Positive Influenza Test Research Articles

Impact of the COVID-19 Pandemic on Influenza Hospital Admissions and Deaths in Wales: Descriptive National Time Series Analysis.

The COVID-19 pandemic and the ensuing implementation of control measures caused widespread societal disruption. These disruptions may also have affected community transmission and seasonal circulation patterns of endemic respiratory viruses. We aimed to investigate the impact of COVID-19-related disruption on influenza-related emergency hospital admissions and deaths in Wales in the first 2 years of the pandemic. A descriptive analysis of influenza activity was conducted using anonymized pathology, hospitalization, and mortality data from the Secure Anonymised Information Linkage Databank in Wales. The annual incidence of emergency hospitalizations and deaths with influenza-specific diagnosis codes between January 1, 2015, and December 31, 2021, was estimated. Case definitions of emergency hospitalization and death required laboratory confirmation with a polymerase chain reaction test. Trends of admissions and deaths were analyzed monthly and yearly. We conducted 2 sensitivity analyses by extending case definitions to include acute respiratory illnesses with a positive influenza test and by limiting admissions to those with influenza as the primary diagnosis. We also examined yearly influenza testing trends to understand changes in testing behavior during the pandemic. We studied a population of 3,235,883 Welsh residents in 2020 with a median age of 42.5 (IQR 22.9-61.0) years. Influenza testing in Wales increased notably in the last 2 months of 2020, and particularly in 2021 to 39,720 per 100,000 people, compared to the prepandemic levels (1343 in 2019). The percentage of influenza admissions matched to an influenza polymerase chain reaction test increased from 74.8% (1890/2526) in 2019 to 85.2% (98/115) in 2021. However, admissions with a positive test per 100,000 population decreased from 17.0 in 2019 to 2.7 and 0.6 in 2020 and 2021, respectively. Similarly, deaths due to influenza with a positive influenza test per 100,000 population decreased from 0.4 in 2019 to 0.0 in 2020 and 2021. Sensitivity analyses showed similar patterns of decreasing influenza admissions and deaths in the first 2 years of the COVID-19 pandemic. Nonpharmaceutical interventions to control COVID-19 were associated with a substantial reduction in the transmission of the influenza virus, with associated substantial reductions in hospital cases and deaths observed. Beyond the pandemic context, consideration should be given to the role of nonpharmaceutical community-driven interventions to reduce the burden of influenza.

Neurological involvement related to the influenza virus in children: A 5-year single-centre retrospective study

IntroductionInflammation related to influenza virus infection can lead to multiple neurological presentations. Encephalitis is one of them, mostly accompanied by seizures, with different profiles depending on the epidemics and previous medical conditions. Materials and methodsAll children presenting neurological symptoms and positive for influenza virus RNA detection in a respiratory sample between November 2018 and April 2023, hospitalized in the Department of Paediatric Neurology of Toulouse Children's Hospital, were retrospectively analysed. ResultsAmong the 1,277 children diagnosed with influenza in our centre, 131 (10.3 %) were hospitalized for neurological features. The year 2020–2021 was marked by zero incidence of positive influenza tests, associated with the COVID-19 pandemic. Among the 131 patients included, 71.6 % were under 5 years old. Most of them (80.9 %) were infected by influenza A virus. The first neurological symptoms were mainly seizures in 73.3 % of patients. Possible or confirmed encephalitis was observed in 29 % of cases, including one acute necrotizing encephalopathy. Few children (6.1 %) presented with acute myositis. Twenty-seven patients (20.6 %) had a personal history of significant previous neurological disorders. Most patients (88.5 %) displayed a rapid favourable outcome, marked by the disappearance of their neurological symptoms within the first 2 days. Anti-epileptic drugs were introduced in 1.5 % of cases, and adapted in 16.8 %, mainly in patients with febrile status epilepticus and an abnormal EEG. ConclusionNeurological features were frequently associated with influenza infection in children; most were transient. Effects on long-term neurodevelopmental outcomes need to be clarified as our follow-up was limited, especially in children with pre-existing neurological conditions.

Can telephone data contribute to a national influenza surveillance system in Australia? A retrospective analysis

Introduction: Data collected from telephone helplines that provide health advice can improve the timeliness and accuracy of disease surveillance, contributing to an appropriate and rapid public health response. We show how these data can forewarn health professionals of increased rates of influenza-like illness (ILI) in the community and discuss implications for COVID-19 syndromic surveillance. Methods: The healthdirect helpline (HH) captures demographic details and characteristics of symptoms from users in 6 Australian states and territories. We compare ILI activity in the HH with ILI activity in emergency department (ED), laboratory, Flutracking and general practice (GP) data using cross-correlation functions. Results: Helpline data correlated strongly with ED data (range in yearly correlations from 0.82-0.99), GP data (0.66 – 0.95) and Flutracking data (0.62-0.89), but yearly correlations with laboratory data varied (0.49-0.95). The highest correlation with laboratory and GP data occurred when HH activity was 1-2 weeks in advance of these data, while correlations with ED and Flutracking data were strongest with no time lag. Discussion: Our analysis demonstrates that the number of ILI-related calls to the HH is a reliable indicator of ILI incidence in Australia. An increase in calls is likely to occur simultaneously with an increase in visits to EDs and prior to an increase in positive laboratory influenza tests and visits to GPs. A surveillance system including these data would assist health practitioners to receive timely and accurate estimates of the level of ILI in the community to better respond to and prepare for seasonal and epidemic influenza.

Antimicrobial prescribing after rapid influenza PCR implementation in the emergency department

IntroInfluenza shares common symptoms with bacterial pneumonia, which may result in unnecessary antibiotic prescriptions in the emergency department (ED) when the diagnosis is unknown. Rapid influenza polymerase chain reaction (PCR) tests have reduced turnaround times compared to standard multiplex PCR respiratory panels allowing for earlier diagnosis, which may improve antimicrobial stewardship outcomes in the ED. This study aims to compare antibiotic and antiviral use before and after deployment of the rapid influenza PCR in the ED. MethodsThis single-center, retrospective, cohort study included pediatric and adult patients discharged from the ED with a positive influenza test using a standard multiplex PCR respiratory panel (January 2017 – July 2019) or rapid PCR (July 2019 – February 2020). The primary endpoint was number of antibiotic prescriptions pre- and post-implementation of the rapid influenza PCR in the ED. Secondary endpoints included number of antiviral prescriptions, duration of antimicrobial therapy, test turnaround time, ED length of stay, 30-day readmission, and adverse events. A multivariable logistic regression evaluated patient factors associated with antimicrobial prescribing. ResultsA total of 620 positive influenza results were identified with 280 patients (standard multiplex PCR = 33; rapid PCR = 247) meeting inclusion criteria. Patients were less likely to be prescribed antibiotics (39.4% vs 8.9%, OR 0.15, 95% CI 0.067–0.34) and more likely to be prescribed antivirals (24.2% vs 61.1%, OR 4.92, 95% CI 2.13–11.34) with the rapid influenza PCR. Rapid influenza PCR significantly reduced ED length of stay (4.9 vs 3.4 h, p < 0.01) and test turnaround time (27 h vs 3.5 h, p < 0.01). Patients at high risk for complications associated with influenza were more likely to be prescribed antiviral therapy (22.7% vs 67.8%, OR 7.16, 95% CI 2.52–20.40). Based on the regression analysis conducted, asthma, (OR 3.5, 95% CI 1.48–8.26), immunosuppression (OR 9.6, 95% CI 1.18–78.2), and age <5 years old (OR 3.1, 95% CI 1.80–5.45) were predictors of antiviral prescribing. ConclusionImplementation of a rapid influenza PCR in the ED reduced antibiotic use and optimized antiviral therapy for patients with influenza including those at higher risk of complications.

Risk factors for infection with influenza A(H3N2) virus on a US university campus, October-November 2021.

Knowledge of the specific dynamics of influenza introduction and spread in university settings is limited. Persons with acute respiratory illness symptoms received influenza testing by molecular assay during October 6-November 23, 2022. Viral sequencing and phylogenetic analysis were conducted on nasal swab samples from case-patients. Case-control analysis of a voluntary survey of persons tested was used to identify factors associated with influenza; logistic regression was conducted to calculate odds ratios and 95% CIs. A subset of case-patients tested during the first month of the outbreak was interviewed to identify sources of introduction and early spread. Among 3268 persons tested, 788 (24.1%) tested positive for influenza; 744 (22.8%) were included in the survey analysis. All 380 sequenced specimens were influenza A (H3N2) virus clade 3C.2a1b.2a.2, suggesting rapid transmission. Influenza (OR [95% CI]) was associated with indoor congregate dining (1.43 [1.002-2.03]), attending large gatherings indoors (1.83 [1.26-2.66]) or outdoors (2.33 [1.64-3.31]), and varied by residence type (apartment with ≥1 roommate: 2.93 [1.21-7.11], residence hall room alone: 4.18 [1.31-13.31], or with roommate: 6.09 [2.46-15.06], or fraternity/sorority house: 15.13 [4.30-53.21], all compared with single-dwelling apartment). Odds of influenza were lower among persons who left campus for ≥1day during the week before their influenza test (0.49 [0.32-0.75]). Almost all early cases reported attending large events. Congregate living and activity settings on university campuses can lead to rapid spread of influenza following introduction. Isolating following a positive influenza test or administering antiviral medications to exposed persons may help mitigate outbreaks.

Traditional definition of healthcare-associated influenza underestimates cases associated with other healthcare exposures in a population-based surveillance system.

To provide comprehensive population-level estimates of the burden of healthcare-associated influenza. Retrospective cross-sectional study. US Influenza Hospitalization Surveillance Network (FluSurv-NET) during 2012-2013 through 2018-2019 influenza seasons. Laboratory-confirmed influenza-related hospitalizations in an 8-county catchment area in Tennessee. The incidence of healthcare-associated influenza was determined using the traditional definition (ie, positive influenza test after hospital day 3) in addition to often underrecognized cases associated with recent post-acute care facility admission or a recent acute care hospitalization for a noninfluenza illness in the preceding 7 days. Among the 5,904 laboratory-confirmed influenza-related hospitalizations, 147 (2.5%) had traditionally defined healthcare-associated influenza. When we included patients with a positive influenza test obtained in the first 3 days of hospitalization and who were either transferred to the hospital directly from a post-acute care facility or who were recently discharged from an acute care facility for a noninfluenza illness in the preceding 7 days, we identified an additional 1,031 cases (17.5% of all influenza-related hospitalizations). Including influenza cases associated with preadmission healthcare exposures with traditionally defined cases resulted in an 8-fold higher incidence of healthcare-associated influenza. These results emphasize the importance of capturing other healthcare exposures that may serve as the initial site of viral transmission to provide more comprehensive estimates of the burden of healthcare-associated influenza and to inform improved infection prevention strategies.

Evaluation of missed influenza vaccination opportunities in the emergency department

BackgroundSeasonal influenza is associated with significant healthcare resource utilization. An estimated 490,000 hospitalizations and 34,000 deaths were attributed to influenza during the 2018–2019 season. Despite robust influenza vaccination programs in both the inpatient and outpatient setting, the emergency department (ED) represents a missed opportunity to vaccinate patients at high risk for influenza who do not have access to routine preventive care. Feasibility and implementation of ED-based influenza vaccination programs have been previously described but have stopped short of describing the predicted health resource impact. The goal of our study was to describe the potential impact of an influenza vaccination program in an urban adult emergency department population using historic patient data. MethodsThis was a retrospective study of all encounters within a tertiary care hospital-based ED and three freestanding EDs during influenza season (defined as October 1 – April 30) over a two-years, 2018–2020. Data was obtained from the electronic medical record (EPIC®). All ED encounters during the study period were screened for inclusion using ICD 10 codes. Patients with a confirmed positive influenza test and no documented influenza vaccine for the current season were reviewed for any ED encounter at least 14 days prior to the influenza-positive encounter and during the concurrent influenza season. These ED visits were deemed a missed opportunity to provide vaccination and potentially prevent the influenza-positive encounter. Healthcare resource utilization, including subsequent ED encounters and inpatient admissions, were evaluated for patients with a missed vaccination opportunity. ResultsA total of 116,140 ED encounters occurred during the study and were screened for inclusion. Of these, 2115 were influenza-positive encounters, which represented 1963 unique patients. There were 418 patients (21.3%) that had a missed opportunity to be vaccinated during an ED encounter at least 14 days prior to the influenza-positive encounter. Of those with a missed vaccination opportunity, 60 patients (14.4%) had subsequent influenza-related encounters, including 69 ED visits and 7 inpatient admissions. ConclusionPatients presenting to the ED with influenza frequently had opportunities to be vaccinated during prior ED encounters. An ED-based influenza vaccination program could potentially reduce influenza-related burden on healthcare resources by preventing future influenza-related ED encounters and hospitalizations.

Early and Increased Influenza Activity Among Children - Tennessee, 2022-23 Influenza Season.

Influenza seasons typically begin in October and peak between December and February (1); however, the 2022-23 influenza season in Tennessee began in late September and was characterized by high pediatric hospitalization rates during November. This report describes a field investigation conducted in Tennessee during November 2022, following reports of increasing influenza hospitalizations. Data from surveillance networks, patient surveys, and whole genome sequencing of influenza virus specimens were analyzed to assess influenza activity and secondary illness risk. Influenza activity increased earlier than usual among all age groups, and rates of influenza-associated hospitalization among children were high in November, reaching 12.6 per 100,000 in children aged <5 years, comparable to peak levels typically seen in high-severity seasons. Circulating influenza viruses were genetically similar to vaccine components. Among persons who received testing for influenza at outpatient clinics, children were twice as likely to receive a positive influenza test result as were adults. Among household contacts exposed to someone with influenza, children were more than twice as likely to become ill compared with adults. As the influenza season continues, it is important for all persons, especially those at higher risk for severe disease, to protect themselves from influenza. To prevent influenza and severe influenza complications, all persons aged ≥6 months should get vaccinated, avoid contact with ill persons, and take influenza antivirals if recommended and prescribed.

COVID-19 Mask Mandates in NY and Their Effect on the Incidence of Flu.

The goal of the study is to quantify the reduction in the cases of influenza and how this decrease in incidence correlates with the execution of masking requirements in public as well as social distancing. Influenza statistics were collected from Northwell Health, a 23-hospital system located throughout New York State. Positive influenza results were collected representing the 2018-2019 Flu season, 2019-2020 Flu season, and compared to the 2020-2021 Flu season, which corresponded to the mask mandates and social distancing measures implemented in NYS. Our data showed a dramatic decrease in influenza rates during the 2020-2021 Flu season, which corresponded to NYS's strict social distancing and mask requirements during the pandemic. This shows a steep decline correlating with the implementation of public health mandates directed at decreasing the spread of aerosolized particles between members of the population. Our data show a significant decrease in the number of positive influenza tests during the same period of time when COVID-19 social distancing and mask-wearing requirements were in effect.

873. Comparison of Antibiotic and Antiviral Use before and after Deployment of Rapid Influenza Testing in the Emergency Department

Abstract Background Influenza shares common symptoms with bacterial pneumonia, resulting in inappropriate prescribing of antibiotics that may lead to increased risk of adverse reactions, antimicrobial resistance, and healthcare costs. Rapid influenza polymerase chain reaction (PCR) tests have reduced turnaround times compared to multiplex PCR respiratory panels allowing for earlier diagnosis, which may improve antimicrobial stewardship outcomes in the emergency department (ED). This study aims to compare antibiotic and antiviral use before and after deployment of a rapid influenza PCR in the ED. Methods This single-center, retrospective, cohort study included pediatric and adult patients discharged from the ED with a positive influenza test with either the multiplex PCR respiratory panel (January 2017 – July 2019) or rapid PCR (July 2019 – February 2020). The primary endpoint was antibiotic use pre- and post-implementation of the rapid influenza PCR in the ED. Secondary endpoints included antiviral use, duration of antimicrobial therapy, test turnaround time, ED length of stay, 30-day readmission, and adverse events. A multivariable regression model evaluated patient factors associated with antimicrobial prescribing. Results A total of 620 positive influenza results were identified with 280 patients (multiplex PCR = 33; rapid PCR = 247) meeting inclusion criteria. Patients were less likely to be prescribed antibiotics (39.4% vs 8.9%, OR 0.15, 95% CI 0.067–0.34) and more likely to be prescribed antivirals (24.2% vs 61.1%, OR 4.92, 95% CI 2.13–11.34) with the rapid influenza PCR. Rapid influenza PCR significantly reduced ED length of stay (4.9 vs 3.4 hours, p &amp;lt; 0.01) and test turnaround time (27 hours vs 3.5 hours, p &amp;lt; 0.01). Patients at high risk for complications associated with influenza were more likely to be prescribed antiviral therapy (25% vs 77.7%, OR 5.27, 95% CI 3.02–9.17). Based on the regression analysis conducted, asthma, (OR 3.5, 95% CI 1.48–8.26), immunosuppression (OR 9.6, 95% CI 1.18–78.2), and age less than 5 years old (OR 3.1, 95% CI 1.80–5.45) are predictors of antiviral prescribing. Conclusion Implementation of a rapid influenza PCR in the ED reduced antibiotic use and optimized antiviral therapy for patients at higher risk of influenza with complications. Disclosures All Authors: No reported disclosures.

2202. Influenza Surveillance of Families in an Observational Household Study 2019-2021

Abstract Background Families with children may be at higher risk for influenza infection. Community transmission can suffer from underreporting as testing is often not performed. We studied the epidemiology of influenza in households with school-aged children using home-based sample collection. Methods We conducted a remote household study surveilling respiratory viruses from November 2019-June 2021, in King County, Washington (WA), USA. Households with school-aged children were enrolled, mailed home specimen collection kits, and asked to self-assess for weekly acute respiratory illness (ARI) using remote survey platforms. Participants with ARI symptoms were prompted to complete serial illness surveys and self-collect/parent collect mid-turbinate nasal swabs. Samples were sent to a University of Washington study laboratory for RT-PCR influenza testing. Influenza rates were compared to WA Department of Health (DOH) reporting. Results A total of 1861 ARI events were reported among 992 adults and 869 children in 470 households; 75 influenza cases were detected (36 influenza A and 39 influenza B). The study participant median age was 32 years (0-84), 10 years (1-49) for influenza A, and 11 years (3-49) for influenza B cases. Overall 13% of households had an influenza case, of which 13 (22%) reported &amp;gt;1 case. A total of 81% of participants reported receipt of one dose of the 2019-2020 influenza vaccine, including 91% of influenza A and 90% of influenza B cases, and 84% received the 2020-2021 influenza vaccine. Like WA DOH, we observed a wave of influenza B cases followed by influenza A in 2019-2020. During influenza season 2020-2021, WA DOH reported 9 positive influenza tests and none observed in our study. Commonly, influenza case-patients reported were fever, cough, rhinorrhea, and fatigue. GI symptoms were more common in children than adults. Of the cases, 92% of influenza A and 78% of influenza B occurred in children. Figure 1.Influenza A and B cases from 2019-2021Figure 2A.Reported Symptoms of Influenza A D0-Day of reported onset, D7-7 days after reported illness onset. No participants &amp;gt;49 years were positive for influenza. D0: 30 participants responded and of respondents, 13% &amp;lt;5 years, 47% 5-12 years, 3% 13-17 years, and 37% 18-49 years. D7: 31 participants responded and of respondents 13% &amp;lt;5 years, 48% 5-11 years, 3% 12-17 years, and 36% 18-49 years. Figure 2B.Reported Symptoms of Influenza B D0-Day of reported onset, D7-7 days after reported illness onset. No participants &amp;gt;49 years were positive for influenza. D0: 28 participants responded and of respondents, 4% &amp;lt;5 years, 57% 5-12 years, 14% 13-17 years, and 25% 18-49 years. D7: 28 participants responded and of respondents, 4% &amp;lt;5 years, 57% 5-11 years, 18% 12-17 years, and 21% 18-49 years. Conclusion Influenza illness in 2019-2020 was initially influenza B, and subsequently replaced by influenza A. Most cases were in children and adolescents, despite at least one dose of influenza vaccine. Symptoms were widely distributed and similar between influenza A and B. Influenza incidence in our cohort declined to zero with the rise of SARS-CoV-2 cases and widespread mitigation efforts. Disclosures Janet A. Englund, MD, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Helen Y. Chu, MD, MPH, Cepheid: Reagents|Ellume: Advisor/Consultant|Gates Ventures: Grant/Research Support|Merck: Advisor/Consultant|Pfizer: Advisor/Consultant.

1897. The Decline of Respiratory Viruses During the SARS-CoV-2 Pandemic: Public Health Interventions vs. Viral Competition?

Abstract Background With the spread of the SARS-CoV-2 pandemic in 2020 and the attendant global precautions such as masking, travel restrictions and social distancing, the WHO FluNet data indicated a decline in flu rates. The CDC data for the 2020-2021 season showed the same decline in US flu as well as other respiratory viruses. Two hypotheses to explain the observed phenomenon are the impact of non-pharmaceutical interventions (NPI) to prevent SARS-CoV-2 infection and suppression of other respiratory viruses by SARS-CoV-2 through a form of resource competition. Methods We conducted a study using the EPIC Slicer Dicer analytics tool and the Yale Internal Medicine COVID-19 Database to retrieve data from the Yale New Haven Health System (YNHHS). We tabulated the total number of positive and negative tests for SARS-CoV-2 and a panel of respiratory viruses from September 2, 2018 to April 30, 2022 to cover pre- and peri-pandemic periods. These results were divided into three age groups: ≤12, 13-59, and ≥60. Epidemic curves of each virus with respect to each other, the season, and the introduction of NPIs were constructed to help differentiate between the two hypotheses. Results Pre-pandemic data from 09/2018 to 02/2020 revealed seasonal spikes in influenza A and B with 254 positive weekly influenza A/B tests from 11/2018 to 02/2019 for a positivity rate of 7.97% and 481 positive weekly tests (10.53% positivity rate [PR]) from November 2019 to February 2020. There were only 0.35 positive weekly influenza A/B tests (0.05% PR) from 11/2020 to 02/2021 with 2018 positive weekly tests (6.45% PR) for SARS-CoV-2 over the same period. From 11/2020 to 02/2021, there were 56 positive weekly influenza A/B tests (1.44% PR) and 4347 positive weekly SARS-CoV-2 tests (10.35% PR). From 07/2021 to 11/2021, there was an increased rate of positive RSV tests (82 per week, 15.76% PR) and rhinovirus tests (58 per week, 18.73% PR). There were 803 positive weekly tests (2.53% positivity rate) for SARS-CoV-2 over this same period. Conclusion Since the start of the SARS-CoV-2 pandemic, the number of positive tests for influenza A/B and seasonal respiratory viruses have not reached pre-pandemic levels across the YNHHS. However, rates of influenza and other respiratory viruses have increased since the relaxation of NPIs. Disclosures All Authors: No reported disclosures.

25 Derivation and Validation of a Clinical Decision Rule to Risk Stratify Emergency Department Patients Diagnosed With Seasonal Influenza

25 Derivation and Validation of a Clinical Decision Rule to Risk Stratify Emergency Department Patients Diagnosed With Seasonal Influenza

Influenza Vaccine Effectiveness: Analysis of the Impact of Repeated Vaccinations in Military Health System Beneficiaries.

Influenza has long burdened the Military Health System (MHS). This study assesses the impact of repeated annual vaccination on influenza vaccine effectiveness (VE). This retrospective, case control study using the test-negative design utilized data extracted from the MHS Data Repository (MDR). Cases had a positive influenza test and controls sought care for an influenza-like illness within 2 weeks of a case, had no positive influenza tests, and were matched by sex, race, age, and location. Vaccine effectiveness was assessed using conditional logistic regression separately for those who received inactivated and live attenuated influenza vaccines (LAIV). A total of 6860 cases and controls were identified in the MDR, among whom 53% were vaccinated in all 3 seasons. Among those who received inactivated influenza vaccine during the current season, VE ranged from 26% to 37% (2012/13 [A(H3N2)]: VE 26%, 95% confidence interval [CI] = 1%-45%; 2013/14 [A(H1N1)pdm09]: VE 37%, 95% CI = 18%-52%; 2014/15 [A(H3N2)]: VE 31%, 95% CI = 17%-42%). The VE ranged from 25% to 49% for those only vaccinated this season (2012/13 [A(H3N2)]: VE 38%, 95% CI = -3% to 63%; 2013/14 [A(H1N1)pdm09]: VE 49%, 95% CI = 11%-71%; 2014/15 [A(H3N2)]: VE 25%, 95% CI = -7% to 48%). The VE was more variable in those who received LAIV in the current season. No statistically significant differences in VE were observed between those frequently vaccinated and those vaccinated only during the current season. These results underscore the value of annual influenza vaccinations for preventing infection while highlighting the need for continued improvements in influenza vaccine effectiveness.

Effect of a multimodal strategy for prevention of nosocomial influenza: a retrospective study at Grenoble Alpes University Hospital from 2014 to 2019

BackgroundA multimodal strategy to prevent nosocomial influenza was implemented in 2015–2016 in Grenoble Alpes University Hospital. Three modalities were implemented in all units: promotion of vaccination among healthcare workers, epidemiologic surveillance and communication campaigns. Units receiving a high number of patients with influenza implemented 2 additional modalities: improvement of diagnosis capacities and systematic surgical mask use. The main objective was to assess the effectiveness of the strategy for reducing the risk of nosocomial influenza.MethodsA study was conducted retrospectively investigating 5 epidemic seasons (2014–2015 to 2018–2019) including all patients hospitalized with a positive influenza test at Grenoble Alpes University Hospital. The weekly number of nosocomial influenza cases was analyzed by Poisson regression and incidence rate ratios (IRR) were estimated.ResultsA total of 1540 patients, resulting in 1559 stays, were included. There was no significant difference between the 5 influenza epidemic seasons in the units implementing only 3 measures. In the units implementing the 5 measures, there was a reduction of nosocomial influenza over the seasons when the strategy was implemented compared to the 2014–2015 epidemic season (IRR = 0.56, 95% CI = 0.23–1.34 in 2015–2016; IRR = 0.39, 95% CI = 0.19–0.81 in 2016–2017; IRR = 0.50, 95% CI = 0.24–1.03 in 2017–2018; IRR = 0.48, 95% CI = 0.23–0.97 in 2018–2019).ConclusionsOur data mainly suggested that the application of the strategy with 5 modalities, including systematic surgical mask use and rapid diagnosis, seemed to reduce by half the risk of nosocomial influenza. Further data, including medico-economic studies, are necessary to determine the opportunity of extending these measures at a larger scale.

Influenza Testing and Treatment Among Patients Hospitalized With Community-Acquired Pneumonia

Influenza is a leading cause of community-acquired pneumonia (CAP), and results of influenza tests can direct therapy. However, among adults hospitalized with CAP, little is known about the frequency and timing of influenza testing, treatment, and their associations with outcomes. In patients with CAP, is testing for influenza associated with antiviral treatment and shorter antibiotic courses, and is early treatment associated with better clinical outcomes? This study included adults admitted with pneumonia in 2010 to 2015 to 179 US hospitals contributing to the Premier database. We assessed influenza testing and compared antimicrobial utilization and the outcomes of test-positive, test-negative, and untested patients. Associations of early antiviral treatment (oseltamivir) with 14-day in-hospital mortality, hospital length of stay, and cost were studied. Among 166,268 patients with CAP, 38,703 (23.3%) were tested for influenza, of whom 11.5%tested positive. Testing increased from 15.4%to 35.6%from 2010 to 2015 and was 28.9%during flu season (October-May) vs8.2%in June to September. Patients testing positive for influenza received antiviral agents more often and antibacterial agents less often and for shorter courses than patients testing negative (5.3 vs6.4days; P< .001). Influenza-positive patients receiving oseltamivir on hospital day 1 (n= 2,585) experienced lower 14-day in-hospital mortality (adjusted OR, 0.75; 95%CI, 0.59-0.96), lower costs (adjusted ratio of means, 0.88; 95%CI, 0.81-0.95), and shorter length of stay (adjusted ratio of means, 0.88; 95%CI, 0.84-0.93) vspatients receiving oseltamivir later or not at all (n= 1,742). Even during flu season, most patients with CAP in this study went untested for influenza. A positive influenza test result was associated with antiviral treatment, and early treatment was associated with lower mortality, suggesting that more widespread testing might improve patient outcomes.

CLINICAL AND LABORATORY FINDINGS IN CHILDREN WITH INFLUENZA INFECTIONS

ABSTRACT Objective: We aimed to show the clinical characteristics of children with influenza infection and the relationship between influenza infections and hemogram parameters, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), neutrophil/monocyte ratio (NMR), and mean platelet volume (MPV). Methods: The data of patients who applied to Necmettin Erbakan University Meram Medical Faculty Pediatrics outpatient clinics and had positive rapid influenza test were scanned through the hospital information system. Results: The median age and neutrophil value in the influenza A group were significantly lower than in the influenza B group (p=.002, p=.008). The median MPV and monocyte value in the influenza A group were significantly higher than in influenza B (p&amp;lt;.00, p=.005). The mean WBC count was found to be significantly higher in hospitalized patients compared to outpatients. (p = .039). There were no significant difference between the groups in terms of NLR, PLR, NMR. Bacteremia was detected significantly more in hospitalized patients compared to outpatients. Underlying chronic diseases were significantly lower in outpatients than in inpatients.(p&amp;lt;.001) Conclusion: There were no difference in the severity of clinical severity between infleunza A and B subgroups and no significant difference was found in terms of hemogram parameters.

Influenza associated pulmonary aspergillosis in california: A case series

• AspICU, IAPA, and EORTC/MSG criteria varied in their ability to capture IAPA cases. • Classic radiographic findings for aspergillosis were not present in these cases. • Few patients in our IAPA case series had traditional aspergillosis risk factors. Invasive pulmonary aspergillosis has been reported to occur in patients who are critically ill with severe influenza. The mortality rate is high. We reviewed electronic medical records from University of California at Los Angeles Health Hospitals for patients who had a positive influenza and Aspergillus test from September 1st, 2019 to May 6th, 2020. We classified cases using definitions from the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG), Aspergillus Intensive Care Unit ( Asp ICU), and Influenza Associated Pulmonary Aspergillosis (IAPA) definition. We identified 8 cases where the patient had both a positive influenza and Aspergillus test. Four (50%) of the 8 patients did not have underlying conditions that were considered typical risk factors for aspergillosis. Seven (87.5%) of the 8 patients were admitted to the intensive care unit and four (50%) of the 8 patients died. One patient met the diagnostic criteria by the EORTC/MSG guidelines, six by the Asp ICU, and seven by the IAPA definition. We found cases of influenza-associated pulmonary aspergillosis in a Los Angeles hospital population. Typical underlying conditions for aspergillosis were absent in four of the 8 cases. The ability to categorize the cases as influenza associated pulmonary aspergillosis varied. Further research and development of more sensitive guidelines to establish a diagnosis of invasive pulmonary aspergillosis in patients critically ill with influenza may be warranted.

Influenza clinical testing and oseltamivir treatment in hospitalized children with acute respiratory illness, 2015-2016.

BackgroundAntiviral treatment is recommended for all hospitalized children with suspected or confirmed influenza, regardless of their risk profile. Few data exist on adherence to these recommendations, so we sought to determine factors associated with influenza testing and antiviral treatment in children.MethodsHospitalized children <18 years of age with acute respiratory illness (ARI) were enrolled through active surveillance at pediatric medical centers in seven cities between 11/1/2015 and 6/30/2016; clinical information was obtained from parent interview and chart review. We used generalized linear mixed‐effects models to identify factors associated with influenza testing and antiviral treatment.ResultsOf the 2299 hospitalized children with ARI enrolled during one influenza season, 51% (n = 1183) were tested clinically for influenza. Clinicians provided antiviral treatment for 61 of 117 (52%) patients with a positive influenza test versus 66 of 1066 (6%) with a negative or unknown test result. In multivariable analyses, factors associated with testing included neuromuscular disease (aOR = 5.35, 95% CI [3.58–8.01]), immunocompromised status (aOR = 2.88, 95% CI [1.66–5.01]), age (aOR = 0.93, 95% CI [0.91–0.96]), private only versus public only insurance (aOR = 0.78, 95% CI [0.63–0.98]), and chronic lung disease (aOR = 0.64, 95% CI [0.51–0.81]). Factors associated with antiviral treatment included neuromuscular disease (aOR = 1.86, 95% CI [1.04, 3.31]), immunocompromised state (aOR = 2.63, 95% CI [1.38, 4.99]), duration of illness (aOR = 0.92, 95% CI [0.84, 0.99]), and chronic lung disease (aOR = 0.60, 95% CI [0.38, 0.95]).ConclusionApproximately half of children hospitalized with influenza during the 2015–2016 influenza season were treated with antivirals. Because antiviral treatment for influenza is associated with better health outcomes, further studies of subsequent seasons would help evaluate current use of antivirals among children and better understand barriers for treatment.

Hospital-acquired influenza in the United States, FluSurv-NET, 2011-2012 through 2018-2019.

To estimate population-based rates and to describe clinical characteristics of hospital-acquired (HA) influenza. Cross-sectional study. US Influenza Hospitalization Surveillance Network (FluSurv-NET) during 2011-2012 through 2018-2019 seasons. Patients were identified through provider-initiated or facility-based testing. HA influenza was defined as a positive influenza test date and respiratory symptom onset >3 days after admission. Patients with positive test date >3 days after admission but missing respiratory symptom onset date were classified as possible HA influenza. Among 94,158 influenza-associated hospitalizations, 353 (0.4%) had HA influenza. The overall adjusted rate of HA influenza was 0.4 per 100,000 persons. Among HA influenza cases, 50.7% were 65 years of age or older, and 52.0% of children and 95.7% of adults had underlying conditions; 44.9% overall had received influenza vaccine prior to hospitalization. Overall, 34.5% of HA cases received ICU care during hospitalization, 19.8% required mechanical ventilation, and 6.7% died. After including possible HA cases, prevalence among all influenza-associated hospitalizations increased to 1.3% and the adjusted rate increased to 1.5 per 100,000 persons. Over 8 seasons, rates of HA influenza were low but were likely underestimated because testing was not systematic. A high proportion of patients with HA influenza were unvaccinated and had severe outcomes. Annual influenza vaccination and implementation of robust hospital infection control measures may help to prevent HA influenza and its impacts on patient outcomes and the healthcare system.