The etiological role of common respiratory viruses in acute respiratory infections in older adults::A systematic review and meta-analysis

Acute respiratory tract infections (ARI) constitute a substantial disease burden in adults and elderly individuals. We aimed to identify all case-control studies investigating the potential role of respiratory viruses in the etiology of ARI in older adults aged ≥65 years. We conducted a systematic literature review (across 7 databases) of case-control studies published from 1996 to 2017 that investigated the viral profile of older adults with and those without ARI. We then computed a pooled odds ratio (OR) with a 95% confidence interval and virus-specific attributable fraction among the exposed (AFE) for 8 common viruses: respiratory syncytial virus (RSV), influenza virus (Flu), parainfluenza virus (PIV), human metapneumovirus (HMPV), adenovirus (AdV), rhinovirus (RV), bocavirus (BoV), and coronavirus (CoV). From the 16 studies included, there was strong evidence of possible causal attribution for RSV (OR, 8.5 [95% CI, 3.9-18.5]; AFE, 88%), Flu (OR, 8.3 [95% CI, 4.4-15.9]; AFE, 88%), PIV (OR, not available; AFE, approximately 100%), HMPV (OR, 9.8 [95% CI, 2.3-41.0]; AFE, 90%), AdV (OR, not available; AFE, approximately 100%), RV (OR, 7.1 [95% CI, 3.7-13.6]; AFE, 86%) and CoV (OR, 2.8 [95% CI, 2.0-4.1]; AFE, 65%) in older adults presenting with ARI, compared with those without respiratory symptoms (ie, asymptomatic individuals) or healthy older adults. However, there was no significant difference in the detection of BoV in cases and controls. This review supports RSV, Flu, PIV, HMPV, AdV, RV, and CoV as important causes of ARI in older adults and provides quantitative estimates of the absolute proportion of virus-associated ARI cases to which a viral cause can be attributed. Disease burden estimates should take into account the appropriate AFE estimates (for older adults) that we report

Risk factors and medical resource utilization of respiratory syncytial virus, human metapneumovirus, and influenza-related hospitalizations in adults—a global study during the 2017–2019 epidemic seasons (hospitalized acute respiratory tract infection [HARTI] study)

Background: Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza are respiratory pathogens leading to hospitalization in adults. Our understanding of the disease burden is limited to data from single-center or 1-season studies in elderly patients. The HARTI study allows comparison of risk factors for progression to severe disease and medical resources utilization (MRU) during and post-hospitalization in adults diagnosed with influenza, RSV, or hMPV. Methods: This was a prospective global study in adults hospitalized with acute respiratory tract infection (40 centers, 12 countries). Participants with influenza, RSV, or hMPV were enrolled in a substudy and followed for up to 3 months postdischarge. Results: Overall, 366 influenza, 238 RSV, and 100 hMPV-infected participants enrolled in the substudy. RSV participants were older and had greater frequency of risk factors and longer duration of symptoms before hospitalization than influenza participants. The RSV and hMPV groups received more bronchodilators, corticosteroids, and oxygen supplementation. No significant differences in intensive care unit admissions or complications were observed. Readmission occurred in 20%-33% of patients within 3 months postdischarge, with the highest rates for RSV and hMPV. In-hospital death occurred in 2.5% of RSV, 1.6% of influenza, and 2% of hMPV participants. In multivariate analyses, length of stay was independently associated with country, renal disease, and increased age; probability of receiving supplemental oxygen was associated with pathogen (hMPV \u3e RSV \u3e influenza), abnormal chest x-ray, and increased age. Conclusions: Although influenza is more frequent, the HARTI study demonstrates greater frequency of underlying risk factors and MRU for RSV and hMPV vs influenza in hospitalized adults, indicating a need for effective interventions

Evaluation of the protective potential of antibody and T cell responses elicited by a novel preventative vaccine towards respiratory syncytial virus small hydrophobic protein

The small hydrophobic (SH) glycoprotein of human respiratory syncytial virus (RSV) is a transmembrane protein that is poorly accessible by antibodies on the virion but has an ectodomain (SHe) that is accessible and expressed on infected cells. The SHe from RSV strain A has been formulated in DPX, a unique delivery platform containing an adjuvant, and is being evaluated as an RSV vaccine candidate. The proposed mechanism of protection is the immune-mediated clearance of infected cells rather than neutralization of the virion. Our phase I clinical trial data dearly showed that vaccination resulted in robust antibody responses, but it was unclear if these immune responses have any correlation to immune responses to natural infection with RSV. Therefore, we embarked on this study to examine these immune responses in older adults with confirmed RSV infection. We compared vaccine-induced (DPX-RSV(A)) immune responses from participants in a Phase 1 clinical trial to paired acute and convalescent titers from older adults with symptomatic laboratory-confirmed RSV infection. Serum samples were tested for anti-SHe IgG titers and the isotypes determined. T cell responses were evaluated by IFN-gamma ELISPOT. Anti-SHe titers were detected in 8 of 42 (19%) in the acute phase and 16 of 42 (38%) of convalescent serum samples. IgG1, IgG3, and IgA were the prevalent isotypes generated by both vaccination and infection. Antigen-specific T cell responses were detected in 9 of 16 (56%) of vaccinated participants. Depletion of CD4(+) but not CD8(+) T cells abrogated the IFN-gamma ELISPOT response supporting the involvement of CD4(+) T cells in the immune response to vaccination. The data showed that an immune response like that induced by DPX-RSV(A) could be seen in a subset of participants with confirmed RSV infection. These findings show that older adults with clinically significant infection as well as vaccinated adults generate a humoral response to SHe. The induction of both SHe-specific antibody and cellular responses support further clinical development of the DPX-RSV(A) vaccine

Utility of serum procalcitonin values in patients with acute exacerbations of chronic obstructive pulmonary disease: a cautionary note

Background: Serum procalcitonin levels have been used as a biomarker of invasive bacterial infection and recently have been advocated to guide antibiotic therapy in patients with chronic obstructive pulmonary disease (COPD). However, rigorous studies correlating procalcitonin levels with microbiologic data are lacking. Acute exacerbations of COPD (AECOPD) have been linked to viral and bacterial infection as well as noninfectious causes. Therefore, we evaluated procalcitonin as a predictor of viral versus bacterial infection in patients hospitalized with AECOPD with and without evidence of pneumonia. Methods: Adults hospitalized during the winter with symptoms consistent with AECOPD underwent extensive testing for viral, bacterial, and atypical pathogens. Serum procalcitonin levels were measured on day 1 (admission), day 2, and at one month. Clinical and laboratory features of subjects with viral and bacterial diagnoses were compared.Results: In total, 224 subjects with COPD were admitted for 240 respiratory illnesses. Of these, 56 had pneumonia and 184 had AECOPD alone. A microbiologic diagnosis was made in 76 (56%) of 134 illnesses with reliable bacteriology (26 viral infection, 29 bacterial infection, and 21 mixed viral bacterial infection). Mean procalcitonin levels were significantly higher in patients with pneumonia compared with AECOPD. However, discrimination between viral and bacterial infection using a 0.25 ng/mL threshold for bacterial infection in patients with AECOPD was poor. Conclusion: Procalcitonin is useful in COPD patients for alerting clinicians to invasive bacterial infections such as pneumonia but it does not distinguish bacterial from viral and noninfectious causes of AECOPD

Global Disease Burden Estimates of Respiratory Syncytial Virus–Associated Acute Respiratory Infection in Older Adults in 2015::A Systematic Review and Meta-Analysis

Respiratory syncytial virus associated acute respiratory infection (RSV-ARI)constitutes a substantial disease burden in older adults≥65 years. We aimed to identify all studies worldwide investigating the disease burden ofRSV-ARIin this population. We estimated thecommunityincidence, hospitalisationrate and in-hospital case fatality ratio (hCFR) of RSV-ARI in older adults stratified by industrialized anddeveloping regions, with data from a systematic review ofstudies published between January 1996 and April 2018, and from 8 unpublished population-based studies. We applied these rate estimates to population estimates for 2015, to calculate the global and regional burdenin older adults with RSV-ARIin community and in hospital duringthat year. We estimated thenumber ofin-hospital RSV-ARIdeaths by combining hCFR with hospital admission estimates from hospital-based studies. In 2015, there were about 1.5million(95% CI 0.3-6.9) episodes of RSV-ARIin older adults in41industrialised countries (data missing in developing countries), and of these 214,000 (~14.5%; 95% CI 100,000-459,000) were admitted to hospitals. The global number of hospital admissionsforRSV-ARI in older adults was estimated at 336,000 (UR 186,000-614,000).We further estimated about 14,000 (UR 5,000-50,000) in-hospital deaths related to RSV-ARIglobally.The hospital admission rate and hCFR were higher for those ≥65 years than those aged 50-64 years. The disease burden of RSV-ARIamong older adults is substantialwith limited data from developing countries; appropriate prevention and management strategiesare needed to reduce this burden

Surveillance recommendations based on an exploratory analysis of respiratory syncytial virus reports derived from the European Influenza Surveillance System

BACKGROUND: Respiratory syncytial virus (RSV) is an important pathogen that can cause severe illness in infants and young children. In this study, we assessed whether data on RSV collected by the European Influenza Surveillance Scheme (EISS) could be used to build an RSV surveillance system in Europe. METHODS: Influenza and RSV data for the 2002–2003 winter season were analysed for England, France, the Netherlands and Scotland. Data from sentinel physician networks and other sources, mainly hospitals, were collected. Respiratory specimens were tested for influenza and RSV mainly by virus culture and polymerase chain reaction amplification. RESULTS: Data on RSV were entered timely into the EISS database. RSV contributed noticeably to influenza-like illness: in England sentinel RSV detections were common in all age groups, but particularly in young children with 20 (40.8%) of the total number of sentinel swabs testing positive for RSV. Scotland and France also reported the highest percentages of RSV detections in the 0–4 year age group, respectively 10.3% (N = 29) and 12.2% (N = 426). In the Netherlands, RSV was detected in one person aged over 65 years. CONCLUSION: We recommend that respiratory specimens collected in influenza surveillance are also tested systematically for RSV and emphasize the use of both community derived data and data from hospitals for RSV surveillance. RSV data from the EISS have been entered in a timely manner and we consider that the EISS model can be used to develop an RSV surveillance system equivalent to the influenza surveillance in Europe

Interleukin-12p40 Modulates Human Metapneumovirus-Induced Pulmonary Disease in an Acute Mouse Model of Infection

The mechanisms that regulate the host immune response induced by human metapneumovirus (hMPV), a newly-recognized member of the Paramyxoviridae family, are largely unknown. Cytokines play an important role in modulating inflammatory responses during viral infections. IL-12p40, a known important mediator in limiting lung inflammation, is induced by hMPV and its production is sustained after the resolution phase of infection suggesting that this cytokine plays a role in the immune response against hMPV. In this work, we demonstrated that in mice deficient in IL-12p40, hMPV infection induced an exacerbated pulmonary inflammatory response and mucus production, altered cytokine response, and decreased lung function. However, hMPV infection in these mice does not have an effect on viral replication. These results identify an important regulatory role of IL-12p40 in hMPV infection

Influenza symptoms and their impact on elderly adults: randomised trial of AS03-adjuvanted or non-adjuvanted inactivated trivalent seasonal influenza vaccines.

Patient-reported outcomes (PROs) are particularly relevant in influenza vaccine trials in the elderly where reduction in symptom severity could prevent illness-related functional impairment