Human rhinovirus is one of the leading causes of pediatric respiratory infections worldwide. Its circulation patterns have shown notable changes in recent years. This study aimed to compare the epidemiologic, clinical and laboratory characteristics of rhinovirus infections and coinfections in 2 consecutive periods to identify shifts in age distribution, symptom patterns, healthcare utilization and pathogen codetection among pediatric patients. A retrospective analysis was conducted at a tertiary pediatric center and included all children aged 0-18 years with laboratory-confirmed rhinovirus infection between December 2023 and October 2025. Two consecutive 11-month periods were compared: December 2023-October 2024 (Period 1) and December 2024-October 2025 (Period 2). Demographic and laboratory parameters were recorded. A total of 572 children with rhinovirus-positive samples were evaluated. The number of cases increased 2.9-fold in December 2024-October 2025 (Period 2) (from 141 to 431; 0.42 vs. 1.22 cases/day), while age and sex distributions remained similar. Children under 6 years represented the most detections, and the proportions of 0-2-year-old children were similar in both periods. Fever, cough and rhinorrhea were significantly less frequent in Period 2. Chest X-ray use increased overall (34.8%-49.7%) but remained unchanged among hospitalized patients. Hospitalization rates were comparable, and antibiotic use declined (60.0%-48.9%). Multivariable analysis showed that neither hospitalization nor antibiotic exposure predicted period assignment. Coinfections increased from 3.5% to 10.2%, though severe outcomes remained rare. Human rhinovirus cases nearly tripled across 2 seasons, yet clinical severity did not increase. Fever, cough and rhinorrhea declined, antibiotic use decreased and hospitalization remained stable. Coinfections became more frequent but did not affect outcomes. These observations suggest that rhinovirus circulation is expanding with a shift toward milder, community-managed illness.

The Rhinovirus Puzzle: Linking Virus and Host Factors to Childhood Asthma.

Background: Viral respiratory tract infections (RTIs) frequently lead to emergency department (ED) presentations and hospital admissions, particularly among older adults and individuals with underlying health conditions. Identifying patients at increased risk for hospitalization is essential for optimizing triage and resource allocation. This study aimed to determine independent demographic, clinical, and virological predictors of hospital admission among adults presenting with confirmed viral RTIs. Methods: A retrospective cohort study was conducted at a tertiary hospital between September 2022 and May 2024. Adult patients with molecularly confirmed viral RTIs were included. Demographic, clinical, and microbiological data were extracted from electronic medical records. Predictors of admission were assessed using univariate and multivariate logistic regression. Results: Among 311 patients, 147 (47.3%) required hospitalization. Hospitalized patients were significantly older and more likely to present with fever, cough, tachypnea, dyspnea, chest pain, comorbidities, and lower or mixed respiratory tract infections (all p < 0.001). In multivariate analysis, older age, fever, cough, and lower or mixed RTIs were strong independent predictors of admission. Several viral pathogens, including human rhinovirus, non–SARS-CoV-2 coronaviruses, influenza A, and parainfluenza virus, were associated with reduced odds of hospitalization. Conclusions: Age, comorbidity burden, and lower respiratory tract involvement are key determinants of hospitalization in viral RTIs. Integrating clinical and virological data may improve risk stratification and guide ED triage during seasonal and emerging respiratory virus activity.

Respiratory viruses such as SARS-CoV-2, influenzas A and B, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human parainfluenza virus type 3 (HPIV-3), and rhinoviruses remain major causes of global morbidity. Their rapid evolution, high transmissibility, and limited therapeutic options, together with the absence of approved vaccines for several pathogens, highlight the need for broad-acting and pathogen-independent antiviral strategies. Nitric oxide exhibits antiviral activity through redox-dependent mechanisms, including S-nitrosylation of cysteine-containing viral proteins and disruption of redox-sensitive structural domains. Clinical studies conducted during the SARS-CoV-2 pandemic demonstrated that a nitric oxide nasal spray (NONS) rapidly reduced nasal viral load and transmission. In this study, we evaluated the in vitro virucidal activity of the NONS against a panel of clinically relevant respiratory viruses representing four major virus families. Virus suspensions of approximately 104 CCID50 were exposed to a full-strength NONS for contact times ranging from 5 s to 2 min at room temperature, followed by neutralization and quantification of residual infectivity using endpoint dilution assays. The NONS rapidly reduced viral infectivity across all viruses tested, achieving >3 log10 reductions within 2 min. SARS-CoV-2 variants including Alpha, Beta, Gamma, Delta, Omicron BA.1, and XBB 2.0 were reduced to levels at or below the assay detection limit within 30 s to 2 min. Influenza A and B viruses showed the fastest loss of infectivity, reaching detection limits within 10–15 s. RSV, hMPV, HPIV-3, and human rhinovirus 14 were similarly inactivated within 1–2 min. These findings demonstrate that the NONS exhibits rapid and broad-spectrum virucidal activity against diverse respiratory viruses and supports its potential role in pandemic preparedness but also seasonal use.

Deep mutational scanning couples a protein's activity to DNA sequencing for high-throughput assessment of the effects of all single amino acid substitutions, but it largely uses indirect assays, like cell proliferation, as proxy for protein activity. Here, we covalently link variant proteins in vivo to an RNA barcode by fusing them to Escherichia coli tRNA (m5U54) methyltransferase TrmA (E358Q). This methyltransferase mutant forms a covalent bond with a tRNA T-arm stem-loop sequence, which we embed in an RNA along with a unique barcode. Following cell lysis, variant proteins are separated in vitro according to their biochemical properties and identified by sequencing their covalently linked barcodes. The in vitro assays can be carried out in highly denaturing conditions, such as 8 M urea, due to the covalent RNA-protein linkage. We use this method, Dosa, to analyze a large pool of FLAG epitope variants for binding to an anti-FLAG-antibody, to profile substrate variants for their cleavage by enteropeptidase and human rhinovirus 3C protease, and to measure the solubility of several hundred Aβ(1-42) variants. This method should be amenable to numerous biochemical assays with proteins produced in E. coli or mammalian cells.

Human rhinovirus (HRV), a member of the Enterovirus genus of the Picornaviridae family is a major respiratory pathogen and the leading cause of upper respiratory tract infections. Given the limited information on HRV prevalence and molecular epidemiology in Northeast India, this study investigated circulating HRV strains in the region from 2015 to 2018. Nasopharyngeal and throat swab samples were collected and RNA was extracted for HRV detection using qRT-PCR. HRV-positive samples were subjected to bidirectional Sanger sequencing targeting the 549 bp VP4/VP2 region. Obtained sequences were aligned and analyzed phylogenetically using bioinformatics tools to determine genotype distribution and genetic diversity. Among 2642 cases, 354 (13.3%) tested positive for HRV. HRV-C was the predominant species (48.7%), followed by HRV-A (38.4%) and HRV-B (7.6%). HRV infection was significantly associated with lower respiratory symptoms such as cough (p<0.001) and breathlessness (p<0.026). The study identified 27 different HRV genotypes in the 39 sequenced samples, with HRV-C15 being the most common (9/39) overall and associated with disease severity (p=0.003). Seasonality analysis indicated peak HRV circulation between August and November (48.8%, 173/354), with the lowest detected in June-July (14.1%). HRV-C was more frequently observed in severe acute respiratory infection (SARI) cases and demonstrated the highest heterogeneity, with an intra-species nucleotide mean p-distance of 24.0 %. In conclusion, this study presents the first report on the prevalence of human rhinovirus (HRV) among influenza-like illness (ILI) cases in Dibrugarh, Assam, India. HRV-C exhibited distinct epidemiological characteristics compared to HRV-A and HRV-B strains. Molecular epidemiological analysis revealed notable nucleotide variation in the VP4/VP2 region, with HRV-C15 emerging as the predominant genotype associated with increased disease severity. Further research involving larger sample sizes and detailed clinical follow-up is essential to better understand the genotype distribution and genetic diversity of HRV strains circulating in the region.

Higher detection rates of Mycoplasma pneumoniae in children with acute respiratory tract infections using oropharyngeal swabs compared to nasopharyngeal swabs.

Human rhinoviruses (hRVs) are major causative agents of the common cold and contribute to lower respiratory tract infections. Although extensive research efforts continue to explore potential therapeutic interventions, no clinically approved antiviral treatment currently exists for hRV infections. This study provides the structural basis of hRV 3C protease inhibition in several serotypes by AG7404, a modified rupintrivir derivative. AG7404 showed potent antiviral activity against hRV-B14, hRV-A16 and hRV-A21 with EC50 values of 0.108, 0.191 and 0.187 µM, respectively, and directly inhibited purified hRV-B14 3C protease with an IC50 of 0.046 µM. The 2.11 Å crystal structure of hRV-B14 3C protease in complex with AG7404 revealed covalent binding to the catalytic Cys146 and occupation of the substrate-binding pockets by the ligand. Comparative structural analyses incorporating ligand-free hRV-B14 3C protease structures as well as rupintrivir-bound 3C protease structures from other hRV serotypes revealed significant conformational variability of the βcII-βdII region. Molecular dynamics simulations of the structural models of hRV-A16 and hRV-A21 3C proteases showed that the binding interactions of AG7404, including critical water-mediated networks, are conserved across serotypes despite sequence variations. These findings offer structural insights into the binding mode of AG7404 and establish a foundation for the rational design of broad-spectrum antivirals targeting hRV 3C proteases.

The role of human rhinovirus (HRV) in adult lower respiratory tract infections (LRTIs) remains controversial due to limited direct evidence of alveolar tropism and age-specific clinical characterization. To determine HRV's clinical impact, validate its capacity to infect lower respiratory tract cells, and identify predictors for HRV-associated pneumonia in adults. In this retrospective study (January 2020-December 2023), all hospitalized adults screened for HRV via RT-PCR were enrolled for analysis. In BALF HRV RNA-positive patients with available transbronchial lung biopsy (TBLB) or transbronchial cryobiopsy (TBCB) specimens, immunofluorescence (IF) staining was used to assess infection of LRT cells. Multivariable logistic regression analyzed demographics, comorbidities, and symptoms. HRV was detected in 4.6% (437/9,544) of patients, with bimodal seasonal peaks (February-April and September-November). Co-infection occurred in 49.0% (214/437), predominantly bacteria (34.1%) and viruses (25.7%). Among the 437 HRV-positive patients, 224 cases complicated with pneumonia, but only 34 (7.8%) met the diagnostic criteria for simple viral pneumonia. Multivariate analysis identified male (OR 2.69, 95% CI 1.04-6.99, P = 0.042), fever (OR 3.79, 95% CI 1.52-9.44, P = 0.004) and cough (OR 7.33, 95% CI 1.64-32.83, P = 0.009) as independent predictors of simple rhinovirus pneumonia. IF staining confirmed HRV VP3 protein in TBLB/TBCB specimens in 61.5% (8/13) of cases, resolving debates about HRV's LRT cells tropism. This study provides the first histological evidence of HRV's LRT cells infection in immunocompetent adults. Despite high co-infection rates, HRV independently drives pneumonia, particularly in males and those with fever or cough.

Recombinant protein expression in heterologous biological systems is an expanding field in synthetic biology. Photosynthetic organisms have the potential to provide an efficient low-cost platform for recombinant protein production because they require minimal growth nutrients and are less susceptible to zoonotic and other contaminants. Cyanobacteria are a class of microorganisms that are gaining as the preferred photosynthetic cell factories for product generation. In this study, the cyanobacterium Synechocystis sp. PCC 6803 was used as a host to stably over-express a functional form of the human interferon α-2 (IFN), as a fusion construct with the abundant CpcB β-subunit of phycocyanin. To cleave and isolate the free form of IFN from the fusion protein, different constructs were designed containing the Tobacco Etch Virus (TEV) or Human Rhinovirus (hrv) 3 C protease cleaving loci, placed between the leading CpcB and trailing IFN moieties of the fusion proteins. The work examined the comparative cleaving efficacy of TEV and HRV proteases in separating IFN from such over-expressed phycocyanin fusion protein complexes. It was concluded that the HRV protease system is superior to that of TEV, and that of other cleaving proteases recently tested, and may thus be incorporated in the toolkit of cyanobacterial synthetic biology for recombinant protein synthesis and isolation.

To explore the clinical epidemiological characteristics of rhinovirus (RV) infection in children hospitalized due to acute respiratory infection (ARI) in the Maternal and Child Health Hospital of Hubei Province. A retrospective, observational study was conducted, including 32 016 children hospitalized with acute respiratory infections (ARI) who underwent targeted high-throughput sequencing (tNGS) at the Maternal and Child Health Hospital of Hubei Province from January 2023 to December 2024. Clinical data were collected to analyze the epidemiological characteristics and related clinical manifestations of RV. Comparisons between groups were performed using the χ2 test, and multivariate logistic regression analysis was applied to identify risk factors associated with RV-related pneumonia. The results showed that the positive rate of RV was 21.28% (6 814/32 016). The positive rates in the age groups of <6 months, 6 months to <1 year, 1 to <3 years, 3 to <6 years, and 6 to ≤14 years were 20.38% (459/2 252), 23.14% (506/2 187), 23.76% (1 462/6 153), 24.66% (2 663/10 801), and 16.23% (1 724/10 623), respectively, with statistically significant differences (χ2=263.403, P<0.05). The detection rate of RV reached two peaks in February and May 2023; in 2024, it remained at a relatively high level from March to June and from October to November. Among the three types of RV, RV-A was the most frequently detected, with a detection rate of 58.95% (4 017/6 814). The mixed detection rate of RV with other pathogens was 51.91% (3 537/6 814). The pathogens mixed with RV were mainly Mycoplasma pneumoniae (MP), followed by parainfluenza virus (PIV), respiratory syncytial virus (RSV), adenovirus (ADV), human metapneumovirus (HMPV), and influenza A virus H3N2. Among the 6 814 RV-positive children included in this study, pneumonia (60.29%) was the most common clinical manifestation following RV infection.The pneumonia incidence rate in the RV mixed detection group was 68.59% (2 426/3 537), and the incidence rate of severe pneumonia was 2.71% (96/3 537). The pneumonia incidence rate in the RV single detection group was 51.33% (1 682/3 277), and the incidence rate of severe pneumonia was 1.83% (60/3 277). The pneumonia incidence rate and the incidence rate of severe pneumonia in the mixed infection group were both higher than those in the single detection group, with statistically significant differences (χ2=211.702, P<0.05; χ2=5.932, P<0.05). Multivariate logistic regression analysis showed that co-infection was the major risk factor for pneumonia in children with RV infection [OR=1.721, 95% confidence interval(CI)=1.581-1.871, P<0.001]. In conclusion, the epidemic season of RV was concentrated in spring and autumn, and the predominant type was RV-A in this study. The age group of 3 to <6 years had the highest positive rate of RV. RV is prone to co-infection with other respiratory pathogens, with MP being the most common. Mixed infection may lead to aggravated conditions and should be given attention in clinical practice.

Human rhinovirus (HRV) is one of the most common viral causes of respiratory tract infections worldwide. The COVID-19 pandemic and non-pharmaceutical interventions significantly altered the epidemiology of respiratory viruses. This study compared HRV genotypic diversity in Mexican children with pneumonia before and during the pandemic. A total of 1983 children with pneumonia were included: 1404 pre-pandemic (2010–2013) and 579 pandemic (2021–2023). Multiplex RT-PCR was used for HRV detection. Genotyping was conducted on 136 samples with Ct < 30 by sequencing the VP4/VP2 region. Species and genotype assignments were validated using BLAST and maximum-likelihood phylogenetic analysis (MEGA XII). HRV positivity increased from 16% (233/1404) before the pandemic to 60.4% (350/579) during the pandemic period. HRV-A and HRV-C predominated in both periods; HRV-C infection was significantly associated with severe pneumonia in the pre-pandemic period (OR 3.520; p = 0.012), but this association was not observed during the pandemic. A total of 72 genotypes were identified without a dominant type in either period. HRV circulation patterns shifted in the context of the COVID-19 pandemic, with a marked increase in prevalence. The high genotypic diversity observed across both periods underscores the importance of continuous molecular surveillance to better understand HRV circulation and its clinical relevance.

Globally, acute respiratory infections (ARI), including pneumonia, remain the leading infectious causes of morbidity and mortality among children under-two years of age. We conducted this longitudinal birth cohort study in a low-income urban community in Dhaka, Bangladesh, to estimate the incidence of ARI and pneumonia and assess their viral etiology. From May 2015 to March 2016, 447 children were enrolled and followed till 2022. In this analysis, we included data from the first two years of children’s lives, which contributed to a total observation of 778 child-years. Nasopharyngeal wash samples were collected during symptomatic episodes, which were tested using rRT-PCR for rhinovirus (RV), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), influenza virus, human parainfluenza virus (HPIV), and adenovirus. We calculated incidence rates using Poisson-based methods with 95% confidence intervals (CI) and stratified age-specific rates into three groups: 0–&lt;6 months, 6–&lt;12 months, and 12–24 months. A total of 2,335 ARIs and 314 pneumonia episodes were documented. At least one respiratory virus was detected in 71% of ARI and 75% of pneumonia episodes. RV was the most frequently detected virus (54% in ARI, 40% in pneumonia), followed by RSV, HPIV, and influenza. The incidence of viral ARI was 212/100 child-years (95% CI: 202–223), and that of viral pneumonia was 30/100 child-years (95% CI: 27–35). The observed incidence of viral ARI and pneumonia during early childhood underscores the need for targeted interventions. Future research should examine environmental and socioeconomic influences, assess preventive strategies, and improve early detection and treatment.

Sewage surveillance revealed the emergence and prevalence of human rhinovirus and human parainfluenza virus in China based on their fecal shedding rates.

Rhinovirus C15 infection induces airway epithelial cell remodeling and robust inflammatory responses: Potential implications for airway obstruction in children.

Genomic surveillance for community-acquired pneumonia of unknown etiology in children.

Bioactive 2-arylbenzofuran and chalcone derivatives from Morus mesozygia Stapf.

Etiology and epidemiology of respiratory infections in community-based influenza-like illness during the COVID-19 pandemic, Vientiane, Lao People's Democratic Republic.

Host-targeted antivirals as broad-spectrum inhibitors of respiratory viruses.

This study aimed to provide a comprehensive overview of SARS-CoV-2 and other respiratory viruses co-infections and analyse the value of Primary Care Centres (PCCs) as a sentinel network for molecular surveillance of paediatric respiratory viral infections in Catalonia (Spain). Between October 2021 and April 2024, upper respiratory tract samples were collected from children under 15 years of age presenting with acute respiratory symptoms at different PCCs across Catalonia. The detection of respiratory viruses was performed using commercial multiplex RT-PCR and transcription-mediated amplification-based assays. The genetic characterisation of select viruses (adenoviruses (AdV), enteroviruses (EV), influenza viruses, SARS-CoV-2) was performed via partial or whole genome sequencing. The results were then compared with hospital-based data and the regional surveillance system (SIVIC). Among 1,401 positive samples from 1,329 cases, the most prevalent viruses were rhinovirus (RV) (22.77%), SARS-CoV-2 (12.35%), influenza A(H3) viruses (11.06%) and AdV (9.21%). Viral circulation followed typical seasonal patterns, with RV and AdV detected year-round, and influenza and respiratory syncytial virus peaking in winter, showing prevalences similar to those observed in hospital settings and broader community settings. Co-infections were frequent (up to 53.3% for bocavirus), while influenza and SARS-CoV-2 showed the lowest co-infection rates, suggesting possible viral interference. Genomic analysis revealed circulation of different EV (e.g., EV-D68, CV-A6, E-11, etc.) and AdV (B3, C2) types, multiple FLUAV and FLUBV genetic clades and SARS-CoV-2 variants consistent with national waves. This study highlights the complexity of respiratory virus circulation and co-infections dynamics in paediatric primary care patients. A notable observation was the generally similar viral distribution between PCCs and the community, reinforcing the value of studying this population. The findings also underscore the importance of continued molecular surveillance to inform public health strategies and clinical management of respiratory infections in children.