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4. Improved detection of hepatitis C virus‐positive blood donors and determination of infection status.

Author

Nishiya, Anna S., de Almeida‐Neto, Cesar, Witkin, Steven S., Ferreira, Suzete C., Salles, Nanci A., Nogueira, Fátima A. H., Oliveira, Claudia Di Lorenzo, Rocha, Vanderson, and Mendrone Júnior, Alfredo more...

Subjects
*BLOOD donors, *HEPATITIS C virus, *RECEIVER operating characteristic curves, *SERODIAGNOSIS, *HEPATITIS
Abstract

Background: In low‐risk populations, variability in the sensitivity of current serological tests for Hepatitis C virus (HCV) blood donor screening may lead to the presence of false‐positive results. This contributes to the unnecessary loss of blood donor samples as well as to difficulty in accurate donor counselling. The present study determined the optimal cut‐off value of a chemiluminescent immunoassay for identification of HCV‐reactive blood donors. Study Design and Methods: In a retrospective cross‐sectional analysis of 193 973 blood donations, 578 samples that were positive for HCV antibody in a chemiluminescent immunoassay and/or RNA screening tests were identified. Blood from 379 of these positive samples was available for retesting by a second confirmatory HCV immunoassay followed by a receiver operating characteristic (ROC) curve analysis. Donors were also recalled for a new analysis. Results: Only 71 (18.7%) blood samples remained HCV‐positive upon retesting, while 233 (61.5%) now tested negative and 75 (19.8%) yielding indeterminate results. A signal to cutoff ratio ≥4.32 was determined as the best differential threshold between a positive and negative result, increasing the positive predictive value from 27.3% to 66.7%. Conclusion: Using a higher threshold for an HCV‐positive blood sample enhances the chemiluminescent immunoassay screening test´s accuracy and helps to improve donor counselling and notification processes. [ABSTRACT FROM AUTHOR] more...

Published
2023
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6. Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil

Author

Nishiya, Anna S., primary, Levi, José E., additional, Almeida‐Neto, Cesar, additional, Witkin, Steven S., additional, Ferreira, Suzete C., additional, Bassit, Leda, additional, Sabino, Ester C., additional, Di‐Lorenzo‐Oliveira, Claudia, additional, Salles, Nanci A., additional, Coutinho, Adenilson S., additional, Bellesa, Maria A., additional, Rocha, Vanderson, additional, and Mendrone‐Jr, Alfredo, additional more...

Published
2021
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8. Detection and analysis of blood donors seropositive for syphilis

Author

Attie, Adriana, primary, de Almeida‐Neto, Cesar, additional, Witkin, Steven, additional, Derriga, Juliana, additional, Nishiya, Anna S., additional, Ferreira, Jerenice E., additional, Costa, Natalia de Souza Xavier, additional, Salles, Nanci, additional, Facincani, Tila, additional, Levi, Jose E., additional, Sabino, Ester C., additional, Rocha, Vanderson, additional, Mendrone‐Jr, Alfredo, additional, and Ferreira, Suzete C., additional more...

Published
2021
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9. Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic

Author

Buss, Lewis F., primary, Prete, Carlos A., additional, Abrahim, Claudia M. M., additional, Mendrone, Alfredo, additional, Salomon, Tassila, additional, de Almeida-Neto, Cesar, additional, França, Rafael F. O., additional, Belotti, Maria C., additional, Carvalho, Maria P. S. S., additional, Costa, Allyson G., additional, Crispim, Myuki A. E., additional, Ferreira, Suzete C., additional, Fraiji, Nelson A., additional, Gurzenda, Susie, additional, Whittaker, Charles, additional, Kamaura, Leonardo T., additional, Takecian, Pedro L., additional, da Silva Peixoto, Pedro, additional, Oikawa, Marcio K., additional, Nishiya, Anna S., additional, Rocha, Vanderson, additional, Salles, Nanci A., additional, de Souza Santos, Andreza Aruska, additional, da Silva, Martirene A., additional, Custer, Brian, additional, Parag, Kris V., additional, Barral-Netto, Manoel, additional, Kraemer, Moritz U. G., additional, Pereira, Rafael H. M., additional, Pybus, Oliver G., additional, Busch, Michael P., additional, Castro, Márcia C., additional, Dye, Christopher, additional, Nascimento, Vítor H., additional, Faria, Nuno R., additional, and Sabino, Ester C., additional more...

Published
2021
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10. COVID-19 herd immunity in the Brazilian Amazon

Author

Buss, Lewis F, primary, Prete, Carlos A, additional, Abrahim, Claudia MM, additional, Mendrone, Alfredo, additional, Salomon, Tassila, additional, de Almeida-Neto, Cesar, additional, França, Rafael FO, additional, Belotti, Maria C, additional, Carvalho, Maria PSS, additional, Costa, Allyson G, additional, Crispim, Myuki AE, additional, Ferreira, Suzete C, additional, Fraiji, Nelson A, additional, Gurzenda, Susie, additional, Whittaker, Charles, additional, Kamaura, Leonardo T, additional, Takecian, Pedro L, additional, Oikawa, Marcio K, additional, Nishiya, Anna S, additional, Rocha, Vanderson, additional, Salles, Nanci A, additional, de Souza-Santos, Andreza A, additional, da Silva, Martirene A, additional, Custer, Brian, additional, Barral-Netto, Manoel, additional, Kraemer, Moritz UG, additional, Pereira, Rafael HM, additional, Pybus, Oliver G, additional, Busch, Michael P, additional, Castro, Márcia C, additional, Dye, Christopher, additional, Nascimento, Vitor H, additional, Faria, Nuno R, additional, and Sabino, Ester C, additional more...

Published
2020
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11. New prevalence estimate of TT virus (TTV) infection in low- and high-risk population from São Paulo, Brazil

Author

BASSIT Leda, TAKEI Kioko, HOSHINO-SHIMIZU Sumie, NISHIYA Anna S., SABINO Ester C., BASSITT Rogério P., FOCACCIA Roberto, D'AMICO Élbio, CHAMONE Dalton F., and RIBEIRO-DOS-SANTOS Gabriela

Subjects
TT virus, Emergent viruses, Parenteral transfusion, Blood bank, Arctic medicine. Tropical medicine, RC955-962, Infectious and parasitic diseases, RC109-216
Abstract

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 São 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%) than the earlier N22-PCR directed to the open reading frame 1 (blood donors, 5.5%, and hemophiliacs, 42.3%). 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%), than in those treated with virus-inactivated clotting factors (9.4%) and blood donors (5.5%). more...

Published
2002

12. Molecular characterization of viruses associated with encephalitis in São Paulo, Brazil

Author

Ferreira, Jerenice E., primary, Ferreira, Suzete C., additional, Almeida-Neto, Cesar, additional, Nishiya, Anna S., additional, Alencar, Cecilia S., additional, Gouveia, Gisele R., additional, Caiaffa-Filho, Helio, additional, Gomes, Helio, additional, de Macedo Santos, Raimunda Telma, additional, Witkin, Steven S., additional, Mendrone-Junior, Alfredo, additional, and Sabino, Ester C., additional more...

Published
2019
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14. Prevalence of human pegivirus (HPgV) infection in patients carrying HIV‐1C or non‐C in southern Brazil

Author

Da Mota, Luísa Dias, primary, Nishiya, Anna S., additional, Finger‐Jardim, Fabiana, additional, Barral, Maria F.M., additional, Silva, Cláudio M., additional, Nader, Maiba M., additional, Gonçalves, Carla V., additional, Da Hora, Vanusa P., additional, Silveira, Jussara, additional, Basso, Rossana P., additional, Soares, Marcelo A., additional, Levi, José E., additional, and Martínez, Ana M.B., additional more...

Published
2016
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15. Genotype distribution of the GB virus C in citizens of São Paulo City, Brazil

Author

Nishiya, Anna S., Ribeiro-Dos-Santos, Gabriela, Bassit, Leda, Focaccia, Roberto, Chamone, Dalton F., and Sabino, Ester C.

Subjects
São Paulo City, 5´non-coding region, GBV-C/HGV, Genotype distribution, Hepatitis G virus, GB-virus C
Abstract

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 São 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% (2/24), 50% (12/24) and 41.7% (10/24), respectively. In conclusion São 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. Há na literatura vários estudos filogenéticos e de distribuição de genótipos do chamado "Vírus GB-C" ou da "Hepatite G", mais conhecido pela dupla sigla "GBV-C/HGV". Ocorre que, em sua grande maioria, estas pesquisas foram realizadas com amostras de grupos ligados epidemiologicamente e não com indivíduos representativos da população geral. O presente estudo é uma continuação do primeiro trabalho no Brasil feito com este tipo de amostragem. Trata-se de análise filogenética e distribuição genotípica do GBV-C/HGV a partir de amostras isoladas dentre mais de 1.000 indivíduos da cidade de São Paulo. Para tanto, um fragmento de 728 pares de base da região 5' não-codificadora (5´NCR) do genoma viral, de 24 amostras, foi sequenciado e submetido à analise filogenética. Foram identificados os genótipos 1, 2a e 2b nas respectivas freqüências: 8,3% (2/24), 50% (12/24) e 41,7% (10/24). Concluindo, São Paulo apresenta uma distribuição de genótipos semelhante à publicada para outros estados e regiões do Brasil, endossando a idéia de que os tipos 1 e 2 teriam vindo com os africanos e europeus, respectivamente, e portanto estariam na população do país desde a sua formação. more...

Published
2003

16. HCV Genotypes, Characterization of Mutations Conferring Drug Resistance to Protease Inhibitors, and Risk Factors among Blood Donors in São Paulo, Brazil

Author

Nishiya, Anna S., primary, de Almeida-Neto, Cesar, additional, Ferreira, Suzete C., additional, Alencar, Cecília S., additional, Di-Lorenzo-Oliveira, Claudia, additional, Levi, José E., additional, Salles, Nanci A., additional, Mendrone, Alfredo, additional, and Sabino, Ester C., additional more...

Published
2014
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