Scielo RSS <![CDATA[Revista Panamericana de Salud Pública]]> http://www.scielosp.org/rss.php?pid=1020-498920030002&lang=en vol. 13 num. 2-3 lang. en <![CDATA[SciELO Logo]]> http://www.scielosp.org/img/en/fbpelogp.gif http://www.scielosp.org <![CDATA[<B>La garantía de sangre segura en las Américas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200001&lng=en&nrm=iso&tlng=en <![CDATA[<B>El fomento de buenos servicios de sangre en la Región de las Américas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200002&lng=en&nrm=iso&tlng=en <![CDATA[<B>Ensuring safe blood in the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200003&lng=en&nrm=iso&tlng=en <![CDATA[<B>Promoting quality blood services in the Region of the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200004&lng=en&nrm=iso&tlng=en <![CDATA[<B>Los servicios de sangre en la Región de las Américas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200005&lng=en&nrm=iso&tlng=en <![CDATA[<B>Blood services in the Region of the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200006&lng=en&nrm=iso&tlng=en <![CDATA[<B>Basic components of a national blood system</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200007&lng=en&nrm=iso&tlng=en En este artículo se resumen la misión y las funciones de los servicios de sangre de un país y se examinan los componentes necesarios para el funcionamiento adecuado y eficiente de un sistema nacional de servicios de sangre. La sangre para transfusión es un recurso nacional y, por tanto, las autoridades sanitarias deben garantizar su disponibilidad, seguridad, calidad y uso eficiente. Para alcanzar estas metas, cada país debe tener un marco jurídico reglamentario para los centros donde se extrae, procesa y transfunde la sangre. Las leyes y los reglamentos sirven de base para la organización del sistema de servicios nacional, identifican las tareas de los interesados directos y garantizan la disponibilidad de los recursos que necesita el sistema. Esas leyes y reglamentos deben basarse en sólidos criterios médicos y técnicos. Dentro de este marco, es importante tener presentes las diversas funciones de los distintos departamentos del ministerio de salud, así como de otras instituciones, organizaciones no gubernamentales y grupos académicos y de los profesionales vinculados con el sistema nacional de servicios de salud. <![CDATA[<B>A study of sociocultural factors related to voluntary blood donation in the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200008&lng=en&nrm=iso&tlng=en OBJETIVO: Obtener información de base sobre los conocimientos, actitudes y prácticas relacionados con la donación voluntaria de sangre, así como la capacidad instalada de los bancos de sangre para la atención de donantes. MÉTODOS: El estudio se realizó en 15 países de la Región: Argentina, Bolivia, Colombia, Costa Rica, Cuba, Ecuador, El Salvador, Guatemala, Jamaica, Nicaragua, Panamá, Paraguay, Perú, República Dominicana y Venezuela, con la cooperación técnica de la Organización Panamericana de la Salud, oficina regional de la Organización Mundial de la Salud. Se utilizó una metodología formativa cualitativa mediante entrevistas a donantes, público en general y personal de salud, así como observación directa, grupos focales, pruebas de conocimientos y revisión documental. RESULTADOS: Se identificaron el conocimiento de las personas sobre la donación, sus creencias, percepciones y actitudes, sus barreras y motivaciones, al igual que los medios más eficaces para transmitir el mensaje a favor de la donación voluntaria. CONCLUSIONES: Esta información servirá como base para diseñar una estrategia en los países encaminada a promover la captación y lealtad de los donantes voluntarios de sangre. Esta estrategia podrá ser el sustento para llevar a la práctica los cambios necesarios en la atención y motivar a los donantes a regresar con regularidad a donar sangre.<hr/>OBJECTIVE: To obtain baseline data for countries of the Americas on knowledge, attitudes, and practices related to voluntary blood donation as well as on the current level and quality of services that blood banks provide to donors. METHODS: The study was conducted in 15 countries in the Americas: Argentina, Bolivia, Colombia, Costa Rica, Cuba, the Dominican Republic, Ecuador, El Salvador, Guatemala, Jamaica, Nicaragua, Panama, Paraguay, Peru, and Venezuela. Technical cooperation for the study came from the Pan American Health Organization. A qualitative formative methodology was applied, utilizing interviews with donors, health workers, and members of the general public; direct observation; focus groups; knowledge tests; and a review of documents. RESULTS: Information was generated on people's knowledge of donation; their beliefs, perceptions, attitudes, and motivations; and their barriers to donating. Knowledge was also gained as to the best means for disseminating messages supporting voluntary donation. CONCLUSIONS: This information will serve as a foundation for designing a strategy in the countries of the Americas that is aimed at establishing and building the loyalty of voluntary blood donors. This strategy can support the implementation of changes needed in the care of donors, and it can also help in motivating donors to regularly return to donate blood. <![CDATA[<B>External serology quality control programs developed in Latin America with the support of PAHO from 1997 through 2000</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200009&lng=en&nrm=iso&tlng=en OBJETIVOS: Con el apoyo de la Organización Panamericana de la Salud (OPS), desarrollamos entre 1997 y 2000 cinco programas de control externo de la calidad en serología (PCECS) en los que participaron entre 13 y 21 bancos de sangre de 11 a 16 países de América Latina. El objetivo fue evaluar el desempeño de los bancos de sangre con respecto al tamizaje serológico realizado en donantes de sangre. MÉTODOS: Como herramienta de trabajo utilizamos conjuntos de 24 muestras de sueros anónimos con reactividades variables para los parámetros de uso obligatorio en el tamizaje serológico de donantes de sangre en Brasil. En cada PCECS enviamos un multipanel a cada institución participante para que lo procesara en las mismas condiciones de su rutina de tamizaje. Cada participante recibió la clave del multipanel para autoevaluación, después de haber devuelto los resultados obtenidos en su laboratorio. Se mantuvo siempre la más estricta confidencialidad sobre los resultados obtenidos individualmente. Al terminar de cada programa, el Centro Organizador (Superintendencia de Serología de la Fundação Pró-Sangue/Hemocentro de São Paulo) elaboró un informe final que contenía toda la información obtenida en el programa y que fue enviado a los participantes. RESULTADOS: En el análisis de los cinco PCECS se observó falta de homogeneidad entre los países con respecto a las estrategias y a los parámetros utilizados en el tamizaje de donantes de sangre. Pocos laboratorios practicaron el tamizaje de los virus linfotrópico de células T humanas (HTLV) (17%, 27%, 35%, 39% y 45%, respectivamente y en orden creciente para los cinco PCECS) y de anticuerpos contra el antígeno nuclear del virus de la hepatitis B (anti-HBc) (42%, 27%, 39%, 50% y 60%). También se observaron diferencias importantes en cuanto a las pruebas o combinaciones de pruebas utilizadas, lo cual puede dificultar el estudio comparativo de los tipos de tamizaje. El número total de resultados positivos falsos osciló alrededor del 2%, correspondiendo el mayor valor al tamizaje de anticuerpos contra el virus de la hepatatis C (anti-VHC) (4,6%) y el menor a anti-Trypanosoma cruzi (0,4%). CONCLUSIONES: Los resultados obtenidos en este trabajo demuestran la necesidad de continuar las acciones de la OPS en América Latina para reforzar los procedimientos de tamizaje serológico en bancos de sangre, incluso los PCECS, hasta que se consiga una uniformidad de procedimientos en la Región de las Américas.<hr/>OBJECTIVE: To evaluate the quality of serological screening of blood donors in five groups of blood banks in Latin America that participated over the 1997-2000 period in an external serology quality control project developed with support from the Pan American Health Organization (PAHO). METHODS: With assistance from PAHO, the Serology Authority of the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo), of São Paulo, Brazil, carried out the external quality control project and served as its "organizing center" (OC). The OC developed five external serology quality control "programs" (ESQCPs), or external evaluation activities, for the respective groups of participating blood banks. There was one ESQCP each in 1997, 1999, and 2000, and there were two in 1998. In these five programs, the number of participating blood banks ranged from 13 to 21, and the number of countries ranged from 11 to 16. In each program, the OC used a set of 24 blinded sera samples with different reactivities for the various infectious agents for which screening is obligatory in Brazil. Each participating institution in each program received a sera set, to be processed using that institution's standard screening procedures. After returning its results to the OC, each participant received an answer key for the sera set, to be used in evaluating its own performance. All the individual results were kept strictly confidential. At the end of each program, the OC prepared and sent to all the participants a final report that contained information on the overall results from that program. RESULTS: An analysis of the five programs showed that there was a lack of homogeneity among the countries with respect to the strategies and the parameters used in screening blood donors. Few laboratories screened for human T-cell-lymphotropic virus (beginning with the 1997 program, the respective rates were 17%, 27%, 35%, 39%, and 45%). Rates of screening were also low for antibodies to the hepatitis B core antigen (again, beginning with the 1997 program, the rates were 42%, 27%, 39%, 50%, and 60%). There were also important differences with respect to which tests and which combinations of tests were used, making it hard to compare the types of screening done. In the five programs, with the various tests used, the overall rate of false positive results fluctuated around 2%. The highest false positive rate for any of the tests, 4.6%, was for antibodies against the hepatitis C virus. The lowest false positive rate, 0.4%, was for antibodies against Trypanosoma cruzi. CONCLUSIONS: These results show the need for PAHO to continue using these external quality control programs as well as other activities in order to strengthen the procedures for serological screening in blood banks in Latin America, until there is more uniformity in the procedures that the countries use. <![CDATA[<B>Availability, safety, and quality of blood for transfusion in the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200010&lng=en&nrm=iso&tlng=en OBJECTIVES: This article has two objectives: (1) to present for countries and territories of the Region of the Americas data on the number of blood donations, proportion of voluntary blood donors versus remunerated blood donors, coverage of screening for infectious agents, and separation of donated blood into its components and (2) to explore the relationships of those characteristics with economic and organizational factors in the countries and territories. METHODS: We carried out comparative analyses using population and health information gathered annually by the Pan American Health Organization (PAHO) from national health officials from the countries in the Americas, as well as economic information (gross national product (GNP) per capita) obtained from publications of the World Bank. RESULTS: There is a direct correlation between the availability of blood for transfusion and GNP per capita. Seven countries with a GNP per capita above US$ 10 000 per year account for 38% of the Regional population but 68% of the Regional blood donations. Voluntary blood donation is more common in the countries with better blood availability. There is no association between GNP per capita and coverage of screening for infectious agents. Nevertheless, of the six countries with a GNP per capita below US$ 1 000, only one of the six screens all units for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen (HBsAg). Countries with a higher proportion of voluntary blood donors tend to have lower prevalence rates of infectious markers. Separation of blood into its components is also more common in countries with higher blood donation rates. CONCLUSIONS: The availability, safety, and quality of blood for transfusion in the Americas needs to be improved. As part of that effort, national policies and strategies must be put into place so that the resources already allocated for blood services are better utilized.<hr/>OBJETIVOS: Este artículo tiene dos objetivos: 1) presentar para los países y territorios americanos datos acerca del número de donaciones de sangre, la proporción de donantes voluntarios y remunerados, la cobertura con pruebas para el tamizaje de agentes infecciosos y la separación de sangre donada en sus diversos componentes, y 2) explorar las relaciones entre estas características y factores económicos y de organización en los países y territorios. MÉTODOS: Llevamos a cabo análisis comparativos usando información poblacional y sanitaria obtenida anualmente por la Organización Panamericana de la Salud (OPS) de las autoridades de salud de los países de las Américas, así como información económica (producto nacional bruto (PNB) per cápita) sacada de publicaciones del Banco Mundial. RESULTADOS: Hay una correlación directa entre la disponibilidad de sangre para transfundir y el PNB per cápita. Siete países con un PNB per cápita mayor de US$ 10 000 anuales representan 38% de la población de la Región, pero 68% de las donaciones en esta. La donación voluntaria de sangre es más común en países donde hay más disponibilidad de sangre. No hay ninguna asociación entre el PNB per cápita y la cobertura con pruebas para el tamizaje de agentes infecciosos. No obstante, de los seis países con un PNB per cápita menor de US$ 1 000, solamente uno somete a tamizaje todas las unidades de sangre para la detección del virus de la inmunodeficiencia humana (VIH), el virus de la hepatitis C (HCV), y el antígeno superficial del virus de la hepatitis B (HBsAg). Los países con una mayor proporción de donantes voluntarios suelen tener una menor prevalencia de positividad a marcadores de infección. La separación de la sangre en sus diversos componentes es también más frecuente en países con tasas más elevadas de donación de sangre. CONCLUSIONES: La disponibilidad, seguridad y calidad de la sangre para transfusión en países de las Américas deben mejorarse. Como parte de una iniciativa de este tipo, hay que poner en marcha políticas y estrategias nacionales a fin de lograr que los recursos ya adjudicados a los servicios de transfusión de sangre sean mejor aprovechados. <![CDATA[<B>The discarding of blood units and the prevalence of infectious diseases in donors at the Pro-Blood Foundation/Blood Center of São Paulo, São Paulo, Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200011&lng=en&nrm=iso&tlng=en OBJETIVO: Analisar a evolução, de 1991 a 2001, do descarte sorológico na Fundação Pró-Sangue/Hemocentro de São Paulo, o maior banco de sangue da América Latina, e verificar a prevalência de doenças infecciosas entre doadores dessa instituição no ano de 2001. MÉTODOS: Foram compilados os dados de descarte sorológico relativos aos anos de 1991 a 2001. Para determinar a prevalência de doenças infecciosas, foram analisadas 9 942 amostras triadas em novembro de 2001, sendo as amostras reativas submetidas a testes confirmatórios. RESULTADOS: Foi encontrada uma diminuição percentual significativa de descarte, de 20% em 1991 para 9% em 2001. A prevalência de doenças infecciosas entre doadores em 2001 foi de 0,04% para vírus da imunodeficiência humana (VIH); 0,21% para vírus da hepatite C (VHC); 0,06% para vírus T-linfotrópico humano (HTLV); para vírus da hepatite B (VHB), as prevalências foram de 0,14% para anti-HBc + HBsAg, 1,68% para anti-HBc + anti-HBs e 1,67% para anti-HBc isolado; 1,10% para sífilis; e 0,14% para doença de Chagas. CONCLUSÃO: A diminuição no descarte e a prevalência de doenças infecciosas entre doadores da Fundação Pró-Sangue/Hemocentro de São Paulo em 2001 refletem o aumento na porcentagem de doadores de repetição nesse banco de sangue.<hr/>OBJECTIVES: To analyze the changes in the proportion of blood units discarded from 1991 through 2001 at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo), which is the largest blood bank in Latin America, and to determine the prevalence of infectious diseases among donors at the Blood Center in November 2001. METHODS: We compiled data concerning the discarding of blood units due to the presence of serological markers for communicable diseases at the Blood Center during the period from 1991 through 2001. To determine the prevalence of infectious diseases, 9 942 screened samples were analyzed in November 2001; all reactive samples underwent confirmatory tests. RESULTS: Over the study period there was a significant decrease in the percentage of units discarded, from 20% in 1991 to 9% in 2001. In November 2001 the prevalence of infectious diseases among donors was: 0.04% for human immunodeficiency virus (HIV), 0.21% for hepatitis C virus (HCV), 0.06% for human T-lymphotropic virus (HTLV), 0.14% for Chagas' disease, and 1.10% for syphilis. For hepatitis B virus, the prevalences found were: 0.14% for anti-HBc and HBsAg, 1.68% for anti-HBc and anti-HBs, and 1.67% for isolated anti-HBc. CONCLUSIONS: The decrease in the discarding of blood units and in infectious diseases among donors at the Blood Center of São Paulo reflects the increase in the Center's percentage of repeat donors. <![CDATA[<B>Seropositivity for human T-lymphotropic virus types I and II among donors at the Municipal Blood Bank of Caracas and associated risk factors</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200012&lng=en&nrm=iso&tlng=en OBJETIVOS: Conocer la proporción de sangre descartada por seropositividad al virus linfotrópico de células T humanas (HTLV) tipos I y II, la prevalencia de dicha infección y los probables factores de riesgo en donantes del Banco Municipal de Sangre de Caracas (BMSC). MÉTODOS: Se evaluaron serológicamente mediante ensayos de inmunoadsorción enzimática (ELISA) 23 413 donantes atendidos entre julio del año 2000 y abril de 2001 en el BMSC. Las muestras repetidamente reactivas (RR) se estudiaron por inmunoblot de Western (WB), como prueba suplementaria. Los donantes positivos o indeterminados por WB fueron citados a la consejería para realizar la confirmación mediante la amplificación de ácidos nucleicos por reacción en cadena de la polimerasa (PCR), recoger datos sobre sus antecedentes de riesgo y asesorarlos acerca de su estado. RESULTADOS. El 0,2% de las donaciones resultaron RR; de ellas 52,1% resultaron positivas en el WB (23 a HTLV I y 2 a HTLV II); 4,1% indeterminadas por WB; 29,2% negativas; y el 14,6% no pudo ser evaluado. Asistieron a la consejería 16 donantes (14 WB positivos a HTLV I, 1 a HTLV II y 1 indeterminado). Todos resultaron positivos en la RCP. No se encontraron diferencias significativas con el grupo control en cuanto a edad, sexo, tipo de donación, número de donaciones previas, antecedentes de transfusiones y comportamiento sexual. Se observaron diferencias significativas según los antecedentes de consumo de drogas no intravenosas (P < 0,05), y altamente significativas (P < 0,001) según los antecedentes de lactancia materna larga. Las madres estudiadas de seis de los donantes positivos que manifestaron haber tenido una larga lactancia materna resultaron positivas, al igual que el hijo mayor de la única pareja positiva de las 13 evaluadas. CONCLUSIONES. Se descartó el 0,2% de la sangre por resultar positiva al HTLV I/II. La prevalencia entre los donantes fue de 0,11%. En el 37,5% de los casos se pudo determinar la probabilidad de transmisión de madre a hijo. La transmisión sexual resultó menos frecuente. Se debe considerar seriamente la implementación del tamizaje serológico del HTLV I/II en los donantes de sangre de Venezuela.<hr/>OBJECTIVE: To conduct research at the Municipal Blood Bank of Caracas (MBBC) and find out the proportion of blood units discarded for being seropositive for human T-lymphotropic virus (HTLV) types I and II, the prevalence of that infection among their donors, and the probable risk factors for that infection among those HTLV-positive donors. METHODS: ELISA serological testing was done with 23 413 donors seen at the MBBC between July 2000 and April 2001. Samples that were repeat reactive (RR) with the ELISA underwent supplementary Western blot (WB) testing. Donors who had a positive or indeterminate WB result were scheduled for counseling in order to carry out confirmatory testing using nucleic acid amplification (NAA), to collect data on their risk background, and to advise them concerning their HTLV status. RESULTS: Of the 23 413 MBBC donors, 48 of them (0.2%) had a donation that was RR. Of those 48, 25 of them (52.1%) were positive on the WB (23 for HTLV-I and 2 for HTLV-II), 2 of them (4.1%) were indeterminate on the WB, 14 of them (29.2%) were negative, and 7 (14.6%) could not be evaluated. Of the 27 donors scheduled for counseling, 16 of them actually attended (14 WB-positive for HTLV-I, 1 WB-positive for HTLV-II, and 1 indeterminate). All 16 of them were positive with the confirmatory NAA testing. When these 16 seropositive donors were compared with a control group of seronegative donors, no significant differences were found with regard to age, sex, type of donation, number of previous donations, history of transfusions, and sexual behavior. However, significant differences were found in two areas: the seropositive donors were more likely to have used non-intravenous drugs (P < 0.05), and the seropositive donors were much more likely to have had an extended breast-feeding period (more than 2 years) as a child (P < 0.001). To assess the probability of mother-to-child transmission, six of the mothers of seropositive donors who had had an extended breast-feeding period were tested, and all six of those mothers were also found to be seropositive. With the 16 seropositive donors who were counseled, the spouse or partner of 13 of them was also tested; only 1 of those 13 was positive, but the oldest son of that couple was also HTLV-positive. CONCLUSIONS: Of the donated blood, 0.2% of the units were discarded for being positive for HTLV-I or HTLV-II, and the prevalence found among the donors was 0.11%. Sexual transmission between an HTLV-positive donor and a partner or spouse was less frequent than was mother-to-child transmission. At present in Venezuela, blood banks are not required to screen donations for HTLV. Given our results at the MBBC, we believe serious consideration should be given to implementing serological screening for HTLV I/II among blood donors throughout Venezuela. <![CDATA[<B>Hemophilia care in the state of Rio de Janeiro, Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200013&lng=en&nrm=iso&tlng=en In the developing countries of the world, few people with hemophilia receive adequate care. Nevertheless, Brazil has made significant advances in the treatment of hemophilia over the last decade. The provision of factor concentrates imported by the Government of Brazil is gradually increasing, and patients receive the concentrates for free. A national register was established as well as a coordinated program for comprehensive care. Of the 6 297 persons with hemophilia in Brazil who were registered as of January 2001, 689 of them (11.1%) were registered in the state of Rio de Janeiro. Of those 689, 664 of them were being monitored at the state's coordinating blood transfusion center, which is located in the city of Rio de Janeiro. Among those 664, factor VIII inhibitors were identified in 81 of them (12.2%). Among 653 of the Rio de Janeiro patients who were tested for transfusion-transmitted diseases, the overall prevalence found was 41.5%, with the specific rates being 13.3% for human immunodeficiency virus (HIV), 2.9% for hepatitis B virus (HBV), and 39.4% for hepatitis C virus (HCV). The state of Rio de Janeiro has adopted a comprehensive hemophilia management approach that includes medical, psychological, and social care. As a result, the quality of life of hemophilia patients has improved noticeably. For example, the rate of hospitalization among patients fell by 30% between 1998 and 2001, and there has also been a decline in the school and work activities that they have missed.<hr/>En los países en desarrollo, pocas personas con hemofilia reciben un tratamiento adecuado. No obstante, el Brasil ha logrado grandes avances en este sentido en el último decenio. La provisión de concentrados de factores de la coagulación importados por el gobierno de Brasil va aumentando gradualmente y los pacientes reciben el concentrado gratis. Un registro nacional se estableció junto con un programa coordinado de atención global. De las 6 297 personas con hemofilia en el Brasil que estaban inscritas en enero de 2001, 689 de ellas (11,1%) estaban inscritas en el estado de Rio de Janeiro. De esas 689, 664 estaban bajo el control del centro coordinador de transfusiones sanguíneas del estado, que se ubica en la ciudad de Rio de Janeiro. De esas 664 personas, 81 (12,2%) mostraron la presencia de inhibidores del factor VIII. Entre los 653 pacientes en Rio de Janeiro que fueron sometidos a pruebas para el tamizaje de enfermedades transmitidas por transfusión, se encontró una prevalencia general de 41,5%, con tasas específicas de 13,3% en el caso del virus de la inmunodeficiencia humana (VIH), de 2,9% en el del virus de la hepatitis B (VHB) y de 39,4% en el del virus de la hepatitis C (VHC). El estado de Rio de Janeiro ha adoptado un programa para el tratamiento global de la hemofilia que abarca atención médica, psicológica y social. Como resultado, la calidad de la vida de los pacientes con hemofilia ha mejorado notablemente. Por ejemplo, la tasa de ingresos en estos pacientes bajó 30% entre 1998 y 2001, y también se ha observado un descenso de las actividades escolares y laborales perdidas a causa de la enfermedad. <![CDATA[<B>The results of an external quality control program for serological screening for antibodies against <I>Trypanosoma cruzi</I> in blood donors in Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200014&lng=en&nrm=iso&tlng=en OBJETIVOS: A partir de 1995 en Brasil se iniciaron programas de control de calidad externo de laboratorios de serología (PCCES) abiertos a la participación de laboratorios de bancos de sangre públicos y privados. Estos programas se han puesto en práctica tres veces al año desde 1995 y cuentan con la participación de más de 100 entidades. El objetivo de este trabajo es analizar los resultados de los ocho últimos programas de evaluación del tamizaje serológico para la enfermedad de Chagas, que se realizaron entre abril de 1999 y agosto de 2001. MÉTODOS: Participaron en los ocho programas laboratorios de serología de instituciones públicas y privadas. El número de laboratorios participantes que entregó los resultados en cada uno de los ocho PCCES fue de 94, 90, 85, 94, 100, 103, 102 y 116, respectivamente. Al inicio de cada PCCES se envió un panel enmascarado a cada institución participante, con un plazo de 60 días para informar los resultados del procesamiento de las muestras. Se utilizaron pruebas de inmunoadsorción enzimática (ELISA), inmunofluorescencia indirecta (IFI) y hemaglutinación indirecta (HAI). Posteriormente, cada institución recibió del centro organizador (PANEL) la clave con los resultados correctos para su autoevaluación. Los paneles estaban compuestos por 24 muestras de sueros con diferentes reactividades a los marcadores obligatorios en el tamizaje serológico de donantes de sangre en Brasil, incluido el de muestras negativas. RESULTADOS: La técnica de ELISA fue la más utilizada en el tamizaje (92%-98%). La estrategia de tamizaje más usada por los laboratorios participantes fue la combinación de una prueba de ELISA y una de HAI (58%-83%). La mayoría de los laboratorios participantes obtuvieron resultados correctos en los diferentes programas sin resultados negativos falsos (83,6%-98,1%). De las 5 406 muestras de suero positivas a anti-Trypanosoma cruzi que hubo en los ocho programas, 85 (1,6%) fueron notificadas de negativas por 58 laboratorios, pero solamente 14 de ellos dejaron de identificar una o más muestras positivas por no conseguir detectarlas por medio de ninguna de las pruebas de tamizaje utilizadas. No se observó ninguna diferencia significativa entre bancos en los ocho programas (P = 0,5936). No se observó asociación entre los resultados negativos falsos y una muestra o sistema diagnóstico en particular. La técnica de HAI presentó el mayor número de resultados negativos falsos (0,7%-7,9%). De los 32 855 resultados obtenidos en muestras de sueros negativas a anti-T. cruzi en los ocho programas, 106 (0,32%) fueron notificados como resultados positivos falsos. Entre 1% y 16% de los laboratorios participantes obtuvieron un resultado positivo falso por programa y entre 0% y 4% notificó más de un resultado positivo falso. La proporción de resultados negativos falsos muestra una tendencia descendente después de 1995. CONCLUSIONES: Los resultados obtenidos en este trabajo apuntan hacia una tendencia desecendente en la proporción de resultados negativos falsos. Al mismo tiempo se observó que la técnica de HAI continúa arrojando el mayor número de resultados negativos falsos. Se sugiere darle preferencia a la técnica ELISA para el tamizaje de donantes de sangre.<hr/>OBJECTIVES: In 1995 a series of external quality control programs (EQCPs) was launched for serology laboratories in Brazil, open to both public and private blood-bank laboratories. These "programs" have been held several times per year since 1995. The objective of this paper is to present the results achieved during eight programs conducted between April 1999 and August 2001, in terms of serological screening for Chagas' disease. METHODS: The participants in these eight EQCPs were serology laboratories from public and private institutions. The number of participants in each respective program that sent in its results was 94, 90, 85, 94, 100, 103, 102, and 116. At the beginning of each EQCP a blinded panel of sera was sent to each participating institution. Each panel consisted of 24 serum samples with different reactivities for the markers for which the serological screening of blood donors is obligatory in Brazil; among the 24 samples were some negative ones. The participants had 60 days to complete their testing and send in their results for evaluation. Later, each participant received an answer key for the sera panel, to use in self-evaluation. RESULTS: The three tests that the participants used most frequently were enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination (IHA), and indirect immunofluorescence (IIF). Of these three, the ELISA was used most often, ranging from 92% to 98% of the laboratories for the eight programs. The screening strategy that was most often used was a combination of an ELISA test and an IHA test (ranging from 58% to 83% of the laboratories for the eight programs). In the various programs, the large majority of participating laboratories (range, 83.6%-98.1%) obtained accurate results without any false negative results. Of the 5 406 tests carried out during the eight programs using positive anti-T. cruzi sera samples, 85 (1.6%) were reported as negative in 58 laboratories. However, only 14 of those laboratories were unable to identify one or more positive samples after using all their screening tests. There were no significant differences found between the blood banks in the eight programs (P = 0.5936). No association was found between false negative results and any particular sample or any specific diagnostic kit. IHA testing had the highest proportion of false negatives, ranging from 0.7% to 7.9% for the eight programs. Of 32 855 tests performed during the eight programs using negative anti-T. cruzi sera, 106 (0.32%) were reported as false positives. The percentage of participating laboratories that had one false positive result per program varied from 1% to 16%, and between 0% and 4% of the labs per program had more than one false positive result. In comparison to testing done in Brazil in 1994-1995, the proportion of false negative results has declined. CONCLUSIONS: The results of this study point to a decrease over time in the proportion of false negative results. In the 1999-2001 programs, the highest percentage of false negative results was found with IHA testing. Therefore, it is recommended to give preference to ELISA testing for screening blood donors. <![CDATA[<B>External evaluation of serology results in blood banks in Colombia</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200015&lng=en&nrm=iso&tlng=en OBJETIVO: Analizar los resultados serológicos obtenidos en los bancos de sangre colombianos que participan en el programa externo de calidad (PEC) con el fin de mejorar la calidad del tamizaje de la sangre según los principales marcadores serológicos de enfermedades infecciosas de posible transmisión sanguínea. MÉTODOS: Se evaluó un panel de seis sueros con diferente reactividad y positividad a anticuerpos contra los virus de la inmunodeficiencia humana (VIH) 1-2, el virus de la hepatitis C (VHC), Trypanosoma cruzi, Treponema pallidum y el virus linfotrópico de células T humanas (HTLV), y contra el antígeno de superficie del virus de la hepatitis B (HBsAg). Las técnicas de tamizaje utilizadas fueron el ensayo de inmunoadsorción enzimática (ELISA), el inmunoensayo enzimático de micropartículas (MEIA) y la hemaglutinación (HA). Se solicitó a los bancos de sangre participantes que aplicaran a los sueros las pruebas que diariamente realizaban para el tamizaje de unidades de sangre y que enviaran los resultados a la Coordinación Nacional de Bancos de Sangre del Instituto Nacional de Salud de Colombia. RESULTADOS: De 46 bancos de sangre que participaron, 43 (93%) devolvieron los resultados en el plazo indicado. La prueba de ELISA fue la más utilizada (83,02%). Se obtuvo un total de 49 (5%) resultados positivos falsos y 12 (3%) resultados negativos falsos. De estos últimos, 50% correspondieron a la detección de la sífilis; 16,7% a la de la enfermedad de Chagas; 16,7% a la de anticuerpos anti-HBc; 8,3% a la de anticuerpos anti-VHC y 8,3% a la del HBsAg. Ochenta por ciento de los resultados discordantes se presentaron en 23 bancos de sangre con un volumen de menos de 6 000 unidades de sangre al año, y 15% en 5 bancos de sangre con un volumen de 6 000 a 12 000 unidades de sangre al año. De los bancos de sangre que recogían más de 12 000 unidades anuales, solo uno notificó tres resultados positivos falsos. No se notificaron resultados negativos falsos. CONCLUSIONES: El porcentaje de resultados negativos falsos (3%) obtenidos durante el PEC puede considerarse elevado, ya que las pruebas que resultan negativas durante el tamizaje de los bancos de sangre no se repiten y la decisión de declarar una unidad de sangre apta para transfusión se basa en ese único resultado. Es preciso revisar minuciosamente los procedimientos para el tamizaje de la sangre, en particular en aquellos centros que tuvieron un desempeño pobre.<hr/>OBJECTIVE: To analyze the serological results found in Colombian blood banks that participate in the external quality program (EQP) of that country's National Institute of Health, in order to improve the quality of the screening of blood for the main serological markers of transfusion-transmitted infectious diseases. METHODS: Each blood bank received a panel of six sera with different reactivity and positivity to hepatitis B surface antigen (HBsAg), as well as to antibodies to HIV 1-2, Trypanosoma cruzi (the causative agent of Chagas' disease), Treponema pallidum (the causative agent of syphilis), hepatitis B core (HBc) antigen, hepatitis C virus (HCV), and human T-lymphotropic virus (HTLV). The screening techniques used were enzyme- linked immunosorbent assay (ELISA), microparticle enzyme immunoassay (MEIA), and hemagglutination. With the panel sera, the participating blood banks were asked to apply the same tests that they use on a daily basis to screen blood units and to send their results to the National Blood Banks Unit of the Colombian National Institute of Health. RESULTS: Of the 46 blood banks participating in the EQP, 43 of them (93%) returned their results within the requested timeframe. The ELISA test was the one that was used most often (83.0%). There were a total of 49 (5%) false positive results and 12 (3%) false negative results. Of those 12 false negative results, 6 of them corresponded to the detection of syphilis, 2 to Chagas' disease, 2 to anti-HBc antibodies, 1 to anti-HCV antibodies, and 1 to HBsAg. Eighty percent of the discordant results came from 23 blood banks that each collected fewer than 6 000 units of blood per year, and 15% came from 5 blood banks that collected 6 000 to 12 000 units per year. One of the blood banks that collected more than 12 000 units annually had three false positive results, and none of those larger blood banks had any false positive results. CONCLUSIONS: The percentage of false negative results (3%) found during the EQP can be considered high, since tests that are negative during blood screening are not repeated, and the decision to declare a unit of blood suitable for transfusion is based on that single result. There is a need to thoroughly review the procedures for screening blood in Colombia, particularly at the centers that performed poorly in this EQP exercise. <![CDATA[<B>Trends in the profile of blood donors at a large blood center in the city of São Paulo, Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200016&lng=en&nrm=iso&tlng=en OBJECTIVE: To describe the trends in the profile of blood donors from 1995 through 2001 at a large blood center in the city of São Paulo, Brazil, particularly following the initiation in 1998 of marketing strategies aimed at substituting replacement donors with altruistic repeat donors. METHODS: Using an information system that had been established at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo) in 1994, we collected information on sex, age, and type of donation for the years 1995-2001. We classified blood donors as either replacement blood donors (if they stated that the reason for donating was that they had a friend or relative in the hospital) or as altruistic donors. First-time blood donors were those who had not donated in our institution since the establishment of the information system. RESULTS: The percentage of repeat altruistic blood donors increased over time as first-time replacement donors declined for both genders. The proportion of altruistic donors climbed from 20% of all blood donors in 1995 to 57% in 2001. In 2001, first-time blood donors represented only 52% of all donors, as contrasted to 88% in 1995. Female donors increased from 20% to 37% of the donors over the period studied. CONCLUSIONS: Our data provide evidence that the São Paulo population has responded well to the marketing strategies that have been introduced in our institution. We believe that similar promotional efforts elsewhere in Brazil would produce comparable, positive results.<hr/>OBJETIVO: Describir las tendencias observadas de 1995 a 2001 en el perfil de los donantes de sangre de un gran centro de hemoterapia en la ciudad de São Paulo, Brasil, particularmente después del lanzamiento en 1998 de estrategias de mercadeo orientadas a sustituir los donantes por reemplazo por donantes altruistas a repetición. MÉTODOS: Usando un sistema de información que había sido establecido en la Fundación Pro-Sangre/Hemocentro de São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo) en 1994, obtuvimos información acerca del sexo y la edad de los donantes y el tipo de donación para el período de 1995-2001. Clasificamos a los donantes de sangre en donantes de reemplazo (si su motivo para donar sangre era la presencia de un pariente u amigo en el hospital) o bien en donantes altruistas. Las personas que donaban su sangre por primera vez fueron aquellas que nunca habían donado sangre en nuestra institución desde que se estableció el sistema de información. RESULTADOS: El porcentaje de donantes altruistas a repetición aumentó a lo largo del tiempo a medida que el número de donantes de reemplazo que donaban sangre por primera vez se redujo en ambos sexos. La proporción de donantes altruistas subió de 20% de todos los donantes en 1995 a 57% en 2001. En 2001, los donantes que donaban por primera vez representaban solamente 52% de todos los donantes de sangre, en comparación con 88% en 1995. La proporción de mujeres donantes subió de 20 a 37% de todos los donantes en el período estudiado. CONCLUSIONES: Nuestros datos confirman que la población de São Paulo, Brasil, ha respondido bien a las estrategias de mercadeo que han sido adoptadas en nuestra institución. Consideramos que la adopción de iniciativas de promoción similares en otras partes del Brasil daría resultados positivos de igual naturaleza. <![CDATA[<B>External performance evaluation of screening in blood banks in Argentina</B>: <B>results and strategies for improvement</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200017&lng=en&nrm=iso&tlng=en OBJETIVOS: Debido a la falta de un programa para la evaluación externa de la calidad del tamizaje de infecciones transmisibles por transfusión (ITT) en los bancos de sangre, el Servicio de Hemoterapia del Hospital Garrahan, de Buenos Aires, Argentina, inició en 1999 un programa continuo con el apoyo de la Organización Panamericana de la Salud (OPS) y la Asociación Argentina de Hemoterapia e Inmunohematología (AAHI). MÉTODOS: Se distribuyó un panel de 12 muestras con reactividad para todos los marcadores tamizados en los bancos de sangre argentinos. El panel se entregó a 52, 102 y 118 laboratorios en 1999, 2000 y 2001, respectivamente. Los laboratorios participantes se clasificaron según su desempeño en: A: menos de 2 resultados positivos falsos (RPF); B: de 2 a 3 PF; C: más de 3 RPF; y D: algún resultado negativo falso. Se efectuaron talleres con los participantes para analizar conjuntamente los resultados. RESULTADOS: Los porcentajes de respuesta de cada año fueron 92,3, 92,2 y 83,9, respectivamente; estos porcentajes de respuesta indican interés en las actividades de evaluación. Sin embargo, el promedio de los laboratorios con clasificación D resultó muy alto (30%), lo que evidencia la presencia de problemas en el desempeño del tamizaje de las ITT. Esto podría asociarse con la dificultad de tomar medidas correctoras en todo el sistema, dado el elevado número de laboratorios involucrados. CONCLUSIONES: Se deben incluir evaluaciones de este tipo en el Programa Nacional de Sangre para el diagnóstico continuo de la situación, la toma de decisiones y el seguimiento de la calidad del tamizaje.<hr/>OBJECTIVES: Because there was no program for the external evaluation of the quality of the screening for transfusion-transmitted infections (TTIs) in blood banks in Argentina, in 1999 the Hemotherapy Service of Garrahan Hospital, in Buenos Aires, launched an ongoing external evaluation program, with the support of the Pan American Health Organization and the Argentine Hemotherapy and Immunohematology Association. METHODS: A panel of 12 samples that were reactive to all the markers screened for in Argentine blood banks was distributed. The panel was delivered to 52 laboratories in 1999, 102 laboratories in 2000, and 118 laboratories in 2001. The participating laboratories were classified into one of four categories according to their performance: A: 0 or 1 false positive (FP) results; B: 2 or 3 FPs; C: 4 or more FPs; and D: at least 1 false negative result. Workshops were held with the participants in order to jointly analyze the results. RESULTS: Out of the laboratories that received the panel of samples, the percentage of laboratories that sent in their results was 92.3% in 1999, 92.2% in 2000, and 83.9% in 2001. These response levels demonstrate the interest in evaluation activities. However, the annual average percentage of the laboratories that received a "D" classification was very high (30%), which indicates that there are problems in the performance of TTI screening. This poor showing could be related to the difficulty in taking corrective measures throughout the system, given the large number of laboratories involved. CONCLUSIONS: Evaluations of this type should be included in Argentina's National Blood Program as a tool for the ongoing assessment of the blood banking situation, for decision-making, and for monitoring the quality of screening. <![CDATA[<B>Neonatal screening for hemoglobinopathies in Rio de Janeiro, Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200018&lng=en&nrm=iso&tlng=en OBJETIVO: Descrever os principais resultados do programa de triagem neonatal para a doença falciforme do Estado do Rio de Janeiro em 15 meses de funcionamento (agosto de 2000 a novembro de 2001). MÉTODOS: A partir de agosto de 2000, amostras de sangue passaram a ser coletadas de todos os recém-nascidos atendidos em postos de atenção básica à saúde no Estado para triagem neonatal da doença falciforme. Essas amostras são submetidas a cromatografia líquida de alta resolução. Se o cromatograma resultante for compatível com a doença falciforme, a criança e seus pais são encaminhados para confirmação diagnóstica e tratamento. RESULTADOS: De agosto de 2000 a novembro de 2001, 99 260 recém nascidos participaram da triagem. Houve um caso de homozigose para Hb C. Um em cada 27 recém-nascidos triados pelo programa apresentou o traço falciforme (Hb AS). A doença falciforme foi constatada em 83 casos (um caso novo para cada 1 196 nascimentos): 62 Hb S, 18 Hb SC, 3 Hb SD. Uma criança não compareceu para confirmação diagnóstica. As 82 crianças acompanhadas apresentaram 15 intercorrências (infecções de vias aéreas superiores, febre, seqüestro esplênico, síndrome mão-pé e crises de vaso-oclusão), motivando sete internações. Houve necessidade de transfusão sangüínea em 15 crianças, mas nenhuma tornou-se alo-imunizada. Os demais bebês estão evoluindo satisfatoriamente com o uso de penicilina profilática. CONCLUSÕES: Nossos dados evidenciam a importância do diagnóstico precoce da doença falciforme, de forma a prevenir e evitar as freqüentes complicações infecciosas enfrentadas por esses pacientes.<hr/>OBJECTIVE: To describe the main results obtained in the first 15 months of neonatal screening for sickle cell disease in the state of Rio de Janeiro, Brazil, from August 2000 to November 2001. METHODS: Starting in August 2000, blood samples began to be collected for sickle cell disease screening from all newborns receiving care in primary health care clinics in the state of Rio de Janeiro. The samples were submitted to high-resolution liquid chromatography. If the resulting chromatogram was compatible with sickle cell disease, the child and the parents were referred for diagnostic confirmation and treatment. RESULTS: Between August 2000 and November 2001, 99 260 newborns were screened. There was one case of homozygous Hb C. On average, one of every 27 newborns who were screened presented sickle cell trait (Hb AS). Sickle cell disease was observed in 83 cases, or one new case in each 1 196 births. The 83 consisted of: 62 Hb S, 18 Hb SC, and 3 Hb SD. One child did not appear for diagnostic confirmation. The 82 children who were followed up by the program presented 15 intercurrent illnesses (upper respiratory infections, fever, splenic sequestration crises, hand-foot syndrome, and vascular occlusion), resulting in seven hospital admissions. Blood transfusions were necessary with 15 children, but none developed alloimmunization. All the other babies were doing well with the use of prophylactic penicillin. CONCLUSIONS: Our data show the importance of early diagnosis for sickle cell disease, so as to prevent the frequent infectious complications faced by these patients. <![CDATA[<B>The Transfusion Medicine Program in Cuba</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200019&lng=en&nrm=iso&tlng=en Cuba's Transfusion Medicine Program (TMP) is a subsystem of the country's National Health System. The TMP's objective is to ensure hemotherapy with blood that is safe and sufficient for all the individuals who need it. The TMP subsystem is made up of the National Commission on Transfusion Medicine, the Institute of Hematology and Immunology, 37 clinical services, 44 blood banks, 120 collection centers, 19 mobile units, and 37 blood certification laboratories. Additional facilities include a laboratory for plasma separation, a laboratory that produces leukocyte interferon and transfer factor, and two laboratories that produce reagents for blood classification and blood diagnosis systems. In Cuba, blood donation is voluntary. Since 1997 approximately 5% of the population per year has donated blood, thus meeting the goal recommended by the Pan American Health Organization of one voluntary blood donation annually for every 20 persons. During 2002, 563 204 blood donations were received, and there were 445 898 transfusions of blood or blood components. All donations are individually screened for HIV 1 and 2, hepatitis B, hepatitis C, and syphilis, thus meeting the country's current regulations. In 2002 these screening measures led to discarding, respectively, 0.12%, 0.60%, 0.71%, and 1.8% of the blood donations. Although the prevalence of human T-cell lymphotropic virus I and II in Cuba is very low, this test will soon be added to the screening process. <![CDATA[<B>Peru's experience with a national blood banking program</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200020&lng=en&nrm=iso&tlng=en This paper describes Peru's experiences with its National Blood Banking Program. Until the mid-1990s, the country faced a host of problems, including the lack of a legal framework to regulate blood banks, a high maternal mortality rate due to a shortage of blood, virtually no voluntary donations, a high risk of infection from transfusions, the use of only whole blood for transfusion, serious disorganization in the blood banks, deficiencies in blood bank supervision and control, no training programs, indifference on the part of health officials, frequent selling of blood, and limited community awareness. Subsequently, a strategic plan was prepared that made it possible to solve many of those problems. Legal instruments were prepared; the rate of voluntary donations rose from 0% to 19.5%; the safety of the blood was improved through compulsory screening of all donated blood units for seven markers of infectious diseases, as well as by placing a national seal of quality on all screened units. The availability of blood doubled, thus meeting 70% of the need; sales of blood decreased; and the use of blood components was improved, with 80% of the blood being fractionated. In addition, supervisory control of 100% of the blood banks in the country was achieved, a national registry was established, the cost-benefit relationship for blood units was improved through centralized screening, internal and external quality control was made mandatory, and prodonation campaigns led to commitments from civil society. While important, all these achievements represent just a first step. This is especially true given that developing the National Blood Banking Program required the participation of outside organizations, such as the Pan American Health Organization, whose support, together with the experience provided by other countries, was key. The Program is facing a number of new challenges, and the progress that has been achieved could be threatened if current activities stagnate or if officials become complacent. <![CDATA[<B>Evaluation of the concomitant use of two different EIA tests for HIV screening in blood banks</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200021&lng=en&nrm=iso&tlng=en OBJECTIVE: In 1998, the Brazilian Ministry of Health made it mandatory for all blood banks in the country to screen donated blood for human immunodeficiency virus (HIV) concomitantly using two different enzyme immunoassay (EIA) tests. Concerned with the best use of available resources, our objective with this study was to evaluate the usefulness of conducting two EIA screening tests instead of just one. METHODS: We analyzed data from 1999 through 2001 obtained by testing 698 191 units of donated blood using two EIA HIV screening tests concomitantly at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo), which is a major blood center in the city of São Paulo, Brazil. All samples reactive in at least one of the two EIA tests were submitted for confirmation by a Western blot (WB) test, and the persons who had donated those samples were also asked to return and provide a follow-up sample. RESULTS: Out of the 698 191 blood units that were donated, 2 718 of them (0.4%) had to be discarded because they were reactive to at least one of the EIA tests. There were two WB-positive donation samples that were reactive in only one HIV EIA screening test. On their follow-up samples, both donors tested WB-negative. These cases were considered false positive results at screening. Of the 2 718 donors who were asked to return and provide a follow-up sample, 1 576 of them (58%) did so. From these 1 576 persons, we found that there were two individuals who had been reactive to only one of the two EIA screening tests and who had also been negative on the WB at screening but who were fully seroconverted on the follow-up sample. We thus estimated that, in comparison to the use of a single EIA screening test, the use of two EIA screening tests would detect only one extra sample out of 410 700 units of blood. CONCLUSIONS: Our data do not support the use of two different, concomitant EIA screening tests for HIV. The great majority of HIV-positive donors have already seroconverted and will be detected using only a single EIA screening test. Only persons who are going through the process of seroconversion may be missed by using a single EIA test and detected using two EIAs for screening. To screen out these individuals and decrease the residual risk of HIV transmission from the blood donated in our center, the use of other techniques, such as nucleic acid testing (NAT) or a p24 antigen assay, would be more effective.<hr/>OBJETIVO: En 1998, el Ministerio de Salud de Brasil decretó que todos los bancos de sangre en el país debían someter toda la sangre donada a un tamizaje para la detección del virus de la inmunodeficiencia humana (VIH) usando concomitantemente dos inmunoensayos enzimáticos (IEE) diferentes. Nuestro objetivo al realizar el presente estudio, resultado de un afán por sacar el máximo provecho a los recursos disponibles, ha sido evaluar la utilidad de hacer un tamizaje con dos IEE en lugar de uno solo. MÉTODOS: Analizamos datos de 1999-2001 obtenidos como resultado del tamizaje de 698 191 unidades de sangre donada mediante dos IEE aplicados concomitantemente en la Fundación Pro-Sangre del Centro de Sangre de São Paulo (Fundação Pró-Sangue/ Hemocentro de São Paulo), que es un centro hematológico importante en la ciudad de São Paulo, Brasil. Toda muestra que fue reactiva en por lo menos uno de los dos IEE fue sometida a un inmunoblot de Western (WB) a manera de confirmación, y a las personas que habían donado la sangre positiva también se les pidió que regresaran para proporcionar una muestra de seguimiento. RESULTADOS: De las 698 191 unidades de sangre que fueron donadas, hubo que descartar 2 718 (0,4%) porque mostraron reactividad a uno de los IEE o ambos. Dos de las muestras donadas que mostraron positividad en el WB fueron reactivas en solamente uno de los IEE de tamizaje. En lo que respecta a las muestras de seguimiento, ambos donantes tuvieron resultados negativos en el WB. Estos resultados se consideraron positivos falsos para fines del tamizaje. De los 2 718 donantes a quienes se les pidió que regresaran para proporcionar una muestra de seguimiento, 1 576 (58%) cumplieron. De estas 1 576 personas, dos habían mostrado reactividad a solamente uno de los IEE de tamizaje, con resultados negativos en el WB, pero habían mostrado una seroconversión completa en la muestra de seguimiento. Por consiguiente, nuestra conclusión es que el tamizaje con dos IEE, en comparación con uno solo, permitiría detectar solamente una muestra adicional de un total de 410 700 unidades de sangre. CONCLUSIONES: Nuestros datos no respaldan la conveniencia de usar concomitantemente dos IEE diferentes para el tamizaje del VIH. La gran mayoría de los donantes con positividad a VIH ya habrán tenido una seroconversión y se pueden detectar con un solo IEE. Solamente aquellas personas que están aún en proceso de seroconversión podrían no ser detectadas mediante un solo IEE, pero sí con dos. Para identificar a estas personas y reducir cualquier riesgo residual de transmitir el VIH por medio de la sangre donada en nuestro centro, sería más eficaz el uso de otras técnicas, tales como las pruebas a base de ácidos nucleicos o un ensayo a base de Agp24. <![CDATA[<B>Quality control of immunologic testing of blood in the Region of the Americas</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200022&lng=en&nrm=iso&tlng=en OBJECTIVE: In 1998, the Brazilian Ministry of Health made it mandatory for all blood banks in the country to screen donated blood for human immunodeficiency virus (HIV) concomitantly using two different enzyme immunoassay (EIA) tests. Concerned with the best use of available resources, our objective with this study was to evaluate the usefulness of conducting two EIA screening tests instead of just one. METHODS: We analyzed data from 1999 through 2001 obtained by testing 698 191 units of donated blood using two EIA HIV screening tests concomitantly at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo), which is a major blood center in the city of São Paulo, Brazil. All samples reactive in at least one of the two EIA tests were submitted for confirmation by a Western blot (WB) test, and the persons who had donated those samples were also asked to return and provide a follow-up sample. RESULTS: Out of the 698 191 blood units that were donated, 2 718 of them (0.4%) had to be discarded because they were reactive to at least one of the EIA tests. There were two WB-positive donation samples that were reactive in only one HIV EIA screening test. On their follow-up samples, both donors tested WB-negative. These cases were considered false positive results at screening. Of the 2 718 donors who were asked to return and provide a follow-up sample, 1 576 of them (58%) did so. From these 1 576 persons, we found that there were two individuals who had been reactive to only one of the two EIA screening tests and who had also been negative on the WB at screening but who were fully seroconverted on the follow-up sample. We thus estimated that, in comparison to the use of a single EIA screening test, the use of two EIA screening tests would detect only one extra sample out of 410 700 units of blood. CONCLUSIONS: Our data do not support the use of two different, concomitant EIA screening tests for HIV. The great majority of HIV-positive donors have already seroconverted and will be detected using only a single EIA screening test. Only persons who are going through the process of seroconversion may be missed by using a single EIA test and detected using two EIAs for screening. To screen out these individuals and decrease the residual risk of HIV transmission from the blood donated in our center, the use of other techniques, such as nucleic acid testing (NAT) or a p24 antigen assay, would be more effective.<hr/>OBJETIVO: En 1998, el Ministerio de Salud de Brasil decretó que todos los bancos de sangre en el país debían someter toda la sangre donada a un tamizaje para la detección del virus de la inmunodeficiencia humana (VIH) usando concomitantemente dos inmunoensayos enzimáticos (IEE) diferentes. Nuestro objetivo al realizar el presente estudio, resultado de un afán por sacar el máximo provecho a los recursos disponibles, ha sido evaluar la utilidad de hacer un tamizaje con dos IEE en lugar de uno solo. MÉTODOS: Analizamos datos de 1999-2001 obtenidos como resultado del tamizaje de 698 191 unidades de sangre donada mediante dos IEE aplicados concomitantemente en la Fundación Pro-Sangre del Centro de Sangre de São Paulo (Fundação Pró-Sangue/ Hemocentro de São Paulo), que es un centro hematológico importante en la ciudad de São Paulo, Brasil. Toda muestra que fue reactiva en por lo menos uno de los dos IEE fue sometida a un inmunoblot de Western (WB) a manera de confirmación, y a las personas que habían donado la sangre positiva también se les pidió que regresaran para proporcionar una muestra de seguimiento. RESULTADOS: De las 698 191 unidades de sangre que fueron donadas, hubo que descartar 2 718 (0,4%) porque mostraron reactividad a uno de los IEE o ambos. Dos de las muestras donadas que mostraron positividad en el WB fueron reactivas en solamente uno de los IEE de tamizaje. En lo que respecta a las muestras de seguimiento, ambos donantes tuvieron resultados negativos en el WB. Estos resultados se consideraron positivos falsos para fines del tamizaje. De los 2 718 donantes a quienes se les pidió que regresaran para proporcionar una muestra de seguimiento, 1 576 (58%) cumplieron. De estas 1 576 personas, dos habían mostrado reactividad a solamente uno de los IEE de tamizaje, con resultados negativos en el WB, pero habían mostrado una seroconversión completa en la muestra de seguimiento. Por consiguiente, nuestra conclusión es que el tamizaje con dos IEE, en comparación con uno solo, permitiría detectar solamente una muestra adicional de un total de 410 700 unidades de sangre. CONCLUSIONES: Nuestros datos no respaldan la conveniencia de usar concomitantemente dos IEE diferentes para el tamizaje del VIH. La gran mayoría de los donantes con positividad a VIH ya habrán tenido una seroconversión y se pueden detectar con un solo IEE. Solamente aquellas personas que están aún en proceso de seroconversión podrían no ser detectadas mediante un solo IEE, pero sí con dos. Para identificar a estas personas y reducir cualquier riesgo residual de transmitir el VIH por medio de la sangre donada en nuestro centro, sería más eficaz el uso de otras técnicas, tales como las pruebas a base de ácidos nucleicos o un ensayo a base de Agp24. <![CDATA[<B>Guidelines for the transfusion of blood and its components</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200023&lng=en&nrm=iso&tlng=en There is no general consensus on the appropriate use of blood and its components. The resulting lack of transfusion guidelines is a weakness in our hospitals and health centers that directly affects good transfusion practice. Based on a literature review, this piece offers some general guidelines on the appropriate use of transfusion therapy. These guidelines can serve as the basis for preparing more-specific guides that take into account the individual needs of each hospital center. <![CDATA[<B>La Dra. Mirta Roses Periago dirige a la OPS en el nuevo milenio</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200024&lng=en&nrm=iso&tlng=en There is no general consensus on the appropriate use of blood and its components. The resulting lack of transfusion guidelines is a weakness in our hospitals and health centers that directly affects good transfusion practice. Based on a literature review, this piece offers some general guidelines on the appropriate use of transfusion therapy. These guidelines can serve as the basis for preparing more-specific guides that take into account the individual needs of each hospital center. <![CDATA[<B>Dr. Mirta Roses Periago leads PAHO in the Millennium</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892003000200025&lng=en&nrm=iso&tlng=en There is no general consensus on the appropriate use of blood and its components. The resulting lack of transfusion guidelines is a weakness in our hospitals and health centers that directly affects good transfusion practice. Based on a literature review, this piece offers some general guidelines on the appropriate use of transfusion therapy. These guidelines can serve as the basis for preparing more-specific guides that take into account the individual needs of each hospital center.