Disease burden of the most commonly detected respiratory viruses in hospitalized patients calculated using the disability adjusted life year (DALY) model.

BACKGROUND: The most common acute infections occur in the respiratory tract. Recent discoveries of several novel viruses have markedly increased the repertoire of agents understood to cause presentations of acute respiratory disease. OBJECTIVES: Further understanding is needed of the relative importance of newly discovered pathogens in the clinical setting to provide clinicians with an indication of appropriate diagnostic and therapeutic targets. To address this, quantification of the disease burden of respiratory viruses in hospitalized patients was undertaken. STUDY DESIGN: Disease burden caused by respiratory viruses in hospitalized patients was quantified using the World Health Organization endorsed DALY model. Diagnostic testing results from samples collected over three years for adenovirus (AdV), influenzas A and B, parainfluenza viruses 1, 2 and 3 (PIV-1, -2 and -3), respiratory syncytial virus (HRSV), and previously published retrospective screening for human metapneumovirus, rhinoviruses, and four respiratory coronaviruses were applied to the DALY model. Disability weights were calculated per 1000 hospitalized patients in age banded groups. RESULTS: Strikingly different disease burden profiles were observed in children and adults. Adenoviruses were among the leading cause of respiratory presentations in children but not adults. HRSV and influenza A were consistently one of the greatest causes of disease regardless of sampled population. Rhinoviruses and PIV-3 were significant pathogens in all groups except those aged 16-64 years. In immunocompromised patients rhinoviruses were the leading viral cause of disease. CONCLUSIONS: These analyses provide a framework which can be used to identify where finite resources should be directed in respiratory therapeutics and vaccine development.

Epidemiology and clinical presentations of the four human coronaviruses 229E, HKU1, NL63, and OC43 detected over 3 years using a novel multiplex real-time PCR method.

Four human coronaviruses (HCoV-229E, HCoV-HKU1, HCoV-NL63, and HCoV-OC43) are associated with a range of respiratory outcomes, including bronchiolitis and pneumonia. Their epidemiologies and clinical characteristics are poorly described and are often reliant on case reports. To address these problems, we conducted a large-scale comprehensive screening for all four coronaviruses by analysis of 11,661 diagnostic respiratory samples collected in Edinburgh, United Kingdom, over 3 years between July 2006 and June 2009 using a novel four-way multiplex real-time reverse transcription-PCR (RT-PCR) assay. Coronaviruses were detected in 0.3 to 0.85% of samples in all age groups. Generally, coronaviruses displayed marked winter seasonality between the months of December and April and were not detected in summer months, which is comparable to the pattern seen with influenza viruses. HCoV-229E was the exception; detection was confined to the winter of 2008 and was sporadic in the following year. There were additional longer-term differences in detection frequencies between seasons, with HCoV-OC43 predominant in the first and third seasons and HCoV-HKU1 dominating in the second (see Results for definitions of seasons). A total of 11 to 41% of coronaviruses detected were in samples testing positive for other respiratory viruses, although clinical presentations of coronavirus monoinfections were comparable to those of viruses which have an established role in respiratory disease, such as respiratory syncytial virus, influenza virus, and parainfluenza viruses. The novel multiplex assay for real-time pan-coronavirus detection enhances respiratory virus diagnosis, overcomes potential diagnostic problems arising through seasonal variation in coronavirus frequency, and provides novel insights into the epidemiology and clinical implications of coronaviruses.