Rate Of Respiratory Syncytial Virus Infection Research Articles

Circulation patterns and molecular characteristics of respiratory syncytial virus among hospitalized children in Tianjin, China, before and during the COVID-19 pandemic (2017–2022)

Respiratory syncytial virus (RSV) is the main pathogen that causes hospitalization for acute lower respiratory tract infections (ALRIs) in children. With the reopening of communities and schools, the resurgence of RSV in the COVID-19 post-pandemic era has become a major concern. To understand the circulation patterns and genotype variability of RSV in Tianjin before and during the COVID-19 pandemic, a total of 19,531 nasopharyngeal aspirate samples from hospitalized children in Tianjin from July 2017 to June 2022 were evaluated. Direct immunofluorescence and polymerase chain reaction (PCR) were used for screening RSV-positive samples and subtyping, respectively. Further analysis of mutations in the second hypervariable region (HVR2) of the G gene was performed through Sanger sequencing. Our results showed that 16.46% (3215/19,531) samples were RSV positive and a delayed increase in the RSV infection rates occurred in the winter season from December 2020 to February 2021, with the average RSV-positive rate of 35.77% (519/1451). The ON1, with H258Q and H266L substitutions, and the BA9, with T290I and T312I substitutions, are dominant strains that alternately circulate every 1–2 years in Tianjin, China, from July 2017 to June 2022. In addition, novel substitutions, such as N296Y, K221T, N230K, V251A in the BA9 genotype, and L226I in the ON1 genotype, emerged during the COVID-19 pandemic. Analysis of clinical characteristics indicated no significant differences between RSV-A and RSV-B groups. This study provides a theoretical basis for clinical prevention and treatment. However, further studies are needed to explore the regulatory mechanism of host immune responses to different lineages of ON1 and BA9 in the future.

Respiratory syncytial virus disease morbidity in Australian infants aged 0 to 6 months: a systematic review with narrative synthesis

BackgroundA significant proportion of the global respiratory syncytial virus (RSV) associated morbidity is accounted for by infants aged 0 to 6 months, who are particularly vulnerable to severe disease. In 2015, 44% of global hospitalisations in infants in this age group were secondary to RSV. The objective of this systematic review is to appraise and synthesise the local evidence of RSV infection morbidity among Australian infants aged 0 to 6 months and to assess the implications for future immunisation strategies.MethodsElectronic databases (Medline, Embase, Pubmed and Global Health) were searched for full-text articles published between 2000 and 2023 in English language. Studies that examined markers of RSV disease morbidity in infants aged 0 to 6 months in Australia who had laboratory confirmed RSV infection were eligible for inclusion. The outcomes of interest were incidence, prevalence, testing rate, positivity rate, mortality, emergency department visits, community health visits, hospitalisation, intensive care unit admission, supplementary oxygen use, mechanical ventilation, risk factors for disease severity and monoclonal antibody use.ResultsThe database search identified 469 studies. After removal of duplicates and full-text review, 17 articles were eligible for inclusion. This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesis without meta-analysis guidelines.ConclusionsQualitative analysis of the included studies showed that Australian infants aged 0 to 6 months have higher rates of RSV testing, positivity and incidence; and more likely to develop severe disease that requires hospitalisation, intensive care unit admission or respiratory support, compared to children and adults of all ages. Aboriginal and Torres Strait Islander infants aged 0 to 6 months demonstrated higher rates of RSV infection and hospitalisation, compared to non-Indigenous infants. Age-related trends persisted in geographic areas with varying seasonal transmission of RSV, and during the SARS-CoV-2 pandemic. Passive immunisation strategies targeting infants in their first 6 months of life, either via vaccination of pregnant women or administration of long-acting monoclonal antibody during infancy, could effectively reduce RSV disease burden in Australia.

Effect of Palivizumab Prophylaxis on Respiratory Syncytial Virus Infection in Very Preterm Infants in the First Year of Life in The Netherlands.

Respiratory Syncytial Virus (RSV) poses a severe threat to infants, particularly preterm infants. Palivizumab, the standard preventive prophylaxis, is primarily utilized in high-risk newborns due to its cost. This study assessed palivizumab's effectiveness in preventing RSV infections in predominantly very preterm infants during their first year of life. Serum samples from a prospective multicentre cohort study in the Netherlands were analyzed to assess RSV infection rates by measuring IgG levels against three RSV proteins: nucleoprotein, pre-fusion, and post-fusion protein. Infants were stratified based on gestational age (GA), distinguishing very preterm (≤32 weeks GA) from moderate/late preterm (>32 to ≤36 weeks GA). In very preterm infants, palivizumab prophylaxis significantly reduced infection rates (18.9% vs. 48.3% in the prophylaxis vs. non-prophylaxis group. Accounting for GA, sex, birth season, and birth weight, the prophylaxis group showed significantly lower infection odds. In infants with >32 to ≤36 weeks GA, the non-prophylaxis group (55.4%) showed infection rates similar to the non-prophylaxis ≤32-week GA group, despite higher maternal antibody levels in the moderate/late preterm infants. In conclusion, palivizumab prophylaxis significantly reduces RSV infection rates in very premature infants. Future research should explore clinical implications and reasons for non-compliance, and compare palivizumab with emerging prophylactics like nirsevimab aiming to optimize RSV prophylaxis and improve preterm infant outcomes.

Transient increased risk of influenza infection following RSV infection in South Africa: findings from the PHIRST study, South Africa, 2016–2018

BackgroundLarge-scale prevention of respiratory syncytial virus (RSV) infection may have ecological consequences for co-circulating pathogens, including influenza. We assessed if and for how long RSV infection alters the risk for subsequent influenza infection.MethodsWe analysed a prospective longitudinal cohort study conducted in South Africa between 2016 and 2018. For participating households, nasopharyngeal samples were taken twice weekly, irrespective of symptoms, across three respiratory virus seasons, and real-time polymerase chain reaction (PCR) was used to identify infection with RSV and/or influenza. We fitted an individual-level hidden Markov transmission model in order to estimate RSV and influenza infection rates and their interdependence.ResultsOf a total of 122,113 samples collected, 1265 (1.0%) were positive for influenza and 1002 (0.8%) positive for RSV, with 15 (0.01%) samples from 12 individuals positive for both influenza and RSV. We observed a 2.25-fold higher incidence of co-infection than expected if assuming infections were unrelated. We estimated that infection with influenza is 2.13 (95% CI 0.97–4.69) times more likely when already infected with, and for a week following, RSV infection, adjusted for age. This equates to 1.4% of influenza infections that may be attributable to RSV in this population. Due to the local seasonality (RSV season precedes the influenza season), we were unable to estimate changes in RSV infection risk following influenza infection.ConclusionsWe find no evidence to suggest that RSV was associated with a subsequent reduced risk of influenza infection. Instead, we observed an increased risk for influenza infection for a short period after infection. However, the impact on population-level transmission dynamics of this individual-level synergistic effect was not measurable in this setting.

Comparative analysis of Respiratory Syncytial Virus frequency rates and viral load in different patient cohorts in a University Hospital in São Paulo, Brazil, over an eight-year period (2005–2013)

Respiratory Syncytial Virus (RSV) poses a global health concern, particularly affecting young children, the elderly, and immunosuppressed individuals. RSV viral load is essential for understanding transmission, disease severity, prevention, and treatment. This retrospective study aimed to analyze the frequency rates and viral loads of RSV infections in different patient cohorts and age groups over an eight-year period in a university hospital in São Paulo, Brazil. This study analyzed 1380 Immunocompetent (IC) and Immunosuppressed (IS) patients with acute respiratory tract infections. IC included patients with chronic Heart Disease (HD), Primary Care service recipients (PC), and a subgroup suspected of having Severe Acute Respiratory Syndrome caused by Influenza A (H1N1)pdm09 virus (SARS H1N1). IS comprised transplant patients and those with HIV infection. Respiratory samples were collected between February 2005 and October 2013, with RSV detection and viral load quantification (Log10 copies of RNA/mL) using RT-qPCR. Overall RSV infection rate was 17.3 %, with higher rates in children (23.9 %) than in adults (12.9 %), particularly in children under two years of age (28.2 %). Children in the SARS H1N1 and PC subgroups had higher infection rates (16.4 % and 34.9 %, respectively), with the highest rate in PC children aged 1 to < 2 years (45.45 %). Adults with HD had a significantly higher frequency rate (27.83 %) than those in the SARS H1N1 (2.65 %) and IS (15.16 %) subgroups and higher hospitalization rate among adults under 65 years. RSV viral load ranged from 2.43 to 10.15 Log10 RNA copies/mL (mean ± SD 5.82 ± 2.19), with hospitalized patients exhibiting significantly higher viral loads (7.34 ± 1.9) than outpatients (4.38 ± 1.89). Elderly bone marrow transplant patients also had significantly higher viral loads (7.57 ± 2.41) than younger adults (5.12 ± 1.87). This study provides insights into the RSV infection patterns in different patient cohorts in Brazil. Further investigations are needed to understand susceptibility and risk factors associated with RSV infection. In conclusion, high RSV viral load among hospitalized patients could serve as a surrogate marker of disease severity. Additionally, patients with chronic heart disease deserve greater attention regarding complications associated with RSV infection.

COPD Exacerbation-Related Pathogens and Previous COPD Treatment.

We evaluated whether the pathogens identified during acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) are associated with the COPD medications used in the 6 months before AE-COPD. We collected the medical records of patients diagnosed with AE-COPD at 28 hospitals between January 2008 and December 2019 and retrospectively analyzed them. Microorganisms identified at the time of AE-COPD were analyzed according to the use of inhaled corticosteroid (ICS) and systemic steroid after adjusting for COPD severity. We evaluated 1177 patients with AE-COPD and available medication history. The mean age of the patients was 73.9 ± 9.2 years, and 83% were males. The most frequently identified bacteria during AE-COPD were Pseudomonas aeruginosa (10%), followed by Mycoplasma pneumoniae (9.4%), and Streptococcus pneumoniae (5.1%), whereas the most commonly identified viruses were rhinovirus (11%) and influenza A (11%). During AE-COPD, bacteria were more frequently identified in the ICS than non-ICS group (p = 0.009), and in the systemic steroid than non-systemic steroid group (p < 0.001). In patients who used systemic steroids before AE-COPD, the risk of detecting Pseudomonas aeruginosa was significantly higher during AE-COPD (OR 1.619, CI 1.007−2.603, p = 0.047), but ICS use did not increase the risk of Pseudomonas detection. The risk of respiratory syncytial virus (RSV) detection was low when ICS was used (OR 0.492, CI 0.244−0.988, p = 0.045). COPD patients who used ICS had a lower rate of RSV infection and similar rate of P. aeruginosa infection during AE-COPD compared to patients who did not use ICS. However, COPD patients who used systemic steroids within 6 months before AE-COPD had an increased risk of P. aeruginosa infection. Therefore, anti-pseudomonal antibiotics should be considered in patients with AE-COPD who have used systemic steroids.

Impact of immunoprophylaxis with palivizumab on respiratory syncytial virus infection in preterm infants less than 35 weeks in Colombian hospitals.

To evaluate the impact of immunoprophylaxis with palivizumab in preterm infants less than 35 weeks in terms of hospitalization rate, intensive care unit requirement, and mortality. A prospective cohort study was conducted at six Colombian hospitals. Preterm infants less than 35 weeks who received at least one dose of palivizumab during the first 6months of life were included. The primary outcome was the hospitalization rate related to respiratory syncytial virus(RSV) infection. A total of 222 newborns participated in the study; 204 (91.8%) completed the 6-month follow-up, and three died during the study. 88.7% received a second dose of palivizumab, 79.7% a third, 34.7% a fourth, and 25.2% a fifth. The nonadjusted incidence rate of RSV infection was 2.4%, and the overall RSV-positive hospitalization rate was 1.9%. The proportion of patients that required Neonatal Intensive Care Unit (NICU) and mechanical ventilation in relation to RSV infection was 1.4%. Discharge with home oxygen, pulmonary dysplasia, and being younger than 6months were significantly associated with respiratory infection. Furthermore, exposition to cigarette smoke was the only factor associated with increased risk of hospitalization. The group that required hospitalization received fewer doses of palivizumab (p = 0.049). No discontinuation of treatment due to adverse events were reported. No death was judged to be related to palivizumab. The hospitalization rate and the need for NICU admission were lower than those reported in the literature. In this real-life setting, palivizumab appears to be effective in preventing serious cases of RSV infection.

ASSESSMENT OF CASES ADMITTED TO THE NEONATAL INTENSIVE CARE UNIT WITH LOWER RESPIRATORY TRACT INFECTION

OBJECTIVE: The purpose of this study is to assess the clinical features, laboratory findings, diagnosis and treatments of neonates in the neonatal intensive care unit with a diagnosis of lower respiratory tract infection (LRTI).MATERIAL AND METHODS: The data of neonates hospitalized in the neonatal intensive care unit of our hospital between 2017 and 2019 with a diagnosis of LRTI was retrospectively obtained from the file records. Demographical features, diagnosis and treatments were analyzed.RESULTS: A total of 57 patients diagnosed with LRTI were included in the study. The mean gestational age of the patients was 36.8 ± 3 weeks and their mean birth weight was 2864 ± 787 g. The 67% (n = 38) of them were term infants and the 33% (n = 19) of them were preterm infants. When the symptoms, examination findings and chest radiographs of the cases were examined at the time of admission, tachypnea, prolonged expiration, and nutritional difficulty in 67% of cases (n = 38), cough in 26% (n = 15) of the cases, fever in 20% (n = 12) of the cases, vomiting in 12% (n = 7) of the cases, apnea in 7% (n = 4)of the cases, and increased aeration in lung imaging in 21% (n = 12) of the cases were detected. Respiratory panel using Polymenase Chain Reaction (PCR) method was investigated in nasopharyngeal swab samples of 61% (n = 35) of the patients, respiratory syncytial virus (RSV) in 57% (n = 20), rhinovirus in 14% (n = 5), and metapneumovirus in 3% (n = 1) of the cases were observed. The 47% of the patients (n = 27) received high-flow oxygen, 26% (n= 15) nasal CPAP, 58% (n=33) antibiotics, 63% (n= 36) inhaler bronchodilator and hypertonic saline treatment.CONCLUSIONS: In accordance with the literature, a high rate of RSV infection was detected in neonates with LRTI in the neonatal intensive care unit of our hospital. Early diagnosis is important to prevent unnecessary use of antibiotics and to prevent nosocomial infections.

998. Forward and Reverse Translational Approaches to Predict Efficacy of the Neutralizing Respiratory Syncytial Virus (RSV) Antibody MK-1654

BackgroundMK-1654 is a respiratory syncytial virus (RSV) F glycoprotein neutralizing monoclonal antibody (mAb) with an extended half-life in late development to prevent RSV infection in infants. Neutralizing mAbs, like MK-1654, have great potential for prophylaxis against viral infection. However, well-validated approaches for clinical dose and efficacy predictions are lacking.MethodsSummary-level literature data from RSV prevention studies were used in a model-based meta-analysis (MBMA) to describe the relationship between RSV incidence rates and serum neutralizing antibody (SNA) titer. The model was validated using viral challenge experiments in cotton rats and phase 3 RSV-A efficacy results in infants for an anti-RSV F mAb, REGN-2222. A phase 2b human RSV challenge study (HCS) in adults was also conducted with MK-1654. Participants (N=70) received 100, 200, 300, or 900 mg of MK-1564 or placebo and were challenged intranasally with RSV 29 days later. RSV viral load and symptomatic infection were monitored. Data from the HCS were compared to model predictions. The MBMA was used to predict efficacy of MK-1654 in a virtual population of pre- and full- term infants.ResultsThe relationship between SNA titer and RSV incidence rate defined using the viral load data from the cotton rat approximated the relationship identified for infants from the clinical MBMA. The MBMA was quantitatively consistent with the phase 3 efficacy results against RSV A for REGN-2222. In the HCS, RSV nasal viral load measured by RT-qPCR and quantitative culture as well as symptomatic infections were decreased in MK-1654 recipients compared to placebo. Incidence rates of RSV infection in the HCS were also consistent with MBMA predictions. The model-based clinical trial simulations for MK-1654 indicated a high probability of substantial efficacy against RSV-associated medically attended lower respiratory tract infection ( >75% for 5 months) for doses ≥75 mg.ConclusionOur MBMA successfully quantified the relationship between RSV SNA and clinically relevant endpoints, including lower respiratory tract infection in infants. MBMA-based efficacy predictions support continued development of the MK-1654 antibody for the prevention of RSV in infants.DisclosuresBrian M. Maas, PharmD, Merck & Co., Inc. (Employee, Shareholder) Jos Lommerse, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Nele Plock, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Radha Railkar, PhD, Merck & Co., Inc. (Employee, Shareholder) S. Y. Amy Cheung, PhD, Certara (Employee, Shareholder) Luzelena Caro, PhD, Merck & Co., Inc. (Employee, Shareholder) Jingxian Chen, PhD, Merck & Co., Inc. (Employee, Shareholder) Wen Liu, MPH, Merck & Co., Inc. (Employee, Shareholder) Ying Zhang, PhD, Merck & Co., Inc. (Employee, Shareholder) Qinlei Huang, MS, Merck & Co., Inc. (Employee, Shareholder) Wei Gao, PhD, Merck & Co., Inc. (Employee, Shareholder) Li Qin, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Jie Meng, MSc, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Han Witjes, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Emilie Schindler, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Benjamin Guiastrennec, PharmD, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Francesco Bellanti, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Daniel Spellman, PhD, Merck & Co., Inc. (Employee, Shareholder) Brad Roadcap, MS, Merck & Co., Inc. (Employee, Shareholder) Amy Espeseth, PhD, Merck & Co., Inc. (Employee, Shareholder) S. Aubrey Stoch, MD, Merck & Co., Inc. (Employee, Shareholder) Eseng Lai, MD, PhD, Merck & Co., Inc. (Employee, Shareholder) Kalpit A. Vora, PhD, Merck & Co., Inc. (Employee, Shareholder) Antonios O. Aliprantis, MD, PhD, Merck & Co., Inc. (Employee, Shareholder) Jeffrey R. Sachs, PhD, Merck & Co., Inc. (Employee, Shareholder)

Influenza A Virus Inhibits RSV Infection via a Two-Wave Expression of IFIT Proteins.

Influenza viruses and respiratory syncytial virus (RSV) are respiratory viruses that primarily circulate worldwide during the autumn and winter seasons. Seasonal surveillance has shown that RSV infection generally precedes influenza. However, in the last four winter seasons (2016–2020) an overlap of the morbidity peaks of both viruses was observed in Israel, and was paralleled by significantly lower RSV infection rates. To investigate whether the influenza A virus inhibits RSV, human cervical carcinoma (HEp2) cells or mice were co-infected with influenza A and RSV. Influenza A inhibited RSV growth, both in vitro and in vivo. Mass spectrometry analysis of mouse lungs infected with influenza A identified a two-wave pattern of protein expression upregulation, which included members of the interferon-induced protein with the tetratricopeptide (IFITs) family. Interestingly, in the second wave, influenza A viruses were no longer detectable in mouse lungs. In addition, knockdown and overexpression of IFITs in HEp2 cells affected RSV multiplicity. In conclusion, influenza A infection inhibits RSV infectivity via upregulation of IFIT proteins in a two-wave modality. Understanding the immune system involvement in the interaction between influenza A and RSV viruses will contribute to the development of future treatment strategies against these viruses.

Epidemiological and Clinical Features of Patients Suffering from Severe Pneumonia Caused by RSV in the Respiratory Center of the Viet Nam National Children's Hospital

Background/Purpose: Pneumonia is a common respiratory and life-threatening disease in pediatrics. Virus is an important cause of pneumonia in children, of which Respiratory syncytial virus (RSV) is the most common cause. The aim of this research is to access the clinical, epidemiological features and risk factors of patients suffering from RSV severe pneumonia.&#x0D; Methods: We studied 250 patients suffering from severe pneumonia caused by RSV from June 2019 to December 2019 in the Respiratory Center of the Vietnam National Children’s Hospital.&#x0D; Results: In Respiratory Center of our hospital, 3472 hospitalizations caused by pneumonia occurred in the last 6 months in 2019; 7.2% of these caused by RSV severe pneumonia. Pneumonia caused by RSV occurred most in male (66,7%), the rate of male/female = 2/1. The mean age was 4,94 ± 6,04 months. The prevalence of RSV in age groups is, respectively, as follows: less than 3 months (21,3%), from 3 months to 6 months (23,4%), from 6 months to 12 months (27%), from 12 months to 24 months (19%), over 2 years (9,3%). The most common symptoms which were accounted for over 80% were rhinorrhea, cough, wheeze, tachypnea and chest recession. The rate of admission increased sharply in December with 25.1% of cases. All hospitalized patients had respiratory distress symptoms with the frequent changes in blood gas, accounting for 59.2% of hypercapnia. The mean of hospitalization was 6,2 ± 7,4 days.&#x0D; Conclusion: the rate of RSV infection increased in the last 6 months in 2019. Most of patients who less than 1 year of age were admitted to hospital because of severe clinical symptoms and respiratory distress. Risk factors were related to the severity of RSV severe pneumonia were: premature, mal-nutrition, bronchopulmonary dysplasia.

The burden of respiratory syncytial virus associated with acute lower respiratory tract infections in Chinese children: a meta-analysis.

BackgroundRespiratory syncytial virus (RSV), which is associated with acute lower respiratory tract infection (ALRTI), is highly common among children. The burden of RSV varies between countries. In China, the actual burden remains unclear. Thus, this meta-analysis aimed to quantify the positive rate of ALRTI-related RSV infections among Chinese children in recent years.MethodsThe PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), WanFang, and Chinese BioMedical (CBM) databases were searched to identify relevant cross-sectional studies published between January 1, 2015 and December 31, 2018. Subsequently, a meta-analysis was performed using R software.ResultsA total of 18 studies involving 66,799 ALRTI cases were finally included in the meta-analysis. Among those ALRTIs cases, the overall positive rate of RSV infection was 16.0% (95% CI: 12.9–19.6%). The rate was significantly higher in children <3 years (19.5%, 95% CI 13.3–27.6%) compared to those ≥3 years (5.6%, 95% CI: 2.3–13.2%; P<0.01). Moreover, stratified analysis revealed that RSV infection was most frequent in children <6 months (31.1%, 95% CI: 21.0–43.5%). The positive detection rate of RSV infection was significantly associated with season (P<0.01), with winter having the highest detection rate (29.0%, 95% CI: 21.3–38.2%), followed by autumn (20.9%, 95% CI: 10.5–37.3%), and summer having the lowest rate (6.4%, 95% CI: 2.3–16.9%). The rate of RSV infection was highest and lowest in November (49.4%, 95% CI: 29.0–70.0%) and June (1.3%, 95% CI: 0.6–2.8%), respectively. When stratified according to geographical region, RSV infections peaked in winter (South: 24.8%, 95% CI: 12.9–42.3%; North: 36.3%, 95% CI: 30.8–42.1%), followed by autumn (South: 13.9%, 95% CI: 6.5–27.4%; North: 32.7%, 95% CI: 20.2–48.3%).ConclusionsIn conclusion, our meta-analysis showed that among Chinese children with ALRTI, 16.0% had RSV infection. RSV infection frequently occurred in children under the age of 3 years, especially in those under 6 months. The rate of RSV infections was highest in winter, followed by autumn.

Molecular epidemiology of influenza, RSV, and other respiratory infections among children in Qatar: A six years report (2012–2017)

BackgroundStudies on the etiology of respiratory infections among children in Qatar and surrounding countries are limited. ObjectivesTo describe the prevalence and seasonality of RSV, influenza, and other respiratory pathogens among children in Qatar. MethodsWe retrospectively collected and analyzed data of 33,404 children (<15 years) presented with influenza-like illness from 2012 to 2017. ResultsAt least one respiratory pathogen was detected in 26,138 (78%) of patients. Together, human rhinoviruses (HRV), respiratory syncytial virus (RSV), and influenza viruses comprised nearly two-thirds of all cases, affecting 24%, 19.7%, and 18.5%, respectively. A prevalence of 5-10% was recorded for adenovirus, parainfluenza viruses (PIVs), human bocavirus (HboV), and human coronaviruses (HCoVs). Human metapneumovirus (HMPV), enteroviruses, M. pneumonia, and parechovirus had prevalences below 5%. While RSV, influenza, and HMPV exhibited strong seasonal activity in the winter, HRV was active during low RSV and influenza circulation. The burden of RSV exceeds that of influenza among young age groups, whereas influenza correlated positively with age. Further, HRV, adenovirus, influenza, and RSV infection rates varied significantly between male and females. ConclusionThis comprehensive multi-year study provides insights into the etiology of ILI among children in Qatar, which represents the Gulf region. Our results reinforce the significance of active surveillance of respiratory pathogens to improve infection prevention and control strategies, particularly among children.

The Association of Respiratory Syncytial Virus Infection and Childhood Asthma: A Meta-Analysis

Objective: To explore the close relationship between respiratory syncytial virus (RSV) infection and acute attack of childhood asthma. Methods: A computer-based search of database from Pumbed, CNKI, Wanfang, Baidu Scholar, Chongqing VIP, GeenMedica was performed to screen the articles about respiratory syncytial virus infection and childhood asthma. Then the literatures were screened out by the selection criteria. The RevMan5.3 software was used to test the heterogeneity and effect values of each study, analyze the sensitivity and publication bias of the literature, and draw on Meta forest plot and Funnel plot. Results: 5 articles conformed to the selection criteria. There were totally 881 cases in the case group, 826 cases in the control group. The results of heterogeneity test showed no heterogeneity between each study (P > 0.05). The fixed-effects model showed the 6.68 (5.06 - 8.82), (Z = 13.38, P < 0.00001). Conclusion: The infection rate of respiratory syncytial virus in children with acute asthma attack is higher than that in remission period. Respiratory syncytial virus infection rate can be used as an indicator of the severity of asthma in children.

2797. Rates of Respiratory Syncytial Virus (RSV) Infection among Hospitalized Adults by Congestive Heart Failure Status—United States, 2015–2017

BackgroundRespiratory syncytial virus (RSV) can cause severe disease in older adults and adults with cardiopulmonary conditions, such as congestive heart failure (CHF). RSV vaccines in development may target adults based on age or medical conditions. We assessed rates of RSV infection in hospitalized adults by CHF status using RSV surveillance conducted through the Centers for Disease Control and Prevention’s Emerging Infections Program, a population-based platform in the United StatesMethodsRSV surveillance was performed during two seasons (2015–2017) from October 1–April 30 at seven US sites covering an annual catchment population up to 13.7 million adults. Adults (≥ 18 years) admitted to a hospital from the catchment area and with laboratory-confirmed RSV infections identified by clinician-directed testing were included. Demographic data and any history of CHF were abstracted from medical charts. For adults ≥ 65 years, county-level CHF prevalence was obtained from 2015 Centers for Medicare and Medicaid Services (CMS) data. To estimate county-level CHF prevalence for adults < 65 years, we used 2015–2016 National Health and Nutrition Examination Survey and CMS data. We calculated crude incidence rates (and 95% exact Poisson confidence intervals) of RSV by CHF status and age group (< 65 years vs. ≥ 65 years) using RSV cases (numerator) and catchment area county-level population estimates from the US Census (denominator).ResultsDuring 2015–2017, a total of 2,211 hospitalized RSV cases were identified; 2,055 (92.9%) had CHF status documented. The majority were ≥ 65 years (n = 1236, 60.1%) and 26.8% (n = 550) had CHF. The crude rate of RSV was 62.7 (95% CI: 57.5–68.2) per 100,000 population in adults with CHF compared with 6.1 (95% CI: 5.7–6.4) per 100,000 population in adults without CHF (rate ratio: 10.3, 95% CI: 9.3–11.3). In both age groups, those with CHF had higher rates of RSV than those without CHF. Rates were highest in adults ≥ 65 years with CHF (73.4 per 100,000 population, 95% CI: 66.4–80.9).ConclusionUsing population-based surveillance, we found that adults with CHF had RSV hospitalization rates 10 times higher than those without CHF. Identifying high-risk populations for RSV infection are critical to inform clinical practice and future RSV vaccine policy.Disclosures All authors: No reported disclosures.

Respiratory Syncytial Virus Vaccines: Are We Making Progress?

Respiratory Syncytial Virus Vaccines: Are We Making Progress?

High Detection Rates of Human Bocavirus in Infants and Small Children with Lower Respiratory Tract Infection from Croatia.

Human bocavirus (HBoV) is known to cause lower respiratory tract infections (LRTI) in children and may result in substantial morbidity and mortality. The aim of this study was to determine HBoV prevalence among hospitalized infants and small children with acute LRTI in Zagreb, Croatia, as well as to evaluate HBoV DNA quantity in samples in relation to the patients' age and co-infection with other respiratory viruses. During winter season 2016/2017, a total of 295 children younger than three years of age who were admitted to hospitals with LRTI were tested for the presence of HBoV, respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV) types 1 to 3, and human metapneumovirus (HMPV). HBoV was detected with a real-time PCR method, and the other viruses were diagnosed using monoclonal antibodies in direct fluorescence assay. Viral etiology was proven in 225/295 (76.3%) of patients. The most commonly diagnosed virus was RSV (59.3%), followed by HBoV (23.1%), PIVs (4.4%), ADV (3.1%), and HMPV (1.4%). HBoV-infected children were older than RSV-infected children; likewise, detection rates of HBoV infection increased with age, while RSV infection rates decreased with age. In 51% of HBoV-positive samples an additional respiratory virus was also detected. There was no difference in HBoV DNA quantity between samples with single virus detection and those with multiple virus detection (p = 0.056), although samples positive only for HBoV showed higher cycle threshold values. There was no difference in HBoV DNA quantity in samples of different age groups (p > 0.05). Frequent detection of HBoV in small children with LRTI, even in combination with other viruses, highlights its role in the pathogenesis of respiratory disease.

War against respiratory syncytial virus. An 8-year experience at a tertiary hospital.

Objectives:To assess the respiratory syncytial virus (RSV) infection incidence rate through the analysis of data collected before and after implementation of a new palivizumab dosing regimen customized for a high-risk Saudi population.Methods:This was a retrospective cohort study performed at Prince Sultan Military Medical City, Riyadh, Saudi Arabia between November 2009 andApril 2017 on 1704 high risk Saudi young children and comparing 3 palivizumab regimens: a 4-week interval dosing regimen starting in either November or mid-September and a 3-week interval dosing regimen starting in mid-September.Results:Despite a decrease in the incidence rate of RSV infection with the three-week interval regimen (3.9% versus 5.9% in seasons 1 and 9.1% in seasons 2), we did not find significant differences among the 3 groups.Conclusion:Expanded use of palivizumab in newborn children could improve outcomes, but further investigation and a careful cost analysis are required.

Meteorological factors on the incidence of MP and RSV pneumonia in children.

BackgroundPneumonia is common in children and mostly caused by many pathogens. The aim of this study was to investigate whether the incidence of pediatric mycoplasma pneumoniae (MP) pneumonia and respiratory syncytial virus (RSV) pneumonia was associated with meteorological factors in Hangzhou, China.MethodsA total of 36500 pneumonia patients were recruited to participate in the study. Nasopharyngeal swabs were collected for the detection of MP and RSV using real-time polymerase chain reaction (RT-PCR) and direct immunofluorescence (DIF) assays, respectively. We used a distributed lag non-linear model (DLNM) to evaluate the correlations between the MP/RSV incidence and meteorological factors.ResultsThe detection rates of MP and RSV were 18.4% and 10.4%, respectively. There was a positive correlation between temperature and the MP infection rate, but RSV infection rate was negatively associated with temperature. Moreover, the impact of temperature on infection with RSV presented evident lag and cumulative effects. There was also an evident lag effect of temperature on the infection rate of MP; however, there was no evident cumulative effect.ConclusionsIn this study, the results showed meteorological factors play an important role in the incidence of these two pathogens. All these results can provide the laboratory basis for the early diagnosis and treatment of pneumonia in children.

Respiratory Syncytial Virus Infection Rates with Limited Use of Palivizumab for Infants Born at 29 to 31+6/7 Weeks Gestational Age.

Immunoprophylaxis with palivizumab can reduce respiratory syncytial virus (RSV) infections and hospitalizations. Criteria in British Columbia limit the use of palivizumab to infants born at 29 to 31+6/7 weeks gestational age, which differ from guidelines of the American Academy of Pediatrics (AAP) and the Canadian Paediatric Society (CPS). To determine whether the limited use of palivizumab affected the frequency of hospital visits by RSV-positive infants (termed "RSV-positive hospital visits") who received approval for palivizumab and those who met the AAP/CPS criteria but did not receive approval for palivizumab. Data sets were generated for the period May 1, 2008, to April 30, 2011, to identify infants with gestational age of 29 to 31+6/7 weeks who were born in or transferred to the Fraser Health authority, RSV-positive results for infants less than 12 months of age who had visited Fraser Health sites and BC Children's Hospital, and palivizumab approvals. Infants were matched across these 3 data sets through their personal health numbers. The study included 359 infants born at 29 to 31+6/7 weeks, of whom 297 met the AAP/CPS criteria. However, only 46 of these 297 received approval for palivizumab according to the BC criteria. Sixteen (4.5%) of the 359 infants had RSV-positive hospital visits during the RSV season (November through March). Of the 46 infants who received approval for palivizumab, 2 (4.3%) had RSV-positive hospital visits, and of the 251 who met the AAP/CPS criteria but did not receive palivizumab approval, 14 (5.6%) had RSV-positive hospital visits. Of the 359 infants, 6 (1.7%) had RSV-positive results while admitted to the neonatal intensive care unit, and 10 (2.8%) tested positive for RSV during a subsequent hospital visit. The frequency of RSV-positive hospital visits did not differ between infants who received and those who did not receive approval for palivizumab in the Fraser Health authority. Limited use of palivizumab for RSV prophylaxis led to reasonable rates of RSV-positive hospital visits in the study population.