EDP-938, a Respiratory Syncytial Virus Inhibitor, in a Human Virus Challenge.

BACKGROUND: Respiratory syncytial virus (RSV) infection causes substantial morbidity and mortality among infants, older adults, and immunocompromised adults. EDP-938, a nonfusion replication inhibitor of RSV, acts by modulating the viral nucleoprotein. METHODS: In a two-part, phase 2a, randomized, double-blind, placebo-controlled challenge trial, we assigned participants who had been inoculated with RSV-A Memphis 37b to receive EDP-938 or placebo. Different doses of EDP-938 were assessed. Nasal-wash samples were obtained from day 2 until day 12 for assessments. Clinical symptoms were assessed by the participants, and pharmacokinetic profiles were obtained. The primary end point was the area under the curve (AUC) for the RSV viral load, as measured by reverse-transcriptase-quantitative polymerase-chain-reaction assay. The key secondary end point was the AUC for the total symptom score. RESULTS: In part 1 of the trial, 115 participants were assigned to receive EDP-938 (600 mg once daily [600-mg once-daily group] or 300 mg twice daily after a 500-mg loading dose [300-mg twice-daily group]) or placebo. In part 2, a total of 63 participants were assigned to receive EDP-938 (300 mg once daily after a 600-mg loading dose [300-mg once-daily group] or 200 mg twice daily after a 400-mg loading dose [200-mg twice-daily group]) or placebo. In part 1, the AUC for the mean viral load (hours × log10 copies per milliliter) was 204.0 in the 600-mg once-daily group, 217.7 in the 300-mg twice-daily group, and 790.2 in the placebo group. The AUC for the mean total symptom score (hours × score, with higher values indicating greater severity) was 124.5 in the 600-mg once-daily group, 181.8 in the 300-mg twice-daily group, and 478.8 in the placebo group. The results in part 2 followed a pattern similar to that in part 1: the AUC for the mean viral load was 173.9 in the 300-mg once-daily group, 196.2 in the 200-mg twice-daily group, and 879.0 in the placebo group, and the AUC for the mean total symptom score was 99.3, 89.6, and 432.2, respectively. In both parts, mucus production was more than 70% lower in each EDP-938 group than in the placebo group. The four EDP-938 regimens had a safety profile similar to that of placebo. Across all dosing regimens, the EDP-938 median time to maximum concentration ranged from 4 to 5 hours, and the geometric mean half-life ranged from 13.7 to 14.5 hours. CONCLUSIONS: All EDP-938 regimens were superior to placebo with regard to lowering of the viral load, total symptom scores, and mucus weight without apparent safety concerns. (ClinicalTrials.gov number, NCT03691623.).

Simultaneous detection of influenza A, B and respiratory syncytial virus in wastewater samples by one-step multiplex RT-ddPCR assay.

BACKGROUND: After the occurrence of the COVID-19 pandemic, detection of other disseminated respiratory viruses using highly sensitive molecular methods was declared essential for monitoring the spread of health-threatening viruses in communities. The development of multiplex molecular assays are essential for the simultaneous detection of such viruses even at low concentrations. In the present study, a highly sensitive and specific multiplex one-step droplet digital PCR (RT-ddPCR) assay was developed for the simultaneous detection and absolute quantification of influenza A (IAV), influenza B (IBV), respiratory syncytial virus (RSV), and beta-2-microglobulin transcript as an endogenous internal control (IC B2M). RESULTS: The assay was first evaluated for analytical sensitivity and specificity, linearity, reproducibility, and recovery rates with excellent performance characteristics and then applied to 37 wastewater samples previously evaluated with commercially available and in-house quantitative real-time reverse transcription PCR (RT-qPCR) assays. IAV was detected in 16/37 (43%), IBV in 19/37 (51%), and RSV in 10/37 (27%) of the wastewater samples. Direct comparison of the developed assay with real-time RT-qPCR assays showed statistically significant high agreement in the detection of IAV (kappa Cohen's correlation coefficient: 0.834, p = 0.001) and RSV (kappa: 0.773, p = 0.001) viruses between the two assays, while the results for the detection of IBV (kappa: 0.355, p = 0.27) showed good agreement without statistical significance. CONCLUSIONS: Overall, the developed one-step multiplex ddPCR assay is cost-effective, highly sensitive and specific, and can simultaneously detect three common respiratory viruses in the complex matrix of wastewater samples even at low concentrations. Due to its high sensitivity and resistance to PCR inhibitors, the developed assay could be further used as an early warning system for wastewater monitoring.

Genomic Analysis and Surveillance of Respiratory Syncytial Virus Using Wastewater-Based Epidemiology.

Respiratory syncytial virus (RSV) causes severe infections in infants, immunocompromised or elderly individuals resulting in annual epidemics of respiratory disease. Currently, limited clinical surveillance and the lack of predictable seasonal dynamics limit the public health response. Wastewater-based epidemiology (WBE) has recently been used globally as a key metric in determining prevalence of severe acute respiratory syndrome coronavirus 2 in the community, but its application to other respiratory viruses is limited. In this study, we present an integrated genomic WBE approach, applying reverse-transcription quantitative polymerase chain reaction and partial G-gene sequencing to track RSV levels and variants in the community. We report increasing detection of RSV in wastewater concomitant with increasing numbers of positive clinical cases. Analysis of wastewater-derived RSV sequences permitted identification of distinct circulating lineages within and between seasons. Altogether, our genomic WBE platform has the potential to complement ongoing global surveillance and aid the management of RSV by informing the timely deployment of pharmaceutical and nonpharmaceutical interventions.

Seasonality, Clinical Characteristics, and Outcomes of Respiratory Syncytial Virus Disease by Subtype Among Children Aged <5 Years: New Vaccine Surveillance Network, United States, 2016-2020.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illnesses in children. RSV can be broadly categorized into 2 major subtypes: A and B. RSV subtypes have been known to cocirculate with variability in different regions of the world. Clinical associations with viral subtype have been studied among children with conflicting findings such that no conclusive relationships between RSV subtype and severity have been established. METHODS: During 2016-2020, children aged <5 years were enrolled in prospective surveillance in the emergency department or inpatient settings at 7 US pediatric medical centers. Surveillance data collection included parent/guardian interviews, chart reviews, and collection of midturbinate nasal plus/minus throat swabs for RSV (RSV-A, RSV-B, and untyped) using reverse transcription polymerase chain reaction. RESULTS: Among 6398 RSV-positive children aged <5 years, 3424 (54%) had subtype RSV-A infections, 2602 (41%) had subtype RSV-B infections, and 272 (5%) were not typed, inconclusive, or mixed infections. In both adjusted and unadjusted analyses, RSV-A-positive children were more likely to be hospitalized, as well as when restricted to <1 year. By season, RSV-A and RSV-B cocirculated in varying levels, with 1 subtype dominating proportionally. CONCLUSIONS: Findings indicate that RSV-A and RSV-B may only be marginally clinically distinguishable, but both subtypes are associated with medically attended illness in children aged <5 years. Furthermore, circulation of RSV subtypes varies substantially each year, seasonally and geographically. With introduction of new RSV prevention products, this highlights the importance of continued monitoring of RSV-A and RSV-B subtypes.

Epidemiology of Respiratory Syncytial Virus in Adults and Children With Medically Attended Acute Respiratory Illness Over Three Seasons.

BACKGROUND: Data on the true prevalence of respiratory syncytial virus (RSV) among medically attended acute respiratory illnesses (MAARI) has been limited by the lack of regular clinical testing of mild to moderate illnesses. Here we present a prospective evaluation of the epidemiology of RSV-associated MAARI across age groups and multimorbidity status over 3 seasons, which is informative in light of the recommendations for shared decision making for vaccination in older adults. METHODS: Ambulatory patients ≥6 months of age meeting a common MAARI case definition were prospectively enrolled in the Michigan Ford Influenza Vaccine Effectiveness (MFIVE) study, a subsite of the US Influenza Vaccine Effectiveness Network. All participants were tested by nasal-throat swab for RSV and influenza, including subtype, independently from clinician-directed testing. Participant illness characteristics and calculated multimorbidity-weighted index (MWI) were collected by in-person survey and electronic medical record review. RESULTS: Over 3 surveillance seasons (fall 2017 to spring 2020), 9.9% (n = 441) of 4442 participants had RSV detected. RSV-associated MAARI was more prevalent than influenza for participants 6 months to 4 years of age. Adults with RSV-MAARI had higher median MWI scores overall compared to influenza-MAARI and controls with neither virus (1.62, 0.40, and 0.64, respectively). CONCLUSIONS: RSV is a significant, underrecognized cause of MAARI in both children and adults presenting for ambulatory care. Multimorbidity is an important contributor to RSV-associated MAARI in outpatient adults, providing information to support shared clinical decision making for vaccination.

Increased Pediatric Respiratory Syncytial Virus Case Counts Following the Emergence of SARS-CoV-2 Can Be Attributed to Changes in Testing.

BACKGROUND: Respiratory syncytial virus (RSV) circulation dropped markedly early in the COVID-19 pandemic, followed by a resurgence with heightened case counts. The "immunity debt" hypothesis proposes that the RSV-naїve pediatric population increased during the period of low transmission. However, the evidence supporting this hypothesis is limited, and the role of changing testing practices in the perceived surge has not been comprehensively evaluated. METHODS: We conducted a multicenter, retrospective analysis of 342 530 RSV encounters and 980 546 RSV diagnostic tests occurring at 32 US pediatric hospitals in 2013-2023. We used interrupted time series analysis to estimate pandemic-associated changes in RSV patient and test volume and to quantify changes in the proportions of patients requiring hospitalization, intensive care, or mechanical ventilation. We quantified the fraction of the shifts in case counts and in the age of diagnosed patients attributable to changes in testing. RESULTS: RSV patient volume increased 2.4-fold (95% confidence interval [CI]: 1.7, 3.5) in 2021-2023 relative to the pre-pandemic phase and was accompanied by an 18.9-fold increase (95% CI: 15.0, 23.9) in RSV test volume. Shifts in patient volume and in patient age were largely attributable to increased testing. The proportions of patients with RSV that required hospitalization, intensive care, or mechanical ventilation declined significantly across all patient age groups. CONCLUSIONS: A surge in RSV testing, rather than in viral circulation, likely underlies the increased case counts observed in 2021-2023. These findings warrant a critical assessment of the immunity debt hypothesis and highlight the importance of considering the testing denominator when surveillance strategies are dynamic.

Genomic Epidemiology of Human Respiratory Syncytial Virus, Minnesota, USA, July 2023-February 2024.

We recently expanded the viral genomic surveillance program in Minnesota, USA, to include human respiratory syncytial virus. We performed whole-genome sequencing of 575 specimens collected at Minnesota healthcare facilities during July 2023-February 2024. Subgroups A and B differed in their genomic landscapes, and we identified 23 clusters of genetically identical genomes.

Analysis of the prevalence and clinical features of respiratory syncytial virus infection in a pediatric hospital in Zhejiang Province from 2019 to 2023.

The aim of this study was to investigate the epidemiological characteristics of respiratory syncytial virus (RSV) infections in children in Zhejiang from 2019 to 2023. Data from pediatric patients who visited the Children's Hospital of Zhejiang University School of Medicine for RSV infection between 2019 and 2023 were analyzed. Nasopharyngeal swabs were collected for RSV antigen detection, and relevant patient information was collected. Factors such as age were analyzed. A total of 673 094 specimens were included from 2019 to 2023, with a rate of positive specimens of 4.74% (31 929/673 094). The highest rate of positive specimens of 10.82%, was recorded in 2021, while the remaining years had a rate of approximately 3%-5%. In terms of seasonal prevalence characteristics, the rate of positive specimens in 2019, 2020, and 2022 peaked in the winter months at approximately 8% and decreased in the summer months, where the rate of positive specimens remained at approximately 0.5%. In contrast, summer is the peak period for RSV incidence in 2021 and 2023, with the rate of positive specimens being as high as 9%-12%. Based on the prevalence characteristics of gender and age, this study found that the detection rate of positive specimens was higher in boys than in girls in 2019-2023. In 2019-2022, among the different age groups, the highest rate of positive specimens was found in children aged 0 to <6 months, and it decreased with age. In 2023, the rate of positive specimens was above 8% in the 0 to <6 months, 6 to <12 months, and 1-2 years age groups, with the highest rate of positive specimens in the 1-2 years age group, and a gradual decrease in the rate of positive specimens with age for children over 3 years of age. Between 2019 and 2023, the epidemiological pattern of RSV changed. A summer peak was observed in 2021 and 2023.

Characterizing human respiratory syncytial virus among children admitted with acute respiratory tract infections from 2019 to 2022.

Respiratory syncytial virus is a major causative agent of lower respiratory tract infection in children, especially infants with substantial morbidity and mortality implications. The virus undergoes continuous evolution documented by accumulation of mutations in the glycoprotein gene necessitating vigilant surveillance to provide essential data to epidemiologists and researchers involved in development of vaccines. This study was aimed to perform molecular characterization of respiratory syncytial virus (RSV) among children ≤ 5 years admitted in hospital. In the current study we observed RSV-A (2019 (n = 95) and 2021 (n = 61) seasons) and RSV-B (2022 season (n = 68)). Phylogenetic analysis revealed all RSV-A strains (n = 47) to be GA.2.3.5 and RSV-B (n = 22) were classified as GB.5.0.5a. Selection pressure analysis identified one positive (P274L/V) and one negative site (P230T) in RSV-A, while in RSV-B there was only one negatively selected site (S295). This study spanning over three seasons contributes to RSV evolutionary dynamics in India emphasizing the importance of on-going surveillance to inform effective public health strategies and vaccine development efforts.

Epidemiology and viral loads of respiratory syncytial virus in hospitalized children prior to and during COVID-19 pandemic in Hangzhou, China.

Non-pharmaceutical interventions (NPIs) implemented to control SARS-CoV-2 have significantly influenced the activity of respiratory pathogens. This study investigated epidemiological changes among hospitalized patients with respiratory syncytial virus (RSV) before (2017-2019) and during (2020-2022) the COVID-19 pandemic in Hangzhou, China. We also examined viral load distribution across demographic and temporal variables. Nasopharyngeal swabs were collected and RSV loads were quantified using reverse transcriptase polymerase chain reaction (RT-qPCR). RSV epidemic characteristics, seasonal dynamics, and viral load distributions were compared between pre- and pandemic years. General linear models were employed to assess associations between viral loads and age. Among 19 742 cases, 1576 and 2092 tested positive during the pre- and pandemic years, respectively. From February to July 2020, the implementation of NPIs led to the cessation of RSV circulation. However, after these measures were relaxed, RSV cases resurged over two consecutive seasons during the pandemic, notably affecting older children compared to those in the pre-pandemic years (1.00 years, IQR: 0.50-2.00 vs. 0.58 years, IQR: 0.27-1.00, p < 0.001). Specifically, in 2021-2022, an off-season resurgence of RSV began earlier (mid-June), lasted longer (40 weeks), and involved more positive cases (1238 cases) than both 2020-2021 and pre-pandemic years. Viral load distribution demonstrated a clear age-related relationship in both pre- and pandemic years, with younger children consistently showing higher viral loads, independently of gender and season (all p-values for trends <0.001). These findings highlight the impact of NPIs on RSV epidemiology and underscore the need to prioritize RSV infection prevention in younger children from the perspective of viral load.

Influenza A, Influenza B, human respiratory syncytial virus and SARSCoV-2 molecular diagnostics and epidemiology in the post COVID-19 era.

BACKGROUND: The concurrent circulation of SARS-CoV-2 with other respiratory viruses is unstoppable and represents a new diagnostic reality for clinicians and clinical microbiology laboratories. Multiplexed molecular testing on automated platforms that focus on the simultaneous detection of multiple respiratory viruses in a single tube is a useful approach for current and future diagnosis of respiratory infections in the clinical setting. METHODS: Two time periods were included in the study: from February to April 2022, an early 2022 period, during the gradual lifting of COVID-19 prevention measures in the country, and from October 2022 to April 2023, the 2022/23 respiratory infections season. We analysed a total of 1,918 samples in the first period and 18,131 respiratory samples in the second period using a multiplex molecular assay for the simultaneous detection of Influenza A (Flu-A), Influenza B (Flu-B), Human Respiratory Syncytial Virus (HRSV) and SARS-CoV-2. RESULTS: The results from early 2022 showed a strong dominance of SARS-CoV-2 infections with 1,267/1,918 (66.1%) cases. Flu-A was detected in 30/1,918 (1.6%) samples, HRSV in 14/1,918 (0.7%) samples, and Flu-B in 2/1,918 (0.1%) samples. Flu-A/SARS-CoV-2 co-detections were observed in 11/1,267 (0.9%) samples, and HRSV/SARS-CoV-2 co-detection in 5/1,267 (0.4%) samples. During the 2022/23 winter respiratory season, SARS-CoV-2 was detected in 1,738/18,131 (9.6%), Flu-A in 628/18,131 (3.5%), Flu-B in 106/18,131 (0.6%), and HRSV in 505/18,131 (2.8%) samples. Interestingly, co-detections were present to a similar extent as in early 2022. CONCLUSION: The results show that the multiplex molecular approach is a valuable tool for the simultaneous laboratory diagnosis of SARS-CoV-2, Flu-A/B, and HRSV in hospitalized and outpatients. Infections with Flu-A/B, and HRSV occurred shortly after the COVID-19 control measures were lifted, so a strong reoccurrence of various respiratory infections and co-detections in the post COVID-19 period was to be expected.

Risk factors for the development of severe or very severe respiratory syncytial virus-related lower respiratory tract infection in Indian infants: A cohort study in Melghat, India.

OBJECTIVES: Respiratory syncytial virus (RSV) is undoubtedly the single most important cause of severe lower respiratory tract infection (LRTI) globally. While new prevention measures in young infants have become available, their use in developing countries is likely many years away. While risk factors for severe or very severe RSV LRTI in impoverished rural areas likely differ to urban areas, there are very few studies, especially those conducted in India, the major country contributing to the global burden of disease. METHODS: Active surveillance for acute LRTI in enrolled infants and children <2 years of age, was conducted through weekly home visits in 93 villages of Melghat, India, from August 2016 to December 2020. Local hospitals and primary health centres were surveyed for admissions of enrolled subjects. Nasopharyngeal swabs were collected from children with severe, or very severe LRTIs and all who died, with RSV testing using nucleic acid tests at ICMR, National Institute of Virology Pune. Risk factors for both RSV associated and non-RSV associated, severe and very severe LRTI were identified through univariate and multivariate logistic regression. RESULTS: There were 483 severe or very severe RSV LRTI cases and 2807 non-RSV severe or very severe LRTI infections in a cohort of 13,318 children. Weight for age z-score ≤-2, the use of kerosene or wood for cooking, obtaining drinking water from a public tap and low gestational age significantly increased the risk of RSV LRTI. A higher wealth score index and water purification were protective. Comparison with non-RSV LRTI showed male sex as an additional risk factor. The analysis highlighted the risk of kerosene use [OR = 17.8 (3.0-104.4) (p ≤ 0.001)] and [OR = 3.4 (0.8-14.4) (p ≤ 0.05)] for RSV and non-RSV LRTIs, respectively. CONCLUSIONS: Nutritional status and environmental air quality are predisposing factors for developing an RSV LRI in young children, factors which are amenable to environmental and behavioural interventions.

Portable and simultaneous detection of four respiratory pathogens through a microfluidic LAMP and real-time fluorescence assay.

Respiratory pathogen infections are seasonally prevalent and are likely to cause co-infections or serial infections during peak periods of infection. Since they often cause similar symptoms, simultaneous and on-site detection of respiratory pathogens is essential for accurate diagnosis and efficient treatment of these infectious diseases. However, molecular diagnostic techniques for multiple pathogens in this field are lacking. Herein, we developed a microfluidic LAMP and real-time fluorescence assay for rapid detection of multiple respiratory pathogens using a ten-channel microfluidic chip with pathogen primers pre-embedded in the chip reaction well. The microfluidic chip provided a closed reaction environment, effectively preventing aerosol contamination and improving the accuracy of the detection results. Its corresponding detection instrument could automatically collect and display the fluorescence curve in real time, which was more conducive to the interpretation of results. The results showed that the developed method could specifically recognize the nucleic acid of influenza A(H1N1), Mycoplasma pneumoniae, respiratory syncytial virus type A, and SARS-CoV-2 with low detection limits of 104 copies per mL or 103 copies per mL. The test results on clinical samples demonstrated that the developed method has high sensitivity (92.00%) and high specificity (100.00%) and even has the capability to differentiate mixed-infection samples. With simple operation and high detection efficiency, the present portable and simultaneous detection assay could significantly improve the efficiency of on-site detection of respiratory infectious diseases and promote the accurate treatment, efficient prevention and control of the diseases.

Genomic characterization of human respiratory syncytial virus circulating in Islamabad, Pakistan, during an outbreak in 2022-2023.

In this study, conducted at the National Institute of Health, Islamabad, during an outbreak of human respiratory syncytial virus (hRSV) from December 2022 to January 2023, the first whole-genome sequences of hRSV isolates from Islamabad, Pakistan, were determined. Out of 10 positive samples, five were sequenced, revealing the presence of two genotypes: RSV-A (GA2.3.5, ON1 strain) and RSV-B (GB5.0.5.a, BA-10 strain). A rare non-synonymous substitution (E232G) in G the protein and N276S in the F protein were found in RSV-A. In RSV-B, the unique mutations K191R, Q209R, and I206M were found in the F protein. These mutations could potentially influence vaccine efficacy and viral pathogenicity. This research underscores the importance of genomic surveillance for understanding RSV diversity and guiding public health responses in Pakistan.

Genomic characteristics of human respiratory syncytial virus from children in China during 2017-2020.

Acute lower respiratory tract infections (ALRTIs) are a leading cause of mortality in young children worldwide due to human respiratory syncytial virus (RSV). The aim of this study was to monitor genetic variations in RSV and provide genomic data support for RSV prevention and control. A total of 105 complete RSV genome sequences were determined during 2017-2020. Phylogenetic analysis showed that all of the RSVA sequences were of genotype ON1, and all of the RSVB sequences were of genotype BA9. Notably, a phylogenetic tree based on the whole genome had more branches than a tree based on the G gene. In comparison to the RSV prototype sequences, 71.43% (50/70) of the ON1 sequences had five amino acid substitutions (T113I, V131N, N178G, H258Q, and H266L) that occurred simultaneously, and 68.57% (24/35) of the BA9 genotype sequences had 12 amino acid substitutions, four of which (A131T, T137I, T288I, and T310I) occurred simultaneously. In the F gene, there were 19 amino acid substitutions, which were mainly located in the antigenic sites Ø, II, V, and VII. Other amino acid substitutions were found in the NS1, NS2, P, SH, and L proteins. No significant evidence of recombination was found in any of the sequences. These findings provide important data that will be useful for prevention, control, and vaccine development against RSV.

Burden of respiratory syncytial virus (RSV) infection in Germany: a systematic review.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection and hospitalizations among infants, young children, and the elderly. This systematic literature review aimed to summarize the epidemiological and economic burden estimates of RSV infection at any age in Germany. METHODS: We conducted a systematic literature search to identify full-text articles published from 2003 to 2023 and reporting data on the epidemiological or economic burden of RSV in Germany. Based on pre-specified eligibility criteria, data on incidence, rates of hospital and intensive care unit (ICU) admission, clinical manifestation, underlying conditions, seasonality, health care resource use and costs were extracted. RESULTS: After screening 315 full-text articles, we included 42 articles in the review. The characteristics of the included studies were heterogenous regarding study population, setting, age groups and RSV-related outcome measures. The most frequently reported epidemiological outcome measures were RSV detection rate (n = 33), followed by clinical manifestation (n = 19), seasonality (n = 18), and underlying conditions of RSV infection (n = 13). RSV detection rates were reported across heterogenous study populations, ranging from 5.2 to 55.4% in pediatric inpatient cases and from 2.9 to 14% in adult inpatient cases. All articles that reported RSV detection rates across several age groups demonstrated the highest burden in infants and young children. Few articles reported RSV-related outcome measures distinctively for the outpatient setting. Health care resource use, such as hospital length of stay, ICU admission rate and treatment of patients with RSV infection were described in 23 articles, of which only one study quantified associated costs from 1999 to 2003 for children ≤ 3 years. In-hospital ICU admission rates varied between 3.6 and 45%, depending on population characteristics as age and underlying conditions. CONCLUSIONS: This systematic review revealed that RSV imposes substantial disease burden in infants, young children, and the elderly in Germany, whereby infants are particularly affected. To date, there has been limited exploration of the impact of RSV infection on healthy children or the elderly in Germany. Given their notably high reported burden in studies, the medical and economic RSV burden in these groups should move more into focus.

Comparative study on the epidemiological characteristics and hazards of respiratory syncytial virus and influenza virus infections among elderly people.

OBJECTIVE: To investigate the epidemiological characteristics and infections of respiratory syncytial virus (RSV) and influenza viruses in hospitalized elderly patients with respiratory tract infections in Suzhou City, China, and to compare the differences in clinical characteristics and economic burden associated with these two infections. METHODS: In this prospective study, pathogenetic testing and clinical data for hospitalized patients aged 60 years and older with respiratory tract infections were collected in five hospitals through stratified cluster sampling from December 2023 to May 2024. Comparative study on epidemic characteristics, clinical features and costs of cases who infected RSV alone and influenza alone were conducted. RESULTS: Among 1,894 cases included, the RSV positivity rate was 5.91% during the 2023-2024 winter-spring season, while the influenza positivity rate was 9.61%. RSV-B was the predominant subtype of RSV, and influenza A (primarily H3N2) was the dominant strain among the influenza-positive cases. Compared with cases infected influenza virus alone, those infected RSV alone had lower occurrence frequency of fever (18.8% vs. 35.7%, P = 0.004), higher occurrence frequency of complications of lower respiratory tract infections (70.8% vs. 54.8%, P = 0.011), higher direct medical costs ($996.2 vs. $841.1, P = 0.017) and total costs ($1019.7 vs. $888.1, P = 0.036). RSV single infection is more common in female cases (P = 0.007) and diabetic cases (P = 0.007) than influenza virus single infection. CONCLUSIONS: During the winter and spring months, RSV is the second most common pathogen after influenza virus among older adults hospitalized for respiratory infections in Suzhou, China. Patients infected RSV are more likely to develop complications with lower respiratory tract infections and have higher medical costs than the influenza. RSV infection in the elderly should be emphasized, especially in female patients and diabetic patients.

Analysis of the epidemic characteristics of common respiratory pathogens infection in children in a 3A special hospital.

OBJECTIVE: To analyze the epidemic characteristics of common respiratory tract infection pathogens in children with respiratory tract infection, and provide scientific basis for the prevention and control of respiratory tract infection. METHODS: A retrospective collection of clinical data was conducted on 11,538 children with respiratory tract infections at Luoyang Maternal and Child Health Hospital from December 2022 to November 2023. The types of respiratory tract infections, including upper and lower respiratory tract infections, as well as five respiratory pathogens: influenza A virus (influenza A), influenza B virus (influenza B virus, adenovirus (ADV), respiratory syncytial virus (RSV), and Mycoplasma pneumoniae (MP) infections, were analyzed and compared for different genders, ages, temperatures, and air quality in different months; And the changes of five pathogens in children with respiratory tract infections of different disease severity. RESULTS: From December 2022 to November 2023, a total of 11,538 children with respiratory infections were included in the analysis, including 6436 males and 5102 females, with an age of 4.92 ± 2.03 years. The proportion of upper respiratory tract infections is as high as 72.17%, and lower respiratory tract infections account for 27.83%. Among them, 2387 were positive for Flu A antigen, with a positive rate of 20.69%, 51 cases were positive for Flu B antigen, and the positive rate was 0.4%, 1296 cases were positive for adv antigen, with a positive rate of 11.23%, 868 cases were positive for RSV antigen, with a positive rate of 7.52%, 2481 cases were positive for MP IgM antibody or MP antigen, and the positive rate was 21.50%. Flu B in male children The infection rate of ADV and MP was higher than that of female children (p < 0.05); Among children in different age groups, the older the age, the older the Flu A The higher the infection rate of MP (p < 0.05), the higher the positive rate of RSV in children with younger age (p < 0.05). The positive rate of ADV in children aged 3-6 years and > 6 years was higher than that in children aged 0-3 years (p < 0.05); Flu A and MP are popular throughout the year, and the positive rate peaks during the period of temperature rise and air quality decline from February to March, and during the period of temperature drop and air quality index rise from August to November, The positive rate of RSV peaked after the turning point of temperature rise from March to April. The infection rate was higher during the period of sharp decline in air quality from March to May and sharp decline in temperature in November, The positive rate of ADV was higher at the turning point of temperature rise from February to March, and then the infection rate decreased. During the period of sharp temperature drop from August to November, the positive rate increased sharply, and the peak of infection occurred; As the disease worsens, The positive rates of Flu A, Flu B, RSV, MP and combined infection with more than two pathogens were all increased (p < 0.05). CONCLUSION: After the new coronavirus epidemic in 2022, Flu A and MP have the highest infection rate of respiratory pathogens in children, showing a peak growth in general, with epidemic characteristics changing with environmental temperature, air quality and seasons. The main disease type is upper respiratory tract infection, MP and adv infections were mainly in male children, Flu A, MP and ADV infections are more common in older children, RSV infection was more common in younger children; Flu A, Flu B, RSV and MP infection and the co infection of more than two pathogens may more easily lead to the occurrence of severe pneumonia.

Resurgence of respiratory syncytial virus infection during COVID-19 pandemic in Pune, India.

INTRODUCTION: Respiratory Syncytial Virus (RSV) is a leading cause of acute lower respiratory infection in children worldwide. Understanding its prevalence, variations, and characteristics is vital, particularly in the context of the COVID-19 pandemic. OBJECTIVE: The study aimed to investigate the RSV positivity rate, subtype prevalence, age and gender distribution, symptomatology, and co-infection rates during pre-pandemic and pandemic periods. METHODS: We analyzed data from 15,381 patients tested for RSV between 2017 and 2023. RESULTS: Our analysis revealed a 7.2% average RSV positivity rate in the pre-pandemic period, with significant fluctuations during the pandemic (1.5% in 2020 to 32.0% in 2021). We observed variations in RSVA and RSVB detection rates. The 0-4 years' age group was consistently the most affected, with a slight male predominance. Fever and cough were common symptoms. Therapeutic interventions, particularly antiviral usage and ventilation requirements, decreased during the pandemic. We also identified variations in co-infection rates with other respiratory viruses. CONCLUSION: Our study offers critical insights into the impact of the COVID-19 pandemic on RSV prevalence, subtype distribution, patient characteristics, and clinical management. These findings underscore the need for ongoing surveillance and adaptive public health responses.

Model correction of diagnostic coding-based RSV incidence for children 0-4 years in the US.

BACKGROUND: Although administrative claims data have a high degree of completeness, not all medically attended Respiratory Syncytial Virus-associated lower respiratory tract infections (RSV-LRTIs) are tested or coded for their causative agent. We sought to determine the attribution of RSV to LRTI in claims data via modeling of temporal changes in LRTI rates against surveillance data. METHODS: We estimated the weekly incidence of LRTI (inpatient, outpatient, and total) for children 0-4 years using 2011-2019 commercial insurance claims, stratified by HHS region, matched to the corresponding weekly NREVSS RSV and influenza positivity data for each region, and modelled against RSV, influenza positivity rates, and harmonic functions of time assuming negative binomial distribution. LRTI events attributable to RSV were estimated as predicted events from the full model minus predicted events with RSV positivity rate set to 0. RESULTS: Approximately 42% of predicted RSV cases were coded in claims data. Across all regions, the percentage of LRTI attributable to RSV were 15-43%, 10-31%, and 10-31% of inpatient, outpatient, and combined settings, respectively. However, when compared to coded inpatient RSV-LRTI, 9 of 10 regions had improbable corrected inpatient LRTI estimates (predicted RSV/coded RSV ratio < 1). Sensitivity analysis based on separate models for PCR and antigen-based positivity showed similar results. CONCLUSIONS: Underestimation based on coding in claims data may be addressed by NREVSS-based adjustment of claims-based RSV incidence. However, where setting-specific positivity rates is unavailable, we recommend modeling across settings to mirror NREVSS's positivity rates which are similarly aggregated, to avoid inaccurate adjustments.