Teste de imunofluorescência indireta para a detecção de anticorpos contra o vírus da encefalite St.Louis

An in house indirect immmunofluorescence assay ( IFA ) in relation to neutralization (NT) reference test, was assessed as a fast and cheap method to carry out serological surveys for St. Louis Encephalitis virus (SLE). Sera obtained from 213 blood donors were analyzed by both tests. The prevalence of seropositivity obtained with IFA was lower than (30.98%) that observed on NT (41.78%). The relative specificity rate of IFA was 96.77% whereas its relative sensitivity rate was 69.66%. Kappa index showed a good correlation between both tests. The results indicate that neutralization assay is still the serological test with the highest sensitivity and specificity relative rates for detecting antibodies against SLE virus. Nevertheless, the IFA could be useful as an alternative test in order to learn the circulation of the Flavivirus genus in a certain area.Com a finalidade de dispor de um método rápido e de baixo custo para realizar estudos séricos dirigidos ao virus da encefalite St.Louis (ESL), avaliamos a técnica de imunofluorescência indireta (IFI) artesanal em relação ao teste referência de neutralização (NT). Examinaram-se 213 soros de doadores de sangue. A prevalência dos anticorpos obtidas na técnica de IFI (30,98%) foi mais baixa do que a pesquisada com NT (41,78%). A taxa de especificidade relativa da IFI foi 96,77%, enquanto sua taxa de sensibilidade relativa foi 69,66%. O índice Kappa demonstrou boa concordância entre os dois testes. Os resultados achados revelam que a NT continua sendo a técnica sorológica de maior taxa de especificidade e sensibilidade relativa para a detecção de anticorpos IgG para o vírus ESL. Contudo, a IFI poderia ser o teste de escolha em estudos da circulação desta arbovirose na população humana

Estudo da prevalência para vírus da encefalite St. Louis relacionado com a idade em uma população de Córdoba, Argentina

A serological screening was performed in 615 individuals aged 0-87 years, living in the city of Cordoba, Argentina to study the relationship between antibody prevalence for the SLE virus and age. A 13.98% prevalence of neutralizing antibodies was obtained and its relation to age was significantly high (p = 0.045). The highest seroprevalence was noted on individuals over 60 years old (>;20%), whereas no subject under 10 was seropositive for this virus. Our results confirm that the agent is endemic in this area and neurological pathology studies should be performed on those individuals aged 60 since they represent the most susceptible group to SLE virus.Com a finalidade de estudar a relação entre prevalência de anticorpo para o vírus da encefalite St. Louis (ESL) e a idade, foram analisados 615 soros de indivíduos entre 0-87 anos de idade, morando na cidade de Córdoba, Argentina. Detectou-se uma prevalência de anticorpos neutralizantes de 13,98% e observou-se uma relação com a idade estatisticamente significante (p = 0,045). A soroprevalência mais alta foi encontrada em indivíduos de mais de 60 anos (>; 20%), enquanto nenhum com menos de 10 anos foi soropositivo para este vírus. Nossos resultados confirmam que o agente é endêmico nesta área. Por esse motivo os autores sugerem que deveríam se realizar estudos de patologias neurológicas nesses indivíduos de 60 anos de idade dado que eles representam o grupo mais suscetível ao vírus ESL

Determination of antibodies to Flavivirus in wild birds from Buenos Aires City

Saint Louis encephalitis virus (SLEV), West Nile virus (WNV) and Ilheus virus (ILHV) are flaviviruses maintained in nature by enzootic transmission networks between mosquitoes and birds. These viruses have been detected in South America and identified as a cause of neurological diseases in humans. There is a record of activity in monkeys and birds for ILHV in Chaco, Corrientes and Misiones; of WNV in horses and birds in the center and east of the country, while SLEV is widely distributed in Argentina and there is virological and serological evidence in birds, humans and various mammals. In order to detect viral circulation in free-living birds in the Autonomous City of Buenos Aires (CABA), seasonal sampling was carried out in the Costanera Sur Ecological Reserve.Para acceder a la videoconferencia completa, hacer clic en "Enlace externo".Sociedad Latinoamericana de Ecología de Vectore

Virus UNA: primeiro registro de infecção em humanos na República Argentina

Una virus (UNAV), Togaviridae family, is widely distributed in South America, where infections have been detected in mosquitoes and vertebrate hosts (humans, birds and horses). We analyzed human sera from Córdoba inhabitants aged 44 to 89 years and using a neutralization test, we found a prevalence of UNAV antibodies of 3.8% (3/79). The low titers detected suggest past infections probably acquired in rural areas of the Province of Córdoba (central Argentina). None sera were found positive for MAYV neutralizing antibodies. This is the first report of human infections by UNAV in Argentina.O virus Una (Togaviridae) tem ampla distribuição na América do Sul, detectando-se infecções até hoje em mosquitos e hospedeiros vertebrados (humanos, aves e cavalos). Mediante a realização do teste de neutralização em soros humanos provenientes de indivíduos entre 44 e 89 anos, da cidade de Córdoba, foi detectada uma prevalência de 3,8% (3/79) de anticorpos para o vírus UNA. Nenhum soro apresentou anticorpos para o vírus Mayaro. Os títulos foram baixos demonstrando-se a presença de infecção passada. Dados epidemiológicos indicam que a infecção ocorreu em áreas rurais da província de Córdoba (centro da Argentina). Os dados aqui expostos representam o primeiro registro de infecção de humanos por vírus Una na República Argentina

Infección de macrófagos con virus encefalitis saint louis: efecto sobre el fenotipo celular y la apoptosis (Programa: enfermedades transmisibles y emergentes).

El Virus Encefalitis Saint Louis (VESL)es un virus neurotrópico que puede provocar en humanos encefalitis, meningitis y cefalea febril. Estudios epidemiológicos demostraron la circulación del virus en Argentina, reportándose el primer brote de encefalitis en Sud-América en Córdoba en el 2005. Los macrófagos tienen un rol muy importante en la patogénesis de las infecciones virales. Estas células son permisivas para la replicación y reservorio viral. Reconocen a los virus mediante receptores de reconocimiento de patrones, incluidos los receptores Toll-like, lo que genera la producción de moléculas antivirales y citoquinas pro-inflamatorias. Los macrófagos expresan diferentes fenotipos según el microambiente tisular y el estímulo externo. Se reconocen los macrófagos activados clásicamente (M1) que liberan citoquinas pro-inflamatorias y los macrófagos activados alternativamente (M2) que producen IL-10 y factor transformante del crecimiento. Como parte de la respuesta del macrófago a la infección viral, prolifera, se diferencia y muere. La apoptosis es un mecanismo de muerte que limita la actividad del macrófago activado. La interacción virus-macrófago ha sido analizada con numerosos tipos de virus. Sin embargo, existe escasa información sobre el impacto de VESL sobre la respuesta inmune innata. La emergencia de esta virosis en nuestro medio amerita abordar distintos aspectos de la respuesta inmune en esta infección. Este proyecto tiene como objetivo estudiar la interacción VESL-macrófago para esclarecer el rol del fenotipo celular y su relación con la depuración viral. Además, analizar la naturaleza y el tenor de los inmunomoduladores liberados y el papel de la apoptosis de los macrófagos en esta infección

Expresión y purificación de la proteína NS1 de SLEV y WNV

2 p.La familia Flaviviridae está compuesta por un alto número de integrantes que se agrupan antigénicamente en complejos bien definidos. El virus de la encefalitis de Saint Louis (SLEV) integra el complejo de la Encefalitis Japonesa, constituyéndose como una zoonosis emergente de importancia sanitaria en nuestro país [1]. Por otro lado, nuestro país enfrenta la emergencia del Flavivirus West Nile (WNV) [2], que ha demostrado tener éxito en el desplazamiento de SLEV en el hemisferio norte. En una infección secuencial con Flavivirus la respuesta inmune del paciente por IgG se detecta en el comienzo de los síntomas, observándose una mayor reactividad cruzada entre virus relacionados. Estas reacciones serológicas cruzadas deben ser resueltas mediante complejos ensayos con una batería de virus del mismo género circulantes en la región. Sin embargo, los resultados serológicos resultantes de infecciones secundarias frecuentemente son indeterminados o de difícil interpretación [3]. Esta situación plantea la necesidad de desarrollar métodos de diagnóstico sencillos que permitan diferenciar una infección producida por estos agentes virales. El objetivo de este trabajo se centra en el clonado y expresión de la proteina NS1 de SLEV y WNV para generar antígenos recombinantes que permitan establecer un ensayo serológico claro y preciso para determinar la identidad del agente etiológico que da lugar a un cuadro de infección relacionado con Flavivirus.Fil: Lorch, Matías Sebastián. Universidad Nacional de Quilmes. Instituto de Microbiología Básica y Aplicada. Laboratorio de Ingeniería Genética y Biología Celular y Molecular. Área de Virosis Emergentes y Zoonóticas; ArgentinaFil: Stephan, Betina. Universidad Nacional de Quilmes. Instituto de Microbiología Básica y Aplicada. Laboratorio de Ingeniería Genética y Biología Celular y Molecular. Área de Virosis Emergentes y Zoonóticas; ArgentinaFil: Spinsanti, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Laboratorio de Arbovirus, Instito de Virología “Dr. Carlos Vanella"; Argentina.Fil: Lozano, Mario. Universidad Nacional de Quilmes. Instituto de Microbiología Básica y Aplicada. Laboratorio de Ingeniería Genética y Biología Celular y Molecular. Área de Virosis Emergentes y Zoonóticas; Argentina.Fil: Goñi, Sandra. Universidad Nacional de Quilmes. Instituto de Microbiología Básica y Aplicada. Laboratorio de Ingeniería Genética y Biología Celular y Molecular. Área de Virosis Emergentes y Zoonóticas; ArgentinaFil: Pubul Martín, Priscila. Universidad Nacional de Quilmes. Instituto de Microbiología Básica y Aplicada. Laboratorio de Ingeniería Genética y Biología Celular y Molecular. Área de Virosis Emergentes y Zoonóticas; ArgentinaEnfermedades Infecciosa

The extent of infectious SARS-CoV-2 shedding in an Argentinean cohort

Background: To analyze the infectious extent of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in different settings where prevention strategies are critical to limit infection spread, we evaluated SARS-COV-2 viability to guide public health policies regarding isolation criteria and infection control. Methods: We attempted viral isolation in 82 nasopharyngeal swabs from 72 patients with conrmed SARS-COV-2 infection. Study population was divided into four groups: (i) Patients during the rst week of symptoms; (ii) Patients with prolonged positive PCR; (iii) Healthcare workers from a hospital participating of an outbreak investigation, with SARS-COV-2 infection conrmed by reverse transcriptase polymerase chain reaction (RT-PCR) and (iv) Recipients of convalescent immune plasma (CIP). Vero Cl76 cell-line (ATCC CRL-587) was used in assays for virus isolation. Plasma samples of CIP recipients were also tested with plaque-reduction neutralization test. Results: We obtained infectious SARS-COV-2 isolates from 15/84 nasopharyngeal swabs. The virus could not be isolated from upper respiratory tract samples collected 10-day after onset of symptoms (AOS) in patients with mild–moderate disease. Conclusion: The knowledge of the extent of SARS-CoV-2 infectivity AOS is relevant for effective prevention measures. This allows to discuss criteria for end isolation despite persistence of positive PCR and improve timing for hospital discharge with consequent availability of critical beds.publishedVersionFil: Blanco, Sebastián. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Aguilar, Juan Javier. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Konigheim, Brenda Salomé. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Konigheim, Brenda Salomé. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Diaz, Luis Adrián. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Diaz, Luis Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Spinsanti, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Beranek, Mauricio. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Beranek, Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Collino, César. Hospital Guillermo Rawson, Córdoba; Argentina.Fil: Diaz, Miguel. Hospital Guillermo Rawson, Córdoba; Argentina.Fil: Barbás, María Gabriela. Ministerio de Salud de la Provincia de Córdoba. Secretaria de Prevención y Promoción de la Salud; Argentina.Fil: Gallego, Sandra Verónica. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Virología Dr. José María Vanella; Argentina.Fil: Gallego, Sandra Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Assessment of arboviruses circulation in wild rodents and birds in the Upper Paraná Atlantic Forest

Arboviruses are transmitted by hematophagous arthropods, many of them of sanitary importance for their impact on health, economy and their wide geographic distribution. In the sylvatic cycle, different wild vectors and hosts are involved. Some of these viruses belong to the Flavivirus and Alphavirus genera and are transmitted by different species of mosquitoes. Several wild vertebrates participate in the sylvatic cycles of these viruses as main or alternative hosts. Our aim was to evaluate the circulation of Flavivirus and Alphavirus genera in the Upper Paraná Atlantic Forest (UPAF) of Misiones, Argentina.Para acceder a la videoconferencia completa, hacer clic en "Enlace externo".Sociedad Latinoamericana de Ecología de Vectore

The impact of Nursing Homes staff education on end-of-life care in residents with advanced dementia: a quality improvement study

Context. End-of-life care in nursing homes (NHs) needs improvement. We carried out a study in 29 NHs in the Lombardy Region (Italy).Objectives. The objective of this study was to compare end-of-life care in NH residents with advanced dementia before and after an educational intervention aimed to improving palliative care.Methods. The intervention consisted of a seven-hour lecture, followed by two 3-hour meetings consisting of case discussions. The intervention was held in each NH and well attended by NH staff. This multicenter, comparative, observational study included up to 20 residents with advanced dementia from each NH: the last 10 who died before the intervention (preintervention group, 245 residents) and the first 10 who died at least three months after the intervention (postintervention group, 237 residents). Data for these residents were collected from records for 60 days and seven days before death.Results. The use of "comfort hydration" (< 1000 mL/day subcutaneously) tended to increase from 16.9% to 26.8% in the postintervention group. The number of residents receiving a palliative approach for nutrition and hydration increased, though not significantly, from 24% preintervention to 31.5% postintervention. On the other hand, the proportion of tube-fed residents and residents receiving intravenous hydration decreased from 15.5% to 10.5%, and from 52% to 42%, respectively. Cardiopulmonary resuscitations decreased also from 52/245 (21%) to 18/237 (7.6%) cases (P = 0.002).Conclusion. The short educational intervention modified some practices relevant to the quality of end-of-life care of advanced dementia patients in NHs, possibly raising and reinforcing beliefs and attitudes already largely present. (C) 2018 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved