RESUMO
There is no comprehensive study available on the natural hepatitis C virus (HCV) polymorphism in sites associated with resistance including all viral genotypes which may present variable susceptibilities to particular direct-acting antivirals (DAAs). This study aimed to analyze the frequencies, genetic barriers, and evolutionary histories of naturally occurring resistance-associated variants (RAVs) in the six main HCV genotypes. A comprehensive analysis of up to 103 RAVs was performed in 2,901, 2,216, and 1,344 HCV isolates for the NS3, NS5A, and NS5B genes, respectively. We report significant intergenotypic differences in the frequencies of natural RAVs for these three HCV genes. In addition, we found a low genetic barrier for the generation of new RAVs, irrespective of the viral genotype. Furthermore, in 1,126 HCV genomes, including sequences spanning the three genes, haplotype analysis revealed a remarkably high frequency of viruses carrying more than one natural RAV to DAAs (53% of HCV-1a, 28.5% of HCV-1b, 67.1% of HCV-6, and 100% of genotype 2, 3, 4, and 5 haplotypes). With the exception of HCV-1a, the most prevalent haplotypes showed RAVs in at least two different viral genes. Finally, evolutionary analyses revealed that, while most natural RAVs appeared recently, others have been efficiently transmitted over time and cluster in well-supported clades. In summary, and despite the observed high efficacy of DAA-based regimens, we show that naturally occurring RAVs are common in all HCV genotypes and that there is an overall low genetic barrier for the selection of resistance mutations. There is a need for natural DAA resistance profiling specific for each HCV genotype.
Assuntos
Farmacorresistência Viral/genética , Genoma Viral , Haplótipos , Hepacivirus/genética , Proteínas não Estruturais Virais/genética , Antivirais/farmacologia , Mapeamento Cromossômico , Hepacivirus/efeitos dos fármacos , Hepacivirus/isolamento & purificação , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/virologia , Humanos , Mutação de Sentido Incorreto , Polimorfismo GenéticoRESUMO
Chikungunya virus (CHIKV) has emerged as a significant public health concern due to its rapid spread and potential for causing debilitating epidemics. In Argentina, the virus has garnered attention since its introduction to the Americas in 2013, due to its growing incidence and impact in neighbouring countries. Here we present a comprehensive analysis of the spatiotemporal dynamics of CHIKV in Argentina, focusing on the evolutionary trajectory of its genetic variants. Through a combination of active surveillance, screening of historical and recent samples, and whole-genome sequencing, we traced the evolutionary history of CHIKV lineages circulating within the country. Our results reveal that two distinct genotypes circulated in Argentina: The Asian lineage during the 2016 epidemic and the ECSA lineage in 2023. This distribution reflects the dominance of particular variants across Latin America. Since 2023, the ECSA lineage has led to a surge in cases throughout the Americas, marking a significant shift. The replacement of lineages in the American region constitutes a major epidemiological event, potentially affecting the dynamics of virus transmission and the clinical outcomes in impacted populations. The spatiotemporal analysis highlights CHIKV's distribution across Argentina and underscores the significant role of human mobility, especially when considering recent epidemics in neighbouring countries such as Paraguay and Uruguay, which have facilitated the spread and introduction of the viral strain into different districts. By integrating epidemiological data with genomic insights, we elucidate the patterns of virus dissemination, highlighting key areas of transmission and potential factors contributing to its spread.
Assuntos
Febre de Chikungunya , Vírus Chikungunya , Evolução Molecular , Genótipo , Filogenia , Argentina/epidemiologia , Vírus Chikungunya/genética , Vírus Chikungunya/classificação , Vírus Chikungunya/isolamento & purificação , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/virologia , Febre de Chikungunya/transmissão , Humanos , Genoma Viral , América Latina/epidemiologia , Sequenciamento Completo do Genoma , Análise Espaço-Temporal , Variação GenéticaRESUMO
CRISPR-Cas12a (also called Cpf1) has been commonly used for genomic editing, based on its ability to generate precise double-stranded DNA (dsDNA) breaks. Recently, it was demonstrated that Cas12a exhibits unspecific ssDNAse activity upon target recognition. This feature allows CRISPR-Cas to be coupled with a ssDNA reporter and generate a fast, accurate and ultrasensitive molecular detection method. Here, we demonstrate that Cas12a was able to detect DNA target sequences corresponding to carbapenemases resistance genes such as KPC, NDM and OXA. Also, with the addition of a reverse-transcription step, we were able to detect viral RNA sequences from DENV, ZIKV and HANTV genomes. In all cases, assay run time was less than two hours. Additionally, we report attomolar levels of detection. This methodology was validated using clinical samples from patients infected with Dengue virus. Reactions were visualized by detection of a fluorescent signal, as well as by the use of a simple lateral flow strip. These results indicate that Cas12a is able to detect both DNA and RNA targets, making it an appropriate and convenient tool to detect all types of pathogens.
Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Proteínas Associadas a CRISPR/genética , Sistemas CRISPR-Cas , Farmacorresistência Bacteriana/genética , Endodesoxirribonucleases/genética , Edição de Genes/métodos , Vírus de RNA/genética , beta-Lactamases/farmacologia , DNA de Cadeia Simples/genética , Dengue/virologia , Vírus da Dengue/genética , Corantes Fluorescentes , Vírus Hantaan/genética , Humanos , Técnicas de Diagnóstico Molecular , Vírus de RNA/patogenicidade , RNA Viral/genética , Zika virus/genéticaRESUMO
Introduction: Cutaneous leishmaniasis caused by L. braziliensis has been historically endemic in Argentina and several cases of visceral leishmaniasis following initial cutaneous leishmaniasis have been reported. Visceral leishmaniasis started to appear in Argentina in 2006 in the city of Posadas, Misiones province, affecting both humans and dogs. Objective: To identify the etiologic agent to species level in patients with visceral leishmaniasis diagnosis in Misiones province and describe its clinical and epidemiological characteristics. Materials and methods: A cohort of 24 patients from Misiones province was studied from 2009 to 2016, all with a confirmed diagnosis of visceral leishmaniasis. To identify the Leishmania species involved, patient samples were analyzed by microscopy, serologic studies, DNA detection, and sequencing. Variables such as age, sex, place of residence, clinical signs and symptoms consistent with visceral leishmaniasis were also recorded. Results: 75% (18/24) of the patients studied were males and 25% (6/24) were younger than 4 years. The most frequent symptom was a prolonged fever in 87.5% of the patients (21/24), followed by splenomegaly in 70.8% (17/24). Leishmania infantum was the only parasite species identified in all patients. Conclusion: This finding constitutes the first molecular identification of the Leishmania infantum species in autochthonous patients of Misiones province, Argentina. This study highlights the importance of PCR for species identification in epidemiological studies of visceral leishmaniosis in Argentina.
Introducción. La leishmaniosis cutánea por Leishmania braziliensis ha sido tradicionalmente endémica en Argentina y se han sido descritos casos de compromiso visceral después de una leishmaniosis cutánea inicial. La leishmaniosis visceral emergió en Argentina en el año 2006 en la ciudad de Posadas, provincia de Misiones, afectando tanto a humanos como a perros. Objetivo. Identificar el agente etiológico a nivel de especie de los pacientes diagnosticados con leishmaniosis visceral en Misiones y describir sus características clínicoepidemiológicas. Materiales y métodos. Se estudió una serie de 24 pacientes con diagnóstico confirmado de leishmaniosis visceral en la provincia de Misiones en el período 2009 al 2016. Para la identificación de Leishmania spp., los pacientes fueron sometidos a estudios diagnósticos indirectos (serológicos) y directos (microscopía, detección de ADN y secuenciación). También, se estudiaron variables como edad, sexo, lugar de residencia, y signos y síntomas clínicos indicativos de leishmaniosis visceral. Resultados. De los 24 pacientes estudiados, 18 (75 %) eran hombres y 6 (25 %) eran menores de cuatro años. La manifestación clínica más frecuente fue el síndrome febril prolongado en 21 (87,5 %) de los pacientes, seguido de esplenomegalia en 17 (70,8 %). Se identificó la especie Leishmania infantum en todos los pacientes estudiados. Conclusión. Este hallazgo constituye la primera identificación de la especie L. infantum en pacientes autóctonos de la provincia de Misiones. El estudio evidenció la importancia de la PCR para el manejo epidemiológico de la leishmaniosis visceral en Argentina.
Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/parasitologia , Adolescente , Adulto , Idoso , Argentina/epidemiologia , Pré-Escolar , DNA de Protozoário/genética , Feminino , Humanos , Lactente , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da PolimeraseRESUMO
INTRODUCCIÓN: La pandemia de COVID-19 ha creado desafíos sin precedentes para los laboratorios de todo el mundo. Los gobiernos nacionales y subnacionales se vieron en la necesidad imperiosa de adaptar instituciones para la detección de SARS-CoV-2 en respuesta a la emergencia sanitaria declarada en 2020. Con el objetivo de aumentar la capacidad de diagnóstico en la provincia de Misiones, se implementó un laboratorio de diagnóstico de excelencia dentro del Instituto Misionero de Biodiversidad. Este artículo comparte los pasos realizados y los desafíos enfrentados, con el fin de que sirva de guía a otras instituciones. MÉTODOS: Las etapas para establecer el laboratorio fueron: adquisición de equipamientos/reactivos, adaptación/renovación del laboratorio, incorporación y capacitación del recurso humano, establecimiento de buenas prácticas y bioseguridad, selección de la metodología de extracción y detección, implementación de controles de calidad y habilitación. RESULTADOS: Desde su habilitación el Laboratorio de Análisis Integral procesó 1186 muestras biológicas de casos sospechosos de COVID-19 y se convirtió así en el segundo laboratorio de referencia provincial. DISCUSIÓN: La eficiente articulación entre el Instituto Misionero de Biodiversidad y el Ministerio de Salud de Misiones logró la rápida implementación de este laboratorio de alta complejidad en una región de importancia epidemiológica.
Assuntos
Contenção de Riscos Biológicos , Técnicas de Diagnóstico Molecular , COVID-19RESUMO
RESUMEN INTRODUCCIÓN: La pandemia de COVID-19 ha creado desafíos sin precedentes para los laboratorios de todo el mundo. Los gobiernos nacionales y subnacionales se vieron en la necesidad imperiosa de adaptar instituciones para la detección de SARS-CoV-2 en respuesta a la emergencia sanitaria declarada en 2020. Con el objetivo de aumentar la capacidad de diagnóstico en la provincia de Misiones, se implementó un laboratorio de diagnóstico de excelencia dentro del Instituto Misionero de Biodiversidad. Este artículo comparte los pasos realizados y los desafíos enfrentados, con el fin de que sirva de guía a otras instituciones. MÉTODOS: Las etapas para establecer el laboratorio fueron: adquisición de equipamientos/reactivos, adaptación/renovación del laboratorio, incorporación y capacitación del recurso humano, establecimiento de buenas prácticas y bioseguridad, selección de la metodología de extracción y detección, implementación de controles de calidad y habilitación. RESULTADOS: Desde su habilitación el Laboratorio de Análisis Integral procesó 1186 muestras biológicas de casos sospechosos de COVID-19 y se convirtió así en el segundo laboratorio de referencia provincial. DISCUSIÓN: La eficiente articulación entre el Instituto Misionero de Biodiversidad y el Ministerio de Salud de Misiones logró la rápida implementación de este laboratorio de alta complejidad en una región de importancia epidemiológica.
ABSTRACT INTRODUCTION: The COVID-19 pandemic has created unprecedented challenges for laboratories around the world. National and subnational governments faced the urgent need to adapt institutions for the detection of SARS-CoV-2 in response to the health emergency declared in 2020. With the aim of increasing diagnostic capacity in the province of Misiones, a diagnostic laboratory of excellence was established within the "Instituto Misionero de Biodiversidad". This article shares the steps taken and the challenges faced, in order to serve as a guide to other institutions. METHODS: The stages to establish the laboratory were: acquisition of equipment/reagents, adaptation/ renovation of the laboratory, incorporation and training of human resources, establishment of good practices and biosafety, selection of the extraction and detection methodology, implementation of quality controls and authorization. RESULTS: Since its authorization, the "Laboratorio de Análisis Integral" has processed 1186 biological samples from suspected cases of COVID-19, becoming the second reference laboratory in Misiones. DISCUSSION: The efficient articulation between the "Instituto Misionero de Biodiversidad" and the provincial Ministry of Health achieved the rapid implementation of this high complexity laboratory in a region of epidemiological importance.
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INTRODUCTION: Hepatitis C virus (HCV) is considered a major public health problem, with 200 million people infected worldwide. The treatment for HCV chronic infection with pegylated interferon alpha plus ribavirin inhibitors is unspecific; consequently, the treatment is effective in only 50% of patients infected. This has prompted the development of direct-acting antivirals (DAA) that target virus proteins. These DAA have demonstrated a potent effect in vitro and in vivo; however, virus mutations associated with the development of resistance have been described. OBJECTIVE: To design and develop an online information system for detecting mutations in amino acids known to be implicated in resistance to DAA. MATERIALS AND METHODS: We have used computer applications, technological tools, standard languages, infrastructure systems and algorithms, to analyze positions associated with resistance to DAA for the NS3, NS5A, and NS5B genes of HCV. RESULTS: We have designed and developed an online information system named Biomedical Mutation Analysis (BMA), which allows users to calculate changes in nucleotide and amino acid sequences for each selected sequence from conventional Sanger and cloning sequencing using a graphical interface. CONCLUSION: BMA quickly, easily and effectively analyzes mutations, including complete documentation and examples. Furthermore, the development of different visualization techniques allows proper interpretation and understanding of the results. The data obtained using BMA will be useful for the assessment and surveillance of HCV resistance to new antivirals, and for the treatment regimens by selecting those DAA to which the virus is not resistant, avoiding unnecessary treatment failures. The software is available at: http://bma.itiud.org.
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BACKGROUND: Continuous surveillance for genetic changes in circulating influenza viruses is needed to guide influenza prevention and control. OBJECTIVES: To compare intra-seasonal influenza genetic diversity of hemagglutinin in influenza A strains isolated from influenza hospital admissions collected at two distinct sites during the same season. STUDY DESIGN: Comparative phylogenetic analysis of full-length hemagglutinin genes from 77 isolated influenza A viruses from the St. Petersburg, Russian Federation and Valencia, Spain sites of the Global Influenza Hospital Surveillance Network (GIHSN) during the 2013/14 season. RESULTS: We found significant variability in A(H3N2) and A(H1N1)pdm09 viruses between the two sites, with nucleotide variation at antigenic positions much lower for A(H1N1)pdm09 than for A(H3N2) viruses. For A(H1N1)pdm09, antigenic sites differed by three to four amino acids from the vaccine strain, two of them common to all tested isolates. For A(H3N2) viruses, antigenic sites differed by six to nine amino acids from the vaccine strain, four of them common to all tested isolates. A fifth amino acid substitution in the antigenic sites of A(H3N2) defined a new clade, 3C.2. For both influenza A subtypes, pairwise amino acid distances between circulating viruses and vaccine strains were significantly higher at antigenic than at non-antigenic sites. Whereas A(H1N1)pdm09 viruses clustered with clade 6B and 94% of A(H3N2) with clade 3C.3, at both study sites A(H3N2) clade 3C.2 viruses emerged towards the end of the season, showing greater pairwise amino acid distances from the vaccine strain compared to the predominant clade 3C.3. CONCLUSIONS: Influenza A antigenic variants differed between St. Petersburg and Valencia, and A(H3N2) clade 3C.2 viruses were characterized by more amino acid differences from the vaccine strain, especially at the antigenic sites.
Assuntos
Monitoramento Epidemiológico , Saúde Global , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/epidemiologia , Influenza Humana/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Variação Genética , Genoma Viral , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , Federação Russa/epidemiologia , Estações do Ano , Análise de Sequência de DNA , Espanha/epidemiologia , Adulto JovemRESUMO
Resumen Introducción. La leishmaniosis cutánea por Leishmania braziliensis ha sido tradicionalmente endémica en Argentina y se han sido descritos casos de compromiso visceral después de una leishmaniosis cutánea inicial. La leishmaniosis visceral emergió en Argentina en el año 2006 en la ciudad de Posadas, provincia de Misiones, afectando tanto a humanos como a perros. Objetivo. Identificar el agente etiológico a nivel de especie de los pacientes diagnosticados con leishmaniosis visceral en Misiones y describir sus características clínico-epidemiológicas. Materiales y métodos. Se estudió una serie de 24 pacientes con diagnóstico confirmado de leishmaniosis visceral en la provincia de Misiones en el período 2009 al 2016. Para la identificación de Leishmania spp., los pacientes fueron sometidos a estudios diagnósticos indirectos (serológicos) y directos (microscopía, detección de ADN y secuenciación). También, se estudiaron variables como edad, sexo, lugar de residencia, y signos y síntomas clínicos indicativos de leishmaniosis visceral. Resultados. De los 24 pacientes estudiados, 18 (75 %) eran hombres y 6 (25 %) eran menores de cuatro años. La manifestación clínica más frecuente fue el síndrome febril prolongado en 21 (87,5 %) de los pacientes, seguido de esplenomegalia en 17 (70,8 %). Se identificó la especie Leishmania infantum en todos los pacientes estudiados. Conclusión. Este hallazgo constituye la primera identificación de la especie L. infantum en pacientes autóctonos de la provincia de Misiones. El estudio evidenció la importancia de la PCR para el manejo epidemiológico de la leishmaniosis visceral en Argentina.
Abstract Introduction: Cutaneous leishmaniasis caused by L. braziliensis has been historically endemic in Argentina and several cases of visceral leishmaniasis following initial cutaneous leishmaniasis have been reported. Visceral leishmaniasis started to appear in Argentina in 2006 in the city of Posadas, Misiones province, affecting both humans and dogs. Objective: To identify the etiologic agent to species level in patients with visceral leishmaniasis diagnosis in Misiones province and describe its clinical and epidemiological characteristics. Materials and methods: A cohort of 24 patients from Misiones province was studied from 2009 to 2016, all with a confirmed diagnosis of visceral leishmaniasis. To identify the Leishmania species involved, patient samples were analyzed by microscopy, serologic studies, DNA detection, and sequencing. Variables such as age, sex, place of residence, clinical signs and symptoms consistent with visceral leishmaniasis were also recorded. Results: 75% (18/24) of the patients studied were males and 25% (6/24) were younger than 4 years. The most frequent symptom was a prolonged fever in 87.5% of the patients (21/24), followed by splenomegaly in 70.8% (17/24). Leishmania infantum was the only parasite species identified in all patients. Conclusion: This finding constitutes the first molecular identification of the Leishmania infantum species in autochthonous patients of Misiones province, Argentina. This study highlights the importance of PCR for species identification in epidemiological studies of visceral leishmaniosis in Argentina.
Assuntos
Adolescente , Adulto , Idoso , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/parasitologia , Argentina/epidemiologia , Reação em Cadeia da Polimerase , DNA de Protozoário/genética , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologiaRESUMO
Until very recently, treatment for chronic hepatitis C virus (HCV) infection has been based on the combination of two non-viral specific drugs: pegylated interferon-α and ribavirin, which is effective in, overall, about 40%-50% of cases. To improve the response to treatment, novel drugs have been designed to specifically block viral proteins. Multiple compounds are under development, and the approval for clinical use of the first of such direct-acting antivirals in 2011 (Telaprevir and Boceprevir), represents a milestone in HCV treatment. HCV therapeutics is entering a new expanding era, and a highly-effective cure is envisioned for the first time since the discovery of the virus in 1989. However, any antiviral treatment may be limited by the capacity of the virus to overcome the selective pressure of new drugs, generating antiviral resistance. Here, we try to provide a basic overview of new treatments, HCV resistance to new antivirals and some considerations derived from a Public Health perspective, using HCV resistance to protease and polymerase inhibitors as examples.
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La infección crónica provocada por el virus de la hepatitis C (VHC) sigue siendo un gran problema de salud pública a nivel mundial, afecta a unos 200 millones de personas en el mundo. Se trata de la primera primera causa de trasplante y de muerte de origen hepático. La evolución natural de la enfermedad es el desarrollo de cirrosis y el riesgo de desarrollo de hepatocarcinoma. Es una enfermedad silenciosa, cuyo diagnóstico mediante la clínica supone detectarla en fases avanzadas. El diagnóstico inicial se realiza mediante la detección de anticuerpos anti-VHC y se confirma demostrando la replicación viral. La indicación de tratamiento se establece tras la evaluación del grado de fibrosis y el genotipo de VHC que ha infectado al paciente.
Chronic infection caused by the hepatitis C virus (HCV) continues to be a public health problem worldwide, affecting about 200 million people worldwide. This is the first leading cause of death and transplantation of hepatic origin. The natural course of the disease is the development of cirrhosis and hepatocellular carcinoma risk development. It is an silent disease, whose diagnosis by clinical signs supposed to detect in advanced stages. The initial diagnosis is made by detecting antibodies anti-HCV and confirmed by demonstrating viral replication. The indication for treatment is established after assessing the degree of fibrosis and HCV genotype has infected the patient.
Assuntos
Humanos , Masculino , Feminino , Adulto , Hepatite C , Epidemiologia Molecular , Transplante de Fígado , Cirrose Hepática , Neoplasias HepáticasRESUMO
Introducción: Los pacientes con insuficiencia renal crónica en tratamiento con hemodiálisis constituyen un grupo de riesgo para la infección con el virus de la hepatitis C. La infección por este virus representa la causa más frecuente de enfermedad hepática crónica en los hemodializados. Objetivo: Evaluar la prevalencia y realizar la caracterización de la infección por el virus de la hepatitis C en un grupo de pacientes en hemodiálisis de la ciudad de Posadas (Argentina). Materiales y métodos: Se evaluó la presencia del virus de la hepatitis C mediante enzimoin-munoanálisis en 113 muestras de sangre total obtenidas por venopunción de pacientes con insuficiencia renal crónica en tratamiento con hemodiálisis. En los casos positivos se confirmó la presencia de genoma viral por medio de una RT-PCR anidada de la región 5´ no codificante del virus de la hepatitis C y se determinó el genotipo y subtipo viral mediante análisis del polimorfismo de longitud de fragmentos de restricción. Resultados: De una población de 113 pacientes con insuficiencia renal crónica en tratamiento con hemodiálisis, el 89,4% (n = 101) de los casos fueron no reactivos para anticuerpos contra el virus de la hepatitis C mediante enzimoinmunoanálisis, mientras que el 10,6% (n = 12) de los casos fueron reactivos. Se confirmó el resultado reactivo en los 12 casos por RT-PCR, y se determinó la infección por genotipo 1a (7/12) y genotipo 2a (5/12). Conclusión: La prevalencia de la infección por el virus de la hepatitis C en este grupo de pacientes en hemodiálisis fue del 10,6%, y los genotipos virales del virus de la hepatitis C encontrados (1a y 2a) coinciden con los genotipos que prevalecen en la población infectada de Argentina.
Introduction: Patients with chronic renal failure on hemodialysis comprise a risk group for infection with hepatitis C. This viral infection is the most common cause of chronic liver disease in hemodialysis. Objective: To evaluate the prevalence and to characterise hepatitis C virus infection in a groupof patients from the city Posadas (Argentina) who are on hemodialysis. Materials and methods: The presence of the virus of hepatitis C was evaluated by enzymeimmuno assay of 113 samples of whole blood obtained from patients with chronic renal failure under going hemodialysis. In positive cases, the presence of the viral genome was confirmed byRT-nested PCR of the 5´-noncoding region of the hepatitis C virus, and the viral genotype and subtype were determined by restricted fragment length polymorphism analysis. Results: Of a population of 113 patients with chronic renal failure on hemodialysis, the detection of hepatitis C virus infection was performed by enzyme immunoassay, of which 89.4%(n = 101) of the cases were non-reactive, and 10.6% (n = 12) of cases were reactive. We confirmed the reactive results in 12 cases by RT-PCR, and we determined that these cases were genotype 1a (7/12) and genotype 2a (5/12). Conclusion: The prevalence of infection with hepatitis C virus in this group of patients onhemodialysis was 10.6%, and the hepatitis C virus genotypes found (1a and 2a) were the same as the prevalent genotypes in the infected population of Argentina.