Respiratory Season Research Articles

Overnutrition, Nasopharyngeal Pathogenic Bacteria and Proinflammatory Cytokines in Infants with Viral Lower Respiratory Tract Infections.

Background: Little is known about the interaction between the nasopharyngeal bacterial profile and the nutritional status in children. In this study, our main goal was to evaluate the associations between overnutrition and the presence of four potentially pathogenic bacteria in the nasopharynx of infants with viral lower respiratory tract infections (LRTI). In addition, we determined whether changes in the nasopharyngeal bacterial profile were associated with mucosal and serum proinflammatory cytokines and with clinical disease severity. Methods: We enrolled 116 children less than 2 years old hospitalized for viral LRTI during two consecutive respiratory seasons (May 2016 to August 2017); their nutritional status was assessed, and nasopharyngeal and blood samples were obtained. S. aureus, S. pneumoniae, H. influenzae, M. catarrhalis, and respiratory viruses were identified in nasopharyngeal samples by qPCR. Cytokine concentrations were measured in nasopharyngeal and blood samples. Disease severity was assessed by the length of hospitalization and oxygen therapy. Results: Nasopharyngeal pathogenic bacteria were identified in 96.6% of the enrolled children, and 80% of them tested positive for two or more bacteria. The presence and loads of M. catarrhalis was higher (p = 0.001 and p = 0.022, respectively) in children with overnutrition (n = 47) compared with those with normal weights (n = 69). In addition, the detection of >2 bacteria was more frequent in children with overnutrition compared to those with normal weight (p = 0.02). Multivariate regression models showed that the presence and loads of S. pneumoniae and M. catarrhalis were associated with higher concentrations of IL-6 in plasma and TNF-α in mucosal samples in children with overnutrition. Conclusions: The nasopharyngeal profile of young children with overnutrition was characterized by an over representation of pathogenic bacteria and proinflammatory cytokines.

Comparison of clinical characteristics and outcomes of hospitalized patients with seasonal coronavirus infection and COVID-19: a retrospective cohort study

BackgroundUnlike SARS-CoV and MERS-C0V, SARS-CoV-2 has the potential to become a recurrent seasonal infection; hence, it is essential to compare the clinical spectrum of COVID-19 to the existent endemic coronaviruses. We conducted a retrospective cohort study of hospitalized patients with seasonal coronavirus (sCoV) infection and COVID-19 to compare their clinical characteristics and outcomes.MethodsA total of 190 patients hospitalized with any documented respiratory tract infection and a positive respiratory viral panel for sCoV from January 1, 2011, to March 31, 2020, were included. Those patients were compared with 190 hospitalized adult patients with molecularly confirmed symptomatic COVID-19 admitted from March 1, 2020, to May 25, 2020.ResultsAmong 190 patients with sCoV infection, the Human Coronavirus-OC43 was the most common coronavirus with 47.4% of the cases. When comparing demographics and baseline characteristics, both groups were of similar age (sCoV: 74 years vs. COVID-19: 69 years) and presented similar proportions of two or more comorbidities (sCoV: 85.8% vs. COVID-19: 81.6%). More patients with COVID-19 presented with severe disease (78.4% vs. 67.9%), sepsis (36.3% vs. 20.5%), and developed ARDS (15.8% vs. 2.6%) compared to patients with sCoV infection. Patients with COVID-19 had an almost fourfold increased risk of in-hospital death than patients with sCoV infection (OR 3.86, CI 1.99–7.49; p < .001).ConclusionHospitalized patients with COVID-19 had similar demographics and baseline characteristics to hospitalized patients with sCoV infection; however, patients with COVID-19 presented with higher disease severity, had a higher case-fatality rate, and increased risk of death than patients with sCoV. Clinical findings alone may not help confirm or exclude the diagnosis of COVID-19 during high acute respiratory illness seasons. The respiratory multiplex panel by PCR that includes SARS-CoV-2 in conjunction with local epidemiological data may be a valuable tool to assist clinicians with management decisions.

Unusual 2020 respiratory syncytial virus bronchiolitis season in Western Australia: Not explained by weather.

To describe and explore the relationship between weather and the unusual 2020 bronchiolitis season in Western Australia during the COVID-19 pandemic. Correlation of meteorological data and presentations of infants with bronchiolitis through the ED of Perth Children's Hospital. The 2020 bronchiolitis epidemic showed a reversal of the usual seasonal pattern. There were no weather events to account for this phenomenon. The bronchiolitis outbreak showed no relationship to local weather patterns. State-mandated COVID-19 public health measures appear as the likely rationale.

Vitamin D-mediated effects on airway innate immunity in vitro.

Vitamin D supplementation has been suggested to enhance immunity during respiratory infection season. We tested the effect of active vitamin D (calcitriol) supplementation on key airway innate immune mechanisms in vitro. Primary human airway epithelial cells (hAECs) grown at the air liquid interface were supplemented with 10-7 M calcitriol for 24 hours (or a time course) and their antimicrobial airway surface liquid (ASL) was tested for pH, viscoscity, and antibacterial and antiviral properties. We also tested hAEC ciliary beat frequency (CBF). Next, we assessed alterations to hAEC gene expression using RNA sequencing, and based on results, we measured neutrophil migration across hAECs. Calcitriol supplementation enhanced ASL bacterial killing of Staphylococcus aureus (p = 0.02) but did not enhance its antiviral activity against 229E-CoV. It had no effect on ASL pH or viscosity at three timepoints. Lastly, it did not affect hAEC CBF or neutrophil migration, although there was a trend of enhanced migration in the presence of a neutrophil chemokine (p = 0.09). Supplementation significantly altered hAEC gene expression, primarily of AMP-related genes including CAMP and TREM1. While vitamin D supplementation did not have effects on many airway innate immune mechanisms, it may provide a useful tool to resolve respiratory bacterial infections.

Short-term exposure to gaseous air pollutants and daily hospitalizations for acute upper and lower respiratory infections among children from 25 cities in China

To examine the short-term association between gaseous air pollutants (CO, NO2, SO2, and O3) and all-cause respiratory disease, acute upper respiratory infections (AURIs) as well as acute lower respiratory infections (ALRIs) among children, we conducted the study from 25 major cities in China. Hospitalization records of children aged 0–18 years due to all-cause respiratory diseases (889,926), AURIs (97,858), and ALRIs (642,154) from 2016 to 2019 were extracted. Concentrations of CO, NO2, SO2, and O3 were averaged across monitoring stations. Generalized additive models were used to estimate the associations between gaseous air pollutants and daily hospitalizations for all-cause respiratory disease, AURIs, and ALRIs. The meta-analysis was used to combine the city-specific estimates. A 10 mg/m3 increase in CO at lag01, and a 10 μg/m3 increase in NO2, SO2, and O3 at lag01 were associated with 1.65% (95%CI, 0.41–2.91), 0.54% (95%CI, 0.30–0.79), 0.60% (95%CI, 0.22–0.99), and 0.23% (95%CI, 0.06–0.39) increase of hospitalizations due to all-cause respiratory disease, respectively. For the disease subtype, O3 only had adverse effects on AURIs, CO and SO2 mainly on ALRIs, and NO2 on both AURIs and ALRIs. Children aged 4–6years were more vulnerable to the effects of CO and NO2, but those aged <1year were more susceptible to SO2 and O3. Besides, the O3 effect was stronger in the warm season than in the cold season. The study indicated that short-term exposure to CO, NO2, SO2, and O3 was associated with increased hospitalization for pediatric respiratory disease, and the association may vary by position of the respiratory tract, age, and season.

Relevance of RSV in hospitalized adults and the need for continued testing

Background: RSV is underrecognized in hospitalized adults. A better understanding of RSV in this population could help prioritize targeted viral-testing resources. Hospitalization and in-hospital outcomes are widely accepted as markers of clinical severity with respect to acute respiratory illness (ARI). We compared characteristics and clinical outcomes between adults hospitalized with ARI from October 2016 through May 2019. Methods: All hospitalized adults (≥ 18 years) who met a standardized case definition of ARI were prospectively enrolled across 3 respiratory seasons from 9 hospitals participating in the US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN). Demographic data were collected during enrollment interviews, and electronic medical records (EMRs) were reviewed to extract comorbidity data. Throat and nasal swabs collected at enrollment were tested for ARI pathogens using real-time PCR assays at respective HAIVEN research laboratory sites. Characteristics and clinical outcomes of participants were compared using χ2 or nonparametric tests where appropriate. Multivariable logistic regression models were used to test associations between infection status, characteristics, and clinical outcomes, adjusting for age, sex, race, Charlson comorbidity index (CCI), body mass index (BMI), site, season, and days to admission. Results: In total, 10,311 adults were included, 22.3% (n = 2,300) were aged 18–49 years, 33.2% (n = 3,423) were aged 50–64 years, and 44.5% (n = 4,588) were aged ≥65 years. Moreover, 6% of adults tested positive for RSV (n = 622), 18.8% positive for influenza (n = 1,940), and 75.1% negative for both (n = 7,749). Obesity and age ≥65 years were significantly associated with RSV detection when compared with participants negative for both RSV and influenza. Patients aged 18–49 years and ≥65 years with RSV had significantly higher median CCI scores compared to patients with influenza (Fig. 1.). The proportion of adults with CHF or COPD was significantly (p-value Conclusions: Severe RSV illness may differ from severe influenza illness, and those infected with RSV may have different characteristics than those infected with influenza. Hospitalized adults with RSV infection were more likely to have underlying cardiopulmonary comorbidities and higher CCI scores as well as experience an extended length of hospital stay and need for mechanical ventilation. These data highlight the importance of retaining testing for RSV in older adults hospitalized with ARI.Funding: NoneDisclosures: None

Healthcare-associated respiratory syncytial virus infections in children’s hospitals

Background: Little is known about the impact of healthcare-associated respiratory syncytial virus (HA-RSV) in hospitalized children. To address this gap, we assessed the epidemiology and clinical impact associated with HA-RSV in a multiseason, multicenter study. Methods: During respiratory viral seasons 2016–2017, 2017–2018, and 2018–2019, we retrospectively identified HA-RSV cases in hospitalized children 72 hours after admission or within 48 hours of discharge in readmitted patients. Due to reduced availability of testing for non–SARS-CoV-2 viruses during the first year of the COVID-19 pandemic, the 2019–2020 season was excluded. We initiated prospective HA-RSV surveillance during the 2020–2021 season and continued surveillance through November 2021 due to the unusual interseasonal RSV community outbreak. We determined demographic and clinical characteristics of HA-RSV cases and explored possible outcomes associated with RSV including transfer to the pediatric ICU and escalation of respiratory support from day −2 to day +4 (day 0 was the day of RSV detection). We explored the timeframe of day −2 to day +4 because events during this timeframe could be attributed to RSV infection. Respiratory support escalation was defined as change from room air to supplemental oxygen, increase in fraction of inspired oxzygen (FiO2) on same respiratory support modality, or change from noninvasive to invasive support. Results: Were identified 86 HA-RSV cases: 20 (23.3%) from 2016–2017, 26 (30.2%) from 2017–2018, 34 (39.5%) from 2018–2019, and 6 (7%) from October 2020–November 2021. HA-RSV was diagnosed a median of 14 days (IQR, 8–45) after admission. Moreover, 29 (33.7%), 31 (36.0%), and 26 (30.2%) cases were aged 60 months during these, respective seasons. Also, 33 (38.4%) had &gt;3 comorbid conditions, most commonly gastrointestinal (n = 33, 38.4%), respiratory (n = 28, 32.6%), and/or congenital–genetic disorders (n = 28, 32.6%). However, 9 (10.5%) had no comorbid conditions. From day −2 to day +4, 15 children (17.4%) were transferred to the PICU and 38 (49.3%) of 77 evaluable cases required respiratory support escalation, most commonly supplemental oxygen delivered by nasal cannula (n = 15, 19.5%). Furthermore, 11 patients (14.3%) required invasive support. Conclusions: HA-RSV was associated with use of healthcare resources, including the need for respiratory support escalation and/or transfer to intensive care. From October 2020 to November 2021, lower numbers of HA-RSV were observed. The reasons for this are unknown, but potentially occurred in parallel to markedly reduced RSV in the community and may have resulted from visitor restrictions, which included no siblings and/or universal masking by hospital staff and visitors.Funding: Funding for this research was provided by Merck Sharp &amp; Dohme, a subsidiary of Merck &amp; Co.Disclosures: None

Circulating Trends of Influenza and Other Seasonal Respiratory Viruses among the US Department of Defense Personnel in the United States: Impact of the COVID-19 Pandemic.

The objective of this study was to evaluate the impact of the COVID-19 pandemic on the circulation of influenza and other seasonal respiratory viruses in the United States. All data were obtained from the US Department of Defense Global Respiratory Pathogen Surveillance Program over five consecutive respiratory seasons from 2016–2017 through to 2020–2021. A total of 62,476 specimens were tested for seasonal respiratory viruses. The circulating patterns of seasonal respiratory viruses have been greatly altered during the pandemic. The 2019–2020 influenza season terminated earlier compared to the pre-pandemic seasons, and the 2020–2021 influenza season did not occur. Moreover, weekly test positivity rates dramatically decreased for most of the seasonal respiratory viruses from the start of the pandemic through spring 2021. After the easing of non-pharmaceutical interventions (NPIs), circulations of seasonal coronavirus, parainfluenza, and respiratory syncytial virus have returned since spring 2021. High rhinovirus/enterovirus activity was evident throughout the 2020–2021 respiratory season. The findings suggest a strong association between the remarkably changed activity of seasonal respiratory viruses and the implementation of NPIs during the COVID-19 pandemic. The NPIs may serve as an effective public health tool to reduce transmissions of seasonal respiratory viruses.

D-29 | Arrhythmia Prevalence and Mortality by Primary Malignancy, Race and Income Disparities, and Respiratory Illness Season: Propensity Score Adjusted Machine Learning Analysis of Over 100 Million Hospitalizations and 3 Years

D-29 | Arrhythmia Prevalence and Mortality by Primary Malignancy, Race and Income Disparities, and Respiratory Illness Season: Propensity Score Adjusted Machine Learning Analysis of Over 100 Million Hospitalizations and 3 Years

Determination of respiratory syncytial virus epidemic seasons by using 95% confidence interval of positivity rates, 2011-2021, Germany.

Based on our national outpatient sentinel surveillance, we have developed a novel approach to determine respiratory syncytial virus (RSV) epidemic seasons in Germany by using RSV positivity rate and its lower limit of 95% confidence interval. This method was evaluated retrospectively on nine RSV seasons, and it is also well‐suited to describe off‐season circulation of RSV in near real time as observed for seasons 2020/21 and 2021/22 during the COVID‐19 pandemic. Prospective application is of crucial importance to enable timely actions for health service delivery and prevention.

Reduced spread of influenza and other respiratory viral infections during the COVID-19 pandemic in southern Puerto Rico.

IntroductionImpacts of COVID-19 mitigation measures on seasonal respiratory viruses is unknown in sub-tropical climates.MethodsWe compared weekly testing and test-positivity of respiratory infections in the 2019–2020 respiratory season to the 2012–2018 seasons in southern Puerto Rico using Wilcoxon signed rank tests.ResultsCompared to the average for the 2012–2018 seasons, test-positivity was significantly lower for Influenza A (p<0.001) & B (p<0.001), respiratory syncytial virus (RSV) (p<0.01), respiratory adenovirus (AdV) (p<0.05), and other respiratory viruses (p<0.001) following March 2020 COVID-19 stay at home orders.ConclusionsMitigation measures and behavioral social distancing choices may have reduced respiratory viral spread in southern Puerto Rico.

Multicenter Evaluation of the BioFire Respiratory Panel 2.1 (RP2.1) for Detection of SARS-CoV-2 in Nasopharyngeal Swab Samples.

ABSTRACTAs the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) begins to overlap with the traditional respiratory season in the Northern Hemisphere, simultaneous testing for SARS-CoV-2 and the other common causes of respiratory infections is imperative. This has led to the development of multiplex respiratory assays that include SARS-CoV-2 as a target. One such assay is the BioFire respiratory panel 2.1 (RP2.1), which is an expansion of the original BioFire FilmArray respiratory panel 2 (RP2) to include SARS-CoV-2. In this multicenter evaluation, we assessed the performance characteristics of the BioFire RP2.1 for the detection of SARS-CoV-2. One or more targets on the panel were detected in 19.3% (101/524) of specimens tested, with SARS-CoV-2 detected in 12.6% (66/524) of specimens. Human rhinovirus/enterovirus was also detected in 32.7% (33/101) and adenovirus in 3.0% (3/101) of positive specimens, with one dual positive for both SARS-CoV-2 and adenovirus being detected. A further breakdown of pathogens by age revealed a 4-fold predominance of human rhinovirus/enterovirus in subjects 0 to 18 years of age, whereas in all other age groups, SARS-CoV-2 was clearly the predominant pathogen. Overall, SARS-CoV-2 results obtained from the BioFire RP2.1 were highly concordant with the composite result, exhibiting 98.4% (61/62) positive percent agreement (95% confidence interval [CI], 91.4 to 99.7%) and 98.9% (457/462) negative percent agreement (95% CI, 97.5 to 99.5%) with further analysis of discordant results suggesting that the concentration of SARS-CoV-2 in the specimens was near the limit of detection (LoD) for both the BioFire RP2.1 and the comparator assays. Overall, the BioFire RP2.1 exhibited excellent performance in the detection of SARS-CoV-2.

Rates of respiratory syncytial virus (RSV)-associated hospitalization among adults with congestive heart failure-United States, 2015-2017.

BackgroundRespiratory syncytial virus (RSV) can cause severe disease in adults with cardiopulmonary conditions, such as congestive heart failure (CHF). We quantified the rate of RSV-associated hospitalization in adults by CHF status using population-based surveillance in the United States.MethodsPopulation-based surveillance for RSV (RSV-NET) was performed in 35 counties in seven sites during two respiratory seasons (2015–2017) from October 1–April 30. Adults (≥18 years) admitted to a hospital within the surveillance catchment area with laboratory-confirmed RSV identified by clinician-directed testing were included. Presence of underlying CHF was determined by medical chart abstraction. We calculated overall and age-stratified (<65 years and ≥65 years) RSV-associated hospitalization rates by CHF status. Estimates were adjusted for age and the under-detection of RSV. We also report rate differences (RD) and rate ratios (RR) by comparing the rates for those with and without CHF.Results2042 hospitalized RSV cases with CHF status recorded were identified. Most (60.2%, n = 1230) were ≥65 years, and 28.3% (n = 577) had CHF. The adjusted RSV hospitalization rate was 26.7 (95% CI: 22.2, 31.8) per 10,000 population in adults with CHF versus 3.3 (95% CI: 3.3, 3.3) per 10,000 in adults without CHF (RR: 8.1, 95% CI: 6.8, 9.7; RD: 23.4, 95% CI: 18.9, 28.5). Adults with CHF had higher rates of RSV-associated hospitalization in both age groups (<65 years and ≥65 years). Adults ≥65 years with CHF had the highest rate (40.5 per 10,000 population, 95% CI: 35.1, 46.6).ConclusionsAdults with CHF had 8 times the rate of RSV-associated hospitalization compared with adults without CHF. Identifying high-risk populations for RSV infection can inform future RSV vaccination policies and recommendations.

Early initiation of the respiratory syncytial virus season in 2021-2022, Greece.

Respiratory syncytial virus (RSV) is the most common viral pathogen causing respiratory disease in the pediatric population. An unexpected sudden upsurge of RSV infections among children was observed in September 2021 in Greece. Forty-one rhinopharyngeal samples from children under the age of 2 years with confirmed RSV bronchiolitis were tested to identify the genotype(s) of the RSV strain(s). The children were hospitalized during September-November 2021 in three tertiary hospitals in northern Greece. A one-step RT-PCR which amplifies a fragment of the second hypervariable region of the G protein gene was applied. PCR products were sequenced, and phylogenetic analysis was performed. Most (80.5%) RSV cases were typed as RSV-A, with RSV-B accounting for 19.5% of cases. RSV-A and RSV-B sequences clustered within the ON1 and BA genotypes, respectively. Asthe same genotypes were detected in cases observed during 2016-2018 in northern Greece, it was suggested that the early upsurge of infections was not related to the emergence of novel strain(s), but it was the result of the absence of immunity among children and their mothers due to the restriction measures taken during the COVID-19 pandemic in the previous RSV season. Awareness is needed to diagnose even the out-of-season RSV infections, while molecular epidemiology plays a key role in monitoring the efficacy of currently available therapeutics and for those under development.

Bacteremia in Adults Admitted from the Emergency Department with Laboratory-Confirmed Respiratory Syncytial Virus.

Collecting blood cultures from patients admitted from the emergency department (ED) with acute respiratory infection (ARI) is common, but the rate of secondary bacteremia in adult patients admitted from the ED with ARI associated with respiratory syncytial virus (RSV) is unknown. Indiscriminate collection of blood cultures can be associated with contaminated blood cultures and increased inappropriate antimicrobial use and health care costs. This study sought to determine the rate and etiology of secondary bacteremia, factors associated with secondary bacteremia, and factors associated with collecting blood cultures in the ED, in adults hospitalized with RSV. We performed a retrospective substudy using data from a prospective study of adults admitted with RSV infections during two respiratory seasons (October 2017 to April 2018 and October 2018 to April 2019). Blood cultures were collected at the discretion of ED providers. We compared demographic and clinical characteristics among those with and without secondary bacteremia and among those with and without blood cultures collected using multivariate logistic regression models. Of the 365 hospitalized RSV-positive patients (mean age 68.8 years), 269 (73.7%) had blood cultures collected in the ED and 18 (6.7%) patients had secondary bacteremia, most commonly from a nonrespiratory source (n=13). Patients with asthma and chronic obstructive pulmonary disease were significantly less likely to have secondary bacteremia. Patients who were immunocompromised, met systemic inflammatory response syndrome criteria, or had pneumonia described on chest x-ray reports were more likely to have blood cultures collected. Overall, 6.7% of adults hospitalized with RSV infections had secondary bacteremia, more commonly from nonrespiratory sources.

Relationships Between Community Virus Activity and Cardiorespiratory Rehospitalizations From Post-Acute Care

Objectives:Quantify the relationship between increasing influenza and respiratory syncytial virus (RSV) community viral activity and cardiorespiratory rehospitalizations among older adults discharged to skilled nursing facilities (SNFs).Design:Retrospective cohort.Setting and Participants:Adults aged ≥65 years who were hospitalized and then discharged to a US SNF between 2012 and 2015.Methods:We linked Medicare Provider Analysis and Review claims to Minimum Data Set version 3.0 assessments, PRISM Climate Group data, and the Centers for Disease Control and Prevention viral testing data. All data were aggregated to US Department of Health and Human Services regions. Negative binomial regression models quantified the relationship between increasing viral activity for RSV and 3 influenza strains (H1N1pdm09, H3N2, and B) and cardiorespiratory rehospitalizations from SNFs. Incidence rate ratios described the relationship between a 5% increase in circulating virus and the rates of rehospitalization for cardiorespiratory outcomes. Analyses were repeated using the same model, but influenza and RSV were considered “in season” or “out of season” based on a 10% positive testing threshold.Results:Cardiorespiratory rehospitalization rates increased by approximately 1% for every 5% increase in circulating influenza A(H3N2), influenza B, and RSV, but decreased by 1% for every 5% increase in circulating influenza A(H1N1pdm09). When respiratory viruses were in season (vs out of season), cardiorespiratory rehospitalization rates increased by approximately 6% for influenza A(H3N2), 3% for influenza B, and 5% for RSV, but decreased by 6% for influenza A(H1N1pdm09).Conclusions and Implications:The respiratory season is a particularly important period to implement interventions that reduce cardiorespiratory hospitalizations among SNF residents. Decreasing viral transmission in SNFs through practices such as influenza vaccination for residents and staff, use of personal protective equipment, improved environmental cleaning measures, screening and testing of residents and staff, surveillance of viral activity, and quarantining infected individuals may be potential strategies to limit viral infections and associated cardiorespiratory rehospitalizations.

Projecting the Combined Health Care Burden of Seasonal Influenza and COVID-19 in the 2020-2021 Season.

Background. In mid-2020, there was significant concern that the overlapping 2020–2021 influenza season and COVID-19 pandemic would overwhelm already stressed health care systems in the Northern Hemisphere, particularly if influenza immunization rates were low. Methods. Using a mathematical susceptible-exposed-infected-recovered (SEIR) compartmental model incorporating the age-specific viral transmission rates and disease severity of Austin, Texas, a large metropolitan region, we projected the incidence and health care burden for both COVID-19 and influenza across observed levels of SARS-CoV-2 transmission and influenza immunization rates for the 2020–2021 season. We then retrospectively compared scenario projections made in August 2020 with observed trends through June 2021. Results. Across all scenarios, we projected that the COVID-19 burden would dwarf that of influenza. In all but our lowest transmission scenarios, intensive care units were overwhelmed by COVID-19 patients, with the levels of influenza immunization having little impact on health care capacity needs. Consistent with our projections, sustained nonpharmaceutical interventions (NPIs) in Austin prevented COVID-19 from overwhelming health care systems and almost completely suppressed influenza during the 2020–2021 respiratory virus season. Limitations. The model assumed no cross-immunity between SARS-CoV-2 and influenza, which might reduce the burden or slow the transmission of 1 or both viruses. Conclusion. Before the widespread rollout of the SARS-CoV-2 vaccine, COVID-19 was projected to cause an order of magnitude more hospitalizations than seasonal influenza because of its higher transmissibility and severity. Consistent with predictions assuming strong NPIs, COVID-19 strained but did not overwhelm local health care systems in Austin, while the influenza burden was negligible. Implications. Nonspecific NPI efforts can dramatically reduce seasonal influenza burden and preserve health care capacity during respiratory virus season.HighlightsAs the COVID-19 pandemic threatened lives worldwide, the Northern Hemisphere braced for a potential “twindemic” of seasonal influenza and COVID-19.Using a validated mathematical model of influenza and SARS-CoV-2 co-circulation in a large US city, we projected the impact of COVID-19–driven nonpharmaceutical interventions combined with influenza vaccination on health care capacity during the 2020–2021 respiratory virus season.We describe analyses conducted during summer 2020 to help US cities prepare for the 2020–2021 influenza season and provide a retrospective evaluation of the initial projections.

A multicenter analysis of inpatient antibiotic use during the 2015-2019 influenza seasons in the United States: Untapped opportunities for antimicrobial stewardship.

Outpatient antibiotic use increases during winter months, but information on temporal changes in inpatient antibiotic use in US hospitals is limited. The use of certain inpatient antibiotics, including extended-spectrum cephalosporins, macrolides, and tetracyclines, was strongly associated with influenza activity during the 2015-2019 viral respiratory seasons.

Effectiveness of 13-Valent Pneumococcal Conjugate Vaccine Against Medically Attended Lower Respiratory Tract Infection and Pneumonia Among Older Adults.

Among older adults, 13-valent pneumococcal conjugate vaccine (PCV13) has been found efficacious against nonbacteremic pneumonia associated with vaccine-serotype pneumococci. However, the burden of lower respiratory tract infection (LRTI) and pneumonia preventable by direct immunization of older adults continues to be debated. We analyzed data from an open cohort of adults aged ≥65 years enrolled in Kaiser Permanente Southern California health plans from 2016 to 2019 who received PCV13 concordant with US Advisory Committee on Immunization Practices guidelines. We estimated PCV13 vaccine effectiveness (VE) via the adjusted hazard ratio for first LRTI and pneumonia episodes during each respiratory season, comparing PCV13-exposed and PCV13-unexposed time at risk for each participant using a self-matched inference framework. Analyses used Cox proportional hazards models, stratified by individual. Among 42700 adults who met inclusion criteria, VE was 9.5% (95% confidence interval [CI], 2.2% to 16.3%) against all-cause medically attended LRTI and 8.8% (95% CI, -.2% to 17.0%) against all-cause medically attended pneumonia. In contrast, we did not identify evidence of protection against LRTI and pneumonia following receipt of the 23-valent pneumococcal polysaccharide vaccine. PCV13 prevented 0.7 (95% CI, .2 to 1.4) and 0.5 (95% CI, .0 to 1.0) cases of LRTI and pneumonia, respectively, per 100 vaccinated persons annually; over 5 years, 1 case of LRTI and 1 case of pneumonia were prevented for every 27 and 42 individuals vaccinated, respectively. PCV13 vaccination among older adults substantially reduced incidence of medically attended respiratory illness. Direct immunization of older adults is an effective strategy to combat residual disease burden associated with PCV13-type pneumococci.

1441. Significant Decrease in the Incidence Rate of Common Outpatient Upper Respiratory Tract Infection Diagnoses per Clinic Visit in the First Respiratory Season of October 2020 to March 2021 During the Covid-19 Pandemic. A Report From an Outpatient Antimicrobial Stewardship Program at a community hospital in Brooklyn

BackgroundAs part of our outpatient Antimicrobial Stewardship Program, we do surveillance of diagnoses and antibiotic use for common upper respiratory tract infections such as acute upper respiratory tract infection, acute bronchitis, sinusitis, and pharyngitis. We sought to evaluate the impact of the Covid-19 pandemic on the incidence rate of upper respiratory tract infection diagnoses per clinic visit during October 2020 to March 2021 season compared to the three prior respiratory seasons. We also sought to reflect of impact of increase in televisits and overlapping symptoms of COVID 19 and upper respiratory tract infections.MethodsOur cohort study extending from October 2017 to March 2021. We collected number of diagnoses of upper respiratory infections and number of unique clinic visits during four consecutive respiratory seasons at our primary care sites via electronic health records.ResultsDuring the recent October 2020 to March 2021 respiratory season which coincided with the second NYC Covid-19 wave, we had 11569 unique clinic visits and 39 diagnoses of an upper respiratory tract infection - incident rate of 1.29. In the three prior respiratory seasons combined, we had 40939 unique clinic visits and 833 diagnoses of an upper respiratory tract infection – incident rate of 1.49. The incident rates showed a dramatic decline using the test based method and the chi square-statistic p< 0.0001 with an incident rate ratio using a poisson exact method of 6.0359. Statistical comparisons of the current season to each prior individual season yielded similar results. The percentage of Tele-visits during the current season was 19% compared to 0% in the 3 prior seasons.ConclusionDuring the first respiratory season from October 2020 to March 2021 in midst of the Covid-19 pandemic which also coincided with the second Covid-19 wave in New York, we saw a statistically significant decrease in incidence of common upper respiratory tract infection diagnoses per clinic visit compared to the three prior respiratory seasons. Overlapping signs and symptoms of upper respiratory tract infections and Covid-19 with the added percentage in Tele-visits did not cause an increase in incidence rates of upper respiratory tract infection diagnoses. Covid-19 related mitigation efforts may have played a role.Disclosures All Authors: No reported disclosures