Rol del virus sincicial respiratorio en una cohorte de adultos mayores / Respiratory Syncytial Virus in the elderly adults

El rol de los virus respiratorios distintos de influenza en las infecciones respiratorias agudas en los adultos mayores ha sido probablemente subestimado. En los últimos años, los avances en técnicas moleculares de diagnóstico han hecho posible la identificación rápida del virus sincicial respiratorio humano (HRSV). Realizamos un estudio prospectivo observacional para evaluar el rol del HRSV en mayores de 65 años que se hospitalizaron por infecciones respiratorias en nuestra institución, ubicada en la ciudad de La Plata, provincia de Buenos Aires. Fueron reclutados 124 pacientes y el HRSV se detectó en 13, influenza B en 9 e influenza A en 8. La presentación clínica más frecuente de los The role of respiratory viruses other than influenza in acute respiratory tract infections among elderly adults has probably been underestimated. Recent advances in molecular diagnosis have made the rapid identification of human respiratory syncitial virus HRSV infection possible. We conducted a prospective observational study to evaluate the role of HRSV in elderly patients (>65 years of age) hospitalized for acute respiratory infections. A total of 124 patients were recruited, HRSV infection was identified in 13 patients, Influenza B in 9 patients and influenza A in 8 patients. The most frequent clinical presentation was bronchospasm and the infection was prevalent in patients with comorbidities. HRSV infections accounted for an important number of hospital admissions and has been associated with high mortality rates (23%). pacientes con HRSV fue el broncoespasmo y afectó principalmente a personas con comorbilidades. HRSV fue responsable de un número importante de internaciones por enfermedad respiratoria aguda en mayores de 65 años en nuestra institución y se asoció a mortalidad elevada (23%).

The role of respiratory viruses other than influenza in acute respiratory tract infections among elderly adults has probably been underestimated. Recent advances in molecular diagnosis have made the rapid identification of human respiratory syncitial virus HRSV infection possible. We conducted a prospective observational study to evaluate the role of HRSV in elderly patients (>65 years of age) hospitalized for acute respiratory infections. A total of 124 patients were recruited, HRSV infection was identified in 13 patients, Influenza B in 9 patients and influenza A in 8 patients. The most frequent clinical presentation was bronchospasm and the infection was prevalent in patients with comorbidities. HRSV infections accounted for an important number of hospital admissions and has been associated with high mortality rates (23%).

Human metapneumovirus in Southern Brazil

INTRODUCTION Infections caused by respiratory viruses are important problems worldwide, especially in children. Human metapneumovirus (hMPV) is a respiratory pathogen and causes severe infections with nonspecific symptoms. This study reports the hMPV occurrence and dissemination in southern Brazil and compares the frequency of occurrence of this virus and the human respiratory syncytial virus (hRSV) in the epidemiological weeks in a three-year period (2009-2011). METHODS: In total, 545 nasopharyngeal (NP) specimens from individuals with Severe Acute Respiratory Syndrome (SARS) who were negative for other seven respiratory viruses were analyzed for the presence of hMPV. Human metapneumovirus was detected by direct immunofluorescence and real-time reverse transcription polymerase chain reaction. RESULTS: hMPV was detected in 109 patients from the main geographic regions of the southernmost state of Brazil, presenting similar overall prevalence in males (46.8%) and females (53.2%). Among children who were less than six years old, hMPV was detected in 99 samples of all age groups, with a higher frequency in infants who were less than one year old (45.7%) compared to all other age groups until six years. hMPV and hRSV infection occurred in almost the same epidemiological weeks (EWs) of each year, with peaks of incidence between EW 31/37 and EW 26/38 for the years 2009 and 2011, respectively. hMPV was further detected in several cases of SARS and it was the only virus detected in three deaths. CONCLUSIONS These findings indicate that hMPV is in circulation in southern Brazil and highlight the importance of diagnosing hMPV for influenza-like illness in the population. (AU)

Padrões de circulação temporal em vírus sincicial respiratório humano dos grupos A e B / Standards of temporal circulatory in human respiratory syncytial virus in groups A e B

O vírus respiratório síncicial humano é classificado em dois grupos principais, A e B. Ambos os grupos contêm múltiplas variantes, reconhecidas por anticorpos monoclonais e técnicas genéticas, notadamente sequenciamento. Com o intuito de caracterizar a epidemiologia molecular de cepas de vírus respiratório sincicial humano, foi realizado o sequenciamento de uma região variável do gene que codifica a proteína responsável pela ligação do respectivo vírus à célula em amostras colhidas durante 5 anos consecutivos em uma comunidade. A análise filogenética realizada identificou clades distintas (genotipos), subsequentemente divididos em subtipos, com base em similiaridade > 96 por cento a nível de nucleotídeo. Foram identificados cinco genotipos e 22 subtipos entre os 123 isolados de vírus respiratório sincicial humano do grupo A e quatro genotipos e seis subtipos entre os 81 isolados do grupo B. Um ou dois genotipos e subtipos representaram no mínimo 50 por cento dos isolados identificados em cada ano. Foi verificada uma altemância no genotipo e subtipo predominantes, circulantes em cada ano, sendo que nenhum genotipo ou subtipo predominou por mais de um ano nos cinco anos do estudo. A consistência na substituição das cepas predominantes sugere que um "shift", mesmo entre as cepas de um mesmo grupo, representaria uma vantagem evolutiva para o vírus. Postulamos que a "nova" cepa circulante em um determinado ano teria maior capacidade de evadir a imunidade previamente induzida a nível da população e consequentemente circular mais eficientemente. A altemância anual apresentada pelas cepas de vírus respiratório sincicial humano pode contribuir para a melhor capacidade do vírus em causar surtos anuais de doença respiratória. Nossos resultados também sugerem que a caracterização de vírus respiratório sincicial humano a nível de grupo e genotipo pode ser necessária para compreender melhor o papel da imunidade protetora, após a infecção natural pelo vírus, bem como para a avaliação dos estudos envolvendo a eficácia de vacinas contra o vírus