Breakthrough infection by hepatitis B virus in a vaccinated blood donor: An emerging threat for transfusion safety in low-endemic countries?

We present the case of a breakthrough infection by hepatitis B virus (HBV), intending to warn about the challenge that HBV represents for transfusion safety. Virological markers for HBV infection were assayed during a blood donor screening by detection of HBsAg, anti-HBc, and viral nucleic acid (HBV DNA) by a nucleic acid test (NAT). Additionally, samples were analyzed for detection of immunoglobulin M anti-HBc, HBeAg, anti-HBe, and anti-HBs. A first-time donor repeatedly tested positive for HBV DNA by NAT and nonreactive for HBV-serological markers of infection. He stated having completed the anti-HBV vaccination schedule; thus, study of anti-Hbs resulted in reactive at protective level (18 mIU/mL). The donor denied clinical symptoms of hepatitis and remained healthy during the follow-up period. 95 days postdonation, NAT was negative, seroconversion of anti-HBc ab was detected, and a significant increase in anti-HBs concentration was measured (>1000 mIU/mL). This is the first case of HBV-breakthrough infection reported in Argentina and to our knowledge, this potential threat to transfusion safety is novel in an HBV low-endemic region with high coverage of HBV vaccination. The occurrence of breakthrough infections challenges the current protocols for the identification of HBV-infected subjects, could be a source of silent HBV transmission.

Hepatitis E virus in blood donors from Argentina: A possible source of viral infection?

BACKGROUND: The hepatitis E virus (HEV) causes acute hepatitis, which can progress to chronicity in immunosuppressed patients. It is transmitted mainly by the fecal-oral or zoonotic routes, but there is current evidence that it can be transmitted by blood transfusions. The objective of the study was to investigate HEV infections in blood donors in Argentina, within the framework of a hemovigilance program. METHODS: A total of 547 samples from Argentinean blood donors, collected in 2016, 2019 and 2020 was studied for IgG and IgM anti-HEV by ELISA (Diapro) and RNA HEV by RT-real time PCR and RT-Nested-PCR. RESULTS: The prevalence of IgG anti-HEV was 3.47% (19/547). No significant differences were registered according to the year studied, sex or age. The presence of RNA HEV was observed in 0.18% (1/547) of the donors studied without serological evidence of infection. CONCLUSIONS: This is the first molecular detection in blood donors from Argentina, showing a molecular prevalence within the range described for RNA-HEV in blood donors from other non-endemic countries, in which immunocompetent RNA-HEV positive donors without serological evidence of infection were identified. The presence of viraemic donors could imply transfusion transmission, which deserves further attention and study.

Fetal and neonatal alloimmune thrombocytopenia: a late or missed diagnosis disease in fetal and perinatal health-care settings.

INTRODUCTION: Even though Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT) has been recognized as the main cause of primary hemorrhagic morbidity and mortality in fetuses and newborns, screening programs to detect pregnancies at risk have not yet been implemented in any country. Moreover, in spite of increased concerns about maternal, fetal and neonatal health care in general, this potentially lethal disease is still underdiagnosed. The aim of this report is to highlight the importance of considering FNAIT in fetal and perinatal health-care settings and show the usefulness of molecular tools in early diagnosis of this clinical entity. METHODS: DNA was extracted from whole blood from parents and newborns; genotyping was performed by in house PCR using sequence-specific primers for typing Human Platelet Antigens (HPA)-1 to -6, -9, and -15, and with commercial HPA-TYPE (BAG HealthCare, Lich, Germany). Anti-HPA antibodies in the maternal serum were detected by the Monoclonal Antibody Solid Phase Platelet antibody Test (MASPAT). Chloroquine-treated platelets were used for the discrimination of platelet-specific antibodies from anti-HLA antibodies. RESULTS: Patients 1 and 2 had severe thrombocytopenia due to incompatibility in HPA-1 and HPA-15, respectively. The third case was a thrombocytopenic neonate with severe bleeding complications other than ICH and in whom differential diagnosis between FNAIT and Von Willebrand congenital disease was necessary; incompatibility in HPA-15 was also demonstrated. Case 4 represents a missed diagnostic opportunity. CONCLUSION: This is the first report of FNAIT cases confirmed by molecular evidence and anti-HPA antibodies detection in Argentina. This report reinforces the relevance of early diagnosis of this clinical entity. Since the delay in FNAIT diagnosis could lead to severe consequences in the fetus and neonates, strategies to approach maternal, fetal, and perinatal health, as well as prevention policies aimed to reduce fetal and neonatal morbidity and mortality should focus on implementing programs to identify high-risk pregnancies and thus reduce thrombocytopenia-related complications in fetuses and newborns.

Establishment of the first platelet-donor registry in Argentina.

BACKGROUND: Platelet transfusions are necessary to prevent and treat haemorrhages in thrombocytopenic patients or those with severe platelet dysfunction. In Latin American countries, including Argentina, blood supplies from voluntary non-remunerated blood donors remain dependent on family replacement donors, since altruistic repeat donors are exceptional and platelet donors are very scarce. The aim of this study was to recruit a group of frequent, voluntary, altruistic blood donors and determine their human platelet antigen (HPA)-genotype in order to establish the first registry of HPA-typed voluntary platelet donors in Argentina. MATERIAL AND METHODS: In this study, we invited and recruited voluntary blood donors who attended the Fundación Banco Central de Sangre between July 2016 and July 2017. DNA was extracted from K2EDTA anticoagulated whole blood and genotyping was performed by polymerase chain reaction, using sequence-specific primers to type the HPA-1 to -6, -9 and -15 systems. A subset of samples was also tested using a commercial HPA-TYPE kit. Donors were invited to join the National Register of Haematopoietic Stem Cell Donors of Argentina. RESULTS: A cohort of 500 platelet donors was recruited and characterised and a database with their personal information, including their genotype for the most relevant HPA alloantigens, was created. Eight of the 500 donors (1.6%) were HPA-1a negative. HPA allelic variants -4b, -6b and -9b were detected for the first time in our population. There was 100% concordance between our in-house assay and the commercial kits in the subset of 150 donor samples assayed in parallel. DISCUSSION: The efforts made to recruit, characterise and register voluntary platelet donors will provide the first sustainable source of HPA and human leukocyte antigen-typed platelets for compatible transfusions in the country. Remarkably, we identified a higher percentage of HPA-1a-negative donors than previously detected in the Argentinean population.

[Features of Bordetella pertussis, Bordetella spp. infection and whopping cough in Córdoba province, Argentina]. / Caracterización de la infección por Bordetella pertussis, Bordetella spp. y coqueluche en la provincia de Córdoba, Argentina.

INTRODUCTION: Whooping cough is a re-emerging infection in the world and Latin America. OBJECTIVE: It was considered relevant to investigate the clinical and epidemiological profile of Bordetella spp. and Bordetella pertussis infection in Córdoba province, Argentina; evaluating, at the same time, the co-infection with virus producing respiratory infections that may be confused with whooping cough. MATERIAL AND METHODS: All whooping cough suspected cases were studied by Polimerase Chain Reaction, amplifying the repeated insertion sequence (IS) 481 and the promoter gene encoding pertussis toxin, between 2011 and 2013. The data were obtained from the clinical and epidemiological records. RESULTS: From 2,588 whooping cough suspected cases, 11.59% was infected by Bordetella spp. and 9.16% was confirmed as Bordetella pertussis infection. The rate of infection was 7.22 and 1.84 per 100,000 for 2011 and 2012, respectively. The infection presented a seasonal tendency and it was mainly found on the group of children between 13 and 24 months old. The co-infection with virus producing respiratory infections, were uncommon. Paroxysmal cough, cyanosis and/or vomiting were predictors of the infection for Bordetella pertussis. DISCUSSION AND CONCLUSIONS: To deal with the re-emergence of whooping cough is important the knowledge of the regional epidemiological situation. This paper shows the situation of these infections in the regional clinical and epidemiological context, and makes the information available for health decision-making.

Caracterización de la infección por Bordetella pertussis, Bordetella spp. y coqueluche en la provincia de Córdoba, Argentina / Features of Bordetella pertussis, Bordetella spp. infection and whopping cough in Córdoba province, Argentina

Introduction: Whooping cough is a re-emerging infection in the world and Latin America. Objective: It was considered relevant to investigate the clinical and epidemiological profile of Bordetella spp. and Bordetella pertussis infection in Córdoba province, Argentina; evaluating, at the same time, the co-infection with virus producing respiratory infections that may be confused with whooping cough. Material and Methods: All whooping cough suspected cases were studied by Polimerase Chain Reaction, amplifying the repeated insertion sequence (IS) 481 and the promoter gene encoding pertussis toxin, between 2011 and 2013. The data were obtained from the clinical and epidemiological records. Results: From 2,588 whooping cough suspected cases, 11.59% was infected by Bordetella spp. and 9.16% was confirmed as Bordetella pertussis infection. The rate of infection was 7.22 and 1.84 per 100,000 for 2011 and 2012, respectively. The infection presented a seasonal tendency and it was mainly found on the group of children between 13 and 24 months old. The co-infection with virus producing respiratory infections, were uncommon. Paroxysmal cough, cyanosis and/or vomiting were predictors of the infection for Bordetella pertussis. Discussion and Conclusions: To deal with the re-emergence of whooping cough is important the knowledge of the regional epidemiological situation. This paper shows the situation of these infections in the regional clinical and epidemiological context, and makes the information available for health decision-making.

Introducción: Coqueluche es una enfermedad reemergente en el mundo y en Latinoamérica. Objetivo: Resultó de interés caracterizar el perfil clínico-epidemiológico de la infección por Bordetella spp. y Bordetella pertussis en Córdoba, Argentina; evaluando además, la frecuencia de infecciones de etiología viral que, por cursar con un síndrome coqueluchoide (SC), pueden ser confundidas con cuadros de coqueluche. Material y Métodos: Los casos sospechosos de coqueluche, se estudiaron por reacción de polimerasa en cadena; amplificando la secuencia repetida de inserción (IS) 481 y la región promotora del gen de la toxina pertussis; entre 2011 y 2013. Los datos de los pacientes se obtuvieron de las fichas clínicoepidemiológicas. Resultados: De 2.588 pacientes, 11,59% presentó una infección por Bordetella spp. y en 9,16% se confirmó una infección por Bordetella pertussis. La tasa de infección fue 7,22 y 1,84 por 100.000 habitantes en 2011 y 2012, respectivamente. La infección presentó una tendencia estacional y se concentró principalmente en niños entre 13 y 24 meses. La tos paroxística, cianosis y/o vómitos fueron predictores de la infección por B. pertussis. La coinfección con virus productores de infecciones respiratorias fue poco frecuente. Discusión y Conclusiones: Es fundamental el conocimiento de la situación epidemiológica regional. Este trabajo presenta la situación de Córdoba y pone a disposición de la comunidad sanitaria la información para la toma de decisiones en el contexto clínico-epidemiológico regional.

Implementación del ensayo de carga viral COBAS Taqman HIV-1 Test, v1. 0, para el diagnóstico de la infección congénita por HIV-1 / Implementation of the viral load assay COBAS Taqman HIV-1 Test, v1.0, for the diagnosis of congenital HIV-1 infection

La transmisión vertical es la principal vía de contagio del HIV en la edad pediátrica. El diagnóstico de la infección congénita antes de los 18meses se realiza mediante ensayos virológicos: detección de genoma viral como ARN plasmático y ADN proviral. La sensibilidad de estos ensayos varía según la edad del niño, con valores de especificidad mayores al 95%. El objetivo de este trabajo fue evaluar el desempeño del ensayo de carga viral (CV) COBAS Taqman HIV-1 Test, v1.0 (Roche), y su concordancia con una PCR múltiple anidada in-house para la detección del ADN proviral. De 341 muestras procesadas, 15 resultaron positivas y 326 negativas por ambas metodologías. Para la metodología de CV, la sensibilidad general fue del 88,2% y la especificidad del 100%. Nuestros resultados indican que la metodología de CV evaluada puede utilizarse como técnica alternativa para el diagnóstico de infección congénita por HIV

Vertical transmission is the main route of HIV infection in childhood. Because of the persistence of maternal HIV antibodies, virologic assays that directly detect HIV are required to diagnose HIV infection in infants younger than 18months of age. The sensitivity of HIV RNA/DNA assays increases as the child becomes older. These tests have specificity values greater than 95%. The aim of this study was to evaluate the performance of the COBAS Taqman HIV-1 Test, v1.0 assay (Roche) and its concordance with a Multiplex Nested-PCR. Of 341 samples processed, 15 were positive and 326 negative by both methods. Sensitivity and specificity overall values for the viral load assay were 88.2% and 100%, respectively. Our results indicate that the COBAS Taqman assay evaluated could be used as an alternative method to diagnose HIV congenital infection

[Implementation of the COBAS Taqman HIV-1 Test, v1.0 for vertical transmission diagnosis]. / Implementación del ensayo de carga viral COBAS Taqman HIV-1 Test, v1.0, para el diagnóstico de la infección congénita por HIV-1.

Vertical transmission is the main route of HIV infection in childhood. Because of the persistence of maternal HIV antibodies, virologic assays that directly detect HIV are required to diagnose HIV infection in infants younger than 18 months of age. The sensitivity of HIV RNA/DNA assays increases as the child becomes older. These tests have specificity values greater than 95%. The aim of this study was to evaluate the performance of the COBAS Taqman HIV-1 Test, v1.0 assay (Roche) and its concordance with a Multiplex Nested-PCR. Of 341 samples processed, 15 were positive and 326 negative by both methods. Sensitivity and specificity overall values for the viral load assay were 88.2% and 100%, respectively. Our results indicate that the COBAS Taqman assay evaluated could be used as an alternative method to diagnose HIV congenital infection.

Implementación del ensayo de carga viral COBAS Taqman HIV-1 Test, v1.0, para el diagnóstico de la infección congénita por HIV-1. / [Implementation of the COBAS Taqman HIV-1 Test, v1.0 for vertical transmission diagnosis].

Vertical transmission is the main route of HIV infection in childhood. Because of the persistence of maternal HIV antibodies, virologic assays that directly detect HIV are required to diagnose HIV infection in infants younger than 18months of age. The sensitivity of HIV RNA/DNA assays increases as the child becomes older. These tests have specificity values greater than 95

. The aim of this study was to evaluate the performance of the COBAS Taqman HIV-1 Test, v1.0 assay (Roche) and its concordance with a Multiplex Nested-PCR. Of 341 samples processed, 15 were positive and 326 negative by both methods. Sensitivity and specificity overall values for the viral load assay were 88.2

and 100

, respectively. Our results indicate that the COBAS Taqman assay evaluated could be used as an alternative method to diagnose HIV congenital infection.

[Sensitivity of the COBAS AmpliScreen™ HIV-1 test v1.5 for HIV-1 detection]. / Sensibilidad del equipo Cobas AmpliScreen™ HIV-1 Test, v1.5, para la detección de HIV-1.

The introduction of nucleic acid amplification techniques (NAT) in blood banks was intended to reduce the residual risk of transfusion-transmitted infections. Co-circulation of a great diversity of HIV-1 variants in Argentina portrays the need to assess the sensitivity of serological and molecular assays available for their detection. In this study, we evaluated the sensitivity of the COBAS AmpliScreen™ HIV-1 Test, version 1.5 (Roche) for the detection of HIV-1 RNA in plasma samples of infected individuals from Argentina. The results of this study reveal that this technique has high sensitivity for the detection of HIV-1 RNA under assay conditions: using mini-pool testing, pools ≥ 50 RNA copies per ml achieved ≥ 92 % sensitivity, whereas in the standard procedure, samples ≥ 207 RNA copies/ml achieved 100 % sensitivity. Moreover, the COBAS AmpliScreen™ HIV-1 Test, version 1.5 (Roche) is suitable for detecting prevailing HIV-1 variants.

Sensibilidad del equipo Cobas AmpliScreenTM HIV-1 Test, v1. 5, para la detección de HIV-1 / Sensitivity of the COBAS AmpliScreenTM HIV-1 Test v1.5 for HIV-1 detection

Las técnicas de amplificación de ácidos nucleicos (NAT) se incorporaron en los bancos de sangre para reducir el riesgo residual de transmisión de infecciones por vía transfusional. La cocirculación de distintas variantes del HIV-1 en Argentina indica la necesidad de evaluar la sensibilidad de los ensayos serológicos y moleculares disponibles para su detección. En este trabajo se evaluó la sensibilidad del equipo COBAS AmpliScreenTM HIV-1 Test, versión 1.5 (Roche), para detectar ARN viral en plasmas de individuos infectados con HIV-1 de Argentina. Los resultados demuestran que esta técnica tiene una alta sensibilidad para detectar ARN de HIV-1 en las condiciones ensayadas: para ensayo de mini-pooles (pooles ≥ 50 copias de ARN/ml), la sensibilidad fue ≥ 92 %, y para procedimiento estándar (plasmas ≥ 207 copias de ARN/ml), la sensibilidad fue 100 %. Además, la técnica COBAS AmpliScreenTM HIV-1 Test, versión 1.5 (Roche), es adecuada para la detección de las variantes de HIV-1 prevalentes

The introduction of nucleic acid amplification techniques (NAT) in blood banks was intended to reduce the residual risk of transfusion-transmitted infections. Co-circulation of a great diversity of HIV-1 variants in Argentina portrays the need to assess the sensitivity of serological and molecular assays available for their detection. In this study, we evaluated the sensitivity of the COBAS AmpliScreenTM HIV-1 Test, version 1.5 (Roche) for the detection of HIV-1 RNA in plasma samples of infected individuals from Argentina. The results of this study reveal that this technique has high sensitivity for the detection of HIV-1 RNA under assay conditions: using mini-pool testing, pools ≥ 50 RNA copies per ml achieved ≥ 92 % sensitivity, whereas in the standard procedure, samples ≥ 207 RNA copies/ ml achieved 100 % sensitivity. Moreover, the COBAS AmpliScreenTM HIV-1 Test, version 1.5 (Roche) is suitable for detecting prevailing HIV-1 variants

Sensibilidad del equipo Cobas AmpliScreenÔäó HIV-1 Test, v1.5, para la detección de HIV-1. / [Sensitivity of the COBAS AmpliScreenÔäó HIV-1 test v1.5 for HIV-1 detection].

The introduction of nucleic acid amplification techniques (NAT) in blood banks was intended to reduce the residual risk of transfusion-transmitted infections. Co-circulation of a great diversity of HIV-1 variants in Argentina portrays the need to assess the sensitivity of serological and molecular assays available for their detection. In this study, we evaluated the sensitivity of the COBAS AmpliScreen HIV-1 Test, version 1.5 (Roche) for the detection of HIV-1 RNA in plasma samples of infected individuals from Argentina. The results of this study reveal that this technique has high sensitivity for the detection of HIV-1 RNA under assay conditions: using mini-pool testing, pools  50 RNA copies per ml achieved  92

sensitivity, whereas in the standard procedure, samples  207 RNA copies/ml achieved 100

sensitivity. Moreover, the COBAS AmpliScreenÔäó HIV-1 Test, version 1.5 (Roche) is suitable for detecting prevailing HIV-1 variants.

Development and validation of a real-time PCR assay for a novel HTLV-1 tax sequence detection and proviral load quantitation.

A quantitative real-time PCR (qPCR) assay using SYBR Green dye was established in order to detect and quantify the proviral DNA of HTLV-1 in peripheral blood mononuclear cells (PBMCs). Primers were designed, and the assay was standardized to amplify a novel, conserved HTLV-1 tax region. Proviral load was normalized to the amount of cellular DNA by quantitation of the human albumin gene. Firstly, the qPCR was assessed determining the specificity, sensitivity, dynamic range and intra- and inter-assay reproducibility of the technique. The limit of detection as determined by PROBIT analysis using dilutions of the standard was 2.97 copies. The assay had an excellent dynamic range from 105 to 10¹ copies per reaction and good intra- and inter-assay reproducibility, CVs less than 2%. Secondly, the performance of the qPCR was tested on 40 HTLV-1 seropositive individuals. Proviral load for HTLV-1 carriers ranged from 2.2×10² to more than 8.3×104 copies/106 PBMCs. The high sensitivity and wide dynamic range allowed the determination of a broad range of HTLV-1 proviral loads in infected individuals. This assay is a valuable alternative diagnostic tool when current available serological assays are insufficient. In addition, it will facilitate the study of the relationship between proviral load and pathogenesis.

Performance of a commercial assay for the diagnosis of influenza A (H1N1) infection in comparison to the Centers for Disease Control and Prevention protocol of real time RT-PCR.

At the time of influenza A (H1N1) emergency, the WHO responded with remarkable speed by releasing guidelines and a protocol for a real-time RT-PCR assay (rRT-PCR). The aim of the present study was to evalúate the performance of the "Real Time Ready Influenza A/H1N1 Detection Set" (June 2009)-Roche kit in comparison to the CDC reference rRT-PCR protocol. The overall sensitivity of the Roche assay for detection of the Inf A gene in the presence or absence of the H1 gene was 74.5 %. The sensitivity for detecting samples that were only positive for the Inf A gene (absence of the H1 gene) was 53.3 % whereas the sensitivity for H1N1-positive samples (presence of the Inf A gene and any other swine gene) was 76.4 %. The specificity of the assay was 97.1 %. A new version of the kit (November 2009) is now available, and a recent evaluation of its performance showed good sensitivity to detect pandemic H1N1 compared to other molecular assays.

Performance of a commercial assay for the diagnosis of influenza A (H1N1) infection in comparison to the Centers for Disease Control and Prevention protocol of real time RT-PCR / Evaluación del desempeño de un equipo comercial para el diagnóstico de influenza A (H1N1) en comparación con el protocolo de RT-PCR en tiempo real diseñado por los Centros de Control y Prevención de Enfermedades (CDC)

At the time of influenza A (H1N1) emergency, the WHO responded with remarkable speed by releasing guidelines and a protocol for a real-time RT-PCR assay (rRT-PCR). The aim of the present study was to evalúate the performance of the "Real Time Ready Influenza A/H1N1 Detection Set" (June 2009)-Roche kit in comparison to the CDC reference rRT-PCR protocol. The overall sensitivity of the Roche assay for detection of the Inf A gene in the presence or absence of the H1 gene was 74.5 %. The sensitivity for detecting samples that were only positive for the Inf A gene (absence of the H1 gene) was 53.3 % whereas the sensitivity for H1N1-positive samples (presence of the Inf A gene and any other swine gene) was 76.4 %. The specificity of the assay was 97.1 %. A new version of the kit (November 2009) is now available, and a recent evaluation of its performance showed good sensitivity to detect pandemic H1N1 compared to other molecular assays.

Durante la pandemia de influenza A (H1N1), la OMS recomendó algoritmos y protocolos de detección del virus mediante RT-PCR en tiempo real. El objetivo del presente estudio fue evaluar el desempeño del equipo que comercializa la empresa Roche, Real Time Ready Influenza A/H1N1 Detection Set (junio de 2009), en comparación con el protocolo de RT-PCR en tiempo real de los CDC. La sensibilidad global del ensayo de Roche para la detección del gen Inf A en presencia o ausencia del gen H1 fue 74,5 %. La sensibilidad para la detección de muestras positivas solo para el gen Inf A (ausencia del gen H1) fue 53,3 % y la sensibilidad para la detección de muestras positivas para H1N1 (presencia del gen Inf A y cualquier otro gen porcino) fue 76,4 %. La especificidad fue 97,1 %. Existe una nueva versión del equipo (noviembre 2009) que, según se ha descrito, presenta buena sensibilidad en comparación con otros ensayos moleculares para detectar H1N1 pandémica.

Performance of a commercial assay for the diagnosis of influenza A (H1N1) infection in comparison to the Centers for Disease Control and Prevention protocol of real time RT-PCR / Evaluación del desempeño de un equipo comercial para el diagnóstico de influenza A (H1N1) en comparación con el protocolo de RT-PCR en tiempo real diseñado por los Centros de Control y Prevención de Enfermedades (CDC)

At the time of influenza A (H1N1) emergency, the WHO responded with remarkable speed by releasing guidelines and a protocol for a real-time RT-PCR assay (rRT-PCR). The aim of the present study was to evalúate the performance of the "Real Time Ready Influenza A/H1N1 Detection Set" (June 2009)-Roche kit in comparison to the CDC reference rRT-PCR protocol. The overall sensitivity of the Roche assay for detection of the Inf A gene in the presence or absence of the H1 gene was 74.5 %. The sensitivity for detecting samples that were only positive for the Inf A gene (absence of the H1 gene) was 53.3 % whereas the sensitivity for H1N1-positive samples (presence of the Inf A gene and any other swine gene) was 76.4 %. The specificity of the assay was 97.1 %. A new version of the kit (November 2009) is now available, and a recent evaluation of its performance showed good sensitivity to detect pandemic H1N1 compared to other molecular assays.(AU)

Durante la pandemia de influenza A (H1N1), la OMS recomendó algoritmos y protocolos de detección del virus mediante RT-PCR en tiempo real. El objetivo del presente estudio fue evaluar el desempeño del equipo que comercializa la empresa Roche, Real Time Ready Influenza A/H1N1 Detection Set (junio de 2009), en comparación con el protocolo de RT-PCR en tiempo real de los CDC. La sensibilidad global del ensayo de Roche para la detección del gen Inf A en presencia o ausencia del gen H1 fue 74,5 %. La sensibilidad para la detección de muestras positivas solo para el gen Inf A (ausencia del gen H1) fue 53,3 % y la sensibilidad para la detección de muestras positivas para H1N1 (presencia del gen Inf A y cualquier otro gen porcino) fue 76,4 %. La especificidad fue 97,1 %. Existe una nueva versión del equipo (noviembre 2009) que, según se ha descrito, presenta buena sensibilidad en comparación con otros ensayos moleculares para detectar H1N1 pandémica.(AU)

Performance of a commercial assay for the diagnosis of influenza A (H1N1) infection in comparison to the Centers for Disease Control and Prevention protocol of real time RT-PCR / Evaluación del desempeño de un equipo comercial para el diagnóstico de influenza A (H1N1) en comparación con el protocolo de RT-PCR en tiempo real diseñado por los Centros de Control y Prevención de Enfermedades (CDC)

At the time of influenza A (H1N1) emergency, the WHO responded with remarkable speed by releasing guidelines and a protocol for a real-time RT-PCR assay (rRT-PCR). The aim of the present study was to evalúate the performance of the "Real Time Ready Influenza A/H1N1 Detection Set" (June 2009)-Roche kit in comparison to the CDC reference rRT-PCR protocol. The overall sensitivity of the Roche assay for detection of the Inf A gene in the presence or absence of the H1 gene was 74.5 %. The sensitivity for detecting samples that were only positive for the Inf A gene (absence of the H1 gene) was 53.3 % whereas the sensitivity for H1N1-positive samples (presence of the Inf A gene and any other swine gene) was 76.4 %. The specificity of the assay was 97.1 %. A new version of the kit (November 2009) is now available, and a recent evaluation of its performance showed good sensitivity to detect pandemic H1N1 compared to other molecular assays.(AU)

Durante la pandemia de influenza A (H1N1), la OMS recomendó algoritmos y protocolos de detección del virus mediante RT-PCR en tiempo real. El objetivo del presente estudio fue evaluar el desempeño del equipo que comercializa la empresa Roche, Real Time Ready Influenza A/H1N1 Detection Set (junio de 2009), en comparación con el protocolo de RT-PCR en tiempo real de los CDC. La sensibilidad global del ensayo de Roche para la detección del gen Inf A en presencia o ausencia del gen H1 fue 74,5 %. La sensibilidad para la detección de muestras positivas solo para el gen Inf A (ausencia del gen H1) fue 53,3 % y la sensibilidad para la detección de muestras positivas para H1N1 (presencia del gen Inf A y cualquier otro gen porcino) fue 76,4 %. La especificidad fue 97,1 %. Existe una nueva versión del equipo (noviembre 2009) que, según se ha descrito, presenta buena sensibilidad en comparación con otros ensayos moleculares para detectar H1N1 pandémica.(AU)

Técnicas moleculares como herramientas para el tamizaje viral. Estado actual del desarrollo de una técnica de RT-Multiplex-Nested PCR para el control de HIV en sangre / Molecular techniques for viral screening. RT-Multiplex-Nested PCR for HIV control in blood

Los índices de morbilidad y mortalidad en receptores de sangre aumentan drásticamente debido a la transmisión de infecciones virales por vía transfusional. Entre los virus transmitidos por sangre, el de mayor impacto sanitario y social es el virus de la inmunodeficiencia humana tipo 1 (HIV-1). A pesar de que la implementación del tamizaje de anticuerpos para HIV en los Bancos de Sangre de Argentina ha permitido reducir considerablemente la transmisión del virus por vía sanguínea, existe en la actualidad evidencia suficiente de la transmisión de HIV por unidades de sangre con serología negativa. En los Bancos de Sangre de la mayoría de los países europeos y en los Estados Unidos se utilizan, desde el año 1999, técnicas de amplificación de ácidos nucleicos (NAT) para detectar HIV y HCV, con el fin de reducir el período de ventana inmunológica. En este trabajo realizamos una actualización del uso de las técnicas moleculares como herramientas de tamizaje de HIV en la sangre destinada a transfusión y presentamos los resultados preliminares obtenidos a partir del desarrollo de una técnica molecular artesanal: transcripción reversa y reacción en cadena de la polimerasa anidada (RT-Multiplex-Nested PCR), de alta sensibilidad y de bajo costo. Los resultados obtenidos demuestran que la sensibilidad y la especificidad de esta técnica para detectar cepas de HIV regionales están dentro de los límites establecidos por las reglamentaciones internacionales. En esta etapa del trabajo se está realizando la validación de la técnica desarrollada utilizando estándares internacionales. Esta última técnica podrá ser utilizada para el control de la sangre en Córdoba, con el fin de reducir el riesgo de transmisión del virus HIV por esta vía.