Genotype distribution of the GB virus C in citizens of Säo Paulo City, Brazil

There has been several studies worldwide on phylogenetics and genotype distribution of the GB-virus C / Hepatitis G virus (GBV-C/HGV). However, in their great majority, those investigations were based on some epidemiologically linked group, rather than on a representative sampling of the general population. The present is a continuation of the first study in Brazil with such a population; it addresses the GBV-C/HGV phylogenetics and genotype distribution based on samples identified among more than 1,000 individuals of the city of Säo Paulo. For this purpose, a 728 bp fragment of the 5 non-coding region (5 NCR) of the viral genome, from 24 isolates, was sequenced and subjected to phylogenetic analysis. Genotypes 1, 2a and 2b were found at 8.3 percent (2/24), 50 percent (12/24) and 41.7 percent (10/24), respectively. In conclusion Säo Paulo displays a genotype distribution similar to the published data for other States and Regions of Brazil, endorsing the notion that types 1 and 2 would have entered the country with African and European people, respectively, since its earliest formation

Programas de control externo de la calidad en serología desarrollados en América Latina con el apoyo de la OPS entre 1997 y 2000 / External serology quality control programs developed in Latin America with the support of PAHO from 1997 through 2000

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 Fundaçäo Pró-Sangue/Hemocentro de Säo 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 por ciento, 27 por ciento, 35 por ciento, 39 por ciento y 45 por ciento, 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 por ciento, 27 por ciento, 39 por ciento, 50 por ciento y 60 por ciento). 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 por ciento, correspondiendo el mayor valor al tamizaje de anticuerpos contra el virus de la hepatatis C (anti-VHC) (4,6 por ciento) y el menor a anti-Trypanosoma cruzi (0,4 por ciento). 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...

Descarte de bolsas de sangue e prevalência de doenças infecciosas em doadores de sangue da Fundação Pró-Sangue/Hemocentro de São Paulo / The discarding of blood units and the prevalence of infectious diseases in donors at the Pro-Blood Foundation/Blood Center of Säo Paulo, Säo Paulo, Brazil

OBJETIVO: Analisar a evoluçäo, de 1991 a 2001, do descarte sorológico na Fundaçäo Pró-Sangue/Hemocentro de Säo Paulo, o maior banco de sangue da América Latina, e verificar a prevalência de doenças infecciosas entre doadores dessa instituiçäo 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 diminuiçäo percentual significativa de descarte, de 20 por cento em 1991 para 9 por cento em 2001. A prevalência de doenças infecciosas entre doadores em 2001 foi de 0,04 por cento para vírus da imunodeficiência humana (VIH); 0,21 por cento para vírus da hepatite C (VHC); 0,06 por cento para vírus T-linfotrópico humano (HTLV); para vírus da hepatite B (VHB), as prevalências foram de 0,14 por cento para anti-HBc + HBsAg, 1,68 por cento para anti-HBc + anti-HBs e 1,67 por cento para anti-HBc isolado; 1,10 por cento para sífilis; e 0,14 por cento para doença de Chagas. CONCLUSÄO: A diminuiçäo no descarte e a prevalência de doenças infecciosas entre doadores da Fundaçäo Pró-Sangue/Hemocentro de Säo Paulo em 2001 refletem o aumento na porcentagem de doadores de repetiçäo nesse banco de sangue

Trends in the profile of blood donors at a large blood center in the city of São Paulo, Brazil

OBJECTIVE: To describe the trends in the profile of blood donors from 1995 through 2001 at a large blood center in the city of Säo 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 Säo Paulo (Fundaçäo Pró-Sangue/Hemocentro de Säo 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 percent of all blood donors in 1995 to 57 percent in 2001. In 2001, first-time blood donors represented only 52 percent of all donors, as contrasted to 88 percent in 1995. Female donors increased from 20 percent to 37 percent of the donors over the period studied. CONCLUSIONS: Our data provide evidence that the Säo 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

Evaluation of the concomitant use of two different EIA tests for HIV screening in blood banks

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 Säo Paulo (Fundaçäo Pró-Sangue/Hemocentro de Säo Paulo), which is a major blood center in the city of Säo 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 percent) 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 percent) 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

New prevalence estimate of TT virus (TTV) infection in low- and high-risk population from Säo Paulo, Brazil

The prevalence of TT virus (TTV) infection was investigated by Polymerase Chain Reaction (PCR) in low- (blood donors and healthy children/adolescents) and high-risk (hemophiliacs) groups from Säo Paulo, Brazil. Primers based on the untranslated region (UTR) of the viral genome proved to be much more ubiquitous, leading to much higher frequencies for both groups ( > or = 81 percent) than the earlier N22-PCR directed to the open reading frame 1 (blood donors, 5.5 percent, and hemophiliacs, 42.3 percent). The UTR-PCR also revealed an interesting profile for healthy children/adolescents: very high prevalence at the early years and significant decrease in male teenagers. The N22-PCR, in turn, demonstrated higher frequency in hemophiliacs treated with fresh blood products (58 percent), than in those treated with virus-inactivated clotting factors (9.4 percent) and blood donors (5.5 percent)