Analytical performance of the Alere(TM) i Influenza A&B assay for the rapid detection of influenza viruses / Evaluación del sistema Alere(TM) i Influenza A&B para la detección rápida de virus de la gripe

The analytical performance of the new Alere(TM) i Influenza A&B kit (AL-Flu) assay, based on isothermal nucleic acids amplification, was evaluated and compared with an antigen detection method, SD Bioline Influenza Virus Antigen Test (SDB), and an automated real-time RT-PCR, Simplexa(TM) Flu A/B & VRS Direct assay (SPX), for detection of influenza viruses. An ‘in-house’ RT-PCR was used as the reference method. Sensitivity of AL-Flu, SDB, and SPX was 71.7%, 34.8%, and 100%, respectively. Specificity was 100% for all techniques. The turnaround time was 13min for AL-Flu, 15min for SDB, and 75min for SPX. The Alere(TM) i Influenza A&B assay is an optimal point-of-care assay for influenza diagnosis in clinical emergency settings, and is more sensitive and specific than antigen detection methods (AU)

Se evaluó el nuevo ensayo Alere(TM) i Influenza A&B kit (AL-Flu), basado en la amplificación isotérmica de ácidos nucleicos, y se comparó con un método de detección de antígeno, SD Bioline Influenza Virus Antigen Test (SDB), y con una RT-PCR en tiempo real automática, Simplexa(TM) Flu A/B & VRS Direct assay (SPX), para la detección de virus de la gripe. Se utilizó una RT-PCR en tiempo real casera como método de referencia. La sensibilidad de AL-Flu, SDB y SPX fue del 71,7%, del 34,8% y del 100%, respectivamente. Se obtuvo una especificidad del 100% con todos los métodos. El tiempo de realización fue de 13min para AL-Flu, de 15min para SDB y de 75min para SPX. El ensayo Alere(TM) i Influenza A&B es óptimo para el diagnóstico de gripe en unidades de urgencias, al ser más sensible y específico que las técnicas de detección de antígeno (AU)

¿Es gripe todo lo que clínicamente parece gripe? / Is flu all that which clinically appears as flu?

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Diagnosis and clinic-pathological findings of influenza virus infection in Brazilian pigs / Diagnóstico, achados clínicos e patológicos da infecção pelo vírus influenza em suínos no Brasil

Influenza A virus (IAV) is a respiratory pathogen of pigs and is associated with the porcine respiratory disease complex (PRDC), along with other respiratory infectious agents. The aim of this study was to diagnose and to perform a clinic-pathological characterization of influenza virus infection in Brazilian pigs. Lung samples from 86 pigs in 37 farrow-to-finish and two farrow-to-feeder operations located in the States of Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Santa Catarina, and Mato Grosso were studied. Virus detection was performed by virus isolation and quantitative real time reverse-transcription PCR (qRT-PCR). Pathologic examination and immunohistochemistry (IHC) were performed in 60 lung formalin-fixed paraffin-embedded tissue fragments. Affected animals showed coughing, sneezing, nasal discharge, hyperthermia, inactivity, apathy, anorexia, weight loss and growth delay, which lasted for five to 10 days. Influenza virus was isolated from 31 (36.0%) lung samples and 36 (41.9%) were positive for qRT-PCR. Thirty-eight (63.3%) lung samples were positive by IHC and the most frequent microscopic lesion observed was inflammatory infiltrate in the alveoli, bronchiole, or bronchi wall or lumen (76.7%). These results indicate that influenza virus is circulating and causing disease in pigs in several Brazilian states.

O vírus influenza A (IAV) é um patógeno respiratório comum de suínos e faz parte do complexo de doenças respiratórias do suíno (PRDC) junto com outros agentes infecciosos. O objetivo deste estudo foi diagnosticar e realizar a caracterização clínica e patológica de casos/surtos de influenza em suínos brasileiros. Foram utilizadas amostras de tecido pulmonar de 86 suínos de 37 granjas de ciclo completo e duas unidades produtoras de leitões localizadas em Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Santa Catarina e Mato Grosso. A detecção viral em fragmentos pulmonares frescos foi realizada através do isolamento viral e da transcrição reversa-PCR em tempo real quantitativa (qRT-PCR). Exame patológico e imuno-histoquímica (IHQ) foram realizados em 60 amostras de pulmão fixadas em formalina 10% e embebidas em parafina. As amostras eram de animais apresentando tosse, espirros, secreção nasal, hipertermia, prostração, apatia, anorexia, perda de peso e ganho de peso reduzido, com duração entre cinco e 10 dias. O vírus influenza foi isolado de 31 (36,0%) amostras e 36 (41,9%) foram positivas na qRT-PCR. Na IHQ, 38 (63,3%) amostras foram positivas e a lesão mais frequentemente observada foi a presença de infiltrado inflamatório na parede e lúmen de vias aéreas (76,7%). Estes resultados indicam que o vírus influenza está circulando e causando lesões e doença respiratória em suínos de diversos Estados do Brasil.

Orientações para o diagnóstico de influenza em suínos / Guidelines for diagnosis of swine influenza

Este trabalho descreve a colheita adequada de amostras, as técnicas/procedimentos disponíveis para o diagnóstico de influenza A em suínos, assim como os resultados e suas respectivas interpretações, para auxiliar médicos veterinários de campo na identificação dessa doença. Em suínos vivos, as amostras adequadas são: secreção nasal, fluido oral e sangue (soro). Para suínos mortos, colher preferencialmente amostras de pulmão com consolidação cranioventral. Secreção nasal e fragmentos de pulmão refrigerado são utilizados para detectar partícula viral viável (isolamento viral - IV) ou ácido nucleico viral (RT-PCR convencional e RT-PCR em tempo real). As amostras não devem ser congeladas, pois o vírus é inativado a -20°C. A caracterização molecular dos isolados é feita pela análise filogenética obtida pelo sequenciamento de DNA. O soro é utilizado para a detecção de anticorpos (Acs) por meio do teste da inibição da hemaglutinação e ELISA. O fluido oral pode ser utilizado para detecção de anticorpo (ELISA) ou de vírus. Fragmentos de pulmão fixados em formol a 10% são examinados microscopicamente para identificar pneumonia broncointersticial e para detecção de antígeno viral pela imuno-histoquímica (IHQ). Para o sucesso do diagnóstico, as amostras devem ser colhidas de suínos que estão preferencialmente na fase aguda da doença, para aumentar as chances de detecção viral. As melhores opções para o diagnóstico de influenza A em suínos vivos são RT-PCR e isolamento viral de amostras de swab nasal ou fluido oral. Pulmão para análise por RT-PCR, isolamento viral ou IHQ é a amostra de escolha em suínos mortos. Testes sorológicos têm valor diagnóstico limitado e são utilizados apenas para determinar o estado imune do rebanho, não indicando doença clínica, pois os Acs são detectados 7-10 dias pós-infecção (fase subaguda). O diagnóstico de influenza é importante para avaliar o envolvimento desse agente no complexo de doença respiratória suína. Além disso, o isolamento do vírus influenza é essencial para o monitoramento dos principais subtipos circulantes em uma determinada região ou país, assim como para a detecção de novos rearranjos virais, já que influenza é considerada uma zoonose.

This article is intended to describe the adequate sample collection, the laboratory procedures/techniques, the expected results and their interpretation for diagnosis of influenza infection in swine, serving as a support for field veterinarians. In live pigs, the samples to be taken are nasal secretions, oral fluids and blood. For dead pigs, preference should be given to samples of cranioventral lung consolidation. Nasal discharge and chilled lung fragments are used for detection of virus (virus isolation - VI) or viral nucleic acids (conventional RT-PCR and real-time RT-PCR). Samples should not be frozen, because the virus is inactivated at -20°C. Molecular characterization of isolates is performed by phylogenetic analysis of gene sequences obtained by DNA sequencing. Serum is used for the detection of antibodies using hemagglutination inhibition (HI) test and ELISA. Oral fluid may be used for either antibody (ELISA) or viral detection. Fragments of lung fixed in 10% formaldehyde are used for histopathological analysis to identify bronchointerstitial pneumonia, and for immunohistochemistry (IHC) for antigens. For a successful diagnosis, sampling should be preferably performed in the acute phase of the disease to improve chances of virus detection. The best options to perform the diagnosis of influenza A in a swine herd are RT-PCR and VI from nasal swabs or oral fluid in live pigs and/or lung tissue for RT-PCR, VI or IHC in dead pigs. Serological tests are of very limited diagnostic value and are useful only to determine the immune status of the herd, not indicating clinical disease, because antibodies are detected after 7-10 days post infection (subacute phase). The diagnosis of influenza is important to evaluate the involvement of this agent in the complex of respiratory diseases in pigs. Furthermore, the isolation of influenza virus is essential for monitoring the main subtypes circulating in a given region or country, as well as for the detection of potential new viral reassortants, because influenza is considered a zoonosis.

Rentabilidad de las muestras respiratorias pediátricas en la red centinela de vigilancia de la gripe en las Islas Baleares / Diagnostic yield of paediatric respiratory samples in the Balearic Islands Sentinel Influenza Surveillance Network

Introducción: La gripe es una enfermedad mundialmente vigilada a través de las redes centinela (RC) que predicen el comportamiento epidemiológico y comunican los datos clínicos y virológicos. Objetivos: Evaluar la rentabilidad de las muestras respiratorias pediátricas en la RC de las Islas Baleares en las últimas 5 temporadas gripales. Material y pacientes: Se tomó un frotis faríngeo para cultivo vírico de los pacientes que cumplían los criterios de gripe. Se inocularon las muestras en la línea celular MDCK. Se revisaron los datos epidemiológicos de cada paciente con cultivo positivo para los virus gripales A y B. Resultados: Durante el período de estudio se analizaron 338 frotis faríngeos de la RC. De éstos, 65 (19,3%) pertenecían a menores de 14 años. El 44,6% de estas muestras fueron positivas frente al 39,1% de las muestras de adultos. El virus gripal A se aisló en 24 muestras pediátricas (82,7%) y el virus gripal B se aisló en 5 muestras (17,3%). La edad media de los pacientes positivos de la RC fue de 8,5 años. En el grupo de 0 a 4 años sólo fueron positivos 3 pacientes (10,3%) y en el grupo de 5 a 14 años fueron positivos 26 pacientes (89,7%). Conclusiones: A pesar de que los pediatras sólo representan el 22% de los médicos de la RC y aportan el 19,3% de las muestras, el porcentaje de positividad y rentabilidad de éstas es superior al de la población adulta (AU)

Introduction: Influenza disease is subjected to surveillance by national networks (RC) that predict the epidemic behaviour by reporting clinical and virological data. Objectives: To evaluate the effectiveness of the paediatric respiratory samples in the Balearic Islands RC in the last five epidemic seasons. Material and patients: A breath sample was taken from paediatric patients in the RC who had flu symptoms. The samples were inoculated in the MDCK cell line. We reviewed the epidemiological data of patients with a culture positive to influenza A and B. Results: A total of 338 pharyngeal swabs from the RC were analysed during the study period. Of these, 65 (19.3%) belonged to <14 years old patients, and 44.6% of the samples were positive as opposed to 39.1% of adult respiratory samples. The influenza A virus was isolated in 24 paediatric samples (82.7%) and the influenza B virus in 5 (17.3%). The mean age of the paediatric patients of the RC who were positive was 8.5 years. Only 3 patients in the 0–4 year old group were positive (10.3%) and 26 patients (89.7%) in the 5–14 years old group. Conclusions: In spite that paediatricians represented only 22% of the RC doctors and obtain the 19.3% of all respiratory samples, the percentage and effectiveness of these is higher that obtained in the adult population (AU)

Impact of respiratory infections by influenza viruses A and B in pediatrics patients from Federal University of Paraná, Brazil

The objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. We retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. A total of 1,033 samples were analyzed, 45 (4.3 percent) of them being reactive to influenza virus. Thirty-one samples were positive to influenza A virus and 14 to influenza B. The frequency of hospitalization in intensive care and medical emergency was found to be high. Three (8.6 percent) patients died, two of them due to respiratory failure. Low frequency of influenza virus infection was observed in the study. The data suggest the need of more efficient epidemiological surveillance measures in order to obtain reliable information to better assess the impact of the virus on our region and determine the need of preventive measures, such as immunization.

Evolución de los grupos de edad y edad media de los pacientes pediátricos infectados por los virus gripales A y B durante el periodo 1995-2005 / Evolution of the age groups and mean age of the pediatric patients infected by influenza virus A and B during the period 1995-2005

Se ha realizado un estudio prospectivo sobre la evolución de los diferentes grupos de edad y edad media de los pacientes pediátricos (0,05). El subtipado de los virus influenza A ha demostrado que 271 (86,8%) pertenecían al subtipo H3 y 41 (13,2%) al subtipo H1 (p<0,05). La edad media de los pacientes estudiados ha sido de 20,7 meses (intervalo 11 días y 15 años). El 73,8% de los pacientes presentaron una edad situada entre 0-2 años (p<0,05), 14,1% entre 2-5 años, 6,1% entre 6-10 años y 6% entre 11-15 años. El porcentaje medio de pacientes entre 0-5 meses ha sido el 24,8% (intervalo 11,1%-47,3%)y de entre 6-23 meses del 29,9% (intervalo 13,6-58,6%). La circulación del virus influenza B/Hong Kong/330/01 en la temporada 2003-2004 determinó unincremento significativo de la edad media de los pacientes (55,2 meses). La posible aplicación de las nuevas recomendaciones para la vacuna antigripal (mujeres embarazadas en el segundo-tercer trimestre y niños sanos entre 6-23 meses) podría determinar una disminución teórica del 65,2% de todos los casos de infección gripal

We report a prospective study about the evolution of different age groups and median age in pediatric patients (under 15 years) with influenza infection detected in ten consecutive flu epidemics (1995-2005). All respiratory samples were submitted to antigen detection and influenza A and B viral isolation (MDCK cell culture). In this period we studied 10.937 respiratory samples; 4.6% were positive for influenzaciruses (3.5% influenza A and 1.1% influenza B). We studied 414 patients, 234 (56,5%) boys and 180 (43.5%) girls. We detected 312 (75.4%) patients with influenza A and 102 (24.6%) with influenza B (p>0.05). The influenza A subtypes detected were 271 (86.8%) H3 and 41 (13.2%) H1 (p<0.05). The median age of patients was 20.7 months (range 11 days to 15 years (pz0.05)), 14,1% between 2-5 years, 6,1% between 6-10 years and 6% between 11-15 years. the median percentage of patients between 0-5 months was 24.8% (range 11.1%-58.6%). The circulation of influenza B/Hong Kong/330/01 virus in the period 2003-2004 was the main cause of increase in the median age of patients (55.2 months). The application of new anti-flu vaccination recommendations (pregnant women second-third trimester and healthy young children between 6-23 months) could theoretically decrease the 65.2% of all pediatric patients with influenza virus infections

Rabdomiólisis severa por influenza A / No disponible

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