Community-acquired respiratory viruses and co-infection among patients of Ontario sentinel practices, April 2009 to February 2010.

Respiratory viruses are known to cocirculate but this has not been described in detail during an influenza pandemic. To describe respiratory viruses, including co-infection and associated attributes such as age, sex or comorbidity, in patients presenting with influenza-like illness to a community sentinel network, during the pandemic A(H1N1)pdm09 in Ontario, Canada. Respiratory samples and epidemiologic details were collected from 1018 patients with influenza-like illness as part of respiratory virus surveillance and a multiprovincial case-control study of influenza vaccine effectiveness. At least one virus was detected in 668 (65·6%) of 1018 samples; 512 (50·3%) had single infections and 156 (15·3%) co-infections. Of single infections, the most common viruses were influenza A in 304 (59·4%) samples of which 275 (90·5%) were influenza A(H1N1)pdm09, and enterovirus/rhinovirus in 149 (29·1%) samples. The most common co-infections were influenza A and respiratory syncytial virus B, and influenza A and enterovirus/rhinovirus. In multinomial logistic regression analyses adjusted for age, sex, comorbidity, and timeliness of sample collection, single infection was less often detected in the elderly and co-infection more often in patients <30 years of age. Co-infection, but not single infection, was more likely detected in patients who had a sample collected within 2 days of symptom onset as compared to 3-7 days. Respiratory viral co-infections are commonly detected when using molecular techniques. Early sample collection increases likelihood of detection of co-infection. Further studies are needed to better understand the clinical significance of viral co-infection.

Peci A ，Winter AL ，Gubbay JB ，Skowronski DM ，Balogun EI ，De Lima C ，Crowcroft NS ，Rebbapragada A ... -  《-》

Influenza and respiratory syncytial virus are the major respiratory viruses detected from prospective testing of pediatric and adult coronial autopsies.

To ascertain the full mortality of influenza and other respiratory viruses, the testing of community autopsy specimens is essential. Respiratory virus PCR and culture were performed on 2418 fresh unfrozen respiratory samples collected from 1611 coronial cases where the death was either unknown or infection was suspected, from July 2007 to June 2011, to detect the common respiratory viruses in children and adults, using standardized microbiological testing. The respiratory virus positive rate was 8·3% (134 cases) with a peak of 28% (42 of 151 cases) in children under 10 years of age. Influenza virus was the commonest respiratory virus (50 cases, 3%), followed by respiratory syncytial virus (RSV) (30 cases, 2%). All tested respiratory viruses were found in children, most commonly adenovirus, enterovirus and RSV, and influenza A and RSV predominated in those over 60 years, but coinfection was uncommon. Almost all influenza cases occurred when influenza was widely circulating in the community but few were diagnosed pre-mortem. Influenza and RSV detection was associated with bronchitis or bronchiolitis in 7 (9%) of the 80 cases and caused pneumonia in 14 (0·8%) deaths overall. Our prospective review of respiratory viruses using standardized testing found a single lower respiratory tract autopsy specimen for respiratory virus PCR would detect most community infections at the time of death.

Speers DJ ，Moss DM ，Minney-Smith C ，Levy A ，Smith DW ... -  《-》

Influenza A viruses dual and multiple infections with other respiratory viruses and risk of hospitalisation and mortality.

Recent literature suggests that dual or multiple virus infections may affect disease severity. However, few studies have investigated the effect of co-infection with influenza A viruses. To identify the association between influenza A and respiratory viruses co-infections with disease outcome. Data for samples from North West England tested between January 2007 and June 2011 was analysed for patterns of co-infection between influenza A viruses and eight respiratory viruses. Risk of hospitalisation to ICU or general ward in single versus co-infections was assessed using logistic regression. Of the 25,596 samples analysed for respiratory viruses 40·7% (10,501) were positive for any virus. Co-infections were detected in 4·7% (137/2879) of all patients with influenza A(H1N1)pdm09, and 7·3% (57/779) of those with other influenza A virus infections. Co-infection between seasonal influenza A viruses and influenza B virus was associated with a significant increase in the risk of admission to ICU/death (OR: 22·0, 95% CI: 2·21-219·8, P=0·008). Respiratory syncytial virus/influenza A (RSV/Flu A) co-infection also increased this risk but was not statistically significant. For influenza A(H1N1)pdm09, RSV and AdV co-infection increased risk of hospitalisation to general ward whereas Flu B increased risk of admission to ICU, but none of these were statistically significant. Co-infection is a significant predictor of disease outcome; combined treatment, introduction of an integrated vaccine for all respiratory viruses and development of multi-target rapid diagnostic tests is recommended. Integration of respiratory viruses' co-infections into public health reports could also contribute to the accumulation of evidence.

Goka E ，Vallely P ，Mutton K ，Klapper P ... -  《-》

Respiratory viral infections during the 2009-2010 winter season in Central England, UK: incidence and patterns of multiple virus co-infections.

Tanner H ，Boxall E ，Osman H 《-》

Impact of viral infections in children with community-acquired pneumonia: results of a study of 17 respiratory viruses.

Little is known about the prevalence of viral infections in children with community-acquired pneumonia (CAP). To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom 17 respiratory viruses were sought in respiratory secretion samples during the acute phase of the disease. The study involved 592 children with radiographically confirmed CAP whose respiratory secretion samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which simultaneously detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV)-A and -B, parainfluenzavirus-1, -2, -3, and -4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus/rhinovirus, and bocavirus. A real-time PCR assay was used to identify the rhinovirus in the enterovirus/rhinovirus-positive samples. A total of 435 children (73·5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31·7%), followed by rhinovirus (n = 144, 24·3%), bocavirus (n = 60, 10·1%), influenza viruses (n = 57, 9·6), and hMPV (n = 49, 8·2%). Viral co-infections were found in 117 children (19·7% of the enrolled children; 26·9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co-infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections (OR 1·72, 95% CI 1·05-2·81). The findings of this study highlight the importance of respiratory viruses (mainly RSV and rhinovirus) in children with CAP and show the characteristics of both the single infections and co-infections associated with the disease.

Esposito S ，Daleno C ，Prunotto G ，Scala A ，Tagliabue C ，Borzani I ，Fossali E ，Pelucchi C ，Principi N ... -  《-》