Characteristics and outcomes of patients hospitalized for infection with influenza, SARS-CoV-2 or respiratory syncytial virus in the season 2022/2023 in a large German primary care centre

Resurgence of common respiratory viruses and mycoplasma pneumoniae after ending the zero-COVID policy in Shanghai

China has adhered to policies of zero-COVID for almost three years since the outbreak of COVID-19, which has remarkably affected the circulation of respiratory pathogens. However, China has begun to end the zero-COVID policies in late 2022. Here, we reported a resurgence of common respiratory viruses and Mycoplasma pneumoniae with unique epidemiological characteristics among children after ending the zero-COVID policy in Shanghai, China, 2023. Children hospitalized with acute respiratory tract infections were enrolled from January 2022 to December 2023. Nine common respiratory viruses and 2 atypical bacteria were detected in respiratory specimens from the enrolled patients using a multiplex PCR-based assay. The data were analyzed and compared between the periods before (2022) and after (2023) ending the zero-COVID policies. A total of 8550 patients were enrolled, including 6170 patients in 2023 and 2380 patients in 2022. Rhinovirus (14.2%) was the dominant pathogen in 2022, however, Mycoplasma pneumoniae (38.8%) was the dominant pathogen in 2023. Compared with 2022, the detection rates of pathogens were significantly increased in 2023 (72.9% vs. 41.8%, p < 0.001). An out-of-season epidemic of respiratory syncytial virus was observed during the spring and summer of 2023. The median age of children infected with respiratory viruses in 2023 was significantly greater than that in 2022. Besides, mixed infections were more frequent in 2023 (23.8% vs. 28.9%, p < 0.001). China is now facing multiple respiratory pathogen epidemics with changing seasonality, altered age distribution, and increasing mixed infection rates among children in 2023. Our finding highlights the need for public health interventions to prepare for the respiratory pathogen outbreaks in the post-COVID-19 era.

Severity of respiratory syncytial virus compared with SARS-CoV-2 and influenza among hospitalised adults ≥65 years

INTRODUCTION

Our aim was to estimate the risk of pneumonia, admission to intensive care unit (ICU) or death in individuals ≥65 years old admitted to hospital with RSV, compared to influenza or COVID-19.

METHODS

We included hospitalised patients from Severe Acute Respiratory Infection Surveillance in Spain between 2021-2024, aged ≥65 years, laboratory confirmed for RSV, influenza or SARS-CoV-2. Using a binomial regression with logarithmic link, we estimated the relative risk (RR) of pneumonia, ICU admission and in-hospital mortality, in patients with RSV compared to influenza or SARS-CoV-2, adjusting for age, sex, season and comorbidities. We stratified the estimates by vaccination status for influenza or SARS-CoV2.

RESULTS

Among patients unvaccinated for influenza or SARS-CoV-2, those with RSV had similar or lower risk of pneumonia [vs. influenza: RR= 0.91 (95% Confidence Interval: 0.72-1.16); vs. SARS-CoV-2: 0.81 (0.67-0.98)], ICU admission [vs. influenza: 0.93 (0.41-2.08); vs. SARS-CoV-2: 1.10 (0.61-1.99)] and mortality [vs. influenza: 0.64 (0.32-1.28); vs. SARS-CoV-2: 0.56 (0.30-1.04)]. Among the vaccinated, results were largely similar except for a higher risk of ICU admission with RSV [vs. influenza: 2.13(1.16-3.89); vs. SARS-CoV-2: 1.83 (1.02-3.28)] CONCLUSIONS: RSV presented similar or lower intrinsic severity than influenza or SARS-CoV2. Among vaccinated patients, RSV was associated to higher ICU-admission, suggesting the potential for preventive RSV vaccination.

Characteristics and outcomes of patients hospitalized for infection with Influenza A, SARS-CoV-2 or respiratory syncytial virus in the season 2023/2024 in a large German primary care centre

BACKGROUND

In addition to the persistence of SARS-CoV-2 infections, those with Influenza A/B and RSV have reappeared in 2022/23. To compare the development of prevalence, clinical outcomes and risk factors, we analysed data of the season 2023/24 from the same region/hospital as for 2022/23.

METHODS

Patients covering the whole age range with a positive polymerase chain reaction (PCR) test for SARS-CoV-2, Influenza A/B, RSV were included from the internal, neurological and paediatric units of the RoMed hospital Rosenheim, Germany/Bavaria, from August 1st 2023 to 29th February 2024.

RESULTS

Of 932 patients included, 912 showed single infections with SARS-CoV-2, Influenza A or RSV (47.9% female, median age 68.0 years; 52.9% SARS-CoV-2, 23.2% Influenza A, 21.8% RSV). Co-infections (2.0%) and Influenza B (0.1%) were negligible. In patients of age ≥ 18 years (n = 628, 68.5% SARS-CoV-2, 26.0% Influenza A, 5.6% RSV), patients with Influenza A were younger compared to SARS-CoV-2 (p < 0.001), with RSV similar to SARS-CoV-2. Heart failure and asthma were the most prevalent comorbidities for RSV, immunosuppression for Influenza A. Admission to Intensive Care Unit (ICU) occurred in 111 patients (17.0% of SARS-CoV-2, 17.2% Influenza A, 28.6% RSV), and 59 patients died (8.8% SARS-CoV-2, 8.6% Influenza A, 20.0% RSV). Low-flow oxygen supplementation and non-invasive ventilation (NIV) were most frequent for RSV (68.6% and 20.0%, respectively), oxygen demand upon admission for Influenza A (39.3%), without differences in high-flow oxygen supply or length of hospital stay. Among patients aged < 18 years (n = 284, 21.4% SARS-CoV-2, 18.0% Influenza A, 57.1% RSV), 15 were admitted to ICU (4.8% SARS-CoV-2, 3.8% Influenza A, 6.0% RSV); none of them died. Oxygen supply via high-flow, low-flow or upon admission was highest for RSV (23.8%, 70.2%, 21.4%, respectively), as well as the length of hospital stay.

CONCLUSION

Between 8/2023 to 2/2024, a large population of patients hospitalized due to respiratory tract infection, showed relative contributions of SARS-CoV-2, Influenza A or RSV similar to those in 2022/23. The findings underline that in both, adults and children, RSV posed a relatively higher clinical risk than Influenza A and SARS-CoV-2, though absolute numbers remained highest for SARS-CoV-2.

Clinical Manifestations and Outcomes in Adults Hospitalized With Respiratory Syncytial Virus and Influenza a/B: A Multicenter Observational Cohort Study

Background

Respiratory syncytial virus (RSV) and influenza cause significant health challenges, particularly for individuals with comorbid conditions and older adults. However, information on the clinical manifestations and outcomes of adults hospitalized with RSV in Europe remains limited.

Methods

This multicenter observational cohort study of adults hospitalized with RSV or influenza A or B from March 2016 to April 2020 investigated the clinical manifestations, mortality risk factors, and association with 90-day mortality rates by logistic regression analysis after adjustment for covariates.

Results

Of 988 patients hospitalized with either virus, 353 had RSV, 347 had influenza A, and 288 had influenza B infection. Patients with RSV, compared with those with influenza A or B, were more likely to have comorbid conditions (83% for RSV vs 72% for influenza A [P = .03] and 74% for influenza B [P = .001]) or pneumonia (41% vs 29% [P = .03] and 24% [P < .001], respectively). After adjustment for covariates, RSV infection was associated with an increased all-cause mortality rate within 90 days compared with influenza B (odds ratio, 2.16 [95% confidence interval, 1.20-3.87]; P = .01) but not influenza A (1.38 [.84-2.29]; P = .21). Increasing age and present pneumonia were identified as independent mortality risk factors in patients with RSV.

Conclusions

Older adults hospitalized with RSV infections are at a higher risk of dying within 90 days of hospitalization than patients admitted with influenza B but at a similar risk as those admitted with influenza A, emphasizing the detrimental effects and severity of older patients being infected with RSV. Our findings underscore the need for strategic testing and vaccination approaches to mitigate the impact of RSV among older adults.

Respiratory syncytial virus infections in adults: a narrative review

Respiratory syncytial virus (RSV), an RNA virus spread by droplet infection that affects all ages, is increasingly recognised as an important pathogen in adults, especially among older people living with comorbidities. Distinguishing RSV from other acute viral infections on clinical grounds alone, with sufficient precision to be clinically useful, is not possible. The reference standard diagnosis is by PCR: point-of-care tests perform less well with lower viral loads. Testing samples from a single respiratory tract site could result in underdetection. RSV is identified in 6-11% of outpatient respiratory tract infection (RTI) consultations in older adults (≥60 years, or ≥65 years, depending on the study) and accounts for 4-11% of adults (≥18 years) hospitalised with RTI, with 6-15% of those hospitalised admitted to intensive care, and 1-12% of all adults hospitalised with RSV respiratory tract infection dying. Community-based studies estimate the yearly incidence of RSV infection at around 3-7% in adults aged 60 years and older in high-income countries. Although RSV accounts for a similar disease burden as influenza in adults, those hospitalised with severe RSV disease are typically older (most ≥60 years) and have more comorbidities, more respiratory symptoms, and are frequently without fever. Long-term sequelae are common and include deterioration of underlying disease (typically heart failure and COPD). There are few evidence-based RSV-specific treatments currently available, with supportive care being the main modality. Two protein subunit vaccines for protection from severe RSV in adults aged 60 years and older were licensed in 2023, and a third-an mRNA-based vaccine-recently gained market approval in the USA. The phase 3 studies in these three vaccines showed good protection against severe disease. Data on real-world vaccine effectiveness in older adults, including subgroups at high risk for RSV-associated hospitalisation, are needed to establish the best use of these newly approved RSV vaccines. New diagnostics and therapeutics are being developed, which will also need rigorous evaluation within their target populations to ensure they are used only for those in whom there is evidence of improved outcomes. There is an urgent need to reconceptualise this illness from one that is serious in children, but far less important than influenza in older people, to thinking of RSV as also a major risk to health for older people that needs targeted prevention and treatment.

Adult patients with severe respiratory syncytial virus infections in the emergency department

Respiratory syncytial virus (RSV) is a seasonal virus known to cause significant morbidity in pediatric patients; however, morbidity in adult patients has not been well investigated. We aimed to characterize adult patients with RSV infection in the emergency department (ED) and their clinical course. During the winter term 2022/23, all adult ED patients were screened for RSV, severe acute respiratory syndrome coronavirus type 2, and influenza infection using point-of-care polymerase chain reaction tests. All symptomatic RSV+ patients were further characterized based on their clinical presentation and course. A group comparison between RSV+ inpatients and RSV+ outpatients was conducted. The potential risk factors for inpatient treatment were evaluated using univariate and multivariate analyses. Of the 135 symptomatic RSV+ patients, 51.9% (70/135) were inpatients. Their length of stay were 9.4 (±10.4) days. Inpatients had a significantly higher mean age, lower oxygen saturation, higher leukocyte count, and higher C-reactive protein levels than outpatients. Among the preconditions, pulmonary diseases, tumors, and immunosuppression were significantly more frequent in the inpatient group. Thirty percent (21/70) of the inpatients required ICU treatment, 11% (8/70) required mechanical ventilation, and 9% (6/70) died. Malaise (P = .021, odds ratio 8.390) and detection of pulmonary infiltrations (P < .001, odds ratio 12.563) were the only independent predictors of inpatient treatment in the multivariate analysis. Our data show that RSV is a medically relevant pathogen among adult ED patients, often requiring inpatient treatment. In particular, elderly patients with some medical preconditions seem to be more prone to a severe course of infection requiring inpatient treatment. Lower respiratory tract involvement, proven by pulmonary infiltrates, seems to be crucial for a more severe disease course.

The Burden of Respiratory Syncytial Virus (RSV) in Germany: A Comprehensive Data Analysis Suggests Underdetection of Hospitalisations and Deaths in Adults 60 Years and Older

INTRODUCTION

In Germany, the estimation of the disease burden of respiratory syncytial virus (RSV) in older adults is limited. This makes it challenging for public health decision-makers to develop evidence-based recommendations for newly available vaccines against RSV for individuals aged 60 years and older (60+). This study investigates publicly available data sources in Germany to address the current gaps in evidence regarding the burden of RSV.

METHODS

Hospitalisation databases from the German Federal Statistical Office and national mortality statistic between 2000 and 2023, as well as regular surveillance reports from the national public health institute since 2014, were utilised to extract, combine and analyse data on RSV-related morbidity and mortality. These data were used to triangulate the age-specific burden of RSV.

RESULTS

The data indicate that the number of RSV-related outpatient consultations ranges between 1,313,100 and 3,911,800 cases per season from 2014/2015 to 2022/2023 for all age groups, with approximately 13.0% of outpatient consultations occurring in adults 60+. The significant increase in hospitalisations over time suggests that heightened testing due to the coronavirus disease 2019 (COVID-19) pandemic revealed the underdetection of inpatient RSV cases in pre-pandemic seasons. In the most recent season recorded, 2022/2023, the data show 12,800 RSV-related hospitalisations in adults 60+ (24% of all RSV-related hospitalisations) and 1340 in-hospital deaths in adults 60+ (93% of all RSV-related deaths).

CONCLUSION

The comparison of pre- to post-pandemic seasons strongly suggest up to a sevenfold underdetection of RSV in individuals 60+, and the analysis of in-hospital mortality reveals higher mortality rates compared with the general German mortality statistics. These findings highlight the urgent need to improve surveillance and implement targeted prevention strategies to mitigate the impact of RSV in older adults.

Cocirculation and coinfection of multiple respiratory viruses during autumn and winter seasons of 2023 in Beijing, China: A retrospective study

China experienced severe epidemics of multiple respiratory pathogens in 2023 after lifting "Zero-COVID" policy. The present study aims to investigate the changing circulation and infection patterns of respiratory pathogens in 2023. The 160 436 laboratory results of influenza virus and respiratory syncytial virus (RSV) from February 2020 to December 2023, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from June 2020 to December 2023, Mycoplasma pneumoniae, adenovirus, and human rhinovirus from January 2023 to December 2023 were analyzed. We observed the alternating epidemics of SARS-CoV-2 and influenza A virus (IAV), as well as the out-of-season epidemic of RSV during the spring and summer of 2023. Cocirculation of multiple respiratory pathogens was observed during the autumn and winter of 2023. The susceptible age range of RSV in this winter epidemic (10.5, interquartile range [IQR]: 5-30) was significantly higher than previously (4, IQR: 3-34). The coinfection rate of IAV and RSV in this winter epidemic (0.695%) was significantly higher than that of the last cocirculation period (0.027%) (p < 0.001). Similar trend was also found in the coinfection of IAV and SARS-CoV-2. The present study observed the cocirculation of multiple respiratory pathogens, changing age range of susceptible population, and increasing coinfection rates during the autumn and winter of 2023, in Beijing, China.

Respiratory Syncytial Virus, Influenza and SARS-CoV-2 in Homeless People from Urban Shelters: A Systematic Review and Meta-Analysis (2023)

Homeless people (HP) are disproportionally affected by respiratory disorders, including pneumococcal and mycobacterial infections. On the contrary, more limited evidence has been previously gathered on influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and very little is known about the occurrence of human respiratory syncytial virus (RSV), a common cause of respiratory tract infections among children and the elderly. The present systematic review was designed to collect available evidence about RSV, influenza and SARS-CoV-2 infections in HP, focusing on those from urban homeless shelters. Three medical databases (PubMed, Embase and Scopus) and the preprint repository medRxiv.org were therefore searched for eligible observational studies published up to 30 December 2023, and the collected cases were pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics. Reporting bias was assessed by funnel plots and a regression analysis. Overall, 31 studies were retrieved, and of them, 17 reported on the point prevalence of respiratory pathogens, with pooled estimates of 4.91 cases per 1000 HP (95%CI: 2.46 to 9.80) for RSV, 3.47 per 1000 HP for influenza and 40.21 cases per 1000 HP (95%CI: 14.66 to 105.55) for SARS-CoV-2. Incidence estimates were calculated from 12 studies, and SARS-CoV-2 was characterized by the highest occurrence (9.58 diagnoses per 1000 persons-months, 95%CI: 3.00 to 16.16), followed by influenza (6.07, 95%CI: 0.00 to 15.06) and RSV (1.71, 95%CI: 0.00 to 4.13). Only four studies reported on the outcome of viral infections in HP: the assessed pathogens were associated with a high likelihood of hospitalization, while high rates of recurrence and eventual deaths were reported in cases of RSV infections. In summary, RSV, influenza and SARS-CoV-2 infections were documented in HP from urban shelters, and their potential outcomes stress the importance of specifically tailored preventive strategies.