029, IC = (-0,070, 0,012); tudo, p = 0,000 (com exceção da inclinação (pós-intervenção), p = 0,170); poder explicativo do modelo, R2 = 0.930. Conclusão: Uma das causas para a diminuição das taxas de BP pode ser devido à introdução do programa de doação de sangue BP de 400 ml no Japão.

Doadores de sangue envelhescentes e idosos: prevalência e reações adversas / Aging and elderly blood donors: prevalence and adverse reactions / Envejecimiento y donantes de sangre elderly: prevalencia y reacciones adversas

Verificou-se a prevalência e reações adversas às doações de sangue em doadores envelhescentes e idosos. Estudo retrospectivo, com dados do sistema informatizado de Hemocentro em Brasília. Do total de 55636 doadores, 6,3% eram envelhescentes; e 0,8%, idosos. Houve menor prevalência de reações adversas nos idosos, sem diferença significativa. Quanto à intensidade das reações, foram leves nos idosos, leves e moderados nos envelhescentes, também sem diferença significativa.

Prevalence and adverse reactions to blood donations were found in aging and elderly donors. Retrospective study with data from the computerized system of Hemocenter in Brasília. Of the 55636 donors, 6.3% were aging and 0.8% elderly. There was a lower prevalence of adverse reactions in the elderly, with no significant difference. Regarding the intensity of the reactions, they were mild in the elderly, mild and moderate in the aging, also without significant difference.

La prevalencia y las reacciones adversas a las donaciones de sangre se encontraron en donantes envejecimiento y ancianos. Estudio retrospectivo con datos del sistema computarizado de Hemocentro en Brasilia. De los 55636 donantes, 6.3% estaban envejeciendo y 0.8% ancianos. Hubo una menor prevalencia de reacciones adversas en los ancianos, sin diferencias significativas. En cuanto a la intensidad de las reacciones, fueron leves en los ancianos, leves y moderados en el envejecimiento, también sin diferencias significativas.

Prevalencia de anticuerpos anti-eritrocitarios en donantes voluntarios de sangre Ecuatorianos / Prevalence of anti-erythrocyte antibodies in Ecuadorian voluntary blood donors / Prevalência de anticorpos anti-eritrocitários em doadores de sangue voluntários equatorianos

El rastreo de anticuerpos anti-eritrocitarios es una de las pruebas pretransfusionales más importantes en medicina transfusional por su aporte en la prevención de reacciones adversas luego de la administración de hemocomponentes. Sin embargo, no todos los bancos de sangre ecuatorianos han incluido esta prueba en sus protocolos de trabajo. Para demostrar su importancia se realizó el presente estudio cuyo propósito fue alertar al sistema nacional de salud sobre la existencia de aloinmunización en la población de donantes de sangre. Se estableció una prevalencia de anticuerpos anti-eritrocitarios del 0,27% y se identificó una mayor frecuencia en el género femenino. Los anticuerpos identificados estuvieron relacionados con los sistemas eritrocitarios Rh (RH), Kell (KEL), Duffy (FY) y Kidd (JK). Una de las limitaciones para la inclusión de esta prueba en los bancos de sangre y servicios de medicina transfusional es el elevado costo de los reactivos y la falta de paneles de células eritrocitarias de composición homocigota y heterocigota para la identificación de anticuerpos anti-eritrocitarios nativos, situación que constituye una oportunidad para que el Ministerio de Salud Pública del Ecuador promueva mejores estrategias para la importación de reactivos, reducción de costos y disponibilidad de paneles de células.

The screening of anti-erythrocyte antibodies is one of the most important pretransfusion tests in transfusion medicine because of its contribution to the prevention of adverse reactions after the administration of blood components, however not all blood banks in Ecuador have included this test in their work protocols. This study has the purpose to alert the national health system about the existence of alloimmunization in the blood donour population. A prevalence of anti-erythrocyte antibodies of 0.27% was established, with a higher frequency being found in the female gender. The identified antibodies are related to the erythrocyte systems Rh (RH), Kell (KEL), Duffy (FY) and Kidd (JK). One of the limitations for the inclusion of this test in blood banks and transfusion medicine services is the excessive cost of serological and gel methodology reagents, and the lack of homozygous and heterozygous erythrocyte cell panels for the identification of native anti-erythrocyte antibodies. That situation constitutes an opportunity for the Ministry of Public Health of Ecuador to promote better strategies for the imports of reagents, cost reduction and availability in the country.

O rastreamento de anticorpos anti-eritrocitários é um dos testes pré-transfusão mais importantes na medicina transfusional pela sua contribuição na prevenção de reações adversas após a administração de componentes sanguíneos. No entanto, nem todos os bancos de sangue do Equador tem incluído esse teste em seus protocolos de trabalho. Para demonstrar a sua importância, foi realizado o presente estudo que teve como objetivo alertar o sistema nacional de saúde sobre a existência de aloimunização na população de doadores de sangue. Foi estabelecida uma prevalência de anticorpos anti-eritrocitários de 0,27%, identificando maior frequência no sexo feminino. Os anticorpos identificados estiveram relacionados com os sistemas eritrocitários Rh (RH), Kell (KEL), Duffy (FY) e Kidd (JK). Uma das limitações para a inclusão destes testes em bancos de sangue e serviços de medicina da transfusão é o alto custo dos reagentes, além da falta de painéis de células eritrocitárias de composição homozigótica e heterozigótica para a identificação de anticorpos anti-eritrocitários nativos, situação que constitui uma oportunidade para que o Ministério da Saúde Pública do Equador promova melhores estratégias para a importação de reagentes, redução de custos e disponibilidade de painéis de células.

Seroprevalencia y detección molecular de Toxoplasma gondii en donantes de un banco de sangre de Cúcuta, Colombia / Seroprevalence and molecular detection of Toxoplasma gondii among donors in a blood bank in Cúcuta, Colombia

Resumen Introducción. La infección por Toxoplasma gondii puede presentarse en los humanos con un amplio rango de manifestaciones que van desde el estado asintomático hasta la enfermedad grave, según el estado inmunológico del individuo. Los mecanismos de transmisión incluyen la transfusión sanguínea, pero poco se sabe sobre la frecuencia del parásito en los bancos de sangre de Colombia. Objetivo. Determinar la prevalencia de la infección con T. gondii en donantes de un banco de sangre de Cúcuta mediante técnicas de diagnóstico serológico y molecular. Materiales y métodos. Se determinaron los anticuerpos IgG e IgM contra T. gondii mediante un inmunoensayo en suero en 348 donantes. Se determinó la frecuencia de ADN de T. gondii utilizando la reacción en cadena de la polimerasa (PCR) en sangre total de donantes seropositivos y se analizaron las variables de interés con base en la información obtenida durante la selección de donantes. Resultados. De los 348 donantes participantes, 134 (38,5 %) presentaron anticuerpos IgG contra T. gondii; dos (0,6 %) de ellos presentaron tanto IgG como IgM y, en dos (1,5 %), se detectó ADN del parásito en la sangre. Un análisis bivariado evidenció una asociación entre la seropositividad para T. gondii y tener más de 26 años de edad (p=0,020). Conclusiones. La prevalencia de la infección con T. gondii encontrada en los donantes de sangre sugiere una exposición significativa al agente, la cual adquiere relevancia al detectarse la parasitemia.

Abstract Introduction: Toxoplasma gondii infection manifests differently in humans according to their immunity ranging from asymptomatic profiles to severe disease. There are multiple transmission mechanisms including blood transfusions, but little is known about the frequency of T. gondii infection in Colombia's blood banks. Objective: To determine the prevalence of T. gondii infection in blood donors of a blood bank in the city of Cúcuta by serological and molecular diagnostic techniques. Materials and methods: We identified IgG and IgM antibodies against T. gondii by immunoassay in serum from 348 donors. The frequency of T. gondii DNA was determined by polymerase chain reaction (PCR) in whole blood from seropositive donors and relevant variables were analyzed based on the information obtained from surveys during blood donor selection. Results: Out of the 348 enrolled donors, 134 (38.5%) showed IgG antibodies against T. gondii; two of them (0.6%) had both IgG and IgM, and in two of them (1.5%), parasite DNA was detected in blood samples. A bivariate analysis indicated an association between seropositivity to T. gondii and being over 26 years of age (p=0.020). Conclusions: The prevalence of T. gondii infection found in the blood donors of this study suggests a significant exposure to the infectious agent that becomes relevant when parasitemia is detected.

Caracterización de donantes de sangre con rastreo de anticuerpos irregulares positivo en Montería, Colombia 2012-2015 / Blood donors characterization with positive irregular antibodies in Montería, Colombia 2012- 2015

Introducción: Los anticuerpos irregulares corresponden a aquellos distintos a los anticuerpos naturales anti-A o anti-B, los cuales pueden aparecer en respuesta a la exposición a un antígeno eritrocitario extraño (transfusión o trasplante) o por incompatibilidad materno-fetal. Objetivo: Caracterizar a los donantes con rastreo de anticuerpos irregulares positivo de un banco de sangre de Montería, Colombia, durante el periodo 2012-2015. Métodos: Estudio transversal y retrospectivo, con fuente de información secundaria, basada en los resultados del rastreo de anticuerpos en los donantes de un banco de sangre de Montería, Colombia, entre los años 2012 y 2015. La población estuvo conformada por todos los donantes voluntarios registrados en el tiempo del estudio (35 248 donantes), a quienes se les realizó rastreo de anticuerpos. Como muestra, se seleccionaron todos los casos que tuvieron resultados positivos (71 donantes). Los datos fueron organizados en tablas y analizados en el software SPSS 21.0, Microsoft Excel y en Epidat versión 3.1. Resultados: El 0,2 por ciento de la población presentó un rastreo de anticuerpos positivo con un intervalo de confianza entre 0,15 y 0,25 por ciento. Los anticuerpos irregulares fueron más frecuentes en los hombres y en donantes O Rh positivo. Se encontraron Ac irregulares con 13 especificidades diferentes, con predomino de anti-M, anti-Lea, anti-D y anti-E y porcentajes respectivos de 27,78 por ciento, 20,83 por ciento, 9,72 por ciento y 8,33 por ciento. El 50 por ciento de los donantes tenía 30,5 años o menos, el 49,3 por ciento había donado previamente y el 9,9 por ciento recibió al menos una transfusión en algún momento de su vida. Conclusión: La frecuencia de donantes con rastreo de anticuerpos irregulares positivo fue baja, el sexo masculino presentó mayor porcentaje, se detectó principalmente en el grupo sanguíneo O y dentro de los anticuerpos irregulares, anti-M presentó una mayor frecuencia(AU)

Introduction: Irregular antibodies correspond to those other than natural anti-A or anti-B antibodies, which may appear in response to exposure to a foreign erythrocyte antigen (transfusion or transplantation) or due to maternal-fetal incompatibility. Objective: To characterize the donors with positive irregular antibody screening of a blood bank in Monteria, Colombia during the period 2012-2015. Methods: Cross-sectional and retrospective study, with secondary information source, based on the results of the antibody screening in donors of a blood bank in Monteria, Colombia from 2012 to 2015. The population consisted of all voluntary donors registered in the study time (35 248 donors), who were screened for antibodies. As a sample, all cases that had positive results (71 donors) were selected. The data was organized in tables and analyzed in the software SPSS 21.0, Microsoft Excel and in Epidat version 3.1. Results: 0.2 percent of the population presented a positive antibody screen with a confidence interval between 0.15 and 0.25 percent Irregular antibodies were more frequent in men and in O Rh positive donors. Thirteen types of irregular antibodies were found, with predominance of anti-M, anti-Lea, anti-D and anti-E and respective percentages of 27.78 percent, 20.83 percent, 9.72 percent and 8.33 percent. 50 percent of the donors were 30.5 years old or less, 49.3 percent had previously donated and 9.9 percent received at least one transfusion at some point in their lives. Conclusion: The frequency of donors with irregular positive antibody screening was low, the male sex had a higher percentage, it was detected mainly in blood group O and within the irregular antibodies, anti-M showed a higher frequency(AU)

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.

Knowledge of blood donation among adults in north-central Nigeria

Background: About half of the population in Nigeria is medically fit for blood donation but only four in one thousand are voluntary donors. The low level of blood donation has been attributed to poor knowledge, misconceptions, myths, bias, poverty, fear, malnutrition among the population. Therefore, this study assessed the knowledge of blood donation among adults in two selected North Central States of Nigeria. Methods: It was a descriptive cross-sectional study. A total of 3104 respondents comprising of adults between 18 and 60 years were involved in the study. A multistage sampling technique was used and the research tool was interviewer-administered questionnaire. The data generated were entered into the computer and subjected to appropriate statistical analysis using EPI INFO computer software package (version 3.5.3). Pearson Chi Square (χ2) was used to test statistical significance and p-value was set at < 0.05. Results: Majority of the respondents 2565 (82.5%) knew that blood donation save lives. More than three-quarters, 2468 (79.5%), knew where to go for voluntary blood donation. About one-third, (37.1%), demonstrated good knowledge of voluntary blood donation. Older respondents (>60 years) had poor knowledge of blood transfusion compared with younger age groups (p<0.001). Respondents' occupation and educational status were significantly associated with knowledge of blood transfusion (p<0.001). Conclusion: Periodic awareness programme on voluntary blood donation in rural and urban areas across Nigeria is needed. In addition, sensitization of the informal sector on the significance of non-remunerated voluntary blood donation should be given priority

Blood Drive Day-related Factors Affecting University Student Blood Donation in Grenada, West Indies: A Case-control Study / Factores relacionados con el Día del Donante de Sangre que afectan la donación de sangre de los estudiantes universitarios en Granada, Antillas: un estudio de casos y controles

ABSTRACT Objective: To determine what factors acting in close temporal proximity to the day of a university campus blood drive are associated with university student blood donation. Methods: An incidence density case-control study was conducted at St George's University, Grenada, West Indies. Cases (69) were students interviewed while donating blood at blood drives (February to April 2010). Controls (437) were non-donating students interviewed on the same days as cases. Exposures of interest were: sources of knowledge of the blood drive, the presence or lack of academic deadlines within a week of the blood drive, and the number of hours of classes on the day of the blood drive. Data were analysed using logistic regression with adjusted odds ratios approximating risk ratios (RRs). Results: Associations with blood donation were higher for electronic and/or personal (RREmail = 5.1; 95% confidence interval (CI): 2.7, 9.6; RRFacebook = 4.3; 95% CI: 2.1, 9.0; RRPersonalReminder = 2.9; 95% CI: 1.6, 5.4) than for impersonal (RRClassAnnouncement = 2.4; 95% CI: 1.3, 4.8) sources of knowledge of the blood drive. Additionally, students with classes only in the morning (RRAMonly = 1.5; 95% CI: 0.7, 2.9) or only in the afternoon (RRPMonly = 1.9; 95% CI: 1.2, 3.2) and those with no academic deadlines within a week of the blood drive were more likely to donate blood. Conclusion: University student blood donation showed a stronger association with personal and/or electronic advertising than with impersonal and/or non-electronic advertising. University blood drives should target students with similar timetables at times of reduced academic stress using personal and electronic modes of advertising.

RESUMEN Objetivo: Determinar qué factores próximos al día de la campaña de donación de sangre en una universidad se asocian con la donación de sangre de los estudiantes universitarios. Métodos: Se realizó un estudio de casos y controles con muestreo por densidad de incidencia en la donación de sangre en la Universidad de Saint George, Granada, Antillas. Los casos (69) eran estudiantes entrevistados durante la campaña de donación (febrero a abril de 2010). Los controles (437) eran estudiantes no donantes entrevistados en los mismos días que los casos. Las manifestaciones de interés fueron: las fuentes de la información sobre la campaña de donación, la presencia o ausencia de fechas topes de tareas académicas en el plazo de una semana antes y después de la campaña de donación, y el número de horas de clases en el día de la donación. Los datos se analizaron usando la regresión logística con razones de posibilidades (odds ratios) ajustados aproximados a las razones de riesgo (RRs). Resultados: Las asociaciones con la donación de sangre eran más altas para las fuentes electrónicas y/o personales de información de la campaña (RRCorreo electrónico = 5.1; 95% intervalo de confianza (IC): 2.7, 9.6; RRFacebook = 4.3; 95%IC: 2.1, 9.0; RRrecordaorio personal = 2.9; 95%IC: 1.6, 5.4) que para las fuentes impersonales (RRanuncios en clase = 2.4; 95% IC: 1.3, 4.8). Además, los estudiantes con clases sólo en la mañana (RRAMsólo = 1.5; 95% IC: 0.7, 2.9) o sólo por la tarde (RRPMsólo = 1.9; 95%: 1.2, 3.2) y aquellos sin fechas topes para tareas académicas en el plazo de una semana antes y después de la campaña de la donación de sangre fueron más propensos a donar sangre. Conclusión: La donación de sangre de los estudiantes de la Universidad demostró una asociación más fuerte con la publicidad personal y/o electrónica que con la publicidad impersonal y/o no-electrónica. Las campañas de donación de sangre en la Universidad deben dirigirse a los estudiantes con horarios similares en los períodos de menos tensión académica usando modos personales y electrónicos de publicidad.

Seroprevalencia de los virus linfotrópicos de células T humanas de tipos I y II en donantes del Banco de Sangre del Hospital Pablo Tobón Uribe, entre 2014 y 2015 / HTLV-I/II seroprevalence in blood donors of Hospital Pablo Tobón Uribe Blood Bank during the period 2014-2015

Resumen Introducción . El virus linfotrópico humano de células T (HTLV) es un retrovirus del cual se conocen varios tipos, entre ellos el HTLV-I y el HTLV-II, los cuales son de importancia clínica por ser los causantes de diferentes enfermedades, como la leucemia y el linfoma de células T del adulto, la paraparesia espástica tropical y la mielopatía asociada al HTLV. Objetivo . Obtener la prevalencia de las reacciones presuntiva y confirmatoria de los virus HTLV-I y HTLV-II en los donantes del Banco de Sangre del Hospital Pablo Tobón Uribe de Medellín, entre el 2014 y el 2015. Materiales y métodos . La información se obtuvo de la base de datos del Banco de Sangre del Hospital Pablo Tobón Uribe. Se analizaron la edad, el sexo y el lugar de procedencia y de residencia de los donantes, así como la reacción en la prueba de tamización (ELISA) y en la prueba confirmatoria (inmunoblot). Resultados . La población de donantes estudiados incluyó a 6.275 hombres y 8.148 mujeres, para un total de 14.423 donantes reclutados entre el 1° de marzo de 2014 y el 30 de junio de 2015. De ellos, 25 resultaron positivos para HTLV-I o HTLV-II en la prueba de tamización (ELISA). En la prueba confirmatoria (inmunoblot), nueve (36 %) pacientes fueron positivos para el HTLV-I o HTLV-II , y de ellos ocho (32 %) lo fueron para el HTLV-I y uno (4 %) para el HTLV-II; la seroprevalencia global fue de 0,06 % (IC95% 0,10-0,25). Conclusiones . Los hallazgos del estudio concordaron con los de estudios similares en áreas no endémicas del país y con los de los estudios consultados a nivel internacional.

Abstract Introduction: The human-T cell lymphotropic virus is a retrovirus with various types known so far. HTLV-I and HTLV-II are of clinically importance as they cause different diseases such as adult T-cell leukemia/lymphoma, tropical spastic paraparesis, and human T-lymphotropic virus type I-associated myelopathy (HAM). Objective: To estimate the prevalence of presumptive and confirmatory reactivity to HTLV-I/II in blood donors of Hospital Pablo Tobón Uribe Blood Bank between 2014 and 2015. Materials and methods: The information was obtained from the Hospital Pablo Tobón Uribe Blood Bank database. We analyzed age, sex, place of origin, and place of residence of donors, and the reactivity using the screening test (ELISA) as well as the confirmatory test (immunoblot). Results: The donor population studied included 6,275 men and 8,148 women, for a total of 14,423 donors recruited between March 1, 2014, and June 30, 2015. Of all tested donors, 25 were positive for HTLV-I/II by the screening test (ELISA). After performing the confirmatory test (immunoblot), only nine patients were positive for HTLV-I/II (36%), of whom eight were reactive to HTLV-I (32%) and one to HTLV-II (4%), for a global seroprevalence of 0.06% (CI 95%: 0.10-0.25). Conclusions: Our findings were consistent with those found in similar studies in non-endemic areas of the country and with those from studies at international level reported in the literature.

Prevalencia de anticuerpos anti Toxoplasma gondii en hemodonantes en la ciudad de Buenos Aires, desde 1967 a 2017 / Prevalence of anti-Toxoplasma gondii antibodies in blood donors in Buenos Aires city, from 1967 to 2017

Se estudió la prevalencia de anticuerpos anti Toxoplasma gondii a los dadores voluntarios de sangre que concurrieron durante el primer cuatrimestre de los años 1997, 2007 y 2017 al Servicio de Hemoterapia del Hospital Alemán de Buenos Aires y se compararon los resultados con el estudio efectuado en el año 1967. Los sueros fueron procesados con el Sabin Feldman Dye Test. La seroprevalencia promedio en 1967 fue 67.0% (IC95%, 64.4%-69.6%), en 1997, 35% (IC95%, 33.3%-38.3%), en 2007, 31.9 % (IC95%, 29.6%-34.2%) y en 2017, 21.2% (IC95%, 19.0%-23.3%). En los cincuenta años que abarca el estudio la disminución de la prevalencia fue de 45.8%, que representa una declinación anual promedio del 0.9%. El descenso fue estadísticamente significativo entre los años 1967 y 1997 y entre 2007 y 2017. En los cuatro estudios se observó un incremento de la prevalencia de infección en función de la edad. La tasa de infección calculada para el año 1967 fue 1.0% y disminuyó en los estudios posteriores, a 0.8% en 1997, 0.7% en 2007 y 0.5% en 2017. Los donantes del último estudio respondieron una encuesta que mostró una correlación estadísticamente significativa entre seroprevalencia de anticuerpos anti-Toxoplasma gondii y la carencia de agua corriente, estudios secundarios no concluidos o la residencia en zona oeste o sur del conurbano bonaerense. No se encontró una asociación significativa con tener un gato como mascota, consumo de carne poco cocida o práctica de jardinería.

A prevalence study of antibodies anti Toxoplasma gondii in voluntary blood donors who attended the hemotherapy service at the Hospital Alemán during the first four months of the years 1997, 2007 and 2017 was carried out and the results were compared to the study carried out in 1967. The sera where processed with the Sabin Feldman Dye Test. The global average seroprevalence in 1967 was 67.0% (CI95%, 64.4%-69.6%); in 1997, 35.0% (CI95%, 33.3%-38.3%); in 2007, 31.9% (CI95%, 29.6%-34.2%) and in 2017, 21.2% (CI95%, 19.0%-23.3%). In the fifty years covered by the study the decline in prevalence was 45.8%, which represents an average annual decline of 0.9%.The decline was statistically significant between 1967 and 1997, and between 2007 and 2017. The four studies demonstrate that infection prevalence increased depending on age. The infection rate for 1967 was 1.0% per year and declined in the next studies to 0.8% in 1997, 0.8% in 2007, and 0.5% in 2017. Donors from the last study responded to a survey that showed a statistically significant correlation between seroprevalence of Toxoplasma gondii antibodies and lack of tap water, unfinished secondary studies or residence in the western or southern part of the Buenos Aires metropolitan area. No significant association was found with having a cat as a pet, the consumption of undercooked meat or the practice of gardening.

Ingesta de hierro y gen HFE en varones adultos de Buenos Aires / Iron intake and HFE gen in male adults from Buenos Aires

El consumo excesivo de hierro (Fe) en portadores de mutaciones en el gen HFE puede resultar en sobrecarga. Para evaluar el riesgo de sobrecarga de Fe fueron investigados 166 varones adultos donantes de sangre de la ciudad de Buenos Aires. Se estimó la ingesta diaria de Fe (IFe), de Fe hemínico y de Fe proveniente de harinas enriquecidas con SO4Fe. Se determinó ferritina sérica y porcentaje de saturación de transferrina (criterio de sobrecarga de Fe: ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%). Las mutaciones C282Y, H63D y S65C fueron investigadas en sangre mediante PCR-RFLP. Todos los participantes cubrieron ampliamente el requerimiento estimado promedio de Fe (6 mg Fe/día) y 3.0% superó el máximo tolerable (45 mg Fe/día). El Fe hemínico correspondió al 9.4% de la IFe y el de harinas enriquecidas al 47.7%. Se observó una asociación entre el aumento de IFe y el de ferritina sérica (p = 0.0472), y el 2.3% de los donantes presentaron ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%. El 29.3% de los donantes eran portadores de los genotipos H63D, S65C o C282Y, asociados a hemocromatosis hereditaria, y tenían valores de saturación de transferrina significativamente mayores a los de los donantes wild type (p = 0.0167). Si bien la incidencia clínica de hemocromatosis hereditaria fue baja en el grupo estudiado (1.2%), el consumo excesivo de Fe plantea un riesgo potencial para la salud de individuos que ignoran sus antecedentes familiares de sobrecarga de Fe.

Excess iron (Fe) intake in subjects carrying certain mutations in the HFE gene may result in Fe overload. To estimate risk of Fe overload, 166 male blood donors (19-65 years) from Buenos Aires city were investigated. Daily Fe intake (FeI), hem Fe intake, and Fe intake from SO4Fe enriched flours were estimated (SARA Computer Program and Food Composition Table, USDA). Serum ferritin and transferrin saturation were determined; criteria for Fe overload was serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. HFE genotypes C282Y, H63D and S65C were analyzed by PCR-RFLP in blood samples. No participant presented FeI lower than the estimated average requirement (6 mg Fe/day) and 3.0% was over the upper level (45 mg Fe/day). Hem Fe and Fe from flour enrichment were 9.4% and 47.7% of daily Fe intake, respectively. A significant association was observed between the increase in serum ferritin (ng/ml) and the increase in FeI (p = 0.0472); 2.3% of the donors presented serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. Genotypes associated with hereditary hemochromatosis (H63D, S65C and C282Y) were found in 29.3% of the donors. The percentage of transferrin saturation was higher in subjects carrying mutation than in wild type subjects (p = 0.0167). Although penetrance of hereditary hemochromatosis in the studied group was only 1.2%, an excessive Fe intake could enhance adverse effects in individuals unaware of any family history of Fe overload.

High prevalence of hepatitis E virus antibodies in Sao Paulo, Southeastern Brazil: analysis of a group of blood donors representative of the general population

Abstract Brazil is a non-endemic country for hepatitis E virus (HEV) infection with seroprevalence from 1% to 4% in blood donors and the general population. However, data on seroprevalence of HEV in the country are still limited. This study evaluated the prevalence of past or present HEV infection in a group of blood donors representative of the general population of the city of Sao Paulo, Southeastern Brazil. Serum samples from 500 blood donors were tested from July to September 2014 by serological and molecular methods. Anti-HEV IgG antibodies were detected in 49 (9.8%) subjects and categorized age groups revealed an age-dependent increase of HEV seroprevalence. Among the anti-HEV IgG positive subjects, only 1 had anti-HEV IgM while none tested positive for HEV-RNA. The present data demonstrate a higher seroprevalence of anti-HEV IgG than previously reported in the region.