Respiratory Syncytial Research Articles

Rational design of uncleaved prefusion-closed trimer vaccines for human respiratory syncytial virus and metapneumovirus.

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause human respiratory diseases and are major targets for vaccine development. In this study, we design uncleaved prefusion-closed (UFC) trimers for the fusion protein (F) of both viruses by examining mutations critical to F metastability. For RSV, we assess four previous prefusion F designs, including the first and second generations of DS-Cav1, SC-TM, and 847A. We then identify key mutations that can maintain prefusion F in a native-like, closed trimeric form (up to 76%) without introducing any interprotomer disulfide bond. For hMPV, we develop a stable UFC trimer with a truncated F2-F1 linkage and an interprotomer disulfide bond. Dozens of UFC constructs are characterized by negative-stain electron microscopy (nsEM), x-ray crystallography (11 RSV-F structures and one hMPV-F structure), and antigenic profiling. Using an optimized RSV-F UFC trimer as bait, we identify three potent RSV neutralizing antibodies (NAbs) from a phage-displayed human antibody library, with a public NAb lineage targeting sites Ø and V and two cross-pneumovirus NAbs recognizing site III. In mouse immunization, rationally designed RSV-F and hMPV-F UFC trimers induce robust antibody responses with high neutralizing titers. Our study provides a foundation for future prefusion F-based RSV and hMPV vaccine development.

Exploring Risk Factors Associated With Intensive Care Unit Admission in a Retrospective Cohort of 631 Children With Bronchiolitis.

Examine the trends and epidemiological features of acute hospitalized bronchiolitis cases among children aged 28 days to 2 years, both before and after the COVID-19 pandemic. Furthermore, evaluate their need for intensive care unit (ICU) admission and identify primary risk factors associated with severe bronchiolitis. A retrospective analysis was conducted on the medical records of paediatric patients admitted to Meyer Children's Hospital in Florence (Italy) from September 2019 to March 2023, with the diagnosis of bronchiolitis. Between 2019 and 2023, bronchiolitis hospitalizations grew by 76%, going from 131 to 230 cases, after the historical minimum of 14 cases in the 2020-2021 season. Respiratory syncytial virus (RSV) infection emerged as the predominant etiological agent, contributing to 76% of hospitalizations in both 2021-2022 and 2022-2023 seasons. Coinfection cases increased fivefold from 2019 to 2023, accounting for 23% of hospitalizations in 2022-2023. In addition, the ICU admission rate increased from 13% in 2019-2020 to 31% of bronchiolitis hospitalizations in 2022-2023. Univariate and multivariate analysis data show that infants below 2 months of age, preterm births, comorbidities and RSV infections were correlated with a higher risk for ICU admission. The growing trend in ICU admissions for acute bronchiolitis in hospitalized children represents a substantial health challenge. Addressing the bronchiolitis epidemic necessitates a strategic focus on RSV prevention through interventions such as vaccines and monoclonal antibodies. Urgent implementation of preventive initiatives, together with continuous surveillance and the establishment of national databases, is imperative and cannot be further deferred.

What Is RSV Infection in Adults?

What Is RSV Infection in Adults?

Characteristics of the respiratory season in 2022—23 and 2023—24 according to data from the city children's hospital

The end of the COVID-19 pandemic in the respiratory disease season of 2022—23 was characterized by an increase in the number of cases, a shift in the classic peaks of morbidity for various infections, and a predominance of influenza and respiratory syncytial virus infection (RSVI). Materials and methods. When compared with the last pandemic season, a later start of the 2023—24 respiratory season was noted with a gradual shift to the usual pre-pandemic period timing of viral morbidity increases. Results. The currently prevailing SARS-CoV-2 Omicron variant has acquired the properties of a common respiratory viral infection, currently all-season, with a mild course, without the need for hospitalization. The number of patients with influenza has decreased and there were no patients with a severe course of this infection. A feature of the first post-pandemic season was the outbreak of mycoplasma infection, which was a reason of large number of pneumonia cases.

Annual Clinical and Economic Burden of Medically Attended Lower Respiratory Tract Illnesses Due to Respiratory Syncytial Virus among US Infants Aged

We developed a model to project the expected annual clinical and economic burden of medically attended lower respiratory tract illnesses due to respiratory syncytial virus (RSV-LRTI) among US infants aged <12 months by combining information on population size, disease rates, mortality rates, and unit costs. Among the 3.7 million US infants aged <12 months each year, a total of 592,700 cases of RSV-LRTI (hospitalizations: 48,499; emergency department visits: 144,599; outpatient clinic visits: 399,602) were projected to occur, yielding total annual costs of $1.6 billion. The annual burden of RSV-LRTI among US infants is considerable, especially among those aged <3 months, who account for 43% of total costs.

Nirsevimab Effectiveness Against Medically Attended Respiratory Syncytial Virus Illness and Hospitalization Among Alaska Native Children - Yukon-Kuskokwim Delta Region, Alaska, October 2023-June 2024.

Respiratory syncytial virus (RSV) is a leading cause of hospitalization among young children. Historically, American Indian and Alaska Native (AI/AN) children have experienced high rates of RSV-associated hospitalization. In August 2023, a preventive monoclonal antibody (nirsevimab) was recommended for all infants aged <8 months (born during or entering their first RSV season) and for children aged 8-19 months (entering their second RSV season) who have increased risk for severe RSV illness, including all AI/AN children. This evaluation in Alaska's Yukon-Kuskokwim Delta region estimated nirsevimab effectiveness among AI/AN children in their first or second RSV seasons during 2023-2024. Among 472 children with medically attended acute respiratory illness (ARI), 48% overall had received nirsevimab ≥7 days earlier (median=91 days before the ARI-related visit). For children in their first RSV season (292), nirsevimab effectiveness was 76% (95% CI = 42%-90%) against medically attended RSV illness and 89% (95% CI = 32%-98%) against RSV hospitalization. For children in their second RSV season (180), effectiveness against medically attended RSV illness was 88% (95% CI=48%-97%). Nirsevimab is effective for preventing severe RSV illness among infants entering their first RSV season and children entering their second season with increased risk for severe RSV, including all AI/AN children.

A self-amplifying RNA RSV prefusion-F vaccine elicits potent immunity in pre-exposed and naïve non-human primates.

Newly approved subunit and mRNA vaccines for respiratory syncytial virus (RSV) demonstrate effectiveness in preventing severe disease, with protection exceeding 80% primarily through the generation of antibodies. An alternative vaccine platform called self-amplifying RNA (saRNA) holds promise in eliciting humoral and cellular immune responses. We evaluate the immunogenicity of a lipid nanoparticle (LNP)-formulated saRNA vaccine called SMARRT.RSV.preF, encoding a stabilized form of the RSV fusion protein, in female mice and in non-human primates (NHPs) that are either RSV-naïve or previously infected. Intramuscular vaccination with SMARRT.RSV.preF vaccine induces RSV neutralizing antibodies and cellular responses in naïve mice and NHPs. Importantly, a single dose of the vaccine in RSV pre-exposed NHPs elicits a dose-dependent anamnestic humoral immune response comparable to a subunit RSV preF vaccine. Notably, SMARRT.RSV.preF immunization significantly increases polyfunctional RSV.F specific memory CD4+ and CD8+ T-cells compared to RSV.preF protein vaccine. Twenty-four hours post immunization with SMARRT.RSV.preF, there is a dose-dependent increase in the systemic levels of inflammatory and chemotactic cytokines associated with the type I interferon response in NHPs, which is not observed with the protein vaccine. We identify a cluster of analytes including IL-15, TNFα, CCL4, and CXCL10, whose levels are significantly correlated with each other after SMARRT.RSV.preF immunization. These findings suggest saRNA vaccines have the potential to be developed as a prophylactic RSV vaccine based on innate, cellular, and humoral immune profiles they elicit.

Computational Evidence for Bisartan Arginine Blockers as Next-Generation Pan-Antiviral Therapeutics Targeting SARS-CoV-2, Influenza, and Respiratory Syncytial Viruses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, and respiratory syncytial virus (RSV) are significant global health threats. The need for low-cost, easily synthesized oral drugs for rapid deployment during outbreaks is crucial. Broad-spectrum therapeutics, or pan-antivirals, are designed to target multiple viral pathogens simultaneously by focusing on shared molecular features, such as common metal cofactors or conserved residues in viral catalytic domains. This study introduces a new generation of potent sartans, known as bisartans, engineered in our laboratories with negative charges from carboxylate or tetrazolate groups. These anionic tetrazoles interact strongly with cationic arginine residues or metal cations (e.g., Zn2+) within viral and host target sites, including the SARS-CoV-2 ACE2 receptor, influenza H1N1 neuraminidases, and the RSV fusion protein. Using virtual ligand docking and molecular dynamics, we investigated how bisartans and their analogs bind to these viral receptors, potentially blocking infection through a pan-antiviral mechanism. Bisartan, ACC519TT, demonstrated stable and high-affinity docking to key catalytic domains of the SARS-CoV-2 NSP3, H1N1 neuraminidase, and RSV fusion protein, outperforming FDA-approved drugs like Paxlovid and oseltamivir. It also showed strong binding to the arginine-rich furin cleavage sites S1/S2 and S2′, suggesting interference with SARS-CoV-2’s spike protein cleavage. The results highlight the potential of tetrazole-based bisartans as promising candidates for developing broad-spectrum antiviral therapies.

Burden of Respiratory Syncytial Virus-Associated Hospitalizations in US Adults, October 2016 to September 2023.

Respiratory syncytial virus (RSV) infection can cause severe illness in adults. However, there is considerable uncertainty in the burden of RSV-associated hospitalizations among adults prior to RSV vaccine introduction. To describe the demographic characteristics of adults hospitalized with laboratory-confirmed RSV and to estimate annual rates and numbers of RSV-associated hospitalizations, intensive care unit (ICU) admissions, and in-hospital deaths. This cross-sectional study used data from the RSV Hospitalization Surveillance Network (RSV-NET), a population-based surveillance platform that captures RSV-associated hospitalizations in 58 counties in 12 states, covering approximately 8% of the US population. The study period spanned 7 surveillance seasons from 2016-2017 through 2022-2023. Included cases from RSV-NET were nonpregnant hospitalized adults aged 18 years or older residing in the surveillance catchment area and with a positive RSV test result. Laboratory-confirmed RSV-associated hospitalization, defined as a positive RSV test result within 14 days before or during hospitalization. Hospitalization rates per 100 000 adult population, stratified by age group. After adjusting for test sensitivity and undertesting for RSV in adults hospitalized with acute respiratory illnesses, rates were extrapolated to the US population to estimate annual numbers of RSV-associated hospitalizations. Clinical outcome data were used to estimate RSV-associated ICU admissions and in-hospital deaths. From the 2016 to 2017 through the 2022 to 2023 RSV seasons, there were 16 575 RSV-associated hospitalizations in adults (median [IQR] age, 70 [58-81] years; 9641 females [58.2%]). Excluding the 2020 to 2021 and the 2021 to 2022 seasons, when the COVID-19 pandemic affected RSV circulation, hospitalization rates ranged from 48.9 (95% CI, 33.4-91.5) per 100 000 adults in 2016 to 2017 to 76.2 (95% CI, 55.2-122.7) per 100 000 adults in 2017 to 2018. Rates were lowest among adults aged 18 to 49 years (8.6 [95% CI, 5.7-16.8] per 100 000 adults in 2016-2017 to 13.1 [95% CI, 11.0-16.1] per 100 000 adults in 2022-2023) and highest among adults 75 years or older (244.7 [95% CI, 207.9-297.3] per 100 000 adults in 2022-2023 to 411.4 [95% CI, 292.1-695.4] per 100 000 adults in 2017-2018). Annual hospitalization estimates ranged from 123 000 (95% CI, 84 000-230 000) in 2016 to 2017 to 193 000 (95% CI, 140 000-311 000) in 2017 to 2018. Annual ICU admission estimates ranged from 24 400 (95% CI, 16 700-44 800) to 34 900 (95% CI, 25 500-55 600) for the same seasons. Estimated annual in-hospital deaths ranged from 4680 (95% CI, 3570-6820) in 2018 to 2019 to 8620 (95% CI, 6220-14 090) in 2017 to 2018. Adults 75 years or older accounted for 45.6% (range, 43.1%-48.8%) of all RSV-associated hospitalizations, 38.6% (range, 36.7%-41.0%) of all ICU admissions, and 58.7% (range, 51.9%-67.1%) of all in-hospital deaths. In this cross-sectional study of adults hospitalized with RSV before the 2023 introduction of RSV vaccines, RSV was associated with substantial burden of hospitalizations, ICU admissions, and in-hospital deaths in adults, with the highest rates occurring in adults 75 years or older. Increasing RSV vaccination of older adults has the potential to reduce associated hospitalizations and severe clinical outcomes.

Infectivity and immunogenicity of live-attenuated respiratory syncytial virus vaccines in HIV-exposed uninfected children

Abstract Background Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory illness among young children. HIV-exposed uninfected (HEU) children experience a higher burden of RSV disease and have immune abnormalities that may influence their responses to live-attenuated RSV vaccines. Methods In a pooled analysis of clinical trials of seven live-attenuated, intranasal RSV vaccines conducted by the IMPAACT Network among children 6 to &amp;lt;25 months of age with serum RSV-neutralizing titers of &amp;lt;1:40, the infectivity and immunogenicity of these vaccines were compared among HEU and HIV-unexposed uninfected (HUU) children. Nasal washes were collected during the first 28 days after vaccination. Serum RSV-neutralizing and anti-RSV F glycoprotein IgG antibodies were measured prior to and 56 days after vaccination, and before and after the following winter season. Results Of 156 children, 90 (58%) were HUU and 66 (42%) were HEU. Seventy-six (84%) HUU and 63 (95%) HEU participants were infected with vaccine (shed vaccine virus and/or had a ≥4-fold rise in serum RSV antibodies at 56 days after vaccination). HUU children had higher serum RSV-neutralizing and anti-RSV F IgG titers prior to vaccination. Compared to HEU children, lower percentages of HUU children had ≥4-fold rises in RSV-neutralizing (67% vs. 88%) and anti-RSV F IgG (70% vs. 89%) titers at 56 days after vaccination. Conclusions Live-attenuated RSV vaccines are highly immunogenic in HEU children. Given their increased burden of RSV disease and higher early-childhood mortality in some settings, HEU children should be prioritized for vaccination against RSV as these vaccines become available.

Immune Responses to Respiratory Syncytial Virus Vaccines: Advances and Challenges

Respiratory Syncytial Virus (RSV) is a leading cause of acute respiratory infections, particularly in children and the elderly. This virus primarily infects ciliated epithelial cells and activates alveolar macrophages and dendritic cells, triggering an innate antiviral response that releases pro-inflammatory cytokines. However, immunity generated by infection is limited, often leading to reinfection throughout life. This review focuses on the immune response elicited by newly developed and approved vaccines against RSV. A comprehensive search of clinical studies on RSV vaccine candidates conducted between 2013 and 2024 was performed. There are three primary target groups for RSV vaccines: pediatric populations, infants through maternal immunization, and the elderly. Different vaccine approaches address these groups, including subunit, live attenuated or chimeric, vector-based, and mRNA vaccines. To date, subunit RSV vaccines and the mRNA vaccine have been approved using the pre-fusion conformation of the F protein, which has been shown to induce strong immune responses. Nevertheless, several other vaccine candidates face challenges, such as modest increases in antibody production, highlighting the need for further research. Despite the success of the approved vaccines for adults older than 60 years and pregnant women, there remains a critical need for vaccines that can protect children older than six months, who are still highly vulnerable to RSV infections.

Abstract 4123849: Respiratory Syncytial Virus (RSV) Cases Involving Hospitalization Are Associated with an Increased Risk of Myocardial Infarction and All−Cause Mortality Among Adults Aged 50 Years and Older

Background: Older adults and adults with comorbidities are at increased risk for severe respiratory syncytial virus (RSV) disease and related complications. Aims: To estimate the risk of myocardial infarction (MI) and all−cause mortality among adults aged ≥50 years hospitalized with RSV compared to those with no recent acute respiratory illness (ARI) and those hospitalized with influenza. Methods: Data from Optum’s de−identified Clinformatics® Data Mart Database were analyzed (October 2015–June 2023) in this retrospective cohort study. Adults aged ≥50 years with ≥12 months of continuous enrollment were assigned to cohorts based on RSV or influenza hospitalization (from ICD−10 codes; RSV and flu cohorts) or no recent ARI (control cohort). Index dates for RSV and flu cohorts were the start of an ARI that included hospitalization. Baseline characteristics were measured in the 12 months pre−index. MI (from ICD−10 codes) and all−cause mortality were measured during follow−up and compared between cohorts using time−varying coefficient multivariable adjusted Cox models (MI results accounted for the competing risk of death). Results: In the RSV cohort (n=14,759), mean age (76.5 years) and mean Charlson comorbidity index (CCI; 3.3) were higher than the flu (n=77,468; 75.4 years, CCI=2.9) and control (n=73,795; 69.5 years, CCI=1.0) cohorts. Adjusted HRs (95% CI) for MI and all−cause mortality risk were significantly higher in the RSV vs control cohort across follow−up, ranging from 30.96 (26.22–36.54) within 30 days post−index to 2.26 (2.04–2.51) &gt;365 days post−index for MI and 10.77 (9.19–12.63) within 30 days post−index to 2.29 (2.18–2.42) &gt;365 days post−index for mortality. Compared to the flu cohort, adjusted MI and mortality risk in the RSV cohort were lower during the 30 days post−index (MI: 0.87 [0.82–0.92]; mortality: 0.84 [0.78–0.90]) but higher &gt;365 days post−index (MI: 1.11 [1.01–1.22]; mortality: 1.05 [1.01–1.10]). Conclusion: MI and all−cause mortality risk were higher for hospitalized RSV cases compared to controls. Smaller differences in outcomes were observed when comparing hospitalized RSV cases with hospitalized influenza cases, with varying direction over time. With existing evidence of increased MI and mortality risk after influenza and these findings on MI and mortality risk after RSV, future research should aim to further understand the impact of RSV on cardiovascular outcomes and assess the role of RSV prevention in lowering the risk of MI and mortality.

Real-world use of multiplex point-of-care molecular testing or laboratory-based molecular testing for influenza-like illness in a 2021 to 2022 US outpatient sample.

While molecular testing is recommended for symptomatic patients suspected of having coronavirus disease 2019 (COVID-19), limited data are available examining real-world use of tests for severe acute respiratory syndrome coronavirus (SARS-CoV-2) and the impact of SARS-CoV-2 testing on patient outcomes. In this retrospective cohort study using de-identified administrative claims data in the Optum Labs Data Warehouse, we identified 2 groups of patients with ≥1 outpatient claims with a procedure code for SARS-CoV-2 testing between January 2021 and September 2022. Group 1 had ≥1 claims with CPT code 0240U or 0241U ("Xpert Xpress") (N = 51,602); Group 2 had ≥1 claims for laboratory-based molecular testing (N = 317,192). Outcomes assessed on the identification date and through the 90-day follow-up included claims evidence of use of SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) tests, diagnosis of active COVID-19, influenza, or RSV, and use of treatments (antivirals for COVID-19, influenza, and RSV and other treatments for COVID-19 and RSV). Patients in Group 1 had fewer tests for SARS-CoV-2, influenza, or RSV (mean ± standard deviation 1.6±1.4 versus 2.6±2.6, standardized difference -0.45), faster time to diagnosis of COVID-19 (median 0 versus 4 days, standardized difference -0.27) or influenza (median 0 versus 5 days, standardized difference -0.74), and faster time to treatment of COVID-19, influenza, or RSV (median 1 versus 5 days, standardized difference 0.16) than patients in Group 2. In this nationwide real-world study of outpatient testing, use of point-of-care molecular multiplex SARS-CoV-2 testing resulted in fewer claims for SARS-CoV-2, influenza, and RSV tests, faster time to diagnosis, and faster time to treatment than laboratory-based molecular testing.

Spatial and temporal transmission dynamics of respiratory syncytial virus in New Zealand before and after the COVID-19 pandemic.

Human respiratory syncytial virus (RSV) is a major cause of acute respiratory infection. In 2020, RSV was eliminated from New Zealand due to non-pharmaceutical interventions (NPI) used to control the spread of SARS-CoV-2. However, in 2021, following a brief quarantine-free travel agreement with Australia, there was a large-scale nationwide outbreak of RSV that led to reported cases more than five-times higher than typical seasonal patterns. We generated 1470 viral genomes of both RSV-A and RSV-B sampled between 2015-2022 from across New Zealand. Using a phylodynamics approach, we used these data to better understand RSV transmission patterns in New Zealand prior to 2020, and how RSV became re-established in the community following the relaxation of COVID-19 restrictions. We found that in 2021, there was a large epidemic of RSV due to an increase in importations, leading to several large genomic clusters of both RSV-A ON1 and RSV-B BA9 genotypes. However, while a number of viral importations were detected, there was also a major reduction in RSV genetic diversity compared to pre-pandemic years. These data reveal the impact of NPI used during the COVID-19 pandemic on other respiratory infections and highlight the important insights that can be gained from viral genomes.

Transferable lessons for care provided to children with intellectual and developmental disabilities based on an analysis of facilitators and barriers to SARS-CoV-2 testing

IntroductionThe purpose of this article is to report on the lessons learned from parents and caregivers of school-age children with intellectual and developmental disabilities (IDD) in Missouri and Maryland regarding the facilitators and barriers to SARS-COV-2 testing.MethodsParents participated in interview sessions that employed fuzzy cognitive mapping (FCM), a reliable knowledge-based method that facilitates democratic discourse to understand how stakeholders make decisions. A total of 94 parents from Missouri (58) and Maryland (36) participated in the FCM sessions.ResultsEight primary barriers and eight primary facilitating factors were identified that influence a successful SARS-COV-2 test. Analyzing the connections between these factors provided valuable information about not only which ideas were most central to the goal of a successful test, but also which factors could be modified to improve the likelihood of success. Results indicate that the physical environment and child preparedness play a central role in successful SARS-COV-2 testing for children with IDD; however, these factors within the context of other invasive procedures should be studied further.DiscussionIt is likely that the findings from this study are transferable to other diagnostic procedures such as influenza, respiratory syncytial virus (RSV), and methicillin-resistant Staphylococcus aureas (MRSA), which require similar testing techniques using a nasopharyngeal swab.

On the issue of the etiology of community-acquired pneumonia in children

According to global statistics, the number of cases of community-acquired pneumonia in children exceeds 150 million per year, and despite the introduction of vaccinations, this figure has not significantly decreased. Respiratory viruses, particularly respiratory syncytial virus, are recognized as the main cause of community-acquired pneumonia among preschool children during non-epidemic periods. Pneumococci also continue to play a significant role among bacterial pathogens. There is a significant increase in the prevalence of M. pneumoniae in the etiological structure of community-acquired pneumonia in recent years. Modern clinical guidelines for the use of antibiotics recommend taking into account patient age, vaccination status, and data on circulating pneumococcal strains when prescribing treatment. The COVID-19 pandemic and its subsequent relaxation of strict restrictions in the last two years have led to changes in the structure of infectious diseases, including the causes of lower respiratory tract infections.

Clinical analysis of 124 cases of mycoplasma pneumoniae infection with conjunctivitis in children

Objective: To explore the distribution characteristics of symptoms and signs of respiratory mycoplasma pneumoniae infection complicated with conjunctivitis in children of different age groups. Methods: A retrospective case series study was conducted. Data of children who were treated in Beijing Children's Hospital Affiliated to Capital Medical University from September 20, 2023 to November 30, 2023, had definite mycoplasma pneumoniae infection as confirmed by mycoplasma pneumoniae nucleic acid or mycoplasma pneumoniae IgM antibody test, and had conjunctivitis as the first diagnosis in ophthalmology department were continuously collected. The included children were divided into infant group (age<4 years), preschool group (age 4 to 6 years), and school-age group (age>6 years) for analysis. Information such as the time of ocular symptoms onset, the time of systemic symptoms onset, conjunctival sac secretion, subconjunctival hemorrhage, conjunctival congestion, corneal epithelial damage, co-infection with other pathogens, and treatment of all children was collected and compared among children of different age groups. Results: During this period, there were a total of 31 133 children with positive laboratory test results for mycoplasma pneumoniae. Among them, 835 children visited the ophthalmology department during the same period, and 124 cases (229 eyes) had conjunctivitis as the first diagnosis. The age was (5.43±2.83) years, including 72 males and 52 females. There were 37 cases (69 eyes) in the infant group, 48 cases (92 eyes) in the preschool group, and 39 cases (68 eyes) in the school-age group. Among the 229 eyes, 179 eyes (78.16%) had conjunctival secretion, all manifested as mucopurulent secretion; 12 eyes (5.24%) had corneal epithelial defect; and 26 eyes (11.35%) had subconjunctival hemorrhage. There was 1 eye (1.45%) with subconjunctival hemorrhage in the infant group, 16 eyes (17.39%) in the preschool group, and 9 eyes (13.24%) in the school-age group. The proportion of subconjunctival hemorrhage in the preschool group and school-age group was higher than that in the infant group (both P<0.05). Thirty-nine cases (31.45%) were found to have co-infection with viruses in laboratory tests, including influenza A virus, adenovirus, respiratory syncytial virus, and coxsackievirus. The proportion of children in all age groups with ocular symptoms first was higher than that with systemic symptoms first. There was no statistically significant difference among children in the three age groups in terms of whether there was conjunctival secretion, whether there was corneal epithelial damage, whether there was co-infection with viruses, and the interval between ocular symptoms and systemic symptoms onset (all P>0.05). Conclusions: The characteristic ocular manifestations of children with mycoplasma pneumoniae infection complicated with conjunctivitis are conjunctival congestion and subconjunctival hemorrhage, and the signs are more obvious in preschool children. The conjunctival sac secretion of such children with conjunctivitis is mostly manifested as mucopurulent. Ocular symptoms may be the first manifestation of mycoplasma pneumoniae infection.

The Impact of Palivizumab for Respiratory Syncytial Virus Prophylaxis on Preschool Childhood Asthma

Background: The respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and is associated with an increased risk of asthma development. Palivizumab, an RSV prophylactic, reduces RSV-related hospitalizations in high-risk infants, but its impact on long-term asthma outcomes remains unclear. This study compares asthma-related healthcare utilization in preschool children born prematurely between those who received Palivizumab (the Prophylaxis (+) group) and those who did not (the Prophylaxis (–) group). Methods: This nationwide, population-based retrospective cohort study utilized data from Clalit Healthcare Services in Israel. The study included children born between 32 + 6 and 34 + 6 weeks of gestational age from 2011 to 2018. Descriptive analysis, univariate analysis, and multivariate logistic regression were performed to compare the Prophylaxis (+) and the Prophylaxis (–) groups. Results: In total, 4503 children were included, with 3287 in the Prophylaxis (+) group and 1216 in the Prophylaxis (–) group. Palivizumab administration was associated with reduced hospitalizations for RSV bronchiolitis (1.8% vs. 3.3%, p = 0.003). However, no significant differences were observed in multivariate analysis for long-term asthma outcomes, including asthma diagnosis (OR = 1.04, CI = 0.84–1.30, p = 0.7) or emergency department visits for asthma (OR = 0.79, CI = 0.54–1.17, p = 0.2). Similarly, Palivizumab administration was not associated with the purchase of short-acting beta-agonists (OR = 1.14, 95% CI 0.98–1.32, p = 0.084), inhaled corticosteroids (OR = 1.1, CI = 0.93–1.32, p = 0.3), or oral corticosteroids (OR = 1.09, CI = 0.94–1.26, p = 0.3). Conclusions: While Palivizumab effectively reduces RSV acute bronchiolitis in preterm infants, it does not significantly impact long-term preschool asthma-related healthcare utilization.

Hospital-based cross-sectional study on the clinical characteristics of children with severe acute respiratory infections in Hungary

BackgroundSevere acute respiratory infection (SARI) is a major cause for hospital admission and associated with high mortality among children worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza viruses and respiratory syncytial virus (RSV) are the most frequently identified pathogens in children with SARI. The duration of care can be affected by the type of infection and patient characteristics. Therefore, the objective of this study was to identify factors affecting the length of hospitalization in children infected with SARS-CoV-2, influenza A and RSV.MethodsWe collected data on 713 children with SARI from the medical databases of a university hospital in Hungary. To examine whether there is a difference in the length of hospitalization in children with the SARI Kruskal-Wallis test was performed. To determine the factors that may have an impact on the duration of care a multiple logistic regression analysis was executed.ResultsOur results showed that among RSV infected patients the proportions of children requiring intensive care (8.94%), mechanical ventilation (8.94%) and oxygen therapy (13.01%) and suffering from pneumonia (29.27%) were larger than among cases with SARS-CoV-2 and influenza A infection. Considering the age distribution and the duration of care in children with SARI, cases with RSV were significantly younger (p < 0.001) and stayed longer in the hospital (median: 5 days, IQR: 4–7 days, p < 0.001) than those with SARS-CoV-2 and influenza A virus. Multiple logistic regression analysis showed that RSV infection (adjusted odds ratio (aOR): 3.25, 95% confidence interval (CI): 1.43–7.38; p = 0.005), pneumonia (aOR: 3.65, 95% CI: 2.14–6.24; p < 0.001), mechanical ventilation or oxygen therapy (aOR: 3.23, 95% CI: 1.29–8.11; p = 0.012) and underlying illnesses (aOR: 2.39, 95% CI: 1.35–4.23; p = 0.003) significantly increased the odds of hospitalization for more than 4 days.ConclusionsOur research showed that of the viruses causing SARI, RSV had the greatest clinical relevance, contributing to hospital stays of more than 4 days in a large share of paediatric patients below 1 year of age. Our results supply new information on children with SARI, and provide evidence for health policy makers to allocate additional resources to hospitals during SARI epidemics.

Observational Study on the Clinical Reality of Community-Acquired Respiratory Virus Infections in Adults and Older Individuals

The impact of common respiratory virus infections on adults and older individuals in the community is unclear, excluding seasonal influenza viruses. We examined FilmArray® tests performed on 1828 children aged &lt;10 years and 10,803 adults, including cases with few respiratory symptoms, between January 2021 and June 2024. Approximately 80% of the children tested positive for ≥1 viruses, while 9.5% of the adults tested positive mostly for severe acute respiratory syndrome corona virus-2 (SARS-CoV-2). Besides SARS-CoV-2 infection, 66 out of 97 patients (68.0%) aged &gt;60 years with rhinovirus/enterovirus (RV/EV), respiratory syncytial virus (RSV), parainfluenza virus-3 (PIV-3), or human metapneumovirus (hMPV) infection required hospitalization, of whom seven died; 26 out of 160 patients (16.3%) aged &lt;60 years required hospitalization mostly because of deterioration of bronchial asthma, with no reported deaths. In older patients with RV/EV infection, three with few respiratory symptoms died due to worsened heart failure. Although the frequency of common respiratory virus infections in older adults is low, it may be overlooked because of subclinical respiratory symptoms, and its clinical significance in worsening comorbidities in older adults should not be underestimated.