RSV Virus Research Articles

Pediatric RSV infection and respiratory coinfections: is a link related to clinical severity? Single center retrospective study

PurposeThe aim of the study was to assess whether there was a difference in terms of severity in paediatric patients assessed for respiratory symptoms in paediatric emergency departments between those who tested positive for RSV and those who presented with viral co-infections in addition to RSV. It was also assessed whether there was a difference between the two groups in terms of need for hospitalisation and ventilation. MethodsThis is a single center study from October 2022 to February 2023, compared two groups of patients: those infected with RSV and those coinfected with RSV and other viruses. Parameters examined included the severity of illness, as measured by the Clinical Respiratory Score (CRS), the need for and duration of hospitalization, and the need for ventilation via high flow nasal cannula (HFNC). ResultsThe correlation with disease severity assessed by CRS in the two groups with RSV only and coinfection was not statistically significant (p-value 0.281). The correlation in the two groups between the need for hospitalization (p-value 1) and the need for ventilation (p-value 0.302) was also not significant. No significant correlation was found between the age of patients and CRS (R=-0.26, p=0.119) and the age of patients and days of hospitalization (R=-0.013, p=0.938). ConclusionThese findings highlight the importance of careful management of RSV infections in children. Despite the limitations, the lack of significant differences in disease severity indicates the need to explore additional preventive strategies, such as RSV vaccination, to improve the clinical approach.

Integrated sentinel surveillance of influenza, SARS-CoV-2, RSV and respiratory viruses in Serbia

Abstract Introduction Integrated sentinel SARI surveillance of influenza, SARS -CoV-2 and RSV has been established in Serbia since 2021-2022 influenza season. Nine sentinel hospitals in 3 cities participated in the SARI surveillance system. The aim of this study is to provide a review of integrated sentinel surveillance of SARI in Serbia in 2023-2024 influenza season, from October 2023 to April 2024. Methods On a weekly basis, both epidemiological and virological data were collected. Surveillance is be conducted year-round. Specimens were tested for influenza, SARS-CoV-2,RSV and other respiratory viruses. Respiratory disease wards, intensive care units (ICUs) and pediatric wards were all represented. Real time polymerase chain reaction (RT-PCR) was used. Results From October 2023 to April 2024, a total of 1571 SARI cases were reported with 100% recorded age. Of these, 35% were 0-4 years old, 16% were 5-14, 6% were 15-29, 14% were 30-64, 18% were 65-79 and 11% were 80+. Among these cases, 1002 (64%) respiratory specimens were collected. The number of positive samples for influenza was 294 (29%). The positivity rate was 10% for SARS-CoV-2 and 19 % for RSV. The highest proportion of laboratory-confirmed influenza cases was 67% in week 04/2023. Then above 50% in week 05/2023 and 06/2023. Type A viruses was predominated, accounting for 97% of all influenza SARI detections. Activity was dominated by A(H3) with 42% positivity rate. Also, collected swabs were tested for rhinoviruses, positivity rate was 26%, for adenoviruses, 12%, for human metapneumovirus, 7% and for parainfluenza 3 viruses, 4%. Conclusions Sustaining and intensified effective integrated surveillance for influenza, SARS-CoV-2,RSV and other respiratory viruses in Serbia is the priority especially in the frame of International Health Regulations. In this way, we improve national capacity for preparedness and emergency response to national and cross-border public health threats. Key messages • Building and maintaining integrated respiratory surveillance that can rapidly integrate the surveillance of a new viruses is crucial. • Establishing well structured surveillance of severe acute respiratory infections, strengthening and expanding respiratory viral surveillance is one the base pillars preparation for future pandemics.

Burden of respiratory syncytial virus, human metapneumovirus and influenza virus infections in Japanese adults in the Hospitalized Acute Respiratory Tract Infection study

BackgroundRespiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus are responsible for acute respiratory tract infections (ARTIs) in adults. We assessed the clinical burden of RSV, hMPV and influenza virus infection among Japanese adults hospitalized with ARTIs. MethodsThe Hospitalized Acute Respiratory Tract Infection (HARTI) study was a multinational, prospective cohort study in adults with ARTIs across the 2017–2019 epidemic seasons. Enrolment in Japan began in Sept 2018 and ran until Oct 2019. The clinical diagnosis of ARTI and the decision to hospitalize the patient were made according to local standard of care practices. Viral testing was performed by reverse transcription polymerase chain reaction. ResultsOf the 173 adults hospitalized with ARTI during this period at the Japan sites, 7 (4.0%), 9 (5.2%), and 11 (6.4%) were positive for influenza virus, RSV, and hMPV, respectively. RSV season was observed from Oct 2018 to Jan 2019, followed by influenza from Dec 2018 to Apr 2019. hMPV was detected across both the RSV and influenza seasons. Two patients with RSV and 1 patient with hMPV required ICU admission whereas none with influenza. Use of antibiotics, bronchodilators and inhaled corticosteroids was high amongst patients with RSV and hMPV at 1, 2, and 3 months’ post-discharge compared with patients with influenza, with few exceptions. ConclusionThese findings highlight the need for a high degree of clinical suspicion for RSV and hMPV infection in adults hospitalized with ARTIs.

The imbalance of pulmonary Th17/Treg cells in BALB/c suckling mice infected with respiratory syncytial virus-mediated intestinal immune damage and gut microbiota changes.

RSV is the most common pathogen causing acute lower respiratory tract infections in infants and young children, but the complex interactions between the immune system and gut microbiota induced by RSV infection still requires further research. In this study, it was suggested that RSV infection in 7-day-old BALB/c suckling mice caused lung inflammation and disruption of Th17/Treg cells development, and altered the composition of gut microbiota through IL-22 induced overexpression of RegⅢγ, leading to intestinal immune injury and disruption of gut microbiota. This research reveals that IL-22 may be the link between the lung and gut. This study may provide a new insight into the intestinal symptoms caused by RSV and other respiratory viruses and the connection between the lung and gut axis, as well as new therapeutic ideas for the treatment of RSV-infected children.

Qingfei Formula Protects against Human Respiratory Syn cytial Virus-induced Lung Inflammatory Injury by Regulating the M APK Signaling Pathway.

Qingfei formula (QF) is an empirical formula that shows good clinical efficacy in treating human respiratory syncytial virus pneumonia (RSVP). However, the underlying mechanism remains unclear. This study explores the possible pharmacological actions of QF in RSVP treatment. We used a network pharmacology approach to identify the active ingredients of QF, forecast possible therapeutic targets, and analyze biological processes and pathways. Molecular docking simulation was used to evaluate the binding capability of active ingredients and therapeutic targets. Finally, in vivo experiments confirmed the reliability of network pharmacology-based prediction of underlying mechanisms. The study identified 92 potential therapeutic targets and corresponding 131 active ingredients. Enrichment analysis showed that QF downregulated the MAPK signaling pathway and suppressed the inflammatory injury to the lungs induced by the RSV virus. Molecular docking simulations demonstrated that the core active ingredients of QF could stably bind to genes associated with the MAPK signaling pathway. QF had a protective effect against pneumonia in RSV-infected mice. The QF group exhibited a significant reduction in the levels of inflammatory mediators, interleukin- 6 (IL-6), interleukin-8 (CXCL8, IL-8), and P-STAT3, compared to the RSV-induced group. The QF group showed remarkably inhibited MAPK1+3(P-ERK1+2) and MAPK8(P-JNK) protein expression. The current study showed that QF downregulated the MAPK signaling pathway, which inhibited pulmonary inflammation triggered by RSV infection. This study recommends the appropriate use of QF in the clinical management of RSVP.

Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015-2021.

Data available for RSV and influenza infections among children < 2 years in Mongolia are limited. We present data from four districts of Ulaanbaatar from April 2015 to June 2021. This study was nested in an enhanced surveillance project evaluating pneumococcal conjugate vaccine (PCV13) impact on the incidence of hospitalized lower respiratory tract infections (LRTIs). Our study was restricted to children aged < 2 years with arterial O2 saturation < 93% and children with radiological pneumonia. Nasopharyngeal (NP) swabs collected at admission were tested for RSV and influenza using qRT-PCR. NP swabs of all patients with radiological pneumonia and of a subset of randomly selected NP swabs were tested for S. pneumoniae (S.p.) by qPCR and for serotypes by culture and DNA microarray. Among 5705 patients, 2113 (37.0%) and 386 (6.8%) had RSV and influenza infections, respectively. Children aged 2-6 months had a higher percentage of very severe RSV infection compared to those older than 6 months (42.2% versus 31.4%, p-value Fisher's exact = 0.001). S.p. carriage was detected in 1073/2281 (47.0%) patients. Among S.p. carriage cases, 363/1073 (33.8%) had S.p. and RSV codetection, and 82/1073 (7.6%) had S.p. and influenza codetection. S.p. codetection with RSV/influenza was not associated with more severe LRTIs, compared to only RSV/influenza cases. In Mongolia, RSV is an important pathogen causing more severe LRTI in children under 6 months of age. Codetection of RSV or influenza virus and S.p. was not associated with increased severity.

Antiviral Rotenoids and Isoflavones Isolated from Millettia oblata ssp. teitensis.

Three new (1-3) and six known rotenoids (5-10), along with three known isoflavones (11-13), were isolated from the leaves of Millettia oblata ssp. teitensis. A new glycosylated isoflavone (4), four known isoflavones (14-18), and one known chalcone (19) were isolated from the root wood extract of the same plant. The structures were elucidated by NMR and mass spectrometric analyses. The absolute configuration of the chiral compounds was established by a comparison of experimental ECD and VCD data with those calculated for the possible stereoisomers. This is the first report on the use of VCD to assign the absolute configuration of rotenoids. The crude leaves and root wood extracts displayed anti-RSV (human respiratory syncytial virus) activity with IC50 values of 0.7 and 3.4 μg/mL, respectively. Compounds 6, 8, 10, 11, and 14 showed anti-RSV activity with IC50 values of 0.4-10 μM, while compound 3 exhibited anti-HRV-2 (human rhinovirus 2) activity with an IC50 of 4.2 μM. Most of the compounds showed low cytotoxicity for laryngeal carcinoma (HEp-2) cells; however compounds 3, 11, and 14 exhibited low cytotoxicity also in primary lung fibroblasts. This is the first report on rotenoids showing antiviral activity against RSV and HRV viruses.

Rationale and protocol for a prospective cohort study of respiratory viral infections in patients admitted from emergency departments of community hospitals: Effect of respiratory Virus infection on EmeRgencY admission (EVERY) study

IntroductionRespiratory syncytial virus (RSV) is a causative virus for the common cold worldwide and can result in hospitalisations and even death in patients with high-risk conditions and older adults. However,...

Actual data regarding the impact of viral respiratory co-infection (Covid 19 and flu/ Respiratory Syncutial Virus RSV) - A systematic review

Abstract: Background. The impact of SARS-CoV-2 infection alongside with influenza and RSV, the major viral agents in pediatric disordes, may be an important concern to the healthcare system. Clinical outcomes of the interaction are unknown. The aim of this systematic review is to contribute at establishing the prevalence of the co-infection, its clinical outcomes and potential risk factors. Methods. A systematical literature search was performed for papers published in PubMed, Scopus, Web of Science, Pedro and Cochrane Library, from January 2020 - the beginning of the COVID 19 pandemic - to June 2023. Our review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methods. Studies were eligible for inclusion if they approached the co-infection COVID 19 and influenza or RSV, and were available in English. Due to the fact that studies conducted on pediatric population are scarce, we included patients of all ages. Results. Out of 159 articles found, 12 were eligible for inclusion. The prevalence of co-infection was between 5% and 12 % for influenza viruses and 10% for RSV. The most common symptoms were high-grade fever, cough, headache, and shortness of breath and the most frequent complications were pneumonia and respir-atory distress. In terms of laboratory findings, co-infected patients presented with signifi-cant lymphopenia and pronounced inflammatory response, as well as a progressive ten-dency towards pneumonia and respiratory distress. Regarding the clinical outcomes of co-infection, the majority of articles indicated that simultaneous infection with SARS-CoV-2 and influenza predisposes to a more severe course of the disease(s), with a longer length of hospital stay and an increased risk of death.Conclusion. Our study underlines that the frequency of such co-infections, although not very high, predisposes to more frequent hos-pitalisations and a longer length of stay, complications including admission to intensive care and more severe outcomes, including life-threatening events. It is therefore essential to determine the epidemiological impact of such an interaction nowadays, in order to in-form and adjust treatment and control and prevention strategies, for limiting co-infection between major respiratory viruses. Due to the lack of studies on children, we were unable to identify specific features of co-infections in this population. Therefore, more studies are needed to evaluate the paediatric population and consequently, our doctoral research en-deavour is warranted.

Non-SARS-CoV-2 respiratory viral detection and whole genome sequencing from COVID-19 rapid antigen test devices: a laboratory evaluation study

There has been high uptake of rapid antigen test device use for point-of-care COVID-19 diagnosis. Individuals who are symptomatic but test negative on COVID-19 rapid antigen test devices might have a different respiratory viral infection. We aimed to detect and sequence non-SARS-CoV-2 respiratory viruses from rapid antigen test devices, which could assist in the characterisation and surveillance of circulating respiratory viruses in the community. We applied archival clinical nose and throat swabs collected between Jan 1, 2015, and Dec 31, 2022, that previously tested positive for a common respiratory virus (adenovirus, influenza, metapneumovirus, parainfluenza, rhinovirus, respiratory syncytial virus [RSV], or seasonal coronavirus; 132 swabs and 140 viral targets) on PCR to two commercially available COVID-19 rapid antigen test devices, the Panbio COVID-19 Ag Rapid Test Device and Roche SARS-CoV-2 Antigen Self-Test. In addition, we collected 31 COVID-19 rapid antigen test devices used to test patients who were symptomatic at The Royal Melbourne Hospital emergency department in Melbourne, Australia. We extracted total nucleic acid from the device paper test strips and assessed viral recovery using multiplex real-time PCR (rtPCR) and capture-based whole genome sequencing. Sequence and genome data were analysed through custom computational pipelines, including subtyping. Of the 140 respiratory viral targets from archival samples, 89 (64%) and 88 (63%) were positive on rtPCR for the relevant taxa following extraction from Panbio or Roche rapid antigen test devices, respectively. Recovery was variable across taxa: we detected influenza A in nine of 18 samples from Panbio and seven of 18 from Roche devices; parainfluenza in 11 of 20 samples from Panbio and 12 of 20 from Roche devices; human metapneumovirus in 11 of 16 from Panbio and 14 of 16 from Roche devices; seasonal coronavirus in eight of 19 from Panbio and two of19from Roche devices; rhinovirus in 24 of 28 from Panbio and 27 of 28 from Roche devices; influenza B in fourof 15 in both devices; and RSV in 16 of 18 in both devices. Of the 31 COVID-19 devices collected from The Royal Melbourne Hospital emergency department, 11 tested positive for a respiratory virus on rtPCR, including one device positive for influenza A virus, one positive for RSV, four positive for rhinovirus, and five positive for SARS-CoV-2. Sequences of target respiratory viruses from archival samples were detected in 55 (98·2%) of 56samples from Panbio and 48 (85·7%) of 56 from Roche rapid antigen test devices. 98 (87·5%) of 112 viral genomes were completely assembled from these data, enabling subtyping for RSV and influenza viruses. All 11samples collected from the emergency department had viral sequences detected, with near-complete genomes assembled for influenza A and RSV. Non-SARS-CoV-2 respiratory viruses can be detected and sequenced from COVID-19 rapid antigen devices. Recovery of near full-length viral sequences from these devices provides a valuable opportunity to expand genomic surveillance programmes for public health monitoring of circulating respiratory viruses. Australian Government Medical Research Future Fund and Australian National Health and Medical Research Council.

Drug repurposing screen identifies lonafarnib as respiratory syncytial virus fusion protein inhibitor.

Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infection in infants, older adults and the immunocompromised. Effective directly acting antivirals are not yet available for clinical use. To address this, we screen the ReFRAME drug-repurposing library consisting of 12,000 small molecules against RSV. We identify 21 primary candidates including RSV F and N protein inhibitors, five HSP90 and four IMPDH inhibitors. We select lonafarnib, a licensed farnesyltransferase inhibitor, and phase III candidate for hepatitis delta virus (HDV) therapy, for further follow-up. Dose-response analyses and plaque assays confirm the antiviral activity (IC50: 10-118 nM). Passaging of RSV with lonafarnib selects for phenotypic resistance and fixation of mutations in the RSV fusion protein (T335I and T400A). Lentiviral pseudotypes programmed with variant RSV fusion proteins confirm that lonafarnib inhibits RSV cell entry and that these mutations confer lonafarnib resistance. Surface plasmon resonance reveals RSV fusion protein binding of lonafarnib and co-crystallography identifies the lonafarnib binding site within RSV F. Oral administration of lonafarnib dose-dependently reduces RSV virus load in a murine infection model using female mice. Collectively, this work provides an overview of RSV drug repurposing candidates and establishes lonafarnib as a bona fide fusion protein inhibitor.

Epidemic profile of common respiratory viruses in association SARS CoV-2 among SARI and ARI-two year study.

COVID-19/SARS CoV-2 continue to pose a threat to human health and placed millions of livelihoods at risk. Surveillance for the other circulating seasonal viruses during this pandemic is necessary to understand the manifestations of the CoV-2 pandemic and their incidence. A detailed study survey was performed on subjects with acute respiratory infections (ARI) and severe acute respiratory infection (SARI) in the King Institute of Preventive Medicine and Research, Chennai from April 2020 to March 2022. A total of 1480 patients presenting with either SARI (41.8%) or ARI (58.1%) were screened for SARS CoV-2 and other respiratory viruses. The SARS CoV-2 real-time PCR was carried out using ICMR-approved kits and other respiratory viruses were detected using the commercially available real-time kit. Out of the 620 SARI patients, 198 (31.9%) were positive for SARS CoV-2 RNA. Out of the 860 ARI patients, 352 (40.9%) were positive for SARS CoV-2 RNA. Among the 550 patients positive for SARS CoV-2, 7 (1.2%) were positive coexistent with other respiratory viruses. Among the 930 patients with negative SARS CoV-2, 222 (23.8%) were positive for other common respiratory viruses (p = 0.001). Influenza viruses (36.9%) predominated followed by RSV (31.9%) and Parainfluenza virus (13.5%). This study suggests that viral coinfections are significantly higher among SARS CoV-2 negative individuals (23.8 vs. 1.2%). It is possibly due to viral interference and the competitive advantage of SARS CoV-2 in modulating the host immunity. Continuous surveillance is necessary for understanding the viral co-infection mechanisms.

Polyendemics: From theory to practice

After COVID-19, there was a resurgence of viral and bacterial diseases globally. Data from January 2023 indicates a shift in infectious disease patterns, with influenza, RSV, SARS-CoV-2, and other viruses prevalent, leading to a termed “polyendemia.” Increased cases of invasive group A beta-hemolytic streptococcal disease (SBEA) and scarlet fever, particularly in children, have been reported in various countries. Several factors contribute to the rise in respiratory infections, including the concept of “immunity debt,” interactions between respiratory viruses, and potential immune dysregulation induced by SARS-CoV-2. Recent reports also highlight increased pneumonia cases in Chinese children, attributed to various respiratory viruses. The implications for clinical practice emphasize prevention, advocating safety measures, and promoting vaccination, especially for influenza and COVID-19. A new monoclonal antibody, nirsevimab, offers passive immunization against RSV. Rapid diagnostic tests for the early identification of viruses or bacteria are recommended. The pediatrician underscores the importance of precise diagnosis for epidemiological understanding and future vaccination encouragement.

Vaccines for prevention of respiratory syncytial virus infection

Respiratory syncytial virus is a virus that causes infections in lower respiratory tract among infants aged under 5 years old, older adults aged above 65 years old and populations with other potential complications. Some susceptible populations to RSV may develop pneumonia and bronchiolitis. The mechanism of RSV virus transmission is through air droplets. The burden of hospitalization causes by the infection of RSV is severe and episodic, with the prevalence mainly concentrated in winter periods. The development of vaccines against RSV virus statutes in the early 1960s, but was paused and halted due to the failure of formalin inactivated vaccine. The current study first reviewed the prevalence, structure, mechanism and development history of RSV and its vaccines, following which the present work focus on a summary of the results of clinical trials of vaccines against RSV on different groups of populations, especially those with special condition, such as older adult and pregnant women.

Patterns of Antibiotic Use in Young Children Hospitalized with RSV in Amman, Jordan

Abstract Introduction Antibiotic misuse is associated with the emergence of antimicrobial-resistant bacteria. It is therefore important to limit antibiotic use for respiratory infections, especially those that are virus-associated. In developing countries, without point-of-care testing for common respiratory viruses (e.g., respiratory syncytial virus, or RSV), clinicians rely on clinical judgment clinicians relay on clinical judgement to distinguish between viral and bacterial causes of illness. We sought to evaluate patterns of antibiotic use in young, hospitalized children with RSV in Amman, Jordan. Methods A prospective acute respiratory viral surveillance study was conducted between January 8 and March 17, 2020. Eligible children were &amp;lt;2 years old presenting with fever and/or respiratory symptoms within 72 hours of hospitalization. Nasal or throat swabs were collected from each child. Research molecular testing for RSV and other respiratory viruses was performed. Demographic and clinical data were collected through parental interviews and chart abstractions. For this analysis, we restricted our study to children with RSV detected by research molecular testing. We classified antibiotic patterns into three categories: 1) 1st line/empiric: ampicillin, ceftriaxone, cefuroxime, cefotaxime, and gentamycin; 2) azithromycin; 3) expanded: vancomycin, amikacin, imipenem/meropenem, and metronidazole. We compared clinical characteristics and outcomes between the three antibiotic groups using Pearson's χ2 test for categorical variables and linear regression with robust standard errors for continuous variables. Results Of the 531 children who were enrolled, 400 (75.3%) were RSV-positive by research molecular testing: 221 (55.3%) were male, median age was 2.9 months (IQR, 1.7–6.4), 174/390 (44.6%) reported consuming an antibiotic prior to hospitalization, and 387 (96.8%) received at least one antibiotic during their hospitalization. The most common antibiotic category was empiric 261 (67.4%), followed by azithromycin (n=106; 27.4%) and expanded (n=16; 4.1%). Table 1 compares clinical and demographic data between antibiotic categories for RSV-positive children during hospitalization. Children in the empiric group had higher mean age and were more likely to be diagnosed with bronchopneumonia at admission, while those in the azithromycin group were more likely to be diagnosed with pertussis-like cough or bronchiolitis at admission. Children in the expanded group were more likely to have fever, be diagnosed with pneumonia at admission, require oxygen, and be admitted to the intensive care unit. Among those who had a blood, urine, and/or CSF culture performed (n=209; 54%), a total of 10 (2.6%) were positive for gram-positive bacteria. Conclusion In our study, most children received an antibiotic during their hospital stay. Antibiotic stewardship programs and the implementation of point-of-care testing in Jordanian hospitals are needed to help limit antibiotic use for RSV.

Disease Prevalence Due to Human Respiratory Syncytial Virus (HRSV) and Molecular Nature of G Gene in Different Geographical Region of India: 2005-2022

Human respiratory syncytial virus (hRSV) is the leading pediatric respiratory pathogen with high morbidity in the first year of life. The morbidity is particularly high in developing countries. it is the most common cause of infant hospitalization and causes a high burden of disease in the elderly. India is a country with vast geographical differences their unique climatic conditions. So, the prevalence of human RSV in different geographical regions is partially understood for a long time. This review was performed by using a different search engine like Google schooler, PubMed, etc. Significant prevalence and specific RSV virus strain circulation were major keywords used for the search in the Indian pediatric population. Annual incidence rates of RSV–associated hospitalization per 1000 children were highest among infants aged 0–5 months, followed by ages 6–23 months, and lowest among children 24–59 months. hRSV was a substantial cause of hospitalization among children aged &lt; 24 months especially those aged &lt;6 months. Prevalence varies from 2.1% to 44% in different geographical regions. hRSV has a more broadly distributed peak timing. numerous studies of the correlation between climatic factors and hRSV incidence across latitudes found variable and inconsistent correlations between hRSV incidence &amp; temperature, and relative humidity in different parts of the tropical region.However, genotypes ON1, NA1, GA5, and GA2 in the hRSV-A group and group hRSV-B BA, BA9, and BA12 were predominantly circulated in India.

Comparative analysis of clinical features of lower respiratory tract infection with respiratory syncytial virus and influenza virus in adults: a retrospective study

BackgroundRespiratory syncytial virus (RSV) infection in adults remains less recognized and understood, both socially and clinically, compared to influenza virus infection. This retrospective study aims to delineate and compare the clinical manifestations of adult RSV and influenza virus infections in the lower respiratory tract, thereby enhancing awareness of RSV lower respiratory tract infection and providing strategic insights for its prevention and treatment.MethodsClinical data from January 2019 to December 2020 were analyzed for 74 patients with RSV and 129 patients with influenza A/B virus lower respiratory tract infections who were admitted to respiratory or intensive care units. All patients had complete clinical data with positive IgM and negative IgG viral antibodies. Comparison parameters included onset timing, baseline data, clinical manifestations, supplementary examination results, treatment methods, and prognosis, while logistic regression was employed to ascertain the correlation of clinical features between the two patient groups.ResultsIn comparison to the influenza group, the RSV group presented less frequently with fever at admission but exhibited a higher incidence of dyspnea and wheezing on pulmonary auscultation (P < 0.01). RSV infection was more prevalent among patients with underlying diseases, particularly chronic obstructive pulmonary disease (COPD) and demonstrated a higher probability of co-infections, most notably with Mycoplasma (P < 0.01). The RSV group had significantly higher lymphocyte counts (P < 0.01) and exhibited more incidences of pleural thickening, pulmonary fibrosis, and emphysema (P < 0.05). The use of non-invasive mechanical ventilation was more common, and hospital stays were longer in the RSV group compared to the influenza group (P < 0.05). Logistic multivariate regression analysis further revealed that age and tachypnea incidence were significantly higher in the RSV group (P < 0.05).ConclusionCompared to influenza virus infection, adults with COPD are more susceptible to RSV infection. Moreover, RSV infection elevates the risk of co-infection with Mycoplasma and may lead to conditions such as pleural thickening, pulmonary fibrosis, and emphysema. The requirement for non-invasive mechanical ventilation is higher in RSV-infected patients, who also tend to have longer hospital stays. Therefore, greater awareness and preventive strategies against RSV infection are imperative.

Epidemiological Changes in Respiratory Viral Infections in Children: The Influence of the COVID-19 Pandemic.

Viruses are the major cause of acute respiratory infections in children, causing important morbimortality. Before the COVID-19 pandemic, in temperate regions, respiratory viruses displayed a typical seasonality in transmission. A disruption in this pattern was observed in several countries during the pandemic, with low prevalence during the typical season, and an interseasonal rise. We evaluated the effects of the COVID-19 pandemic in the epidemiology of non-COVID viral respiratory infections in children, in a tertiary care hospital in Portugal. Between March 2020 and August 2022, nasopharyngeal samples from children with respiratory symptoms in the Emergency Department (ED) and the Pediatric Ward were tested for RSV, influenza and other respiratory viruses, by real-time reverse transcriptase PCR (RT-PCR). A seasonal variation was observed from 2018 to 2020, with prevalence increasing in winter (mainly RSV and influenza). In the winter of 2020/21, when measures to mitigate SARS-CoV-2 transmission were stricter, there was a disruption of the seasonal pattern, with unusually low numbers. In the summer of 2021, when measures were being relaxed, there was an atypical rise. In June 2021, RSV was first detected and peaked in October. Influenza (Influenza A H3) was detected for the first time in February 2022, peaking in March/April. These findings show a disruption of the seasonality of viral respiratory infections in children during the pandemic, with a virtual elimination during the months of usually higher prevalence, and a subsequent out-of-season increase, coinciding with variations in the measures implemented to control the SARS-CoV-2 transmission, and confirming their efficacy.

TLR7 activation at epithelial barriers promotes emergency myelopoiesis and lung antiviral immunity.

Monocytes are heterogeneous innate effector leukocytes generated in the bone marrow and released into circulation in a CCR2-dependent manner. During infection or inflammation, myelopoiesis is modulated to rapidly meet the demand for more effector cells. Danger signals from peripheral tissues can influence this process. Herein we demonstrate that repetitive TLR7 stimulation via the epithelial barriers drove a potent emergency bone marrow monocyte response in mice. This process was unique to TLR7 activation and occurred independently of the canonical CCR2 and CX3CR1 axes or prototypical cytokines. The monocytes egressing the bone marrow had an immature Ly6C-high profile and differentiated into vascular Ly6C-low monocytes and tissue macrophages in multiple organs. They displayed a blunted cytokine response to further TLR7 stimulation and reduced lung viral load after RSV and influenza virus infection. These data provide insights into the emergency myelopoiesis likely to occur in response to the encounter of single-stranded RNA viruses at barrier sites.

Clinical relevance of viral codetection in infants with respiratory syncytial virus bronchiolitis

IntroductionRespiratory syncytial virus (RSV) is the main cause of severe bronchiolitis, especially in infants. The aim of this study is to assess whether codetection of RSV and other respiratory viruses could affect the severity of this infection comparing with unique RSV detection. MethodsA prospective study from 2016 to 2019 including children under 2 years who were admitted in the Emergency Service of the Hospital Universitari Arnau de Vilanova de Lleida (Spain) was performed. Nasopharyngeal samples from all patients were sent to the laboratory for RSV real-time PCR detection (GeneXpert®). A multiplex PCR that detects other respiratory viruses was done in all RSV-positive samples. Patients’medical records were checked to collect clinical data (hospital length of stay, BROSJOD score, ICU admission, need for ventilatory support or transfer to a reference hospital). Patients were divided in two groups: infants with unique RSV detection and infants with viral codetection. Bivariant analyses were performed to analyze the data obtained. ResultsDuring the period of study 437 RSV bronchiolitis were diagnosed. In 199 of them (177/437; 45,5%) another respiratory virus was detected concomitantly. Bivariant analyses do not show statistically significant differences between both groups. ConclusionsViral codetection in infants with RSV bronchiolitis is frequent. However, it does not seems to affect the severity of this infection.