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1.
Goiânia; SES-GO; 24 ago. 2020. 1-3 p. [].
Non-conventional in Portuguese | LILACS, ColecionaSUS, CONASS, SES-GO | ID: biblio-1222963

ABSTRACT

A pandemia desencadeada pelo novo coronavírus (COVID-19) é um desafio mundial. A rapidez com que o agente etiológico é transmitido, aumento exponencial de casos e a inexistência de vacinas e tratamentos eficazes contra o patógeno, têm acarretado em mudanças profundas no cotidiano das pessoas e também sérias consequências socioeconômicas. Trabalho conduzido por Giordano et al, concluiu que medidas restritivas de isolamento social, combinadas com testagem em massa e rastreamento de contatos são ações necessárias para interromper a pandemia em curso.


The pandemic triggered by the new coronavirus (COVID-19) is a worldwide challenge. The speed with which the etiological agent is transmitted, exponential increase of cases and the lack of vaccines and effective treatments against the pathogen, have resulted in profound changes in people's daily lives and also serious socioeconomic consequences. Work conducted by Giordano et al concluded that restrictive measures of social isolation, combined with mass testing and contact tracking are necessary actions to stop the ongoing pandemic.


Subject(s)
Humans , Male , Female , Pregnancy , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Serologic Tests/standards , Coronavirus Infections/prevention & control , Coronavirus Infections/virology
2.
Rev. bras. parasitol. vet ; 29(4): e018020, 2020. tab
Article in English | LILACS | ID: biblio-1144232

ABSTRACT

Abstract Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum. Serological methods are the most common diagnostic techniques used for the diagnosis of the CanL. The objective of our study was to estimate the sensitivity and specificity of one in-house ELISA kit (ELISA UNIZAR) and three commercially available serological tests (MEGACOR Diagnostik GmbH) including an immunochromatographic rapid test (FASTest LEISH®), an immunofluorescent antibody test (MegaFLUO LEISH®) and an enzyme-linked immunosorbent assay (MegaELISA LEISH®), using latent class models in a Bayesian analysis. Two hundred fifteen serum samples were included. The highest sensitivity was achieved for FASTest LEISH® (99.38%), ELISA UNIZAR (99.37%), MegaFLUO LEISH® (99.36%) followed by MegaELISA LEISH® (98.49%). The best specificity was obtained by FASTest LEISH® (98.43%), followed by ELISA UNIZAR (97.50%), whilst MegaFLUO LEISH® and MegaELISA LEISH® obtained the lower specificity (91.94% and 91.93%, respectively). The results of present study indicate that the immunochromatographic rapid test evaluated FASTest LEISH® show similar levels of sensitivity and specificity to the quantitative commercial tests. Among quantitative serological tests, sensitivity and specificity were similar considering ELISA or IFAT techniques.


Resumo A leishmaniose canina (Lcan) é uma causada pela Leishmania infantum. Os métodos sorológicos são as técnicas diagnósticas mais utilizadas para o diagnóstico da leishmaniose canina. O objetivo do nosso estudo foi estimar a sensibilidade e a especificidade de um kit ELISA interno (ELISA UNIZAR) e de três testes sorológicos disponíveis comercialmente, feitos pelo mesmo fabricante (MEGACOR Diagnostik GmbH), incluindo um teste rápido imunocromatográfico (FASTest LEISH®), um teste de anticorpos imunofluorescentes (Megafluo LEISH®) e um ensaio de imunoabsorção enzimática (Megaelisa LEISH®), utilizando-se modelos de classe latentes numa análise bayesiana. Foram incluídas duzentas e quinze amostras de soro. A maior sensibilidade foi alcançada para Fastest LEISH® (99,38%), ELISA UNIZAR (99,37%), Megafluo LEISH® (99,36%) seguida por Megaelisa LEISH® (98,49%). A melhor especificidade foi obtida por FASTest LEISH® (98,43%), seguida por ELISA UNIZAR (97,50%), enquanto Megafluo LEISH® e Megaelisa LEISH® obtiveram a menor especificidade (91,94% e 91,93%, respectivamente). Os resultados do presente estudo indicam que o teste rápido imunocromatográfico, avaliado por FASTest LEISH® mostra níveis similares de sensibilidade e especificidade aos testes comerciais quantitativos incluídos. Entre os testes sorológicos quantitativos, a sensibilidade e a especificidade foram semelhantes, considerando-se as técnicas de ELISA ou IFI.


Subject(s)
Animals , Dogs , Serologic Tests/standards , Leishmaniasis/diagnosis , Leishmaniasis/veterinary , Leishmania infantum/immunology , Dog Diseases/diagnosis , Latent Class Analysis , Enzyme-Linked Immunosorbent Assay/standards , Enzyme-Linked Immunosorbent Assay/veterinary , Serologic Tests/veterinary , Antibodies, Protozoan/blood , Bayes Theorem
3.
Einstein (Säo Paulo) ; 18: eAO5078, 2020. tab
Article in English | LILACS | ID: biblio-1056051

ABSTRACT

ABSTRACT Objective: To evaluate the performance of indirect immunofluorescence for serological diagnosis of dengue virus in a population with high prevalence of arboviruses. Methods: Two-hundred serum samples from patients with clinical suspicion of dengue fever were tested by immunoenzymatic and indirect immunofluorescence assay BIOCHIP® mosaic. Specificity, sensitivity and Kappa coefficient were calculated. Discordant samples were tested by polymerase chain reaction for confirmation. Results: Of the 200 samples, 20% were positive and 80% negative for anti-dengue virus IgM antibodies in the immunoenzymatic test. Of the 40 positives, 25% were negative in indirect immunofluorescence. Of these ten discordant results, only 20% were also negative in the polymerase chain reaction (PCR). Of the 160 negatives in the immunoenzymatic test, 5% were positive in indirect immunofluorescence. Of these nine discordant results, 33% were positive in the PCR. The Kappa coefficient was 0.7 (0.572-0.829). Sensitivity and specificity of indirect immunofluorescence were respectively 75% and 94%. For anti-dengue virus IgG antibodies, of the 200 samples, 15.5% were positive and 84.5% were negative in the immunoenzymatic test. Of the 31 positives, 12.9% were negative in indirect immunofluorescence. Of these four discordant results, 25% were negative in the PCR. Of the 169 negatives, 8% were positive in indirect immunofluorescence. Of these 14 discordant results, 64% were also positive in the PCR. The Kappa coefficient was 0.695 (0.563-0.83). Sensitivity and specificity of indirect immunofluorescence were 87.1% and 91.7%, respectively. Conclusion: For diagnosis of acute infection, the immunoenzymatic test is enough, and the use of additional methods is not warranted. Replacing the immunoenzymatic test by indirect immunofluorescence would compromise the sensitivity for IgM. However, indirect immunofluorescence can distinguish three arboviruses simultaneously, an advantage during concomitant epidemics.


RESUMO Objetivo: Avaliar o desempenho da imunofluorescência indireta no diagnóstico sorológico de dengue em uma população com alta prevalência de arboviroses. Métodos: Duzentas amostras de soro de pacientes com suspeita clínica de dengue foram testadas por ensaio imunoenzimático e imunofluorescência indireta mosaico BIOCHIP®. Foram calculados especificidade, sensibilidade e coeficiente Kappa. Nas amostras discordantes, realizou-se reação em cadeia da polimerase como método confirmatório. Resultados: Das 200 amostras, 20% foram positivas e 80% negativas para IgM antivírus da dengue no ensaio imunoenzimático. Das 40 positivas, 25% foram negativas na imunofluorescência indireta. Destas dez negativas, apenas 20% eram também negativas na reação em cadeia da polimerase. Das 160 negativas no ensaio imunoenzimático, 5% foram positivas na imunofluorescência indireta. Por fim, dentre as nove discordantes, 33% tiveram vírus da dengue detectado na reação em cadeia da polimerase. O coeficiente Kappa foi 0,70 (0,57-0,82). Sensibilidade e especificidade por imunofluorescência indireta foram, respectivamente, 75% e 94%. Para IgG antivírus da dengue, de 200 amostras, 15,5% foram positivas e 84,5% negativas no ensaio imunoenzimático. Das 31 positivas, 12,9% foram negativas na imunofluorescência indireta. Destas quatro discordantes, 25% apresentaram vírus da dengue não detectado na reação em cadeia da polimerase. Das 169 negativas, 8% foram positivas na imunofluorescência indireta. Destas, 64% foram positivas também na reação em cadeia da polimerase. O coeficiente Kappa foi 0,695 (0,56-0,83). Sensibilidade e a especificidade por imunofluorescência indireta foram, respectivamente, 87,1% e 91,7%. Conclusão: Ensaio imunoenzimático seria suficiente para diagnóstico sorológico de infecção aguda, não justificando a incorporação da imunofluorescência indireta. Substituir ensaio imunoenzimático pela imunofluorescência indireta poderia comprometer a sensibilidade para IgM. Contudo, a imunofluorescência indireta auxilia diferenciar três arboviroses simultaneamente, sendo vantajoso em epidemias concomitantes.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
4.
Einstein (Säo Paulo) ; 18: eRW4890, 2020. tab, graf
Article in English | LILACS | ID: biblio-1056050

ABSTRACT

ABSTRACT Objective To demonstrate the impact of pneumococcal conjugate vaccine in Streptococcus pneumoniae carriage status in children younger than 5 years in Latin America and the Caribbean. Methods A systematic literature review was carried out on the direct and indirect effects of pneumococcal vaccine in the carriage status, after implementation in childhood immunization programs. Studies carried out in children younger than 5 years were selected from the PubMed® and Virtual Health Library databases, and data collected after implementation of pneumococcal vaccine in Latin America and the Caribbean, between 2008 and 2018. Results From 1,396 articles identified, 738 were selected based on titles and abstracts. After duplicate removal, 31 studies were eligible for full-text reading, resulting in 6 publications for analysis. All selected publications were observational studies and indicated a decrease in the carriage and vaccine types, and an increase in the circulation of non-vaccine serotypes, such as 6A, 19A, 35B, 21 and 38. We did not identify changes in the antimicrobial resistance after vaccine implementation. Conclusion A decrease in the carriage status of vaccine types and non-vaccine types was detected. The continuous monitoring of pneumococcal vaccine effect is fundamental to demonstrate the impact of the carriage status and, consequently, of invasive pneumococcal disease, allowing better targeting approaches in countries that included pneumococcal vaccine in their immunization programs. Our study protocol was registered in PROSPERO (www.crd.york.ac.uk/prospero) under number CRD42018096719.


RESUMO Objetivo Demonstrar o impacto das vacinas pneumocócicas conjugadas no estado de portador de Streptococcus pneumoniae em crianças menores de 5 anos na América Latina e no Caribe. Métodos Foi realizada revisão sistemática da literatura sobre os efeitos diretos e indiretos da vacina pneumocócica no estado de portador em crianças menores de 5 anos, após a implantação da vacina nos calendários de imunização infantil. A partir de dados da PubMed®e da Biblioteca Virtual da Saúde, foram selecionados estudos de portador em crianças menores de 5 anos, com dados coletados após implementação da vacina de 2008 a 2018, na América Latina e no Caribe. Resultados Dos 1.396 artigos identificados, 738 foram selecionados mediante leitura de títulos e resumos. Após a extração dos duplicados, 31 foram elegíveis para leitura do texto completo, restando 6 artigos para análise. Todos os estudos selecionados eram observacionais e indicavam diminuição do portador e tipos vacinais, e aumento da circulação de sorotipos não vacinais, como 6A, 19A, 35B, 21 e 38. Não foi observada alteração na resistência antimicrobiana após a introdução da vacina. Conclusão Detectou-se redução no estado de portador, dos tipos vacinais e não vacinais. O monitoramento contínuo do efeito das vacinas pneumocócicas é fundamental, para demonstrar o impacto do estado de portador e, consequentemente, da doença pneumocócica invasiva, permitindo o melhor direcionamento nas ações em saúde para os países que incluíram a vacina no calendário de imunização. Nosso protocolo de estudo foi registrado no PROSPERO (www.crd.york.ac.uk/prospero) sob o número CRD42018096719.


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
5.
Mem. Inst. Oswaldo Cruz ; 115: e200214, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135280

ABSTRACT

BACKGROUND Chagas disease, resulting from Trypanosoma cruzi infections, continues to be a health concern mainly in Latin American countries where the parasite is endemic. The laboratory diagnosis of a chronic infection is determined through serological assays for antibodies against T. cruzi and several tests are available that differ in key components, formats and methodologies. To date, no single test meets the criteria of a gold standard. The situation is further complicated by the difficulties associated with performance comparisons between different immunoassays or methodologies executed at different times and geographical areas. OBJECTIVE To improve the diagnosis of Chagas disease, the WHO coordinated the development of two International Biological Reference Standards for antibodies against anti-T. cruzi: NIBSC 09/186 and NIBSC 09/188 that respectively represent geographical regions with the highest prevalence of TcII and TcI lineages of the parasite. METHODS The principle goal of this study was to verify the behavior of these standards when assayed by several commercially available serological tests that employ different methods to capture and detect human anti-T. cruzi antibodies. FINDINGS AND MAIN CONCLUSIONS The results reinforce the recommendation that these standards be considered for performance evaluations of commercialised immunoassays and should be an integral step in the development of new test components or assay paradigms.


Subject(s)
Humans , Trypanosoma cruzi/isolation & purification , Serologic Tests/standards , Chagas Disease/diagnosis , Reference Standards , Trypanosoma cruzi/immunology , World Health Organization , Immunoassay/methods , Serologic Tests/methods , Antibodies, Protozoan/blood , Chagas Disease/parasitology
6.
Acta bioquím. clín. latinoam ; 53(4): 505-510, dic. 2019. tab
Article in Spanish | LILACS | ID: biblio-1124028

ABSTRACT

Si bien el control de calidad en determinaciones cuantitativas tiene amplia difusión, hay extensa bibliografía que lo avala y está en constante actualización, no sucede lo mismo cuando se refiere a pruebas cualitativas como las que se utilizan en diagnósticos serológicos. Es importante antes de la utilización de esta prueba serológica en el laboratorio disponer de información acerca de su caracterización, utilidad y algoritmos de trabajo más convenientes. Si bien se cuenta con poca bibliografía para estas pruebas, es posible definir parámetros de desempeño que el laboratorio debe tener en cuenta para poder liberar resultados confiables y de utilidad clínica. Tanto el control de calidad interno como el externo son dos valiosas herramientas orientadas a cumplir con la misión de los laboratorios en la cual el objetivo principal es la seguridad del paciente. Desde el Programa de Evaluación Externa de la Calidad se ofrecen varios subprogramas para el control de pruebas serológicas, que proporcionan a cada participante una evaluación objetiva del comportamiento de su laboratorio, información de los métodos disponibles y la identificación de factores que puedan afectar sus resultados.


Although the quality control in quantitative determinations has wide dissemination, an extensive bibliography that supports it and it is constantly being updated, this is not the case when referring to qualitative tests such as those used in serological diagnoses. Before using this serological test in the laboratory, it is important to have information about its characterization, usefulness and more convenient working algorithms. Although there is little literature for these tests, it is possible to define performance parameters that the laboratory must take into account to be able to release reliable and clinically useful results. Both internal and external quality control are valuable tools aimed at fulfilling the mission of laboratories in which the main objective is patient safety. From the External Quality Assessment Programme, several subprogrammes are offered for the control of serological tests, providing each participant with an objective evaluation of the behaviour of their laboratory, information on the available methods and the identification of factors that can affect the results.


Embora o controle de qualidade em determinações quantitativas possua ampla divulgação e haja extensa bibliografia que o apoie e esteja em constante atualização, o mesmo não acontece quando se refere a testes qualitativos, como os utilizados em diagnósticos sorológicos. Antes de usar esse teste sorológico em laboratório, é importante ter informações sobre sua caracterização, utilidade e algoritmos de trabalho mais convenientes. Embora exista pouca literatura para esses testes, é possível definir parâmetros de desempenho que o laboratório deve levar em consideração para poder liberar resultados confiáveis e clinicamente úteis. O controle de qualidade interno e externo são duas ferramentas valiosas destinadas a cumprir a missão dos laboratórios na qual o objetivo principal é a segurança do paciente. A partir do Programa de Avaliação Externa da Qualidade, são oferecidos vários subprogramas para o controle de testes sorológicos, proporcionando a cada participante uma avaliação objetiva do comportamento de seu laboratório, informações sobre os métodos disponíveis e identificação de fatores que possam afetar os resultados.


Subject(s)
Humans , Serologic Tests/methods , Serologic Tests/standards , Quality Control , Serologic Tests , Total Quality Management , Diagnosis , Efficiency , Patient Safety , Laboratories , Methods
7.
Rev. argent. transfus ; 36(2/3): 131-134, 2010. tab, graf
Article in Spanish | LILACS | ID: lil-671957

ABSTRACT

El análisis de productos no conformes es un aspecto clave en la seguridad de la sangre. La producción de hemocomponentes ha avanzado pero muchos son los aspectos que deben ser valorados en relación a la aceptación de productos con el fin de evitar los efectos adversos que se pueden suscitar. Se realizó un análisis de todos los productos obtenidos entre Enero-Abril de 2009 y se obtuvo los productos que fueron descartados y las razones por las cuales se tomó la decisión de descarte, así como el análisis del error y las acciones preventivas y correctivas empleadas. El producto no conforme representó un 7% del total de unidades obtenidas entre Enero y Abril del 2009.


The Nonconforming product analysis is a key in the blood safety. The hemocomponents production has been advanced but there are many aspects to consider and thus. to avoid adverse effects. The analysis included the unsatisfied products and the reasons why they are nonconforming. The analysis searched the preventive and corrective actions. The nonconforming product was 7% of the product obtained since January - April 2009 at the Dr. Max Peralta Hospital.


Subject(s)
Blood Safety , Device Approval , Quality Control , Blood Banks/standards , Costa Rica , Serologic Tests/standards
8.
Mem. Inst. Oswaldo Cruz ; 104(5): 797-800, Aug. 2009. tab
Article in English | LILACS | ID: lil-528093

ABSTRACT

In nearly all of the previous multicentre studies evaluating serological tests for Trypanosoma cruzi infection, sera samples from Central or South American countries have been used preferentially. In this work we compared the reliability of the serological tests using Mexican sera samples that were evaluated in four independent laboratories. This included a reference laboratory in Brazil and three participant laboratories, including one in Central America and two in Mexico. The kappa index between Brazilian and Honduran laboratories reached 1.0 and the index for the Mexican laboratories reached 0.94. Another finding of this study was that the source of antigen did not affect the performance of the serological tests.


Subject(s)
Humans , Antibodies, Protozoan/blood , Antigens, Protozoan/immunology , Chagas Disease/diagnosis , Laboratories/standards , Serologic Tests/standards , Trypanosoma cruzi/immunology , Antibodies, Protozoan/immunology , Antigens, Protozoan , Brazil , Enzyme-Linked Immunosorbent Assay , Honduras , Mexico , Sensitivity and Specificity , Serologic Tests/methods
10.
Article in English | IMSEAR | ID: sea-20591

ABSTRACT

BACKGROUND & OBJECTIVE: India has a high prevalence of HIV-1, hapatitis C and B virus (HCV and HBV) in the blood donors but has yet to implement nucleic acid testing (NAT) in blood screening. We undertook a multicentre evaluation of blood donor testing by NAT for simultaneous detection of HIV-1, HBV and HCV in a single tube and also to determine the feasibility of NAT implementation in India's low volume setting. METHODS: A total of 12,224 unlinked samples along with their serological results were obtained from representative eight blood banks in India and were individually manually tested by the Procleix Ultrio Assay (Chiron Corp. Emeryville, CA) for simultaneous detection of HIV-1, HCV, and HBV. RESULTS: Of the 12,224 samples tested, 209 (1.71%) were seroreactive. One hundred thirty three samples (1.09%) were reactive by Ultrio assay, 84 samples were seroreactive but NAT non reactive. There were eight NAT yield cases: 1 HIV, 1 HIV-HCV co-infection, and 6 HBV. INTERPRETATION & CONCLUSION: Our observed NAT yield for all three viruses was 1 in 1528 (0.065%). We estimate NAT could interdict 3272 infectious donations a year among our approximate 5 million annual donations.


Subject(s)
Blood Banks , Blood Donors , Female , HIV Infections/diagnosis , HIV-1/metabolism , Hepacivirus/metabolism , Hepatitis B/diagnosis , Hepatitis B virus/metabolism , Hepatitis C/diagnosis , Humans , India , Male , Mass Screening/methods , Nucleic Acid Amplification Techniques/standards , RNA, Viral/analysis , Serologic Tests/standards
12.
Acta gastroenterol. latinoam ; 37(2): 104-109, Jun. 2007. graf, tab
Article in Spanish | LILACS | ID: lil-472412

ABSTRACT

Introducción: la infección con Helicobacter pylori (H. pylori) y la eficacia de las pruebas serológicas para su diagnóstico presentan variabilidad entre diferentes regiones geográficas. Objetivo: el objetivo del presente trabajo fue determinar la eficacia de la serología como diagnóstico de infección por H. pylori y el mejor valor de corte para la población local. Materiales y métodos: se evaluaron 48 pacientes, 27 hombres y 21 mujeres, con una edad promedio de 29.2 años. En cada paciente se realizaron 3 pruebas para el diagnóstico de H. pylori: erología dosaje de anticuerpos tipo IgG (MÉTODO), serología dosaje de anticuerpos de tipo IgA (MÉ- TODO) e histología. Se obtuvieron los parámetros de eficacia y la curva de rendimiento diagnóstico de la serología IgG e IgA utilizando a la histología como estándar ideal. Resultados: el punto de corte de mayor eficacia para la serología IgG fue de 16 U/ml [sensibilidad 81%, especificidad 65%, valor predictivo positivo (VPP) 81%, valor predictivo negativo (VPN) 65% y exactitud diagnóstica 75%] y para la serología IgA fue de 17 U/ml (sensibilidad 61%, especificidad 53%, valor redictivo positivo 70%, valor predictivo negativo 43% y exactitud diagnóstica 58%). El área bajo la curva fue de 67% (IC 95%: 50 a 84) y de 54.4% (IC 95%: 38 a 72) para la IgG e IgA respectivamente. Conclusiones: la serología es una herramienta valiosa para el diagnóstico de infección por H. pylori en nuestra oblación donde hay alta prevalencia, especialmente por su bajo costo y fácil realización, pero fue necesaria una disminución del valor de corte sugerido para obtener mayor eficacia diagnóstica.


Introduction: The infection with Helicobacter pylori (H. pylori), and the diagnostic efficacy of the serologic tests has certain variability among the different geographic regions. Objective: The objective of the present work was to find the local validation of serological methods for diagnosis of H. pylori infection and to determine the best cutoff value for the local population. Materials and methods: Forty-eight patients were evaluated, 27 males and 21 females, with a mean age of 29.2 years. On each patient, 3 tests for H. pylori diagnosis were performed: IgG serology, IgA serology, and histology. We performed IgG and IgA serologic test for H. pylori infection and a histological examination for each patient. Efficacy parameters as well as the ROC curve were obtained for the IgG and IgA serology using histology as the gold standard. Results: The cutoff point with the highest efficacy for IgG serology was 16 U/ml (sensitivity 81%, specificity 65%, positive predictive value 81%, negative predictive value 65%, and accuracy 75%), and for IgA serology was 17 U/ml (sensitivity 61%, specificity 53%, positive predictive value 70%, negative predictive value 43%, and accuracy 58%). The area under the curve was 67.1% (CI 95%: 50 to 84.1) and 54.4% (CI 95%: 38.3 to 72.5) for IgG and IgA respectively. Conclusion: The serology is a valuable tool in our population with high prevalence of H. pylori, especially due to its low cost and easy performance, but a reduction of the cutoff value was necessary to obtain more sensibility and a more adequate identification of true positives cases.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Helicobacter Infections/diagnosis , Immunoglobulin A/blood , Immunoglobulin G/blood , Cohort Studies , Cross-Sectional Studies , Ecuador , Sensitivity and Specificity , Serologic Tests/methods , Serologic Tests/standards , Urban Population
15.
Rev. panam. salud pública ; 14(6): 371-376, dic. 2003. mapas, tab, graf
Article in Spanish | LILACS | ID: lil-355663

ABSTRACT

Dar a conocer los resultados de cuatro controles externos de la calidad del diagnóstico serológico del dengue realizados en la Región de las Américas en el período de 1996- 2001 y presentar los resultados obtenidos por los laboratorios participantes. MÉTODOS: Se realizaron controles externos de la calidad del diagnóstico serológico del dengue en 1996-1997, 1998-1999, 1999-2000 y 2000-2001. Paneles compuestos por 20 sueros (12 de estos positivos a anticuerpos IgM contra el dengue) fueron enviados a laboratorios de la Región para que participaran en los controles realizados. Los sueros de los paneles eran negativos a anticuerpos contra el virus de la inmunodeficiencia humana y el virus de la hepatitis C, así como al antígeno de superficie de la hepatitis B, y fueron almacenados a -20 °C hasta su envío en refrigeración a los laboratorios participantes. La presencia de anticuerpos IgM se determinó mediante un ensayo inmunoenzimático (ELISA) de captura, mientras que el título de anticuerpos IgG se determinó por inhibición de la hemoaglutinación o ELISA de IgG. Los resultados de la determinación de anticuerpos IgM contra el dengue que no coincidían con los del centro de referencia se consideraron discordantes. El título de anticuerpos IgG se consideró discordante cuando los resultados difirieron en dos diluciones o más con respecto al resultado del centro de referencia. RESULTADOS: Un total de 27 laboratorios recibió 59 paneles de sueros de 1996 a 2001, y se recibieron los resultados del análisis de 54 de esos paneles (91,5 por ciento). De 1 080 sueros (20 X 54), 95,6 por ciento coincidieron con el laboratorio de referencia en cuanto a los resultados de la detección de anticuerpos IgM contra el dengue. Además, en 47 paneles (87 por ciento) la coincidencia con el laboratorio de referencia se observó en 90 por ciento de las muestras del panel o más. De los 27 paneles para los cuales se recibieron los resultados de los títulos de anticuerpos IgG contra el dengue, 22 (81,5 por ciento) coincidieron con el centro de referencia. Tomando en conjunto los cuatro controles realizados, 22 laboratorios coincidieron con el centro de referencia en 90 por ciento de las muestras o más y 13 en 100 por ciento de las muestras en cuanto a la presencia de IgM. CONCLUSIONES: Los resultados indican que la mayoría de los laboratorios participantes mostraron un excelente desempeño en la detección de anticuerpos IgG e IgM contra el dengue. No obstante, las deficiencias encontradas ...


Subject(s)
Humans , Dengue/diagnosis , Laboratories/standards , Serologic Tests/standards , Americas , Antibodies, Viral/blood , Dengue Virus/immunology , Dengue/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Quality Control
17.
Rev. panam. salud pública ; 13(2/3): 91-102, Feb.-Mar. 2003. tab, graf
Article in Spanish | LILACS | ID: lil-346095

ABSTRACT

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...


Subject(s)
Humans , Blood Banks/standards , Blood Donors/classification , Mass Screening/standards , Quality Control , Serologic Tests/standards , Blood Banks/organization & administration , Enzyme-Linked Immunosorbent Assay , Latin America , Laboratories/standards , Pan American Health Organization , Program Evaluation , Research Support as Topic
18.
Rev. panam. salud pública ; 13(2/3): 149-153, Feb.-Mar. 2003. tab
Article in Spanish | LILACS | ID: lil-346103

ABSTRACT

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 por ciento), 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


Subject(s)
Humans , Blood Banks/standards , Blood Transfusion/standards , Mass Screening/standards , Quality Control , Serologic Tests/standards , Argentina , Blood Banks/organization & administration , Laboratories/standards , National Health Programs , Program Evaluation
19.
Rev. panam. salud pública ; 13(2/3): 165-171, Feb.-Mar. 2003. graf
Article in Spanish | LILACS | ID: lil-346106

ABSTRACT

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 percent to 19.5 percent; 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 percent of the need; sales of blood decreased; and the use of blood components was improved, with 80 percent of the blood being fractionated. In addition, supervisory control of 100 percent 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


Subject(s)
Humans , Blood Banks/organization & administration , National Health Programs/organization & administration , Blood Donors , Blood Banks/standards , Blood Transfusion/standards , Hematology/organization & administration , National Health Programs/standards , Peru , Program Evaluation , Quality Control , Serologic Tests/standards
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