Clinical outcomes of adults hospitalized for laboratory confirmed respiratory syncytial virus or influenza virus infection

Respiratory Syncytial Virus Sequelae Among Adults in High-Income Countries: A Systematic Literature Review and Meta-analysis

INTRODUCTION

Respiratory syncytial virus (RSV) can cause severe respiratory infections in adults; however, information on associated sequelae is limited. This systematic literature review aimed to identify sequelae in adults within 1 year following RSV-related hospitalization or resolution of acute infection.

METHODS

Studies were identified from Embase, MEDLINE, LILACS, SciELO, and grey literature. Random-effects meta-analyses using restricted maximum likelihood were used to calculate the proportions and relative risks of sequelae in patients with RSV compared with controls (patients with RSV-negative influenza-like illness, influenza, and parainfluenza) per follow-up period, population, and treatment setting, where possible.

RESULTS

Twenty-one relevant studies covering the period from 1990 to 2019 were included. Among the general population, the most frequent clinical sequela was sustained function loss (33.5% [95% CI 27.6-39.9]). Decline in lung function and cardiovascular event or congestive heart failure were also identified. Utilization sequelae were readmission (highest at > 6 months after discharge) and placement in a skilled nursing facility. The only subpopulation with data regarding sequelae was transplant patients. Among lung transplant patients, the most frequently reported clinical sequelae were decline in lung function, followed by graft dysfunction and bronchiolitis obliterans syndrome. Pooled relative risks were calculated for the following sequela with controls (primarily influenza-positive patients): cardiovascular event (general population) and pulmonary impairment (hematogenic-transplant patients) both 1.4 (95% CI 1.0-2.0) and for readmission (general population) 1.2 (95% CI 1.1-1.3).

CONCLUSIONS

Although less data are available for RSV than for influenza or other lower respiratory tract infections, RSV infection among adults is associated with medically important sequelae, with a prevalence similar to other respiratory pathogens. RSV sequelae should be included in disease burden estimates.

Respiratory syncytial virus-related hospital stays in adults in France from 2012 to 2021: A national hospital database study

BACKGROUND

Respiratory syncytial virus (RSV) causes lower respiratory tract infections (LRTI) that may lead to hospitalization or death. The present study aimed to assess the burden of RSV infections in hospitalized adults.

METHODS

RSV-related hospitalizations were identified from the nationwide hospital claims database in France (PMSI) from 2012 to 2021 using ICD-10 codes J12.1, J20.5, J21.0 or B97.4, and outcomes assessment focused on 2016-2020. In-hospital outcomes included length of stay, need for intensive care (ICU) and in-hospital all-cause mortality. Post-discharge outcomes included 30-day readmission for decompensation, 90-day RSV-related readmission, and 30 and 60-day in-hospital mortality.

RESULTS

A cumulated number of 17 483 RSV-related stays were identified representing a rate of 72.0 cases per million stays. The outcomes assessment included 12,987 patients: 55.8 % were females and the mean age was 74.1 ± 16.4 years, with 57 % ≥ 75 years. Most of patients (78.6 %) had at least one comorbidity, mainly chronic respiratory (56.3 %) and cardiovascular diseases (41.3 %), or diabetes (23.5 %). A co-infection was found in 22.4 %, primarily bacterial (12 %). The mean length of stay was 12.3 ± 13.1 days. Overall, 10.9 % were admitted to an ICU and in-hospital mortality was 7.3 %. In-hospital outcomes were higher in cases of co-infection. Among 12 033 patients alive at discharge from the index stay, 6.5 % were readmitted with RSV within 90 days, 8.1 % for decompensation within 30 days, and 5.6 % died within 60-day.

CONCLUSION

This study demonstrated the high burden of RSV infections in older adults and those with chronic conditions, and the need for preventive strategies.

From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults

Respiratory syncytial virus (RSV) is increasingly recognized as being implicated in acute illness in older adults, with a significant weight in hospitalizations for respiratory illness and death. By means of a best-evidence review, this paper aims to investigate whether RSV can be considered a forgotten pathogen in older patients, looking at trends in the literature volume and exploring possible epidemiological and clinical features underlying the focus given to it. We then present an assessment of its disease burden and present and future strategies for its reduction, particularly in light of the recent availability of new vaccines.

Comparison of mortality and outcomes of four respiratory viruses in the intensive care unit: a multicenter retrospective study

This retrospective study aimed to compare the mortality and burden of respiratory syncytial virus (RSV group), SARS-CoV-2 (COVID-19 group), non-H1N1 (Seasonal influenza group) and H1N1 influenza (H1N1 group) in adult patients admitted to intensive care unit (ICU) with respiratory failure. A total of 807 patients were included. Mortality was compared between the four following groups: RSV, COVID-19, seasonal influenza, and H1N1 groups. Patients in the RSV group had significantly more comorbidities than the other patients. At admission, patients in the COVID-19 group were significantly less severe than the others according to the simplified acute physiology score-2 (SAPS-II) and sepsis-related organ failure assessment (SOFA) scores. Using competing risk regression, COVID-19 (sHR = 1.61; 95% CI 1.10; 2.36) and H1N1 (sHR = 1.87; 95% CI 1.20; 2.93) were associated with a statistically significant higher mortality while seasonal influenza was not (sHR = 0.93; 95% CI 0.65; 1.31), when compared to RSV. Despite occurring in more severe patients, RSV and seasonal influenza group appear to be associated with a more favorable outcome than COVID-19 and H1N1 groups.

Epidemiology and Disease Burden of Respiratory Syncytial Virus Infection in Adults

Respiratory syncytial virus (RSV) constitutes a significant cause of respiratory illness and mortality among older adults, a demographic that is expanding with considerable impact on healthcare systems worldwide. The actual burden of RSV in this population may still be underestimated, owing to factors such as low awareness and suboptimal diagnostic sensitivity in adults, the lack of robust RSV surveillance systems, and the infrequent use of diagnostic testing. Recent advancements in respiratory virus detection have spurred further exploration into appropriate preventive and therapeutic strategies. The recent approval of two vaccines highlights the critical need for the precise estimation of the RSV disease burden to optimize the effectiveness and cost-efficiency of immunization programs. This narrative review aimed to summarize the existing knowledge of the RSV burden in adults with a particular focus on older adults, incorporating data from Korea. Overall, current estimates indicate that the annual RSV attack rate in the general adult population ranges from 1 - 7%, increasing to approximately 4 - 10% among elderly and high-risk groups. The in-hospital mortality rate can be estimated to be around 7 - 10%, rising up to 40% among intensive care unit-admitted patients. To elucidate RSV's disease burden, further continuing research, including population-based studies, is necessary.

Respiratory syncytial virus in adults with comorbidities: an update on epidemiology, vaccines, and treatments

BACKGROUND

Respiratory syncytial virus (RSV) is widely known as a frequent cause of respiratory distress among adults, particularly in older people. Recent years have witnessed several improvements in respiratory virus detection, leading to more questions about therapeutic management strategies.

OBJECTIVES

This narrative review focuses on the RSV burden in older people and adults with risk factors and provides an update on the main recent developments regarding managing this infection.

SOURCES

A comprehensive PubMed search was conducted till August 2023 to identify studies on RSV among the adult population. We included observational studies, RCTs on vaccines, and different therapies.

CONTENT

This review should give clinicians an overview of RSV epidemiology and burden among older people and adults with pre-existing risk factors, the most recent randomized clinical trials on RSV vaccines, and the existing data on the different therapeutics existing and under development.

IMPLICATIONS

There is a growing body of evidence on RSV burden in adults. The landscape of preventive and curative treatments is quickly evolving.

Burden of respiratory syncytial virus in adults in the United Kingdom: A systematic literature review and gap analysis

Despite the growing recognition of a potentially significant respiratory syncytial virus (RSV) disease burden in adults, relevant evidence in the United Kingdom (UK) is limited. This systematic literature review (SLR) aimed to identify the disease burden of RSV in UK adults, including certain high-risk subgroups and existing evidence gaps. Published studies (2011 onwards) reporting epidemiological, economic and clinical burden outcomes in UK adults (≥15 years) with RSV were identified from indexed databases, including MEDLINE, Embase and the Cochrane library. High-risk groups included elderly (≥65 years), immunocompromised, co-morbid and co-infected patients. Outcomes included RSV incidence/prevalence, mortality, clinical presentation and direct/indirect resource use/costs. Twenty-eight publications on 28 unique studies were identified, mostly in general/respiratory indicator (n = 17), elderly (n = 10) and immunocompromised (n = 6) cohorts. Main outcomes reported in the general/respiratory indicator cohort were RSV infection incidence (seasonal/annual: 0.09-17.9%/6.6-15.1%), mortality (8,482 deaths/season) and direct resource use (including mean general practitioner [GP] episodes/season: 487,247). Seasonal/annual incidence was 14.6-26.5%/0.7-16% in high-risk cohorts. Attributed to RSV in the elderly were 7,915 deaths/season and 175,070 mean GP episodes/season. Only two studies reported on co-morbid cohorts. Clinical burden outcomes were only reported in general and immunocompromised patients, and no evidence was found in any cohort on indirect economic burden or RSV complications. Evidence captured suggests that RSV may have a substantial burden in UK adults. However, available data were limited and highly heterogenous, with further studies needed to characterise the burden of RSV in adults and to validate our findings.

Vaccination against Community-Acquired Pneumonia in Spanish Adults: Practical Recommendations by the NeumoExperts Prevention Group

In the adult population, community-acquired pneumonia (CAP) is a serious disease that is responsible for high morbidity and mortality rates, being frequently associated with multidrug resistant pathogens. The aim of this review is to update a practical immunization prevention guideline for CAP in Spain caused by prevalent respiratory pathogens, based on the available scientific evidence through extensive bibliographic review and expert opinion. The emergence of COVID-19 as an additional etiological cause of CAP, together with the rapid changes in the availability of vaccines and recommendations against SARS-CoV-2, justifies the need for an update. In addition, new conjugate vaccines of broader spectrum against pneumococcus, existing vaccines targeting influenza and pertussis or upcoming vaccines against respiratory syncytial virus (RSV) will be very useful prophylactic tools to diminish the burden of CAP and all of its derived complications. In this manuscript, we provide practical recommendations for adult vaccination against the pathogens mentioned above, including their contribution against antibiotic resistance. This guide is intended for the individual perspective of protection and not for vaccination policies, as we do not pretend to interfere with the official recommendations of any country. The use of vaccines is a realistic approach to fight these infections and ameliorate the impact of antimicrobial resistance. All of the recently available scientific evidence included in this review gives support to the indications established in this practical guide to reinforce the dissemination and implementation of these recommendations in routine clinical practice.

Clinical Outcome of Viral Respiratory Tract Infections in Hospitalized Adults in Norway: High Degree of Inflammation and Need of Emergency Care for Cases With Respiratory Syncytial Virus

Background

The clinical features and outcomes of viral respiratory tract infections (RTIs) in adults have not been thoroughly studied, especially the respiratory syncytial virus (RSV) disease burden. It has become apparent that outbreaks of RSV in the elderly are associated with increased hospitalization rates. However, little data exists on the severity of such viral RTIs in adults, particularly the need for hospitalization, respiratory support and intensive care.

Methods

We conducted a retrospective observational single-center study at Østfold Hospital Trust, Norway, during three winter seasons 2015–2018. Patients ≥18 years with either influenza A, influenza B, RSV A/B, human metapneumovirus, parainfluenza virus 1–4 or adenovirus detected in respiratory specimens were included, if they were hospitalized 14 days prior or following the detection date, with signs of RTI. Hospital records on treatment and outcome were investigated, as well as mortality of all causes up to 30 days from discharge.

Results

Of the 1222 infection events that were included, influenza A was the most frequent virus detected (39%), while 179 infection events (14.6%) were due to RSV. Influenza B counted for 24% of the infection events, human metapneumovirus 13%, parainfluenza virus 9% and adenovirus 1%. Patients admitted with RSV more often suffered from COPD and congestive heart failure than patients with influenza A. In addition, RSV patients were overrepresented in the urgent response NEWS score (National Early Warning Score) category ≥5. RSV patients also showed signs of more severe inflammation, with WBC ≥11.1 × 10⁹/L and CRP >100 mg/L, and they were more often treated with antibiotic agents during their hospital stay. However, we found no differences in the need for ICU admission or mortality.

Conclusion

Patients with RSV had more often high values for markers of inflammation and elevated NEWS score when compared to patients hospitalized with other common respiratory viruses. Taken into account that they suffered more frequently from comorbidities like COPD, these patients needed hospitalization more urgently. These findings highlight the need for further investigations on RSV disease in adults and the elderly.