Oseltamivir shortens hospital stays of critically ill children hospitalized with seasonal influenza: a retrospective cohort study

Clinical recommendations for the inpatient management of lower respiratory tract infections in children and adolescents with severe neurological impairment in Germany

Children and adolescents with severe neurological impairment (SNI) require specialized care due to their complex medical needs. In particular, these patients are often affected by severe and recurrent lower respiratory tract infections (LRTIs). These infections, including viral and bacterial etiology, pose a significant risk to these patients, often resulting in respiratory insufficiency and long-term impairments. Using expert consensus, we developed clinical recommendations on the management of LRTIs in children and adolescents with SNI. These recommendations emphasize comprehensive multidisciplinary care and antibiotic stewardship. Initial treatment should involve symptomatic care, including hydration, antipyretics, oxygen therapy, and respiratory support. In bacterial LRTIs, antibiotic therapy is initiated based on the severity of the infection, with aminopenicillin plus a beta-lactamase inhibitor recommended for community-acquired LRTIs and piperacillin-tazobactam for patients with chronic lung disease or tracheostomy. Ongoing management includes regular evaluations, adjustments to antibiotic therapy based on pathogen identification, and optimization of supportive care. Implementation of these recommendations aims to improve the diagnosis and treatment of LRTIs in children and adolescents with SNI. What is Known: • Children and adolescents with severe neurological impairment are particularly affected by severe and recurrent lower respiratory tract infections (LRTIs). • The indication and choice of antibiotic therapy for bacterial LRTI is often difficult because there are no evidence-based treatment recommendations for this heterogeneous but vulnerable patient population; the frequent overuse of broad-spectrum or reserve antibiotics in this patient population increases selection pressure for multidrug-resistant pathogens. What is New: • The proposed recommendations provide a crucial framework for focused diagnostics and treatment of LRTIs in children and adolescents with severe neurological impairment. • Along with recommendations for comprehensive and multidisciplinary therapy and antibiotic stewardship, ethical and palliative care aspects are taken into account.

Misclassification of Both Influenza Infection and Oseltamivir Exposure Status in Administrative Data

This cross-sectional study examines documented hospitalization for influenza and administration of neuraminidase inhibitors in US children.

Influenza in Children and Adolescents: Epidemiology, Management, and Prevention

EDUCATION GAP

Influenza is among the most common infectious causes of pediatric emergency department visits and hospitalizations. Clinicians should use evidence-based guidelines to learn how to identify, manage, prevent, and treat influenza cases. Disease caused by influenza virus can be mitigated with appropriate treatment and prevention efforts.

OBJECTIVES After completing this article, readers should be able to:

1. Describe the virology and epidemiology of influenza.

2. List the clinical features and complications of influenza infections.

3. List the benefits and limitations of testing modalities for the diagnosis of influenza.

4. Appropriately apply American Academy of Pediatrics, Infectious Diseases Society of America, and Centers for Disease Control and Prevention (CDC) treatment guidelines for influenza or suspected influenza.

5. Describe the importance of influenza vaccination.

Guideline-Concordant Antiviral Treatment in Children at High Risk for Influenza Complications

BACKGROUND

National guidelines recommend antiviral treatment for children with influenza at high risk for complications regardless of symptom duration. Little is known about concordance of clinical practice with this recommendation.

METHODS

We performed a cross-sectional study of outpatient children (aged 1-18 years) at high risk for complications who were diagnosed with influenza during the 2016-2019 influenza seasons. High-risk status was determined using an existing definition that includes age, comorbidities, and residence in a long-term care facility. The primary outcome was influenza antiviral dispensing within 2 days of influenza diagnosis. We determined patient- and provider-level factors associated with guideline-concordant treatment using multivariable logistic regression.

RESULTS

Of the 274 213 children with influenza at high risk for influenza complications, 159 350 (58.1%) received antiviral treatment. Antiviral treatment was associated with the presence of asthma (aOR, 1.13; 95% confidence interval [CI], 1.11-1.16), immunosuppression (aOR, 1.10; 95% CI, 1.05-1.16), complex chronic conditions (aOR, 1.04; 95% CI, 1.01-1.07), and index encounter in the urgent care setting (aOR, 1.3; 95% CI, 1.26-1.34). Factors associated with decreased odds of antiviral treatment include age 2-5 years compared with 6-17 years (aOR, 0.95; 95% CI, .93-.97), residing in a chronic care facility (aOR, .61; 95% CI, .46-.81), and index encounter in an emergency department (aOR, 0.66; 95% CI, .63-.71).

CONCLUSIONS

Among children with influenza at high risk for complications, 42% did not receive guideline-concordant antiviral treatment. Further study is needed to elucidate barriers to appropriate use of antivirals in this vulnerable population.

Incidence of and risk factors for influenza-associated hospital encounters in pediatric solid organ transplant recipients

Few studies have defined the incidence of and risk factors for influenza infection in pediatric solid organ transplant (SOT) recipients. We used a linkage between the Pediatric Health Information System and the Scientific Registry of Transplant Recipients databases to identify posttransplant influenza-associated hospital encounters (IAHEs) in pediatric SOT recipients of single-organ transplants. Among 7997 unique pediatric SOT recipients transplanted between January 01, 2006, and January 06, 2016, estimated 1- and 3-year posttransplant cumulative incidence rates of IAHEs were 2.7% (95% CI, 2.4%-3.1%) and 7.4% (95% CI, 6.8%-8.0%), respectively. One- and 3-year cumulative incidence rates of severe IAHEs were 0.3% (95% CI, 0.2%-0.5%) and 0.9% (95% CI, 0.7%-1.2%), respectively. Multivariable analysis showed that the organ type (adjusted subdistribution hazard ratio [aSHR]-kidney: reference, liver: 0.64 [95% CI, 0.49-0.84], and heart: 0.72 [95% CI, 0.57-0.93]), race/ethnicity (aSHR-non-Hispanic White: reference, non-Hispanic Black: 1.63 [95% CI, 1.29-2.07], Hispanic 1.57 [95% CI, 1.27-1.94]), and increasing age at transplant (aSHR, 0.93 [95% CI, 0.91-0.94]) were significantly associated with IAHE occurrence. Heart transplant recipients had a near statistically significant increase in hazard for severe IAHE (aSHR 1.96 [0.92-3.49]). Our findings may help guide future influenza prevention efforts and facilitate intervention impact assessment measurement in pediatric SOT recipients.

The Hospital Recovery Scale: A clinically useful endpoint in patients hospitalized with influenza

BACKGROUND

Currently, no single best primary endpoint exists for measuring the efficacy of treatments in seriously ill patients with respiratory infections, such as influenza, who require hospitalization. The Hospital Recovery Scale is an ordinal endpoint used to evaluate treatment outcomes in clinical studies of hospitalized patients infected with influenza.

METHODS

To determine whether Hospital Recovery Scale outcomes correspond to those for other clinical endpoints in patients hospitalized due to influenza, data from the phase 3 randomized, double-blind ZORO clinical trial (NCT01231620) were analyzed. Randomized influenza-infected patients were divided into subgroups of interest based on prespecified baseline and infection-related characteristics, as well as randomized treatment arms (intravenous zanamivir 300 mg or 600 mg, or oral oseltamivir 75 mg). Clinical endpoints relevant to this population were included to analyze differences in outcomes between the subgroups, and correspondence of these endpoints and hospital recovery endpoint was evaluated.

RESULTS

Data from 488 patients were analyzed. There were strong correlations (ρ_s > 0.8) between the Hospital Recovery Scale assessed on the day after completion of a 5-day antiviral therapy (Day 6) and both time to hospital discharge and time to intensive care unit discharge, and moderate to strong correlations (0.6 < ρ_s < 0.8) between the Hospital Recovery Scale on Day 6 and several other relevant clinical endpoints.

CONCLUSIONS

The Hospital Recovery Scale is applicable as a primary endpoint in trials to evaluate new therapies for severely ill patients hospitalized due to influenza, and may have utility in other severe respiratory illnesses such as COVID-19.

Association of Early Oseltamivir With Improved Outcomes in Hospitalized Children With Influenza, 2007-2020

Importance

Oseltamivir is recommended for all children hospitalized with influenza, despite limited evidence supporting its use in the inpatient setting.

Objective

To determine whether early oseltamivir use is associated with improved outcomes in children hospitalized with influenza.

Design, Setting, and Participants

This multicenter retrospective study included 55 799 children younger than 18 years who were hospitalized with influenza from October 1, 2007, to March 31, 2020, in 36 tertiary care pediatric hospitals who participate in the Pediatric Health Information System database. Data were analyzed from January 2021 to March 2022.

Exposures

Early oseltamivir treatment, defined as use of oseltamivir on hospital day 0 or 1.

Main Outcomes and Measures

The primary outcome was hospital length of stay (LOS) in calendar days. Secondary outcomes included 7-day hospital readmission, late (hospital day 2 or later) intensive care unit (ICU) transfer, and a composite outcome of in-hospital death or use of extracorporeal membrane oxygenation (ECMO). Inverse probability treatment weighting (IPTW) based on propensity scoring was used to address confounding by indication. Mixed-effects models were used to compare outcomes between children who did and did not receive early oseltamivir treatment. Outcomes were also compared within high-risk subgroups based on age, presence of a complex chronic condition, early critical illness, and history of asthma.

Results

The analysis included 55 799 encounters from 36 hospitals. The median (IQR) age of the cohort was 3.61 years (1.03-8.27); 56% were male, and 44% were female. A total of 33 207 patients (59.5%) received early oseltamivir. In propensity score-weighted models, we found that children treated with early oseltamivir had shorter LOS (median 3 vs 4 days; IPTW model ratio, 0.52; 95% CI, 0.52-0.53) and lower odds of all-cause 7-day hospital readmission (3.5% vs 4.8%; adjusted odds ratio [aOR], 0.72; 95% CI, 0.66-0.77), late ICU transfer (2.4% vs 5.5%; aOR, 0.41; 95% CI, 0.37-0.46), and the composite outcome of death or ECMO use (0.9% vs 1.4%; aOR, 0.63; 95% CI, 0.54-0.73).

Conclusions and Relevance

Early use of oseltamivir in hospitalized children was associated with shorter hospital stay and lower odds of 7-day readmission, ICU transfer, ECMO use, and death. These findings support the current recommendations for oseltamivir use in children hospitalized with influenza.

Assessment of Temporal Patterns and Patient Factors Associated With Oseltamivir Administration in Children Hospitalized With Influenza, 2007-2020

IMPORTANCE

Oseltamivir therapy is recommended for all pediatric inpatients with influenza, particularly those with high-risk conditions, although data regarding its uptake and benefits are limited.

OBJECTIVE

To describe temporal patterns and independent patient factors associated with the use of oseltamivir and explore patterns in resource use and patient outcomes among children hospitalized with influenza.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter retrospective cross-sectional study was conducted at 36 tertiary pediatric hospitals participating in the Pediatric Health Information System in the US. A total of 70 473 children younger than 18 years who were hospitalized with influenza between October 1, 2007, and March 31, 2020, were included.

EXPOSURES

Hospitalization with a diagnosis of influenza.

MAIN OUTCOMES AND MEASURES

The primary outcome was the use of oseltamivir, which was described by influenza season and by hospital. Patient factors associated with oseltamivir use were assessed using multivariable mixed-effects logistic regression models. Secondary outcomes were resource use (including antibiotic medications, chest radiography, supplemental oxygen, positive pressure ventilation, central venous catheter, and intensive care unit [ICU]) and patient outcomes (length of stay, late ICU transfer, 7-day hospital readmission, use of extracorporeal membrane oxygenation, and in-hospital mortality), which were described as percentages per influenza season.

RESULTS

Among 70 473 children hospitalized with influenza, the median (IQR) age was 3.65 (1.05-8.26) years; 30 750 patients (43.6%) were female, and 39 715 (56.4%) were male. Overall, 16 559 patients (23.5%) were Black, 36 184 (51.3%) were White, 14 133 (20.1%) were of other races (including 694 American Indian or Alaska Native [1.0%], 2216 Asian [3.0%], 372 Native Hawaiian or Pacific Islander [0.5%], and 10 850 other races [15.4%]), and 3597 (5.1%) were of unknown race. A total of 47 071 patients (66.8%) received oseltamivir, increasing from a low of 20.2% in the 2007-2008 influenza season to a high of 77.9% in the 2017-2018 season. Use by hospital ranged from 43.2% to 79.7% over the entire study period and from 56.5% to 90.1% in final influenza season studied (2019-2020). Factors associated with increased oseltamivir use included the presence of a complex chronic condition (odds ratio [OR], 1.42; 95% CI, 1.36-1.47), a history of asthma (OR, 1.31; 95% CI, 1.23-1.38), and early severe illness (OR, 1.19; 95% CI, 1.13-1.25). Children younger than 2 years (OR, 0.81; 95% CI, 0.77-0.85) and children aged 2 to 5 years (OR, 0.83; 95% CI, 0.79-0.88) had lower odds of receiving oseltamivir. From the beginning (2007-2008) to the end (2019-2020) of the study period, the use of antibiotic medications (from 74.4% to 60.1%) and chest radiography (from 59.2% to 51.7%) decreased, whereas the use of oxygen (from 33.6% to 29.3%), positive pressure ventilation (from 10.8% to 7.9%), and central venous catheters (from 2.5% to 1.0%) did not meaningfully change. Patient outcomes, including length of stay (median [IQR], 3 [2-5] days for all seasons), readmissions within 7 days (from 4.0% to 3.4%), use of extracorporeal membrane oxygenation (from 0.5% to 0.5%), and in-hospital mortality (from 1.1% to 0.8%), were stable from the beginning to the end of the study period.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of children hospitalized with influenza, the use of oseltamivir increased over time, particularly among patients with high-risk conditions, but with wide institutional variation. Patient outcomes remained largely unchanged. Further work is needed to evaluate the impact of oseltamivir therapy in this population.

Vital sign predictors of severe influenza among children in an emergent care setting

Background

Decisions regarding the evaluation of children with influenza infection rely on the likelihood of severe disease. The role of early vital signs as predictors of severe influenza infection in children is not well known. Our objectives were to determine the value of vital signs in predicting hospitalization/recurrent emergency department (ED) visits due to influenza infection in children.

Methods

We conducted a prospective study of children aged 6 months to 8 years of age with influenza like illness evaluated at an ED/UC from 2016–2018. All children underwent influenza testing by PCR. We collected heart rate, respiratory rate and temperature, and converted heart rate (HR) and respiratory rate (RR) to z-scores by age. HR z scores were further adjusted for temperature. Our primary outcome was hospitalization/recurrent ED visits within 72 hours. Vital sign predictors with p< 0.2 and other clinical covariates were entered into a multivariable logistic regression model to determine odds ratios (OR) and 95% CI; model performance was assessed using the Brier score and discriminative ability with the C statistic.

Results

Among 1478 children, 411 (27.8%) were positive for influenza, of which 42 (10.2%) were hospitalized or had a recurrent ED visit. In multivariable analyses, adjusting for age, high-risk medical condition and school/daycare attendance, higher adjusted respiratory rate (OR 2.09, 95%CI 1.21–3.61, p = 0.0085) was a significant predictor of influenza hospitalization/recurrent ED visits.

Conclusions

Higher respiratory rate adjusted for age was the most useful vital sign predictor of severity among young children with PCR-confirmed influenza.

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

BACKGROUND

Antiviral 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.

METHODS

Hospitalized 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.

RESULTS

Of 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]).

CONCLUSION

Approximately 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.

Delayed Influenza Treatment in Children With False-Negative Rapid Antigen Test: A Retrospective Single-Center Study in Korea 2016-2019

BACKGROUND

We aimed to examine the delay in antiviral initiation in rapid antigen test (RAT) false-negative children with influenza virus infection and to explore the clinical outcomes. We additionally conducted a medical cost-benefit analysis.

METHODS

This single-center, retrospective study included children (aged < 10 years) with influenza-like illness (ILI), hospitalized after presenting to the emergency department during three influenza seasons (2016-2019). RAT-false-negativity was defined as RAT-negative and polymerase chain reaction-positive cases. The turnaround time to antiviral treatment (TAT) was from the time when RAT was prescribed to the time when the antiviral was administered. The medical cost analysis by scenarios was also performed.

RESULTS

A total of 1,430 patients were included, 7.5% were RAT-positive (n = 107) and 2.4% were RAT-false-negative (n = 20). The median TAT of RAT-false-negative patients was 52.8 hours, significantly longer than that of 4 hours in RAT-positive patients (19.2-100.1, P < 0.001). In the multivariable analysis, TAT of ≥ 24 hours was associated with a risk of severe influenza infection and the need for mechanical ventilation (odds ratio [OR], 6.8, P = 0.009 and OR, 16.2, P = 0.033, respectively). The medical cost varied from $11.7-187.3/ILI patient.

CONCLUSION

Antiviral initiation was delayed in RAT-false-negative patients. Our findings support the guideline that children with influenza, suspected of having severe or progressive infection, should be treated immediately.

Clinical Influenza Testing Practices in Hospitalized Children at United States Medical Centers, 2015-2018

At nine US hospitals that enrolled children hospitalized with acute respiratory illness (ARI) during 2015-2016 through 2017-2018 influenza seasons, 50% of children with ARI received clinician-initiated testing for influenza and 35% of cases went undiagnosed due to lack of clinician-initiated testing. Marked heterogeneity in testing practice was observed across sites.

Influenza Antiviral Treatment and Length of Stay

BACKGROUND

Antiviral treatment is recommended for hospitalized patients with suspected and confirmed influenza, but evidence is limited among children. We evaluated the effect of antiviral treatment on hospital length of stay (LOS) among children hospitalized with influenza.

METHODS

We included children <18 years hospitalized with laboratory-confirmed influenza in the US Influenza Hospitalization Surveillance Network. We collected data for 2 cohorts: 1 with underlying medical conditions not admitted to the ICU (n = 309, 2012-2013) and an ICU cohort (including children with and without underlying conditions; n = 299, 2010-2011 to 2012-2013). We used a Cox model with antiviral receipt as a time-dependent variable to estimate hazard of discharge and a Kaplan-Meier survival analysis to determine LOS.

RESULTS

Compared with those not receiving antiviral agents, LOS was shorter for those treated ≤2 days after illness onset in both the medical conditions (adjusted hazard ratio: 1.37, P = .02) and ICU (adjusted hazard ratio: 1.46, P = .007) cohorts, corresponding to 37% and 46% increases in daily discharge probability, respectively. Treatment ≥3 days after illness onset had no significant effect in either cohort. In the medical conditions cohort, median LOS was 3 days for those not treated versus 2 days for those treated ≤2 days after symptom onset (P = .005).

CONCLUSIONS

Early antiviral treatment was associated with significantly shorter hospitalizations in children with laboratory-confirmed influenza and high-risk medical conditions or children treated in the ICU. These results support Centers for Disease Control and Prevention recommendations for prompt empiric antiviral treatment in hospitalized patients with suspected or confirmed influenza.

Antiviral Use in Canadian Children Hospitalized for Influenza

OBJECTIVES

Antivirals are recommended for children hospitalized with influenza but are underutilized. We describe antiviral prescribing during influenza admissions in Canadian pediatric centers and identify factors associated with antiviral use.

METHODS

We performed active surveillance for laboratory-confirmed influenza hospitalizations among children ≤16 years old at the 12 Canadian Immunization Monitoring Program Active hospitals, from 2010-2011 to 2018-2019. Logistic regression analyses were used to identify factors associated with antiviral use.

RESULTS

Among 7545 patients, 57.4% were male; median age was 3 years (interquartile range: 1.1-6.3). Overall, 41.3% received antiviral agents; 72.8% received antibiotics. Antiviral use varied across sites (range, 10.2% to 81.1%) and influenza season (range, 19.9% to 59.6%) and was more frequent in children with ≥1 chronic health condition (52.7% vs 36.7%; P < .001). On multivariable analysis, factors associated with antiviral use included older age (adjusted odds ratio [aOR] 1.04 [95% confidence interval (CI), 1.02-1.05]), more recent season (highest aOR 9.18 [95% CI, 6.70-12.57] for 2018-2019), admission during peak influenza period (aOR 1.37 [95% CI, 1.19-1.58]), availability of local treatment guideline (aOR 1.54 [95% CI, 1.17-2.02]), timing of laboratory confirmation (highest aOR 2.67 [95% CI, 1.97-3.61] for result available before admission), presence of chronic health conditions (highest aOR 4.81 [95% CI, 3.61-6.40] for cancer), radiographically confirmed pneumonia (aOR 1.39 [95% CI, 1.20-1.60]), antibiotic treatment (aOR 1.51 [95% CI, 1.30-1.76]), respiratory support (1.57 [95% CI, 1.19-2.08]), and ICU admission (aOR 3.62 [95% CI, 2.88-4.56]).

CONCLUSIONS

Influenza antiviral agents were underused in Canadian pediatric hospitals, including among children with high-risk chronic health conditions. Prescribing varied considerably across sites, increased over time, and was associated with patient and hospital-level characteristics. Multifaceted hospital-based interventions are warranted to strengthen adherence to influenza treatment guidelines and antimicrobial stewardship practices.

Rate of use and effectiveness of oseltamivir in the treatment of influenza illness in high-risk populations: A systematic review and meta-analysis

BACKGROUND

Oseltamivir is recommended in the treatment of influenza illness in high-risk populations, including those with chronic heart and lung diseases.

OBJECTIVES

We conducted a systematic review and meta-analysis to determine the rate of use and effectiveness of oseltamivir in these groups of patients.

METHODS

The protocol for the systematic review was registered on PROSPERO (CRD42019125998). Medline, EMBASE, Cochrane CENTRAL, and CINAHL were searched for observational studies and randomized controlled trials published up to 16 February 2020. Quality appraisal of final studies was conducted using GRADE guidelines. Data were extracted using a predeveloped template. Main outcomes measured included the rate of use of oseltamivir for influenza-like-illness and its effectiveness in reducing disease severity in patients with cardiopulmonary diseases. Outcomes measured for effectiveness were influenza-related complications (respiratory infections and asthma exacerbations), hospitalization rates, and time to freedom from illness. Risk of bias was assessed using Cochrane's Risk of Bias 2.0 tool for randomized trials and Cochrane's Risk of Bias in nonrandomized Studies of Interventions tool for nonrandomized trials. Where data were available, pooled analyses were conducted. Dichotomous variables were evaluated using the Mantel-Hansel method. A random effect model was applied. Summary measures were reported as risk ratios where relevant.

RESULTS

Our systematic review identified nine studies. Oseltamivir use ranged from 25% to 100%. When oseltamivir group was compared to placebo, rates of respiratory tract infections reduced by 28% (RR = 0.72, 95% CI = 0.59-0.90), hospitalization reduced by 52% (RR = 0.48, 95% CI = 0.28-0.80) and median time to illness alleviation decreased by 10.4 to 120 hours. There was no significant reduction in asthma exacerbation rates.

CONCLUSIONS

Our systematic review suggests that the use of oseltamivir is beneficial in reducing disease severity, however, its use in high-risk population remains suboptimal.

Influenza species and subtypes circulation among hospitalized patients in Laleh hospital during two influenza seasonal (2016-2017 and 2017-2018) using a multiplex Real Time-Polymerase Chain Reaction

The introduction of polymerase chain reaction (PCR) techniques has improved the detection of respiratory viruses, particularly with the use of multiplex real-time technique with the capability of simultaneous detection of various pathogens in a single reaction. The aim of this study was to apply the above technology for the diagnosis of influenza infections and at the same time to differentiate between common flu species between hospitalized patients in Laleh hospital (Iran) between two flu seasons (2016-2017 and 2017-2018). Different respiratory specimens were collected from 540 patients from a period of December 2016 to May 2018 and were sent to the laboratory for molecular diagnosis. RNAs were extracted and subsequently, a multiplex real time PCR identifying flu A, flu B and typing flu A (H1N1) was carried out. The mean age of patients was 47.54±23.96. 216 (40%) and 321 (60%) of subjects were male and female, respectively. 219 out of 540 (40.5%) were positive for influenza infection including flu A (n=97, 44.3%), flu A (H1N1) (n=45, 20.7%) and flu B (n=77, 35%). Flu A was the dominant species on 2016-2017 and flu B was the major species on 2017-2018. Flu A (H1N1) was comparable in both time periods. Flu infections were most frequently diagnosed in age groups 21-40. Flu-positive patients suffered more from body pain and sore throat than flunegative patients with significant statistical difference (P values <0.001). The mean duration of hospitalization was shorter for flu-positive patients (P value = 0.016). Application of multiplex real time PCR could facilitate the influenza diagnosis in a short period of time, benefiting patients from exclusion of bacterial infections and avoiding unnecessary antibiotic therapy. Influenza diagnosis was not achieved in up to 60% of flu-like respiratory infections, suggesting the potential benefit of adopting the same methodology for assessing the involvement of other viral or/and bacterial pathogens in those patients.

Diagnosis and Management of Pediatric Influenza in the Era of Rapid Diagnostics

Influenza is a significant cause of childhood morbidity and death; it contributes to up to 16% of hospitalizations for respiratory illnesses worldwide. Novel rapid viral diagnostic tests, including molecular diagnostic tests, have the potential to significantly affect both time to diagnosis and selection of optimal anti-infective therapy. However, little is known about current treatment algorithms used in US hospitals. In this study, for hospitalized children in the United States, we aimed to define the current approaches to influenza diagnosis and treatment and to explore reasons for their potential variation. In this study, we aimed to define the current approaches to pediatric influenza diagnosis and treatment in US hospitals, and to explore reasons for their potential variation. Our results suggest a rise in the availability and use of rapid molecular diagnostic testing in addition to continued variability in anti-infective management, particularly with regard to antiviral use.

Neuraminidase Inhibitors and Hospital Length of Stay: A Meta-analysis of Individual Participant Data to Determine Treatment Effectiveness Among Patients Hospitalized With Nonfatal 2009 Pandemic Influenza A(H1N1) Virus Infection

BACKGROUND

The effect of neuraminidase inhibitor (NAI) treatment on length of stay (LoS) in patients hospitalized with influenza is unclear.

METHODS

We conducted a one-stage individual participant data (IPD) meta-analysis exploring the association between NAI treatment and LoS in patients hospitalized with 2009 influenza A(H1N1) virus (A[H1N1]pdm09) infection. Using mixed-effects negative binomial regression and adjusting for the propensity to receive NAI, antibiotic, and corticosteroid treatment, we calculated incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Patients with a LoS of <1 day and those who died while hospitalized were excluded.

RESULTS

We analyzed data on 18 309 patients from 70 clinical centers. After adjustment, NAI treatment initiated at hospitalization was associated with a 19% reduction in the LoS among patients with clinically suspected or laboratory-confirmed influenza A(H1N1)pdm09 infection (IRR, 0.81; 95% CI, .78-.85), compared with later or no initiation of NAI treatment. Similar statistically significant associations were seen in all clinical subgroups. NAI treatment (at any time), compared with no NAI treatment, and NAI treatment initiated <2 days after symptom onset, compared with later or no initiation of NAI treatment, showed mixed patterns of association with the LoS.

CONCLUSIONS

When patients hospitalized with influenza are treated with NAIs, treatment initiated on admission, regardless of time since symptom onset, is associated with a reduced LoS, compared with later or no initiation of treatment.

Clinical Features and Outcomes of Immunocompromised Children Hospitalized With Laboratory-Confirmed Influenza in the United States, 2011-2015

BACKGROUND

Existing data on the clinical features and outcomes of immunocompromised children with influenza are limited.

METHODS

Data from the 2011-2012 through 2014-2015 influenza seasons were collected as part of the Centers for Disease Control and Prevention (CDC) Influenza Hospitalization Surveillance Network (FluSurv-NET). We compared clinical features and outcomes between immunocompromised and nonimmunocompromised children (<18 years old) hospitalized with laboratory-confirmed community-acquired influenza. Immunocompromised children were defined as those for whom ≥1 of the following applies: human immunodeficiency virus/acquired immunodeficiency syndrome, cancer, stem cell or solid organ transplantation, nonsteroidal immunosuppressive therapy, immunoglobulin deficiency, complement deficiency, asplenia, and/or another rare condition. The primary outcomes were intensive care admission, duration of hospitalization, and in-hospital death.

RESULTS

Among 5262 hospitalized children, 242 (4.6%) were immunocompromised; receipt of nonsteroidal immunosuppressive therapy (60%), cancer (39%), and solid organ transplantation (14%) were most common. Immunocompromised children were older than the nonimmunocompromised children (median, 8.8 vs 2.8 years, respectively; P < .001), more likely to have another comorbidity (58% vs 49%, respectively; P = .007), and more likely to have received an influenza vaccination (58% vs 39%, respectively; P < .001) and early antiviral treatment (35% vs 27%, respectively; P = .013). In multivariable analyses, immunocompromised children were less likely to receive intensive care (adjusted odds ratio [95% confidence interval], 0.31 [0.20-0.49]) and had a slightly longer duration of hospitalization (adjusted hazard ratio of hospital discharge [95% confidence interval], 0.89 [0.80-0.99]). Death was uncommon in both groups.

CONCLUSIONS

Immunocompromised children hospitalized with influenza received intensive care less frequently but had a longer hospitalization duration than nonimmunocompromised children. Vaccination and early antiviral use could be improved substantially. Data are needed to determine whether immunocompromised children are more commonly admitted with milder influenza severity than are nonimmunocompromised children.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Characteristics and Outcomes of Young Children Hospitalized With Laboratory-confirmed Influenza or Respiratory Syncytial Virus in Ontario, Canada, 2009-2014

BACKGROUND

Respiratory illnesses are a major contributor to pediatric hospitalizations, with influenza and respiratory syncytial virus (RSV) causing substantial morbidity and cost each season. We compared the characteristics and outcomes of children 0-59 months of age who were hospitalized with laboratory-confirmed influenza or RSV between 2009 and 2014 in Ontario, Canada.

METHODS

We included hospitalized children who were tested for influenza A, influenza B and RSV and were positive for a single virus. We characterized individuals by their demographics and healthcare utilization patterns and compared their hospital outcomes, in-hospital cost and postdischarge healthcare use by virus type and by presence of underlying comorbidities.

RESULTS

We identified and analyzed 7659 hospitalizations during which a specimen tested positive for influenza or RSV. Children with RSV were the youngest whereas children with influenza B were the oldest [median ages 6 months (interquartile range: 2-17 months) and 25 months (interquartile range: 10-45 months), respectively]. Complex chronic conditions were more prevalent among children with all influenza (sub)types than RSV (31%-34% versus 20%). In-hospital outcomes were similar by virus type, but in children with comorbidities, postdischarge outcomes varied. We observed no differences in in-hospital cost between viruses or by presence of comorbidities [overall median cost: $4150 Canadian dollars (interquartile range: $3710-$4948)].

CONCLUSIONS

Influenza and RSV account for large numbers of pediatric hospitalizations. RSV and influenza were similar in terms of severity and cost in hospitalized children. Influenza vaccination should be promoted in pregnant women and young children, and a vaccine against RSV would mitigate the high burden of RSV.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Early Use of Anti-influenza Medications in Hospitalized Children With Tracheostomy

BACKGROUND

Early administration of anti-influenza medications is recommended for all children hospitalized with influenza. We investigated whether early use of anti-influenza medications is associated with improved outcomes in children with tracheostomy hospitalized with influenza.

METHODS

We performed a multicenter retrospective cohort study through the Pediatric Health Information System database for patients aged 30 days to 19 years who were discharged between October 1, 2007, and September 30, 2015 with diagnostic codes for both influenza and tracheostomy. Our primary predictor was receipt of anti-influenza medications on hospital day 0 or 1. We used propensity score matching to adjust for confounding by indication. Primary outcomes were length of stay (LOS) and 30-day all-cause revisit rate (emergency department visit or hospital admission).

RESULTS

Of 1436 discharges screened, 899 met inclusion criteria. The median admission age was 5 years (interquartile range: 2-10). The majority had multiple complex chronic conditions (median 3; interquartile range: 3-4) and technology dependence, such as gastrostomy tube (73.6%). After matching 772 unique admissions by propensity score, LOS was shorter for the cohort receiving early anti-influenza medications (6.4 vs 7.5 days; P = .01) without increase in revisit rate (27.5% vs 24.1%; P = .28). More than 80% in both cohorts received empirical antibiotics, and the duration of antibiotic therapy was similar (5.0 vs 5.6 days; P = .11).

CONCLUSIONS

Early use of anti-influenza medications in children with tracheostomy hospitalized with influenza is associated with shorter LOS, but these children continue to receive antibiotics despite identification and treatment of their viral infections.

Pediatric influenza and illness severity: what is known and what questions remain?

PURPOSE OF REVIEW

Influenza causes a range of illnesses in children, from uncomplicated self-limited illness to severe disease and death. This review provides an update on the severity and burden of influenza in US children over recent seasons.

RECENT FINDINGS

The 2017-2018 influenza season was widespread and severe across all ages, including children. Disease severity is influenced by influenza virologic characteristics and host factors, as well as public health interventions such as influenza vaccination and antiviral treatment. In recent influenza A (H3N2)-predominant seasons (2016-2017 and 2017-2018), influenza vaccination effectiveness was higher in younger children compared with older children and adolescents, although the reasons for this are unclear. Interestingly, even in seasons when influenza A (H3N2) viruses predominate, influenza A (H1N1)pdm09 and B viruses can play a large role in severe pediatric disease. Although children less than 5 years of age and those with underlying medical conditions are at increased risk for severe disease, influenza-associated hospitalizations and deaths occur every season in healthy children.

SUMMARY

Influenza causes a substantial burden of outpatient visits, hospitalizations, and deaths among children. Ongoing research is important to better characterize factors that contribute to influenza severity, and to identify strategies to improve the impact of influenza vaccination and treatment.

Updates on Influenza Vaccination in Children

Influenza vaccination is recommended for all children 6 months of age and older who do not have contraindications. This article provides an overview of information concerning burden of influenza among children in the United States; US-licensed influenza vaccines; vaccine immunogenicity, effectiveness, and safety; and recent updates relevant to use of these vaccines in pediatric populations. Influenza antiviral medications are discussed. Details concerning vaccine-related topics may be found in the current US Centers for Disease Control and Prevention/Advisory Committee on Immunization Practices recommendations for use of influenza vaccines (https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/flu.html). Additional information on influenza antivirals is located at https://www.cdc.gov/flu/professionals/antivirals/index.htm.

Influenza

Influenza A and B viruses are orthomyxoviruses with three important envelope glycoproteins: hemagglutinin (HA), neuraminidase (NA), and matrix proteins. Influenza viruses have developed ways to evade the body's immune response using an antigenic variation known as antigenic shift (replacement of HA and NA antigens with novel subtypes from noninfluenza viruses) and drift (mutations within antibody-binding sites in HA and or NA). Because of new influenza viruses constantly emerging from antigenic shift and drift, new influenza vaccines are required each year. Human-to-human transmission of influenza occurs each winter and early spring through small-particle aerosols or droplets. The influenza virus attacks epithelial cells of the upper and lower respiratory tract, with the potential for secondary bacterial infection and acute respiratory distress syndrome (ARDS). The symptoms of influenza infection include fever, headache, cough, sore throat, myalgia, and nasal congestion. Lower respiratory tract manifestations such as pneumonia and bronchiolitis are virtually indistinguishable from other viral infections. Children with certain comorbidities, such as chronic lung disease and severe neurologic impairment, are at higher risk of influenza-related complications. The most reliable test for influenza is reverse transcription polymerase chain reaction (RT-PCR). Rapid antigen tests have lower sensitivity and specificity and are not reliable during periods of low influenza activity. Antiviral treatment with NA inhibitors can shorten the duration of fever, symptoms, and hospitalization, especially when started within 48 hours of influenza illness onset. Prevention of influenza through annual influenza vaccination is recommended for all children 6 months of age and older. The vaccines contain three or four influenza subtypes, chosen depending on the circulating strains. The two formulations approved for children are the inactivated influenza vaccine (IIV) and live-attenuated influenza vaccine (LAIV).

Influenza A/H3N2 virus infection in immunocompromised ferrets and emergence of antiviral resistance

Influenza viruses can cause severe life threatening infections in high-risk patients, including young children, the elderly and patients with compromised immunity due to underlying medical conditions or immunosuppressive treatment. The impaired immunity of these patients causes prolonged virus infection and combined with antiviral treatment facilitates the emergence of viruses with resistance mutations. The diverse nature of their immune status makes them a challenging group to study the impact of influenza virus infection and the efficacy of antiviral therapy. Immunocompromised ferrets may represent a suitable animal model to assess influenza virus infection and antiviral treatment strategies in immunocompromised hosts. Here, ferrets were given a daily oral solution of mycophenolate mofetil, tacrolimus and prednisolone sodium phosphate to suppress their immune system. Groups of immunocompromised and immunocompetent ferrets were inoculated with an A/H3N2 influenza virus and were subsequently treated with Oseltamivir or left untreated. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was performed on the throat and nose specimens to study virus replication during the course of infection. All immunocompromised ferrets had prolonged presence of viral RNA and a higher total amount of virus shedding compared to the immunocompetent ferrets. Although Oseltamivir reduced the total amount of virus shedding from the nose and throat of treated ferrets, it also resulted in the emergence of the neuraminidase R292K resistance substitution in all these animals, as determined by mutation specific RT-PCR and next-generation sequencing. No additional mutations that could be associated with the emergence of the R292K resistance mutation were detected. The immunocompromised ferret model can be used to study A/H3N2 virus shedding and is a promising model to study new antiviral strategies and the emergence of antiviral resistance in immunocompromised hosts.

Antiviral treatment of childhood influenza: an update

PURPOSE OF REVIEW

Influenza virus can cause severe or life-threatening infection in children. This review provides an update on antiviral medications available to treat and prevent influenza in both healthy children and children with underlying medical conditions, and recommendations on their appropriate use in the outpatient and inpatient settings.

RECENT FINDINGS

Despite the significant morbidity and mortality associated with influenza infection, a large number of children hospitalized with influenza do not receive specific antiviral treatment with a neuraminidase inhibitor. Although the effectiveness of this intervention has been debated, several recent observational studies have shown the potential benefits conferred by early antiviral treatment. Oral oseltamivir and inhaled zanamivir remain the best studied antiviral agents for influenza treatment and prevention. In addition, the US Food and Drug Administration recently approved peramivir, a novel neuraminidase inhibitor available for intravenous administration.

SUMMARY

Children with suspected or documented influenza infection benefit from early antiviral treatment with neuraminidase inhibitors that can shorten illness duration, decrease symptom severity, and lower the risk of complications leading to hospitalization and death. Unless contraindicated, all hospitalized children, children with underlying medical conditions, and those with severe or progressive symptoms of influenza should receive specific antiviral treatment for influenza with a neuraminidase inhibitor. Additionally, antiviral treatment of influenza-infected children in the outpatient setting should be strongly considered.

Efficacy and Safety of Intravenous Peramivir Compared With Oseltamivir in High-Risk Patients Infected With Influenza A and B Viruses: A Multicenter Randomized Controlled Study

BACKGROUND

Clinical studies comparing the different neuraminidase inhibitors for treatment of at-risk patients with influenza have not been performed. To optimize such treatments, we assessed the efficacy and safety of intravenous peramivir compared with oral oseltamivir in treating seasonal influenza A or B virus infection.

METHODS

A multicenter, randomized, controlled clinical trial was conducted from December 2012 to May 2014 in high-risk patients infected with seasonal influenza. A total of 92 adult inpatients and outpatients with high risk factors (HRFs) were treated by either a single intravenous infusion of peramivir (600 mg) or oral administration of oseltamivir (75 mg, twice per day for 5 days).

RESULTS

The median times to clinical stability (time to reach <37°C) were 40.0 hours (95% confidence interval [CI] = 23.3-64.5) and 37.8 hours (95% CI = 26.3-45.3) in the peramivir and oseltamivir groups, respectively; these values did not reveal a significant difference. The virus titer and change of mean total symptom scores decreased similarly with both treatments. Results of step-wise regression suggested that virus type was a significantly effective prognostic factor with respect to illness resolution. Adverse events (AEs) with peramivir and oseltamivir occurred in 2.2% (n = 1/46) and 13.0% (n = 6/46) of patients, respectively. The severity of AEs was mild in all cases except 2 patients who showed pneumonia or COPD aggravation; both were in the oseltamivir group.

CONCLUSIONS

Intravenous peramivir was effective based on the result of direct comparison with oral oseltamivir. Thus our data show that peramivir is a useful option for the treatment of influenza-infected patients with HRFs.

Neurological Complications of Respiratory Disease

The respiratory and central nervous systems are intimately connected. Ventilatory control is strictly regulated by central mechanisms in a complex process that involves central and peripheral chemoreceptors, baroreceptors, the cardiovascular system, and specific areas of the brain responsible for autonomic control. Disorders of the lung and respiratory system can interfere with these mechanisms and temporarily or permanently disrupt this complex network resulting in mild to severe neurological sequelae. This article explores the wide variety of neurological problems resulting from respiratory dysfunction, with emphasis on its pathophysiology, clinical features, prognosis, and long-term outcome.

Oseltamivir Use Among Children and Adults Hospitalized With Community-Acquired Pneumonia

BACKGROUND

Data on oseltamivir treatment among hospitalized community-acquired pneumonia (CAP) patients are limited.

METHODS

Patients hospitalized with CAP at 6 hospitals during the 2010-2012 influenza seasons were included. We assessed factors associated with oseltamivir treatment using logistic regression.

RESULTS

Oseltamivir treatment was provided to 89 of 1627 (5%) children (<18 years) and 143 of 1051 (14%) adults. Among those with positive clinician-ordered influenza tests, 39 of 61 (64%) children and 37 of 48 (77%) adults received oseltamivir. Among children, oseltamivir treatment was associated with hospital A (adjusted odds ratio [aOR], 2.76; 95% confidence interval [CI], 1.36-4.88), clinician-ordered testing performed (aOR, 2.44; 95% CI, 1.47-5.19), intensive care unit (ICU) admission (aOR, 2.09; 95% CI, 1.27-3.45), and age ≥2 years (aOR, 1.43; 95% CI, 1.16-1.76). Among adults, oseltamivir treatment was associated with clinician-ordered testing performed (aOR, 8.38; 95% CI, 4.64-15.12), hospitals D and E (aOR, 3.46-5.11; 95% CI, 1.75-11.01), Hispanic ethnicity (aOR, 2.06; 95% CI, 1.18-3.59), and ICU admission (aOR, 2.05; 95% CI, 1.34-3.13).

CONCLUSIONS

Among patients hospitalized with CAP during influenza season, oseltamivir treatment was moderate overall and associated with clinician-ordered testing, severe illness, and specific hospitals. Increased clinician education is needed to include influenza in the differential diagnosis for hospitalized CAP patients and to test and treat patients empirically if influenza is suspected.

Influenza and the use of oseltamivir in children

Influenza is an infectious disease which causes significant morbidity and mortality. In the USA, approximately 200 000 hospital admissions and 36 000 deaths occur annualy due to severe influenza infections. Although influenza often causes a simple respiratory infection, it sometimes causes disorders affecting several organs including the lung, heart, brain, liver and muscles or serious life-threatening primary viral or secondary bacterial pneumonia. Currently, oseltamivir is the most important and effective drug for severe influenza infections. Severe influenza infections can be controlled and related deaths may be prevented with initiation of this drug especially within first 2 days. Oseltamivir is usually well tolerated and its most commonly reported side effect is related with the gastrointestinal system. In conclusion, the course of influenza changes in a positive direction and the rates of complications and mortality significantly reduce in patients in whom oseltamivir treatment is initiated as soon as possible.

Rising Oseltamivir Use Among Hospitalized Children in a Postpandemic Era

BACKGROUND

Oseltamivir prescribing among pediatric inpatients with influenza varied from 2% to 48% prior to the 2009 H1N1 pandemic. After the pandemic, prescribing guidelines were expanded, and studies reported benefits for hospitalized children. Post-pandemic prescribing practices among children are unclear.

OBJECTIVES

To report the rate of oseltamivir use and to identify factors associated with its use among inpatients with confirmed influenza infection from 2010 to 2014 at a tertiary children's hospital.

METHODS

We conducted a retrospective cohort study of inpatients with polymerase chain reaction-confirmed influenza from December 2010 to April 2014 at Children's Hospital Colorado. The primary outcome was oseltamivir use. Variables regarding demographics, underlying medical conditions, diagnoses, and hospital course were also explored. Univariate and multivariate logistic regression analyses were performed.

RESULTS

Among 395 inpatients with influenza, 323 (82%) received oseltamivir. In univariate analyses, oseltamivir use was associated with admission within 48 hours of symptom onset (89% vs 77%), ICU admission (88% vs 79%), longer length of stay (90% for >6 days vs 77% for ≤2 days), and influenza A H1N1 infection (P < .05 for all). In multivariate logistic regression analysis, longer length of stay, illness during the 2013-2014 season, and admission within 48 hours of symptom onset were associated with higher odds of oseltamivir use.

CONCLUSIONS

Oseltamivir use for children with influenza in the postpandemic era is increasing at our institution, aligning with official recommendations and reported benefits. We report highest use for patients in the 2013-2014 season, those who present early in their illness, and those requiring a prolonged hospital stay.

Occupational exposures to influenza among healthcare workers in the United States

The objective of this study is to estimate the annual number of occupational exposures to influenza among healthcare workers that result from providing direct and supportive care to influenza patients in acute care, home care and long-term care settings. Literature review was used to identify healthcare utilization for influenza, and worker activity patterns. This information was used, with Monte Carlo simulation, to tabulate the mean annual number of occupational exposures. Given a medium-sized epidemic with a 6% annual symptomatic influenza incidence proportion, the mean number of occupational exposures was estimated to be 81.8 million annually. Among the approximately 14 million healthcare workers, this corresponds to 5.8 exposures per worker annually, on average. Exposures, however, are likely concentrated among subsets of healthcare workers. Occupational exposures were most numerous in ambulatory care settings (38%), followed by long-term care facilities (30%) and home care settings (21%). The annual number of occupational exposures to influenza is high, but not every occupational exposure will result in infection. Some infection control activities, like patient isolation, can reduce the number of occupational exposures.

Economic analysis of rapid and sensitive polymerase chain reaction testing in the emergency department for influenza infections in children

BACKGROUND

Rapid multiplex polymerase chain reaction (PCR) assays simultaneously detect several respiratory viral pathogens with high sensitivity. Maximizing detection of influenza at the point of care has the potential to reduce unnecessary antibiotic use, laboratory tests and hospitalizations. However, the cost-effectiveness of rapid multiplex PCR assays for influenza has not been compared with other diagnostic methods in children.

METHODS

For children presenting to the emergency department with influenza-like illness, we compared costs and outcomes using 4 different testing strategies for detection of influenza: (1) a rapid multiplex PCR platform (FilmArray); (2) traditional PCR; (3) direct-fluorescent antibody and (4) rapid antigen tests. Costs were assessed from the hospital perspective, and effectiveness was defined as quality-adjusted life years (QALYs). Input parameters were obtained from previous studies, and the model was run separately for children aged 3-36 months and 3-18 years.

RESULTS

Rapid multiplex PCR testing was the most effective testing strategy for children in both age groups. The incremental cost-effectiveness when compared with rapid antigen tests was $115,556 per QALY for children aged 3-36 months and from $228,000 per QALY for children aged 3-18 years. The cost-effectiveness of rapid multiplex PCR was sensitive to estimates for influenza prevalence, the proportion of patients treated with antivirals and the cost per test.

CONCLUSIONS

Our model identifies scenarios in which identification of influenza in the emergency department using rapid multiplex PCR testing is a cost-effective strategy for infants and children 3 months through 18 years. Including detection of other respiratory viruses in the analysis would further improve cost-effectiveness.

Canadian Acute Respiratory Illness and Flu Scale (CARIFS) for clinical detection of influenza in children

BACKGROUND

Validated clinical scales, such as the Canadian Acute Respiratory Illness and Flu Scale (CARIFS), have not been used to differentiate influenza (FLU) from other respiratory viruses.

METHODS

Secondary analysis of a prospective cohort presenting to the emergency department (ED) with an influenza-like infection from 2008 to 2010. Subjects were children aged 0 to 19 years who had a venipuncture and respiratory virus polymerase chain reaction. Demographics and CARIFS items were assessed during the ED visit; comparisons were made between FLU and non-FLU subjects.

RESULTS

The 203 subjects had median age 30.5 months; 61.6% were male. Comorbid conditions (51.2%) were common. FLU was identified in 26.6%, and were older than non-FLU patients (69.7 vs 47.9 months, P = .02). Demographic, household factors, and mean CARIFS score did not differ between FLU (33.7), and non-FLU (32.0) (mean difference 1.6, 95% CI: -2.0 to 5.2) groups.

CONCLUSIONS

CARIFS cannot discriminate between FLU and non-FLU infection in ED children with influenza-like infection.

The burden of influenza hospitalizations in infants from 2003 to 2012, United States

BACKGROUND

Little information is available describing the epidemiology and clinical characteristics of those <12 months hospitalized with influenza, particularly at a population level.

METHODS

We used population-based, laboratory-confirmed influenza hospitalization surveillance data from 2003 to 2012 seasons to describe the impact of influenza by age category (<3, 3 to <6 and 6 to <12 months). Logistic regression was used to explore risk factors for intensive care unit (ICU) admission. Adjusted age-specific, influenza-associated hospitalization rates were calculated and applied to the number of US infants to estimate national numbers of hospitalizations.

RESULTS

Influenza was associated with an annual average of 6514 infant hospitalizations (range 1842-12,502). Hospitalization rates among infants <3 months were substantially higher than the rate in older infants. Most hospitalizations occurred in otherwise healthy infants (75%) among whom up to 10% were admitted to the ICU and up to 4% had respiratory failure. These proportions were 2-3 times higher in infants with high risk conditions. Infants <6 months were 40% more likely to be admitted to the ICU than older infants. Lung disease (adjusted odds ratio 1.80; 95% confidence interval 1.22-2.67), cardiovascular disease (adjusted odds ratio: 4.16; 95% confidence interval: 2.65-6.53), and neuromuscular disorder (adjusted odds ratio: 2.99; 95% confidence interval: 1.87-4.78) were risk factors for ICU admission among all infants.

CONCLUSIONS

The impact of influenza on infants, particularly those very young or with high risk conditions, underscores the importance of influenza vaccination, especially among pregnant women and those in contact with young infants not eligible for vaccination.

Severe complications in influenza-like illnesses

OBJECTIVE

Data on complications from upper respiratory infection are limited. We examined development of severe complications in children presenting to the emergency department (ED) for moderate to severe influenza-like illness (ILI).

METHODS

Prospective cohort study of children 0 to 19 years presenting to a tertiary care children's hospital ED during peak respiratory viral seasons from 2008 to 2010. Subjects included had moderate to severe ILI, defined by performance of venipuncture and nasopharyngeal multiplex polymerase chain reaction for respiratory viruses. Severe complications (respiratory failure, encephalopathy, seizures, pneumonia, bacteremia, death) were prospectively determined. Risk factors for severe complications were collected, including demographics, comorbidities, and household exposures.

RESULTS

There were 241 enrolled subjects with median age of 27.4 months (interquartile range 8.9-68.5); 59.3% were boys and 48.5% were black. High-risk conditions were present in 53.5%. Severe complications developed in 35.3% (95% confidence interval [CI] 29.3-41.3), most frequently pneumonia (26.1%). The risk for severe complications was increased in subjects with neurologic or neuromuscular conditions (relative risk 4.0; 95% CI 1.9-8.2). No specific respiratory virus was associated with development of severe complications. Among patients with influenza, severe complications were greater with subtype H1N1 infection (relative risk 1.45, 95% CI 0.99-2.13, P = .048), and were at highest risk for pneumonia (relative risk 4.2, 95% CI 1.2-15.9).

CONCLUSION

In children presenting to the ED for moderate to severe ILI, those with neurologic and neuromuscular disease are at increased risk for severe complications. Development of severe complications did not differ by infecting virus; however, risk of severe complications was greater with subtype H1N1 compared with other influenza.

Pediatric complex chronic conditions classification system version 2: updated for ICD-10 and complex medical technology dependence and transplantation

BACKGROUND

The pediatric complex chronic conditions (CCC) classification system, developed in 2000, requires revision to accommodate the International Classification of Disease 10th Revision (ICD-10). To update the CCC classification system, we incorporated ICD-9 diagnostic codes that had been either omitted or incorrectly specified in the original system, and then translated between ICD-9 and ICD-10 using General Equivalence Mappings (GEMs). We further reviewed all codes in the ICD-9 and ICD-10 systems to include both diagnostic and procedural codes indicative of technology dependence or organ transplantation. We applied the provisional CCC version 2 (v2) system to death certificate information and 2 databases of health utilization, reviewed the resulting CCC classifications, and corrected any misclassifications. Finally, we evaluated performance of the CCC v2 system by assessing: 1) the stability of the system between ICD-9 and ICD-10 codes using data which included both ICD-9 codes and ICD-10 codes; 2) the year-to-year stability before and after ICD-10 implementation; and 3) the proportions of patients classified as having a CCC in both the v1 and v2 systems.

RESULTS

The CCC v2 classification system consists of diagnostic and procedural codes that incorporate a new neonatal CCC category as well as domains of complexity arising from technology dependence or organ transplantation. CCC v2 demonstrated close comparability between ICD-9 and ICD-10 and did not detect significant discontinuity in temporal trends of death in the United States. Compared to the original system, CCC v2 resulted in a 1.0% absolute (10% relative) increase in the number of patients identified as having a CCC in national hospitalization dataset, and a 0.4% absolute (24% relative) increase in a national emergency department dataset.

CONCLUSIONS

The updated CCC v2 system is comprehensive and multidimensional, and provides a necessary update to accommodate widespread implementation of ICD-10.

Influenza vaccination and treatment in children with neurologic disorders

Influenza viruses cause substantial morbidity in children each year, especially among children with specific chronic conditions. In particular, neurologic disorders have emerged as a strong risk factor for influenza-related complications. Children with these disorders may be vulnerable due to diminished respiratory muscle strength, decreased muscle tone or impaired mobility, which can compromise pulmonary function and the ability to handle secretions. Although they represent a small fraction of the general pediatric population, children with neurologic disorders make up a disproportionately high number of those children who are hospitalized and die as a result of influenza-associated complications. Annual vaccination is the most effective way to prevent influenza and its complications, and is recommended for all children 6 months through 18 years of age, including children with neurologic disorders. Family members and those who work with these children in institutional, educational and daycare settings should also be vaccinated against influenza annually. However, there have been few studies of influenza vaccination specifically in this population. In addition, vaccine effectiveness may vary from year to year and vaccination will not prevent all infections. Early empiric antiviral treatment should be started promptly in these children if they present to healthcare providers with symptoms suspicious for influenza. This article reviews influenza epidemiology in children with neurologic disorders and what is known about vaccines and other methods of protecting this vulnerable population from influenza-related complications.

Morbidity of peripherally inserted central catheters in pediatric complicated appendicitis

BACKGROUND

The purpose of this study was to compare postoperative outcomes of pediatric patients with complicated appendicitis managed with or without a peripherally inserted central catheter (PICC).

METHODS

Patients aged ≤18 y in the Pediatric Health Information System database with complicated appendicitis that underwent appendectomy during their index admission in 2000-2012 were grouped by whether they had a PICC placed using relevant procedure and billing codes. Rates of subsequent encounters within 30 d of discharge along with associated diagnoses and procedures were determined. A propensity score-matched (PSM) analysis was performed to account for differences in baseline exposures and severity of illness.

RESULTS

We included 33,482 patients with complicated appendicitis; of whom, 6620 (19.8%) received a PICC and 26,862 (80.2%) did not. The PICC group had a longer postoperative length of stay (median 7 versus 5 d, P<0.001) and were more likely to undergo intra-abdominal abscess drainage during the index admission (14.4% versus 2.1%, P<0.001), and have a reencounter (17.5% versus 11.4%, P<0.001) within 30 d of discharge. However, in the PSM cohort (n=4428 in each group), outcomes did not differ between treatment groups, although the PICC group did have increased odds for the development of other postoperative complications (odds ratio=3.95, 95% confidence interval: 1.45, 10.71).

CONCLUSIONS

After accounting for differences in severity of illness by PSM, patients managed with PICCs had a similar risk for nearly all postoperative complications, including reencounters. Postoperative management of pediatric complicated appendicitis with a PICC is not clearly associated with improved outcomes.

Existing data analysis in pediatric critical care research

Our objectives were to review and categorize the existing data sources that are important to pediatric critical care medicine (PCCM) investigators and the types of questions that have been or could be studied with each data source. We conducted a narrative review of the medical literature, categorized the data sources available to PCCM investigators, and created an online data source registry. We found that many data sources are available for research in PCCM. To date, PCCM investigators have most often relied on pediatric critical care registries and treatment- or disease-specific registries. The available data sources vary widely in the level of clinical detail and the types of questions they can reliably answer. Linkage of data sources can expand the types of questions that a data source can be used to study. Careful matching of the scientific question to the best available data source or linked data sources is necessary. In addition, rigorous application of the best available analysis techniques and reporting consistent with observational research standards will maximize the quality of research using existing data in PCCM.

The burden of seasonal and pandemic influenza in infants and children

The burden of influenza is unevenly distributed, with more severe outcomes in children aged <5 years than older children and adults. In spite of this, immunisation policies for young children are far from universal. This article provides an overview of the published evidence on the burden of influenza in children worldwide, with a particular interest in the impact of pandemic influenza in 2009-2010 (caused by the H1N1pdm09 virus). In an average season, up to 9.8 % of 0- to 14-year olds present with influenza, but incidence rates can be markedly higher in younger children. Children aged <5 years have greater rates of hospitalisation and complications than their older counterparts, particularly if the children have co-existing illnesses; historically, this age group have had higher mortality rates from the disease than other children, although during the 2009-2010 pandemic the median age of those who died of influenza was higher than in previous seasons. Admissions to hospital and emergency departments appear to have been more frequent in children with H1N1pdm09 infections than during previous seasonal epidemics, with pneumonia continuing to be a common complication in this setting. Outcomes in children hospitalised with severe disease also seem to have been worse for those infected with H1N1pdm09 viruses compared with seasonal viruses. Studies in children confirm that vaccination reduces the incidence of seasonal influenza and the associated burden, underlining the importance of targeting this group in national immunisation policies.

CONCLUSIONS

Children aged <5 years are especially vulnerable to influenza, particularly that caused by seasonal viruses, and vaccination in this group can be an effective strategy for reducing disease burden.

Antiviral treatment and vaccination for influenza A(H1N1)pdm09 virus: lessons learned from the pandemic

The influenza pandemic that was declared by the World Health Organization in June 2009 created a new scenario for the use of influenza antivirals and vaccination. The new strain, influenza A(H1N1)pdm09, was resistant to amantadine and rimantadine, and the most frequently used antiviral was oseltamivir. Randomized studies were not performed comparing neuraminidase inhibitors with placebo. Nevertheless, experience from prospective and retrospective cohorts indicated that these drugs were useful for improving the prognosis of patients admitted to hospitals, especially for those with more severe disease. Treatment with oseltamivir was associated with a reduction in days of fever, length of hospital stay, use of mechanical ventilation and mortality. Treatment was more effective if it was begun within the first 48 h after the onset of symptoms, but it was also useful if begun later. A safe and effective vaccine to prevent disease from this new influenza strain was available in developed countries soon after the pandemic began; thus, the rate of adverse effects was comparable to that of seasonal influenza vaccines. The main barrier to its use was the concern of target populations about its necessity and safety. Therefore, the challenges for future pandemics will be to increase the population coverage of the vaccine in developed countries and to make it affordable for developing countries.

Neuraminidase inhibitors for critically ill children with influenza

OBJECTIVE

Timely treatment with neuraminidase inhibitor (NAI) drugs appears to improve survival in adults hospitalized with influenza. We analyzed California surveillance data to determine whether NAI treatment improves survival in critically ill children with influenza.

METHODS

We analyzed data abstracted from medical records to characterize the outcomes of patients aged 0 to 17 years hospitalized in ICUs with laboratory-confirmed influenza from April 3, 2009, through September 30, 2012.

RESULTS

Seven hundred eighty-four influenza cases aged <18 years hospitalized in ICUs had information on treatment. Ninety percent (532 of 591) of cases during the 2009 H1N1 pandemic (April 3, 2009-August 31, 2010) received NAI treatment compared with 63% (121 of 193) of cases in the postpandemic period (September 1, 2010-September 30, 2012; P < .0001). Of 653 cases NAI-treated, 38 (6%) died compared with 11 (8%) of 131 untreated cases (odds ratio = 0.67, 95% confidence interval: 0.34-1.36). In a multivariate model that included receipt of mechanical ventilation and other factors associated with disease severity, the estimated risk of death was reduced in NAI-treated cases (odds ratio 0.36, 95% confidence interval: 0.16-0.83). Treatment within 48 hours of illness onset was significantly associated with survival (P = .04). Cases with NAI treatment initiated earlier in illness were less likely to die.

CONCLUSIONS

Prompt treatment with NAIs may improve survival of children critically ill with influenza. Recent decreased frequency of NAI treatment of influenza may be placing untreated critically ill children at an increased risk of death.

Oseltamivir treatment for influenza in hospitalized children without underlying diseases

AIM

To determine whether the treatment with oseltamivir improves the outcome of children with confirmed influenza infection and no other underlying disease.

METHODS

Multicentric, retrospective study performed in 10 hospitals of Madrid between September 2010 and June 2012. All children admitted to the hospitals with confirmed influenza infections were eligible. Children with risk factors for serious disease and nosocomial influenza infections were excluded. Asthma was not considered an exclusion factor. The study compared patients treated and untreated with oseltamivir. Fever duration, oxygen support, antibiotics administration, length of hospital stay, intensive care admission and bacterial complications were analyzed. To compare variables, χ(2) test, Fisher exact test, ANOVA or Mann-Whitney U test were used.

RESULTS

Two hundred eighty-seven children were included and 93 of them were treated with oseltamivir (32%). There were no significant differences between treated and untreated patients in days of fever after admission (1.7 ± 2; 2.1 ± 2.9, P > 0.05), length of stay (5.2 ± 3.6; 5.5 ± 3.4, P > 0.05), days of hypoxia (1.6 ± 2.3; 2.1 ± 2.9, P > 0.05), diagnosis of bacterial pneumonia (10%; 17%, P > 0.05), intensive care admission (6.5%; 1.5%,P > 0.05) or antibiotic prescription (44%; 51%, P > 0.05). There were no differences when the population was stratified by age (below or over 1 year) or by the presence or absence of asthma.

CONCLUSIONS

There were no proven benefits of treatment with oseltamivir in hospitalized pediatric patients without the underlying diseases or risk factors for developing a serious illness, including those with asthma.

Complications and associated bacterial coinfections among children hospitalized with seasonal or pandemic influenza, United States, 2003-2010

BACKGROUND

Data on the range and severity of influenza-associated complications among children are limited. We describe the frequency and severity of complications in hospitalized children aged <18 years with seasonal influenza (during 2003-2009) and 2009 pandemic influenza A(H1N1) (during 2009-2010).

METHODS

Population-based surveillance for laboratory-confirmed influenza hospitalizations was conducted among 5.3 million children in 10 states. Complications were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes in medical records.

RESULTS

During 2003-2010, 7293 children hospitalized with influenza were identified, of whom 6769 (93%) had complete ICD-9 code data. Among the 6769 children, the median length of hospitalization was 3 days (interquartile range, 2-4 days), 975 (14%) required intensive care, 359 (5%) had respiratory failure, and 40 (1%) died. The most common complications were pneumonia (in 28% of children), asthma exacerbations (in 22% [793/3616] aged ≥ 2 years), and dehydration (in 21%). Lung abscess/empyema, tracheitis, encephalopathy, bacteremia/sepsis, acute renal failure, and myocarditis were rare (each ≤ 2% of children) but associated with a median hospitalization duration of ≥ 6 days, and 48%-70% of children required intensive care. Bacterial cultures with positive results were identified in 2% of children (107/6769); Staphylococcus aureus and Streptococcus pneumoniae were most commonly identified.

CONCLUSIONS

Complications contribute substantially to the disease burden among children hospitalized with influenza, through intensive care requirements and prolonged hospitalization, highlighting the importance of primary prevention with influenza vaccination.