Respiratory infection in institutions during early stages of pandemic (H1N1) 2009, Canada

Critical evaluation of FDA-approved respiratory multiplex assays for public health surveillance

Introduction: Clinical management and identification of respiratory diseases has become more rapid and increasingly specific due to widespread use of PCR(polymerase chain reaction) multiplex technologies. Although significantly improving clinical diagnosis, multiplexed PCR assays could have a greater impact on local and global disease surveillance. The authors wish to propose methods of evaluating respiratory multiplex assays to maximize diagnostic yields specifically for surveillance efforts.

Areas covered: The authors review multiplexed assays and critically assess what barriers have limited these assays for disease surveillance and how these barriers might be addressed. The manuscript focuses specifically on the case study of using multiplexed assays for surveillance of respiratory pathogens. The authors also provide a method of validation of specific surveillance measures.

Expert commentary: Current commercially available respiratory multiplex PCR assays are widely used for clinical diagnosis; however, specific barriers have limited their use for surveillance. Key barriers include differences in testing phase requirements and diagnostic performance evaluation. In this work the authors clarify phase testing requirements and introduce unique diagnostic performance measures that simplify the use of these assays on a per target basis for disease surveillance.

Human metapneumovirus prevalence and molecular epidemiology in respiratory outbreaks in Ontario, Canada

Human metapneumovirus (hMPV) has been identified previously as a cause of respiratory outbreaks in adults, including the elderly. The objective of this study was to document respiratory outbreaks that were caused by hMPV in Ontario, Canada and to identify the various circulating genotypes during April 2009–February 2012. The majority of the outbreaks that were part of this study were in adults (>65 years). Total nucleic acid extraction was done on 123 residual anonymized clinical specimens from 51 different respiratory outbreaks. Specimens were subjected to PCR amplification and Sanger sequencing targeting the F and G genes of hMPV. Phylogenetic analysis was performed to identify genotypes. HMPV accounted for 195 (8.5%) of 2,292 respiratory outbreaks. Genotype A2b was most prevalent, detected in 28 (54.9%) of 51 typed hMPV‐positive outbreaks. The genotype A2b2 that was described recently was also identified. In earlier reports, subtype A1 was reported in Canada which was absent in the specimens typed in this study. This shift in genotype may be significant in terms of disease severity, and for any future vaccine considerations. Regular testing for hMPV should be done as part of outbreak investigation. J. Med. Virol. 87:269–274, 2015. © 2014 Wiley Periodicals, Inc.

Respiratory viral infections in institutions from late stage of the first and second waves of pandemic influenza A (H1N1) 2009, Ontario, Canada

Please cite this paper as: Asner et al. (2012) Respiratory viral infections in institutions from late stage of the first and second waves of pandemic A (H1N1) 2009, Ontario, Canada. Influenza and Other Respiratory Viruses 6(3), e11–e15.

We report the impact of respiratory viruses on various outbreak settings by using surveillance data from the late first and second wave periods of the 2009 pandemic. A total of 278/345(78·5%) outbreaks tested positive for at least one respiratory virus by multiplex PCR. We detected A(H1N1)pdm09 in 20·6% of all reported outbreaks of which 54·9% were reported by camps, schools, and day cares (CSDs) and 29·6% by long‐term care facilities (LCFTs), whereas enterovirus/human rhinovirus (ENT/HRV) accounted for 62% outbreaks of which 83·7% were reported by long‐term care facilities (LCTFs). ENT/HRV was frequently identified in LTCF outbreaks involving elderly residents, whereas in CSDs, A(H1N1)pdm09 was primarily detected.

Viral aetiology of influenza-like illness in Belgium during the influenza A(H1N1)2009 pandemic

The purpose of this investigation was to determine the proportion of influenza-like illness (ILI) attributable to specific viruses during the influenza A(H1N1)2009 pandemic and to describe the demographic and clinical characteristics of ILI due to respiratory viruses in Belgium. Nasopharyngeal swabs were collected from ILI patients by general practitioners (GPs) and paediatricians (PediSurv) and analysed for viruses. Of 139 samples collected from children <5 years of age by PediSurv, 86 were positive, including 28 influenza (20%), 27 respiratory syncytial virus (RSV) (19%), 21 rhinovirus (17%), 12 human metapneumovirus (hMPV) (9%) and ten parainfluenza virus (PIV) (7%). Of 810 samples received from GPs, 426 were influenza (53%). Of 312 influenza-negative samples, 41 were rhinovirus (13%), 13 RSV (4%), 11 PIV (4%) and three hMPV (1%). Influenza mostly affected the 6-15 years old age group. Other respiratory viruses were commonly detected in the youngest patients. Similar clinical symptoms were associated with different respiratory viruses. Influenza A(H1N1)2009 was the most detected virus in ILI patients during the 2009-2010 winter, suggesting a good correlation between ILI case definition and influenza diagnosis. However, in children under 5 years of age, other respiratory viruses such as RSV were frequently diagnosed. Furthermore, our findings do not suggest that the early occurrence of the influenza A(H1N1)2009 epidemic impacted the RSV epidemic in Belgium.

Transmission and control in an institutional pandemic influenza A(H1N1) 2009 outbreak

A pandemic influenza A(H1N1) 2009 outbreak in a summer school affected 117/276 (42%) students. Residential social contact was associated with risk of infection, and there was no evidence for transmission associated with the classroom setting. Although the summer school had new admissions each week, which provided susceptible students the outbreak was controlled using routine infection control measures (isolation of cases, basic hygiene measures and avoidance of particularly high-risk social events) and prompt treatment of cases. This was in the absence of chemoprophylaxis or vaccination and without altering the basic educational activities of the school. Modelling of the outbreak allowed estimation of the impact of interventions on transmission. These models and follow-up surveillance supported the effectiveness of routine infection control measures to stop the spread of influenza even in this high-risk setting for transmission.

Frequency of detection of upper respiratory tract viruses in patients tested for pandemic H1N1/09 viral infection

Molecular testing of 270 consecutive nasopharyngeal swab samples taken in May and June 2009 and 274 samples from patients hospitalized between July and December 2009 showed similar findings of respiratory viruses, with influenza A pandemic virus H1N1/09 being the most represented, followed by human parainfluenza virus type 3 and rhinoviruses. Statistical analyses suggested virus cocirculation in the absence of viral interference.