The burden of influenza illness in children with asthma and other chronic medical conditions

Factors Associated with Antiviral Drug Use Among Commercially Insured Children at High Risk for Complications of Influenza

OBJECTIVES

To evaluate the prevalence of antiviral drug use in children in the US with influenza at high risk for complications and to identify factors associated with dispensing.

STUDY DESIGN

We conducted a retrospective cohort study of outpatient visits for individuals < 18 years during the 2016-2020 influenza seasons using the Merative MarketScan Commercial Claims and Encounter database. High-risk status was defined using Infectious Disease Society of America definitions and included: age, specific comorbidities, pregnancy or postpartum status, and living in a long-term care facility. The primary outcome was antiviral (oseltamivir, zanamivir, baloxavir) dispensing within 2 days of influenza diagnosis. We determined clinical factors associated with antiviral dispensing using modified Poisson regression.

RESULTS

A total of 372 372 influenza episodes were identified among 331 389 children at high risk for influenza complications and included in this study. The median (IQR) age was 4.0 years (2.0, 9.0). Overall, during 201 638 (54.1%) episodes of the influenza, antiviral treatment was dispensed. Factors associated with increased antiviral use included asthma, West and South US geographic regions, urgent care settings, and specific health insurance plans. Factors associated with decreased antiviral use include younger age, emergency department setting, Midwest and Northeast geographic regions, and health insurance plans.

CONCLUSION

Despite national guidelines recommending that all children at high risk for influenza complications receive antiviral treatment, nearly half of these children at high-risk did not receive an antiviral in our study. We identify several factors associated with decreased antiviral treatment that may serve to inform future interventions aiming to improve the care of vulnerable children with influenza.

Congenital Heart Defects and Concurrent Diagnoses in Influenza Hospitalization in the Pediatric Health Information System Study, 2004-2019

Influenza is associated with adverse outcomes in children, although modification by additional medical conditions is not well-documented. We aimed to compare outcomes in children with versus without congenital heart defects (CHDs) who were hospitalized for influenza. We retrospectively evaluated patients 1-18y hospitalized for influenza in the Pediatric Health Information (PHIS) database from 2004 to 2019. Outcomes were compared by CHD presence and then by CHD severity (minor biventricular, major biventricular, and single ventricle disease) using log-binomial regression adjusted for propensity scores accounting for age at admission, sex, and history of asthma. Outcomes included inpatient mortality, intensive care unit (ICU) admission, mechanical ventilation, and length of stay (LOS) > 12 days. To evaluate for effect modification by genetic diagnoses, analyses were repeated stratified by CHD and genetic diagnosis. Among 55,161 children hospitalized for influenza, 2369 (4.3%) had CHDs, including 963 with minor biventricular, 938 with major biventricular, and 468 with single ventricle CHDs. Adjusting for propensity scores, children with CHDs had higher mortality (4.1% versus 0.9%) compared to those without CHDs (risk ratio [RR] 2.5, 95% confidence interval [CI] 1.9-3.4). Children with CHDs were at higher risk of mechanical ventilation (RR 1.6, 95% CI 1.6-1.7), ICU admission (RR 1.9, 95% CI 1.8-2.1), and LOS > 12 days (RR 2.2, 95% CI 2.0-2.3). Compared to those with neither CHD nor genetic condition, children with both had significantly higher risk of all outcomes, with the largest difference for LOS > 12 days (RR 2.3, 95% CI 2.0-2.7). Children with CHDs hospitalized for influenza are particularly susceptible to adverse outcomes compared to those without CHDs. Future studies are needed to corroborate findings in light of influenza vaccination.

Predictors of Severity of Influenza-Related Hospitalizations: Results From the Global Influenza Hospital Surveillance Network (GIHSN)

BACKGROUND

The Global Influenza Hospital Surveillance Network (GIHSN) has since 2012 provided patient-level data on severe influenza-like-illnesses from >100 participating clinical sites worldwide based on a core protocol and consistent case definitions.

METHODS

We used multivariable logistic regression to assess the risk of intensive care unit admission, mechanical ventilation, and in-hospital death among hospitalized patients with influenza and explored the role of patient-level covariates and country income level.

RESULTS

The data set included 73 121 patients hospitalized with respiratory illness in 22 countries, including 15 660 with laboratory-confirmed influenza. After adjusting for patient-level covariates we found a 7-fold increase in the risk of influenza-related intensive care unit admission in lower middle-income countries (LMICs), compared with high-income countries (P = .01). The risk of mechanical ventilation and in-hospital death also increased by 4-fold in LMICs, though these differences were not statistically significant. We also find that influenza mortality increased significantly with older age and number of comorbid conditions. Across all severity outcomes studied and after controlling for patient characteristics, infection with influenza A/H1N1pdm09 was more severe than with A/H3N2.

CONCLUSIONS

Our study provides new information on influenza severity in underresourced populations, particularly those in LMICs.

The impact of anthropogenic climate change on pediatric viral diseases

The adverse effects of climate change on human health are unfolding in real time. Environmental fragmentation is amplifying spillover of viruses from wildlife to humans. Increasing temperatures are expanding mosquito and tick habitats, introducing vector-borne viruses into immunologically susceptible populations. More frequent flooding is spreading water-borne viral pathogens, while prolonged droughts reduce regional capacity to prevent and respond to disease outbreaks with adequate water, sanitation, and hygiene resources. Worsening air quality and altered transmission seasons due to an increasingly volatile climate may exacerbate the impacts of respiratory viruses. Furthermore, both extreme weather events and long-term climate variation are causing the destruction of health systems and large-scale migrations, reshaping health care delivery in the face of an evolving global burden of viral disease. Because of their immunological immaturity, differences in physiology (e.g., size), dependence on caregivers, and behavioral traits, children are particularly vulnerable to climate change. This investigation into the unique pediatric viral threats posed by an increasingly inhospitable world elucidates potential avenues of targeted programming and uncovers future research questions to effect equitable, actionable change. IMPACT: A review of the effects of climate change on viral threats to pediatric health, including zoonotic, vector-borne, water-borne, and respiratory viruses, as well as distal threats related to climate-induced migration and health systems. A unique focus on viruses offers a more in-depth look at the effect of climate change on vector competence, viral particle survival, co-morbidities, and host behavior. An examination of children as a particularly vulnerable population provokes programming tailored to their unique set of vulnerabilities and encourages reflection on equitable climate adaptation frameworks.

Short Message Service Reminder Nudge for Parents and Influenza Vaccination Uptake in Children and Adolescents With Special Risk Medical Conditions: The Flutext-4U Randomized Clinical Trial

Importance

Children with chronic medical conditions are at increased risk of severe influenza. Uptake of influenza vaccination in children and adolescents with these identified special risk medical conditions (SRMCs) is suboptimal.

Objective

To assess the effectiveness of Flutext-4U, a parent short message service (SMS) reminder nudge intervention, in increasing influenza immunization in children and adolescents with SRMCs.

Design, Setting, and Participants

This randomized clinical trial was conducted at a tertiary pediatric hospital in Adelaide, South Australia, from April 15 to September 30, 2021. Children and adolescents aged 6 months to younger than 18 years with SRMCs and a subspecialist outpatient appointment over a 5-month period during the Australian seasonal influenza vaccination season (April-August 2021) were eligible to participate. Follow-up was until September 30, 2021.

Interventions

Participants were randomly assigned (1:1 ratio) to control: clinician nudges (hospital vaccine availability, ease of access, and recommendation from hospital subspecialists) or SMS intervention (control conditions plus an additional SMS reminder nudge to parents), with randomization stratified by age group (<5 years, 5-14 years, or >14 to <18 years).

Main Outcomes and Measures

The primary outcome was influenza vaccination, as confirmed by the Australian Immunisation Register.

Results

A total of 600 participants (intervention group: 298 [49.7%]; mean [SD] age, 11.5 [4.6] years; 162 female participants [54.4%]; control group: 302 [50.3%]; mean [SD] age, 11.4 [4.7] years; 155 female participants [51.3%]) were included. Influenza vaccination was 38.6% (113 of 293) in the SMS intervention group compared with 26.2% (79 of 302) in the control group (adjusted odds ratio [aOR], 1.79; 95% CI, 1.27-2.55; P = .001). Time to vaccine receipt was significantly lower among SMS participants (adjusted hazard ratio, 1.67; 95% CI, 1.25-2.22; P < .001). For participants randomly assigned by June 15, a significantly greater proportion receiving the SMS intervention were vaccinated during the optimal delivery period April to June 30 (SMS group: 40.0% [76 of 190] vs 25.4% [50 of 197]; aOR, 1.97; 95% CI, 1.28-3.06; P = .002).

Conclusions and Relevance

Results of this randomized clinical trial suggest that an additional SMS reminder nudge for parents delivered in the tertiary care hospital setting to children and adolescents with SMRCs resulted in higher influenza vaccine uptake compared with clinician nudges alone.

Trial Registration

ANZCTR Identifier: ACTRN12621000463875.

Days of Flooding Associated with Increased Risk of Influenza

Influenza typically causes mild infection but can lead to severe outcomes for those with compromised lung health. Flooding, a seasonal problem in Iowa, can expose many Iowans to molds and allergens shown to alter lung inflammation, leading to asthma attacks and decreased viral clearance. Based on this, the hypothesis for this research was that there would be geographically specific positive associations in locations with flooding with influenza diagnosis. An ecological study was performed using influenza diagnoses and positive influenza polymerase chain reaction tests from a de-identified large private insurance database and Iowa State Hygienic Lab. After adjustment for multiple confounding factors, Poisson regression analysis resulted in a consistent 1% associated increase in influenza diagnoses per day above flood stage (95% confidence interval: 1.00–1.04). This relationship remained after removal of the 2009–2010 influenza pandemic year. There was no associated risk between flooding and influenza-like illness as a nonspecific diagnosis. Associated risks between flooding and increased influenza diagnoses were geographically specific, with the greatest risk in the most densely populated areas. This study indicates that populations who live, work, or volunteer in flooded environments should consider preventative measures to avoid environmental exposures to mitigate illness from influenza in the following year.

Influenza-Related Knowledge, Beliefs, and Experiences Among Caregivers of Hospitalized Children

OBJECTIVE

Caregivers frequently decline influenza vaccine for their hospitalized child. In this study, we aimed to examine factors impacting their influenza vaccine decision-making.

METHODS

We conducted a cross-sectional survey study of English- and Spanish-speaking caregivers of children hospitalized at a tertiary care pediatric hospital between November 2017 and April 2018. The survey assessed influenza-related knowledge, beliefs, experiences, and vaccine hesitancy. Multivariable logistic regression examined associations between survey responses and child influenza vaccination status at admission (already vaccinated versus not yet vaccinated this season) and, among caregivers with vaccine-eligible children, influenza vaccine acceptance (versus declination) for their child during hospitalization.

RESULTS

Caregivers (N =522; 88.9% response rate) were mostly non-Hispanic white (66.9%) and English-speaking (97.7%). At admission, 63.2% of children were already vaccinated this season. The caregiver view that influenza vaccination is important for their child's health was the strongest positive predictor of having an already vaccinated child (adjusted odds ratio [aOR]: 3.16; 95% confidence interval [CI]: 2.46-4.05); vaccine hesitancy was the strongest negative predictor (aOR: 0.61; 95% CI: 0.50-0.75). Among caregivers with vaccine-eligible children, 30.3% accepted influenza vaccine for their hospitalized child. Their belief regarding the child health benefits of influenza vaccination was associated with vaccine acceptance during hospitalization (aOR: 6.87; 95% CI: 3.38-13.96). Caregiver vaccine hesitancy and agreement that children with mild illness should delay vaccination negatively impacted vaccine acceptance (aOR: 0.39; 95% CI: 0.25-0.62; aOR: 0.33; 95% CI: 0.20-0.56, respectively).

CONCLUSIONS

We identified key factors impacting influenza vaccine decision-making among caregivers of hospitalized children, a critical step to improving uptake in this population.

Association between asthma and influenza vaccine uptake among US adolescents: a retrospective survey study

OBJECTIVE

Despite longstanding recommendations for children with asthma to receive the influenza vaccine, vaccine uptake in this population remains low. We used the nationally representative National Immunization Survey-Teen to analyze the impact of asthma on adolescent influenza vaccination rates.

METHODS

Adolescents ages 13-17 years with provider-reported data on vaccine coverage were included in the analysis. The primary outcome was being up-to-date on influenza vaccination, defined as receiving the seasonal influenza vaccine in at least one of the past 3 years, and was analyzed using logistic regression. Asthma was defined by parent report of whether the adolescent has ever been told by a health professional that he or she has asthma. Data were collected in 2016-2017 and analyzed in 2020.

RESULTS

Of 36,655 adolescents in the analytic sample (mean age 15 years, 49% female), 55% were up-to-date on influenza vaccination, and 21% had been diagnosed with asthma. On bivariate analysis, vaccination was more common among adolescents who had been diagnosed with asthma compared to those who were not (60% vs. 53%, P < 0.001). On multivariable analysis, asthma diagnosis was associated with greater likelihood of being up-to-date on seasonal influenza vaccination (adjusted odds ratio: 1.29; 95% confidence interval: 1.22, 1.36; P < 0.001).

CONCLUSIONS

Seasonal influenza vaccination rates remain low among adolescents. Despite concerns about vaccine effectiveness in children with asthma, this diagnosis was associated with increased likelihood of influenza vaccination, possibly in relation to increased health care use (and exposure to vaccine encouragement) among adolescents with asthma.

A paucigranulocytic asthma host environment promotes the emergence of virulent influenza viral variants

Influenza virus has a high mutation rate, such that within one host different viral variants can emerge. Evidence suggests that influenza virus variants are more prevalent in pregnant and/or obese individuals due to their impaired interferon response. We have recently shown that the non-allergic, paucigranulocytic subtype of asthma is associated with impaired type I interferon production. Here, we seek to address if this is associated with an increased emergence of influenza virus variants. Compared to controls, mice with paucigranulocytic asthma had increased disease severity and an increased emergence of influenza virus variants. Specifically, PB1 mutations exclusively detected in asthmatic mice were associated with increased polymerase activity. Furthermore, asthmatic host-derived virus led to increased disease severity in wild-type mice. Taken together, these data suggest that at least a subset of patients with asthma may be more susceptible to severe influenza and may be a possible source of new influenza virus variants.

Knowledge, attitudes, and practices of seasonal influenza vaccination in postpartum women, Honduras

Background

Influenza during pregnancy may cause serious neonatal outcomes including stillbirth, fetal distress, preterm birth, congenital abnormalities, and stunted growth. Pregnant women are the highest priority group for seasonal influenza vaccination, but low coverage has been repeatedly reported in this population. Understanding reasons for and for not receiving the seasonal influenza vaccine is needed to design communication strategies to increase vaccination coverage. This study aimed to describe knowledge, attitudes, and practices (KAP) of seasonal influenza vaccination among women giving birth in public maternity hospitals in Honduras.

Methods

From August 20–October 8, 2018, we conducted a cross-sectional KAP survey regarding seasonal influenza vaccinations to a sample of postpartum women who gave birth in maternity hospitals and clinics from the Ministry of Health of Honduras and Honduran Social Security Institute. We reported frequency distributions for demographics, KAP of influenza vaccine, and vaccination coverage. We used logistic regression to analyze unadjusted and adjusted associations between sociodemographic characteristics and influenza vaccination.

Results

We surveyed 842 postpartum women in 17 healthcare facilities. Of 534 postpartum women with term pregnancy and verified vaccinations, 417 (78.1%; 95% CI: 74.6–81.6%) were vaccinated for influenza. Factors associated with verified influenza vaccination included receipt of vaccination recommendations by a healthcare worker during prenatal check-ups (aOR: 16.46; 95% CI: 9.73–27.85), concurrent chronic disease (aOR: 5.00; 95% CI: 1.25–20.07), and influenza vaccination of other children in the household (aOR: 2.28; 95% CI: 1.19–4.39). The most cited reasons for vaccination were perceived benefits for both mother and infant and easy access. Reasons for non-vaccination were: vaccine was not offered and fear of side effects, harm to the infant, and needles or pain caused by injection.

Conclusion

Influenza vaccination was well received among postpartum women in Honduras. Increasing clinician recommendations for vaccination and assuring the vaccine is readily available to women during prenatal visits may increase vaccination rates.

Influenza in Children

Influenza poses a significant disease burden on children worldwide, with high rates of hospitalization and substantial morbidity and mortality. Although the clinical presentation of influenza in children has similarities to that seen in adults, there are unique aspects to how children present with infection that are important to recognize. In addition, children play a significant role in viral transmission within communities. Growing evidence supports the idea that early influenza infection can uniquely establish lasting immunologic memory, making an understanding of how viral immunity develops in this population critical to better protect children from infection and to facilitate efforts to develop a more universally protective influenza vaccine.

Impact of congenital heart disease on outcomes among pediatric patients hospitalized for influenza infection

Background

Young children and those with chronic medical conditions are at risk for complications of influenza including cardiopulmonary compromise. Here we aim to examine risks of mortality, clinical complications in children with congenital heart disease (CHD) hospitalized for influenza.

Methods

We analyzed data from in-hospital pediatric patients from 2003, 2006, 2009, 2012 and 2016 using the nationally representative Kids Inpatient Database (KID). We included children 1 year and older and used weighted data to compare the incidence of in-hospital mortality and rates of complications such as respiratory failure, acute kidney injury, need for mechanical ventilation, arrhythmias and myocarditis.

Results

Data from the KID estimated 125,470 children who were admitted with a diagnosis of influenza infection. Out of those, 2174(1.73%) patients had discharge diagnosis of CHD. Children with CHD who required hospitalization for influenza had higher in-hospital mortality (2.0% vs 0.5%), with an adjusted OR (aOR) of 2.8 (95% CI: 1.7–4.5). Additionally, acute respiratory failure and acute kidney failure were more likely among patients with CHD, with aOR of 1.8 (95% CI: 1.5–2.2) and aOR of 2.2 (95% CI: 1.5–3.1), respectively. Similarly, the rate of mechanical ventilatory support was higher in patients with CHD compared to those without, 14.1% vs 5.6%, aOR of 1.9 (95% CI: 1.6–2.3). Median length of hospital stay in children with CHD was longer than those without CHD [4 (IQR: 2–8) days vs. 2 (IQR: 2–4) days]. Outcomes were similar between those with severe vs non-severe CHD.

Conclusions

Children with CHD who require hospital admission for influenza are at significantly increased risk for in-hospital mortality, morbidities, emphasizing the need to reinforce preventative measures (e.g. vaccination, personal hygiene) in this particularly vulnerable population.

Respiratory viruses in pediatric emergency department patients and their family members

Background

Respiratory viral infections account for a substantial fraction of pediatric emergency department (ED) visits. We examined the epidemiological patterns of seven common respiratory viruses in children presenting to EDs with influenza‐like illness (ILI). Additionally, we examined the co‐occurrence of viral infections in the accompanying adults and risk factors associated with the acquisition of these viruses.

Methods

Nasopharyngeal swab were collected from children seeking medical care for ILI and their accompanying adults (Total N = 1315). Study sites included New York Presbyterian, Bellevue, and Tisch hospitals in New York City. PCR using a respiratory viral panel was conducted, and data on symptoms and medical history were collected.

Results

Respiratory viruses were detected in 399 children (62.25%) and 118 (17.5%) accompanying adults. The most frequent pathogen detected was human rhinovirus (HRV) (28.81%). Co‐infection rates were 14.79% in children and 8.47% in adults. Respiratory syncytial virus (RSV) and parainfluenza infections occurred more often in younger children. Influenza and HRV occurred more often in older children. Influenza and coronavirus were mostly isolated in winter and spring, RSV in fall and winter and HRV in fall and spring. Children with HRV were more likely to have history of asthma. Adults with the same virus as their child often accompanied ≤ 2‐year‐old‐positive children and were more likely to be symptomatic compared to adults with different viruses.

Conclusions

Respiratory viruses, while presenting the same suite of symptoms, possess distinct seasonal cycles and affect individuals differently based on a number of identifiable factors, including age and history of asthma.

Serious outcomes of medically attended, laboratory-confirmed influenza illness among school-aged children with and without asthma, 2007-2018

Background

Asthma was associated with influenza hospitalizations in children during the 2009 pandemic, but it is unclear if asthma is associated with serious illness during seasonal epidemics. Little is known regarding the effect of vaccination on influenza severity in children with asthma.

Methods

Children aged 5‐17 years in a community cohort presenting with acute respiratory illness were prospectively enrolled and tested for influenza from 2007‐08 through 2017‐18 (excluding the 2009‐10 pandemic season). Data from the electronic health record were extracted to determine asthma status and serious outcomes associated with influenza infection. A serious outcome was defined as hospitalization, emergency department visit, and/or pneumonia diagnosis within 30 days of symptom onset. Multivariable logistic regression models were used to assess asthma status and effect of vaccination on odds of a serious outcome.

Results

One thousand seven hundred and sixty four medically‐attended influenza infections among school‐aged children were included. Asthma was confirmed in 287 (16%) children. A serious influenza‐associated outcome occurred in 104 (6%) children. The odds of a serious outcome did not differ between those with confirmed asthma and those without asthma [adjusted odds ratio (aOR): 1.35, 95% confidence interval (CI): (0.77‐2.35), P = .3]. The effect of vaccination on serious outcomes was not modified by asthma status [aOR for children without asthma: 0.55 (95% CI: 0.28‐1.07), children with asthma: 1.39 (95% CI: 0.53‐3.69); interaction P‐value = .12].

Conclusions

Asthma was not a risk factor for serious illness among children with influenza. Additional studies are needed to better understand the role of influenza vaccination in preventing serious outcomes among children with asthma.

Decreased Risk of Influenza in Child and Adolescent Patients with Attention-Deficit Hyperactivity Disorder Following Methylphenidate Treatment: A Nationwide Cohort Study in Taiwan

BACKGROUND

Young individuals with attention-deficit hyperactivity disorder (ADHD) may have an elevated risk of influenza because of the difficulty in complying with the behavioral procedures that help protect against influenza. Moreover, the effects of sufficient methylphenidate treatment on influenza have received little attention.

OBJECTIVE

This study evaluated the association between ADHD medication usage and influenza and assessed the effect of duration of ADHD treatment on the risk of influenza using a nationwide population-based database.

METHODS

This study investigated methylphenidate usage and the risk of influenza among children and adolescents with ADHD. We identified 5259 young individuals aged less than 18 years who were diagnosed as having ADHD between 1996 and 2013 from the National Health Insurance Research Database of Taiwan, and we tested whether methylphenidate use affects influenza risk using Cox proportional hazard models.

RESULTS

After controlling for confounding factors, the results indicated that influenza risk significantly reduced in the group of ADHD patients who were prescribed methylphenidate for 90 days and more (hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.52-0.75, p<0.001), demonstrating a 38% reduction in the risk of influenza in this group. However, this was not observed in the group of ADHD patients who used methylphenidate for 1-90 days (HR: 0.69, 95% CI: 0.89-1.05, p=0.12).

CONCLUSION

The lower incidence of influenza observed in the group prescribed with methylphenidate for a longer period highlights the importance of compliance to medication and psychoeducation with regard to ADHD management.

Using big data to predict pertussis infections in Jinan city, China: a time series analysis

This study aims to use big data (climate data, internet query data and school calendar patterns (SCP)) to improve pertussis surveillance and prediction, and develop an early warning model for pertussis epidemics. We collected weekly pertussis notifications, SCP, climate and internet search query data (Baidu index (BI)) in Jinan, China between 2013 and 2017. Time series decomposition and temporal risk assessment were used for examining the epidemic features in pertussis infections. A seasonal autoregressive integrated moving average (SARIMA) model and regression tree model were developed to predict pertussis occurrence using identified predictors. Our study demonstrates clear seasonal patterns in pertussis epidemics, and pertussis activity was most significantly associated with BI at 2-week lag (r_BI = 0.73, p < 0.05), temperature at 1-week lag (r_temp = 0.19, p < 0.05) and rainfall at 2-week lag (r_rainfall = 0.27, p < 0.05). No obvious relationship between pertussis peaks and school attendance was found in the study. Pertussis cases were more likely to be temporally concentrated throughout the epidemics during the study period. SARIMA models with 2-week-lagged BI and 1-week-lagged temperature had better predictive performance (β_{search query} = 0.06, p = 0.02; β_temp = 0.16, p = 0.03) with large correlation coefficients (r = 0.67, p < 0.01) and low root mean squared error (RMSE) value (r = 3.59). The regression tree model identified threshold values of potential predictors (search query, climate and SCP) for pertussis epidemics. Our results showed that internet query in conjunction with social and climatic data can predict pertussis epidemics, which is a foundation of using such data to develop early warning systems.

Exploring strategies to promote influenza vaccination of children with medical comorbidities: the perceptions and practices of hospital healthcare workers

BACKGROUND

To explore how the influenza vaccine is promoted and delivered to children with medical comorbidities in the hospital setting, as well as the facilitators of and barriers to vaccination from the healthcare worker perspective.

METHODS

Semi-structured interviews were conducted with staff members (n = 17) at a paediatric hospital in Sydney, Australia between April and July 2018. This included nurses, clinical nurse consultants, pediatricians and department heads. The interviews were transcribed and analysed iteratively to generate the major themes.

RESULTS

Approaches used to promote and/or deliver the influenza vaccine varied among the participants. Some described the vaccine as an ingrained component of their clinical consultation. Others acknowledged that there was missed opportunities to discuss or provide the vaccine, citing competing priorities as well as a lack of awareness, time and resources. Participants perceived that some parents had concerns about safety and appropriateness of the vaccine for their child. While there was some support for sending reminders and/or educating patients through the hospital, there were differing perspectives on whether tertiary centres should be delivering the vaccine.

CONCLUSION

Hospital-based interventions to increase vaccine uptake must consider the needs of staff. Easily accessible information and increased awareness of the recommendations among staff may lead to improved uptake in this hospital. Additional resources would be required to increase on-site delivery of the vaccine.

High expression levels of influenza virus receptors in airway of the HBV-transgenic mice

In the human population, influenza A viruses are associated with acute respiratory illness and are responsible for millions of deaths annually. Avian and human influenza viruses typically have a different α2-3- and α2-6-linked sialic acid (SA) binding preference. Only a few amino acid changes in the haemagglutinin on the surface of avian influenza viruses (AIV) can cause a switch from avian to human receptor specificity, and the individuals with pathognostic chronic diseases might be more susceptible to AIV due to the decreased expression level of terminal α2-3-linked SA in their saliva. Here, using lectin and virus histochemical staining, we observed the higher expression levels of α2-3/6-linked SA influenza virus receptors in the airway of HBV-transgenic mice compared with that of control mice due to the significant decrease in control mice during ageing, which imply that this is also a risk factor for individuals with pathognostic chronic diseases susceptible to influenza viruses. Our findings will help understand the impact on influenza virus pathogenesis and transmission.

Parent Intent and Willingness to Immunize Children Against Influenza in the Pediatric Emergency Department

OBJECTIVES

To determine rates of influenza immunization among children treated in a pediatric emergency department (ED) and to ascertain parent willingness for children to receive influenza vaccine (IV) in the ED.

METHODS

Interviews were conducted with parents of children 6 months or older evaluated in the ED for minor illness or injury. Demographic data, IV history, and intent and willingness to receive future IV were recorded during the summer of 2013. Participants were contacted in March 2014 to assess IV status, barriers to obtaining IV, and willingness to obtain IV in the ED. Chart review determined number of patients who were at high risk.

RESULTS

Of 457 families approached, 285 (62%) were enrolled. Two hundred forty-two (85%) intended to vaccinate; 83% reported willingness to receive IV at a future ED visit. Common reasons for not receiving IV were concerns about adverse effects (31%) and lack of time or interest (24%). Of the 224 participants (79%) reached in follow-up, 112 (50%) had received IV in the prior season. Among those who did not receive IV, 65 (66%) had intended to vaccinate, and 54 (55%) indicated they would have accepted IV in the ED. Fifty-three (54%) of unvaccinated patients at follow-up had high risk of influenza complications.

CONCLUSIONS

Our data support an IV program in the pediatric ED as a means of increasing vaccination rates, particularly among high-risk patients. Parents are often concerned about adverse effects of IV, and providers should target education in this area.

Pediatric Inpatient Immunizations: A Literature Review

CONTEXT

Timely vaccine uptake in children remains suboptimal. Eliminating missed opportunities is key to increasing childhood immunization rates, and hospitalization offers another potential setting to vaccinate.

OBJECTIVE

To better understand pediatric inpatient immunization programs, including vaccination rates of inpatients, parental and provider attitudes, barriers to vaccine delivery, and interventions to increase provision of inpatient vaccines.

DATA SOURCES

A search was conducted of PubMed, Embase, and Web of Science to identify articles and conference abstracts related to pediatric inpatient immunization.

STUDY SELECTION

Inclusion criteria were studies published in English between January 1990 and January 2019 in which pediatric vaccination in the hospital setting was discussed. Findings from 30 articles and conference abstracts were summarized and organized by topic area.

DATA EXTRACTION

Abstracts were screened for relevance, articles were read, and themes were identified.

RESULTS

Children who are hospitalized have been shown to have lower immunization rates compared with the general population, with 27% to 84% of pediatric inpatients due or overdue for vaccines nationally when verified with official records. Unfortunately, little is done to catch up these children once they have been identified. Access to accurate vaccine histories remains a major barrier in inpatient immunization programs because providers frequently under document and parents over recall a child's vaccine status. Strategies identified to increase inpatient vaccination included creation of a multidisciplinary immunization team, educational interventions, visual reminders, catch-up vaccine plans, order sets, and nursing-driven screening. When offered inpatient vaccination, a majority of parents accepted immunizations for their children.

CONCLUSIONS

Hospitalization may provide an opportunity to augment vaccine uptake. Further research is needed to develop evidence-based strategies to overcome barriers to inpatient vaccination.

Evaluation of a novel micro/nanofluidic chip platform for the detection of influenza A and B virus in patients with influenza-like illness

We introduced a novel micro/nanofluidic chip platform (MNCP), which is based on an isothermal nucleic acid amplification method. This study aimed to evaluate the MNCP method for influenza A and B viruses detecting and subtyping using throat swab samples from patients with influenza-like illness (ILI). A total of 266 throat swab samples from 266 non-repeated patients with ILI were tested for influenza A and B viruses using three methods, MNCP, a rapid influenza diagnostic test (RIDT), and real-time reverse transcription polymerase chain reaction (rRT-PCR). The results of MNCP were compared to those obtained by rRT-PCR and RIDT and the performance of MNCP was further evaluated. Compared with rRT-PCR results, the rates of sensitivity, specificity, overall concordance, and the kappa value of MNCP were 98.89%, 96.97%, 97.65%, and 0.95 for influenza A virus; 94.95%, 99.38%, 97.68%, and 0.95 for influenza B virus, respectively. Subtypes of influenza A viruses, e.g., A(H1N1)pdm09, A(H3N2), and A(not subtyped), and influenza B viruses could be distinguished in one MNCP assay within 1 h. Compared with rRT-PCR and MNCP, RIDT showed poor clinical sensitivity for influenza virus detection. This study showed MNCP is rapid, sensitive and versatile detecting system with potential for clinical application in pathogen diagnosis for patients with ILI.

Impact of influenza on hospitalization rates in children with a range of chronic lung diseases

BACKGROUND

Data on burden of severe influenza in children with a range of chronic lung diseases (CLDs) remain limited.

METHOD

We performed a cohort study to estimate burden of influenza-associated hospitalization in children with CLDs using population-based linked data. The cohort comprised all children in New South Wales, Australia, born between 2001 and 2010 and was divided into five groups, children with: (a) severe asthma; (b) bronchopulmonary dysplasia (BPD); (c) cystic fibrosis (CF); (d) other congenital/chronic lung conditions; and (e) children without CLDs. Incidence rates and rate ratios for influenza-associated hospitalization were calculated for 2001-2011. Average cost/episode of hospitalization was estimated using public hospital cost weights.

RESULTS

Our cohort comprised 888 157 children; 11 058 (1.2%) had one of the CLDs. The adjusted incidence/1000 child-years of influenza-associated hospitalization in children with CLDs was 3.9 (95% CI: 2.6-5.2) and 0.7 (95% CI: 0.5-0.9) for children without. The rate ratio was 5.4 in children with CLDs compared to children without. The adjusted incidence/1000 child-years (95% CI) in children with severe asthma was 1.1 (0.6-1.6), with BPD was 6.0 (3.7-8.3), with CF was 7.4 (2.6-12.1), and with other congenital/chronic lung conditions was 6.9 (4.9-8.9). The cost/episode (95% CI) of influenza-associated hospitalization was AUD 19 704 (95% CI: 11 715-27 693) for children with CLDs compared to 4557 (95% CI: 4129-4984) for children without.

DISCUSSION

This large population-based study suggests a significant healthcare burden associated with influenza in children with a range of CLDs.

School-based self-management interventions for asthma in children and adolescents: a mixed methods systematic review

BACKGROUND

Asthma is a common respiratory condition in children that is characterised by symptoms including wheeze, shortness of breath, chest tightness, and cough. Children with asthma may be able to manage their condition more effectively by improving inhaler technique, and by recognising and responding to symptoms. Schools offer a potentially supportive environment for delivering interventions aimed at improving self-management skills among children. The educational ethos aligns with skill and knowledge acquisition and makes it easier to reach children with asthma who do not regularly engage with primary care. Given the multi-faceted nature of self-management interventions, there is a need to understand the combination of intervention features that are associated with successful delivery of asthma self-management programmes.

OBJECTIVES

This review has two primary objectives.• To identify the intervention features that are aligned with successful intervention implementation.• To assess effectiveness of school-based interventions provided to improve asthma self-management among children.We addressed the first objective by performing qualitative comparative analysis (QCA), a synthesis method described in depth later, of process evaluation studies to identify the combination of intervention components and processes that are aligned with successful intervention implementation.We pursued the second objective by undertaking meta-analyses of outcomes reported by outcome evaluation studies. We explored the link between how well an intervention is implemented and its effectiveness by using separate models, as well as by undertaking additional subgroup analyses.

SEARCH METHODS

We searched the Cochrane Airways Trials Register for randomised studies. To identify eligible process evaluation studies, we searched MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, the Cochrane Database of Systematic Reviews (CDSR), Web of Knowledge, the Database of Promoting Health Effectiveness Reviews (DoPHER), the Database of Abstracts of Reviews of Effects (DARE), the International Biography of Social Science (IBSS), Bibliomap, Health Technology Assessment (HTA), Applied Social Sciences Index and Abstracts (ASSIA), and Sociological Abstracts (SocAbs). We conducted the latest search on 28 August 2017.

SELECTION CRITERIA

Participants were school-aged children with asthma who received the intervention in school. Interventions were eligible if their purpose was to help children improve management of their asthma by increasing knowledge, enhancing skills, or changing behaviour. Studies relevant to our first objective could be based on an experimental or quasi-experimental design and could use qualitative or quantitative methods of data collection. For the second objective we included randomised controlled trials (RCTs) where children were allocated individually or in clusters (e.g. classrooms or schools) to self-management interventions or no intervention control.

DATA COLLECTION AND ANALYSIS

We used qualitative comparative analysis (QCA) to identify intervention features that lead to successful implementation of asthma self-management interventions. We measured implementation success by reviewing reports of attrition, intervention dosage, and treatment adherence, irrespective of effects of the interventions.To measure the effects of interventions, we combined data from eligible studies for our primary outcomes: admission to hospital, emergency department (ED) visits, absence from school, and days of restricted activity due to asthma symptoms. Secondary outcomes included unplanned visits to healthcare providers, daytime and night-time symptoms, use of reliever therapies, and health-related quality of life as measured by the Asthma Quality of Life Questionnaire (AQLQ).

MAIN RESULTS

We included 55 studies in the review. Thirty-three studies in 14,174 children provided information for the QCA, and 33 RCTs in 12,623 children measured the effects of interventions. Eleven studies contributed to both the QCA and the analysis of effectiveness. Most studies were conducted in North America in socially disadvantaged populations. High school students were better represented among studies contributing to the QCA than in studies contributing to effectiveness evaluations, which more commonly included younger elementary and junior high school students. The interventions all attempted to improve knowledge of asthma, its triggers, and stressed the importance of regular practitioner review, although there was variation in how they were delivered.QCA results highlighted the importance of an intervention being theory driven, along with the importance of factors such as parent involvement, child satisfaction, and running the intervention outside the child's own time as drivers of successful implementation.Compared with no intervention, school-based self-management interventions probably reduce mean hospitalisations by an average of about 0.16 admissions per child over 12 months (SMD -0.19, 95% CI -0.35 to -0.04; 1873 participants; 6 studies, moderate certainty evidence). They may reduce the number of children who visit EDs from 7.5% to 5.4% over 12 months (OR 0.70, 95% CI 0.53 to 0.92; 3883 participants; 13 studies, low certainty evidence), and probably reduce unplanned visits to hospitals or primary care from 26% to 21% at 6 to 9 months (OR 0.74, 95% CI 0.60 to 0.90; 3490 participants; 5 studies, moderate certainty evidence). Self-management interventions probably reduce the number of days of restricted activity by just under half a day over a two-week period (MD 0.38 days 95% CI -0.41 to -0.18; 1852 participants; 3 studies, moderate certainty evidence). Effects of interventions on school absence are uncertain due to the variation between the results of the studies (MD 0.4 fewer school days missed per year with self-management (-1.25 to 0.45; 4609 participants; 10 studies, low certainty evidence). Evidence is insufficient to show whether the requirement for reliever medications is affected by these interventions (OR 0.52, 95% CI 0.15 to 1.81; 437 participants; 2 studies; very low-certainty evidence). Self-management interventions probably improve children's asthma-related quality of life by a small amount (MD 0.36 units higher on the Paediatric AQLQ(95% CI 0.06 to 0.64; 2587 participants; 7 studies, moderate certainty evidence).

AUTHORS' CONCLUSIONS

School-based asthma self-management interventions probably reduce hospital admission and may slightly reduce ED attendance, although their impact on school attendance could not be measured reliably. They may also reduce the number of days where children experience asthma symptoms, and probably lead to small improvements in asthma-related quality of life. Many of the studies tested the intervention in younger children from socially disadvantaged populations. Interventions that had a theoretical framework, engaged parents and were run outside of children's free time were associated with successful implementation.

Parental Vaccine Hesitancy and Declination of Influenza Vaccination Among Hospitalized Children

OBJECTIVES

Parents frequently decline the influenza vaccine for their child during hospitalization. In this study, we aimed to assess the role of vaccine hesitancy in these declinations.

METHODS

This cross-sectional survey study was conducted among English-speaking parents of influenza vaccine-eligible children who were hospitalized between October 2014 and April 2015. Between July 2015 and September 2015, parents were recruited via mail to complete the validated Parent Attitudes about Childhood Vaccines (PACV) survey (modified for influenza vaccination). PACV scores (0-100 scale) were dichotomized into scores of ≥50 (hesitant) and <50 (nonhesitant). The primary outcome was parental declination of the influenza vaccine for their child during hospitalization. A secondary outcome was the declination reason documented during hospitalization. The main independent variable was parental vaccine hesitancy status, determined by the PACV score. Multivariable logistic regression was used to examine the association between vaccine hesitancy and influenza vaccine declination, adjusting for sociodemographic, visit, and clinical characteristics. The relationship between vaccine hesitancy and declination reason was also explored.

RESULTS

Of 199 parents (18% response rate), 24% were vaccine hesitant and 53% declined the influenza vaccine for their child during hospitalization. Vaccine hesitancy (versus nonhesitancy) was associated with declining influenza vaccination (adjusted odds ratio: 6.4; 95% confidence interval: 2.5-16.5). The declination reason differed by vaccine hesitancy status, with a higher proportion of parents who were hesitant versus nonhesitant reporting "vaccine concern" or "vaccine unnecessary."

CONCLUSIONS

Vaccine hesitancy was prevalent in this limited sample of parents of hospitalized children and associated with influenza vaccine declination. Additional investigation in a large, diverse, prospectively recruited cohort is warranted given the potential sampling bias present in this study.

Severe Obesity in Children May Not Pose Independent Risk for Influenza Complications

PURPOSE

Subsets of children are targeted for influenza vaccination due to known conditions that increase the risk of influenza complications. The purpose of this study was to determine if severe obesity in children suggests targeted vaccination.

DESIGN AND METHODS

A retrospective chart review of a large Midwestern pediatric hospital identified 188 cases of influenza complications (defined as requiring hospitalization or death) aged 2 to <20 years old from August 1, 2010 through June 30, 2013. Severe obesity was defined as body mass index (BMI) ≥99% for age and gender, with patients grouped by severe obesity status (yes vs. no). Cases were reviewed for previously identified risk conditions for influenza complications (e.g., asthma, pneumonia, diabetes), and were classified as having or not having a known high risk condition.

RESULTS

Of 188 cases, 174 (93%) had a high-risk condition, while only 14 (7%) had no known condition. All 14 (100%) with no known high-risk condition had a BMI <99%. All 15 (100%) with BMI ≥99% had a known high-risk condition. The association between severe obesity status and influenza complications was not statistically significant (p = 0.61).

CONCLUSIONS

This suggests that severe obesity in children is not an independent high-risk condition for influenza complications defined as requiring hospitalization or resulting in death, once other known influenza risk factors are considered.

IMPLICATIONS

Based on this data, clinicians should not target children for influenza vaccination based on weight status. We cannot comment about whether severe obesity represents increased risk for less severe cases of influenza.

Using Google Trends and ambient temperature to predict seasonal influenza outbreaks

BACKGROUND

The discovery of the dynamics of seasonal and non-seasonal influenza outbreaks remains a great challenge. Previous internet-based surveillance studies built purely on internet or climate data do have potential error.

METHODS

We collected influenza notifications, temperature and Google Trends (GT) data between January 1st, 2011 and December 31st, 2016. We performed time-series cross correlation analysis and temporal risk analysis to discover the characteristics of influenza epidemics in the period. Then, the seasonal autoregressive integrated moving average (SARIMA) model and regression tree model were developed to track influenza epidemics using GT and climate data.

RESULTS

Influenza infection was significantly corrected with GT at lag of 1-7 weeks in Brisbane and Gold Coast, and temperature at lag of 1-10 weeks for the two study settings. SARIMA models with GT and temperature data had better predictive performance. We identified autoregression (AR) for influenza was the most important determinant for influenza occurrence in both Brisbane and Gold Coast.

CONCLUSIONS

Our results suggested internet search metrics in conjunction with temperature can be used to predict influenza outbreaks, which can be considered as a pre-requisite for constructing early warning systems using search and temperature data.

Respiratory Viruses and Treatment Failure in Children With Asthma Exacerbation

: media-1vid110.1542/5771275574001PEDS-VA_2017-4105Video Abstract OBJECTIVES: Respiratory pathogens commonly trigger pediatric asthma exacerbations, but their impact on severity and treatment response remains unclear.

METHODS

We performed a secondary analysis of the Determinants of Oral Corticosteroid Responsiveness in Wheezing Asthmatic Youth (DOORWAY) study, a prospective cohort study of children (aged 1-17 years) presenting to the emergency department with moderate or severe exacerbations. Nasopharyngeal specimens were analyzed by RT-PCR for 27 respiratory pathogens. We investigated the association between pathogens and both exacerbation severity (assessed with the Pediatric Respiratory Assessment Measure) and treatment failure (hospital admission, emergency department stay >8 hours, or relapse) of a standardized severity-specific treatment. Logistic multivariate regressions were used to estimate average marginal effects (absolute risks and risk differences [RD]).

RESULTS

Of 958 participants, 61.7% were positive for ≥1 pathogen (rhinovirus was the most prevalent [29.4%]) and 16.9% experienced treatment failure. The presence of any pathogen was not associated with higher baseline severity but with a higher risk of treatment failure (20.7% vs 12.5%; RD = 8.2% [95% confidence interval: 3.3% to 13.1%]) compared to the absence of a pathogen. Nonrhinovirus pathogens were associated with an increased absolute risk (RD) of treatment failure by 13.1% (95% confidence interval: 6.4% to 19.8%), specifically, by 8.8% for respiratory syncytial virus, 24.9% for influenza, and 34.1% for parainfluenza.

CONCLUSIONS

Although respiratory pathogens were not associated with higher severity on presentation, they were associated with increased treatment failure risk, particularly in the presence of respiratory syncytial virus, influenza, and parainfluenza. This supports influenza prevention in asthmatic children, consideration of pathogen identification on presentation, and exploration of treatment intensification for infected patients at higher risk of treatment failure.

Exploiting routinely collected severe case data to monitor and predict influenza outbreaks

Background

Influenza remains a significant burden on health systems. Effective responses rely on the timely understanding of the magnitude and the evolution of an outbreak. For monitoring purposes, data on severe cases of influenza in England are reported weekly to Public Health England. These data are both readily available and have the potential to provide valuable information to estimate and predict the key transmission features of seasonal and pandemic influenza.

Methods

We propose an epidemic model that links the underlying unobserved influenza transmission process to data on severe influenza cases. Within a Bayesian framework, we infer retrospectively the parameters of the epidemic model for each seasonal outbreak from 2012 to 2015, including: the effective reproduction number; the initial susceptibility; the probability of admission to intensive care given infection; and the effect of school closure on transmission. The model is also implemented in real time to assess whether early forecasting of the number of admissions to intensive care is possible.

Results

Our model of admissions data allows reconstruction of the underlying transmission dynamics revealing: increased transmission during the season 2013/14 and a noticeable effect of the Christmas school holiday on disease spread during seasons 2012/13 and 2014/15. When information on the initial immunity of the population is available, forecasts of the number of admissions to intensive care can be substantially improved.

Conclusion

Readily available severe case data can be effectively used to estimate epidemiological characteristics and to predict the evolution of an epidemic, crucially allowing real-time monitoring of the transmission and severity of the outbreak.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5671-7) contains supplementary material, which is available to authorized users.

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.

Comparison of incidence and cost of influenza between healthy and high-risk children <60 months old in Thailand, 2011-2015

Introduction

Thailand recommends influenza vaccination for children aged 6 months to <36 months, but investment in vaccine purchase is limited. To inform policy decision with respect to influenza disease burden and associated cost in young children and to support the continued inclusion of children as the recommended group for influenza vaccination, we conducted a prospective cohort study of children in Bangkok hospital to estimate and compare influenza incidence and cost between healthy and high-risk children.

Methods

Caregivers of healthy children and children with medical conditions (‘high-risk’) aged <36 months were called weekly for two years to identify acute respiratory illness (ARI) episodes and collect illness-associated costs. Children with ARI were tested for influenza viruses by polymerase chain reaction. Illnesses were categorized as mild or severe depending on whether children were hospitalized. Population-averaged Poisson models were used to compare influenza incidence by risk group. Quantile regression was used to examine differences in the median illness expenses.

Results

During August 2011-September 2015, 659 healthy and 490 high-risk children were enrolled; median age was 10 months. Incidence of mild influenza-associated ARI was higher among healthy than high-risk children (incidence rate ratio [IRR]: 1.67; 95% confidence interval [CI]: 1.13–2.48). Incidence of severe influenza-associated ARI did not differ (IRR: 0.40; 95% CI: 0.11–1.38). The median cost per mild influenza-associated ARI episode was $22 among healthy and $25 among high-risk children (3–4% of monthly household income; difference in medians: -$1; 95% CI for difference in medians: -$9 to $6). The median cost per severe influenza-associated ARI episode was $232 among healthy and $318 among high-risk children (26–40% and 36–54% of monthly household income, respectively; difference in medians: 110; 95% CI for difference in medians: -$352 to $571).

Conclusions

Compared to high-risk children, healthy children had higher incidence of mild influenza-associated ARI but not severe influenza-associated ARI. Costs of severe influenza-associated ARI were substantial. These findings support the benefit of annual influenza vaccination in reducing the burden of influenza and associated cost in young children.

Distinction between rhinovirus-induced acute asthma and asthma-augmented influenza infection

BACKGROUND

Rhinovirus (RV) is an established trigger of asthma attacks, whereas such a link is less consistent for influenza virus (IFV).

OBJECTIVE

In the context of precision medicine, we hypothesized that IFV infection may cause a condition essentially different from RV, and we investigated this by evaluating clinical characteristics of RV/IFV-positive and -negative children with respiratory symptoms and/or fever.

METHODS

One thousand two hundred and seven children, 6 months to 13 years old, hospitalized for flu-like illness were recruited in this cross-sectional study. Collected information included demographics, medical history, symptoms/physical findings/diagnosis at presentation and treatment. Nasal secretions were PCR-tested for IFV/RV. Associations were evaluated with adjusted logistic regression models.

RESULTS

Rhinovirus positivity was associated with an asthma-like presentation, including increased wheeze/effort of breathing/diagnosis of acute asthma, and decreased fever/vomiting. Conversely, IFV⁺ children presented with less wheeze/effort of breathing/diagnosis of acute asthma, while they were more frequently febrile. In those with previous asthma history, both viruses induced wheeze; however, IFV was uniquely associated with a more generalised and severe presentation including fever, rales, intercostal muscle retractions and lymphadenopathy. These symptoms were not seen in RV⁺ asthmatics, who had fewer systemic signs and more cough.

CONCLUSIONS AND CLINICAL RELEVANCE

In children with respiratory symptoms and/or fever, RV but not IFV is associated with wheeze and an asthma-like presentation. In those with an asthma history, IFV causes more generalised and severe disease that may be better described as "asthma-augmented influenza" rather than an "asthma attack." Differences in the acute conditions caused by these viruses should be considered in the design of epidemiological studies.

Influenza A Virus Reassortment Is Limited by Anatomical Compartmentalization following Coinfection via Distinct Routes

Exchange of gene segments through reassortment is a major feature of influenza A virus evolution and frequently contributes to the emergence of novel epidemic, pandemic, and zoonotic strains. It has long been evident that viral diversification through reassortment is constrained by genetic incompatibility between divergent parental viruses. In contrast, the role of virus-extrinsic factors in determining the likelihood of reassortment has remained unclear. To evaluate the impact of such factors in the absence of confounding effects of segment mismatch, we previously reported an approach in which reassortment between wild-type (wt) and genetically tagged variant (var) viruses of the same strain is measured. Here, using wt/var systems in the A/Netherlands/602/2009 (pH1N1) and A/Panama/2007/99 (H3N2) strain backgrounds, we tested whether inoculation of parental viruses into distinct sites within the respiratory tract limits their reassortment. Using a ferret (Mustella putorius furo) model, either matched parental viruses were coinoculated intranasally or one virus was instilled intranasally whereas the second was instilled intratracheally. Dual intranasal inoculation resulted in robust reassortment for wt/var viruses of both strain backgrounds. In contrast, when infections were initiated simultaneously at distinct sites, strong compartmentalization of viral replication was observed and minimal reassortment was detected. The observed lack of viral spread between upper and lower respiratory tract tissues may be attributable to localized exclusion of superinfection within the host, mediated by innate immune responses. Our findings indicate that dual infections in nature are more likely to result in reassortment if viruses are seeded into similar anatomical locations and have matched tissue tropisms.IMPORTANCE Genetic exchange between influenza A viruses (IAVs) through reassortment can facilitate the emergence of antigenically drifted seasonal strains and plays a prominent role in the development of pandemics. Typical human influenza infections are concentrated in the upper respiratory tract; however, lower respiratory tract (LRT) infection is an important feature of severe cases, which are more common in the very young, the elderly, and individuals with underlying conditions. In addition to host factors, viral characteristics and mode of transmission can also increase the likelihood of LRT infection: certain zoonotic IAVs are thought to favor the LRT, and transmission via small droplets allows direct seeding into lower respiratory tract tissues. To gauge the likelihood of reassortment in coinfected hosts, we assessed the extent to which initiation of infection at distinct respiratory tract sites impacts reassortment frequency. Our results reveal that spatially distinct inoculations result in anatomical compartmentalization of infection, which in turn strongly limits reassortment.

Cost-effectiveness of Strategies for Offering Influenza Vaccine in the Pediatric Emergency Department

IMPORTANCE

Influenza is a significant public health burden, causing morbidity and mortality in children, yet vaccination rates remain low. Vaccination in the pediatric emergency department (PED) setting may be beneficial but, to date, has not been proven to be cost-effective.

OBJECTIVE

To compare the cost-effectiveness of 4 strategies for PED-based influenza vaccine: offering vaccine to all patients, only to patients younger than 5 years, only to high-risk patients (all ages), or to no patients.

DESIGN, SETTING, AND PARTICIPANTS

Using commercial decision analysis software, a cost-effectiveness analysis was performed from January 1, 2016, to June 1, 2017, to compare influenza vaccine strategies at a tertiary, urban, freestanding PED with an estimated 60 000 visits per year among a hypothetical cohort of children visiting the above PED during influenza season. Sensitivity analyses estimated the effect of uncertainties across a variety of input variables (eg, influenza prevalence, vaccine price and effectiveness, and costs of complications).

MAIN OUTCOMES AND MEASURES

The primary outcomes were cost and incremental cost-effectiveness ratio in dollars per influenza case averted. Secondary outcomes included total societal costs, hospitalizations and deaths averted, and quality-adjusted life-years gained.

RESULTS

Offering influenza vaccine to all eligible patients has the lowest cost, at $114.45 (95% CI, $55.48-$245.45) per case of influenza averted. This strategy saves $33.51 (95% CI, $18-$62) per case averted compared with no vaccination, and averages 27 fewer cases of influenza per 1000 patients. Offering vaccine to all patients resulted in 0.72 days (95% CI, 0.18-1.78 days) of quality-adjusted life-years lost, whereas offering to none resulted in 0.91 days (95% CI, 0.25-2.2 days) of quality-adjusted life-years lost. In sensitivity analyses, this strategy remains robustly cost-effective across a wide range of assumptions. In addition to being the most cost-effective strategy regardless of age or risk status, routine vaccination in the PED results in a net societal monetary benefit under many circumstances. In Monte Carlo analysis, offering vaccine to all patients was superior to other strategies in at least 99.8% of cases.

CONCLUSIONS AND RELEVANCE

Although few PEDs routinely offer influenza vaccination, doing so appears to be cost-effective, with the potential to significantly reduce the economic (and patient) burden of pediatric influenza.

Changes in trends and impact of testing for influenza in infants with fever <90 days of age

BACKGROUND

Infants aged <90 days who present with fever commonly undergo various invasive procedures due to the risk of bacterial infection in this age group. A great proportion of cases, however, are due to viral infection, including influenza. The aim of this study was therefore to assess the impact of influenza testing in infants <90 days with fever, as well as analyze the subject characteristics to identify which infants should be considered for such testing.

METHODS

Clinical characteristics and trends in influenza virus testing and treatment were analyzed among febrile infants <90 days who presented to the emergency room and were diagnosed with influenza during 2005-2015.

RESULTS

Among 5,347 febrile infants aged <90 days, 963 (18%) underwent influenza virus test. A total of 114 (11.8%) were diagnosed with influenza. The positivity rate reached 67% of febrile infants during epidemics. Of them, 83 had a history of family contact. While more than half presented with upper respiratory symptoms, 34% had only fever without respiratory symptoms. A decrease in antibiotic use and admission rates during the study period among infants diagnosed with influenza was seen (P for trend <0.05).

CONCLUSIONS

During the influenza epidemic season, diagnostic tests for influenza based on a detailed contact history are necessary in assessing the cause of fever. Targeted testing for influenza may lead to a decrease in antibiotic use and admission rates in young infants.

Vaccination Coverage of Adolescents With Chronic Medical Conditions

INTRODUCTION

Adolescents with chronic medical conditions (CMCs) are at increased risk of vaccine-preventable infections. Little is known about their vaccine uptake.

METHODS

This retrospective cohort study included 3,989 adolescents aged 11-17 years receiving care at academically affiliated pediatric clinics between August 2011 and June 2013. Data were abstracted from the medical center's electronic health record and immunization registry in 2014. Vaccination coverage, timeliness, and missed opportunities were evaluated and analyzed in 2015-2016.

RESULTS

Adolescents with CMCs had lower human papillomavirus vaccination initiation than those without CMCs (81.3% vs 85.0%), although this difference was only observed in stratified analysis among males (adjusted relative risk=0.90, 95% CI=0.85, 0.96), aged 13-17 years (adjusted relative risk=0.94, 95% CI=0.91, 0.98), and those with more primary care visits (adjusted relative risk=0.94, 95% CI=0.91, 0.98). Adolescents with CMCs had greater influenza vaccination coverage and timeliness than those without CMCs (2011-2012 season: 66.9% vs 50.1%; adjusted hazards ratio=1.27, 95% CI=1.15, 1.40; 2012-2013 season: 73.8% vs 64.5%; adjusted hazards ratio=1.20, 95% CI=1.10, 1.31). Only 32.1% and 18.2% of eligible adolescents had received pneumococcal polysaccharide and 13-valent pneumococcal conjugate vaccines, respectively. Missed opportunities were higher among adolescents with versus without CMCs for human papillomavirus vaccination initiation (4.2 vs 2.7, p<0.001), meningococcal vaccination (4.0 vs 2.9, p<0.001), and influenza vaccination (2011-2012 season: 2.1 vs 1.7, p<0.001; 2012-2013 season: 2.0 vs 1.6, p<0.001). Missed opportunities for pneumococcal vaccination were common.

CONCLUSIONS

Pockets of undervaccination and missed opportunities exist among adolescents with CMCs. Greater, more timely influenza vaccination suggests that optimal vaccination of high-risk adolescents is possible.

Continuity of Care in Infancy and Early Childhood Health Outcomes

BACKGROUND AND OBJECTIVES

Continuity of care is a key aspect of the patient-centered medical home and improves pediatric outcomes. Health care reform requires high-quality data to demonstrate its continued value. We hypothesized that increased provider continuity in infancy will reduce urgent health care use and increase receipt of preventive services in early childhood.

METHODS

Continuity, using the Usual Provider of Care measure, was calculated across all primary care encounters during the first year of life in a prospectively-constructed cohort of 17 773 infants receiving primary care from birth through 3 years at 30 clinics. Health care utilization and preventive care outcomes were measured from ages 1 to 3 years. Confounders, including chronic conditions, number of sick visits in the first year, socioeconomic status, and site, were addressed by using multivariable regression models incorporating a propensity score.

RESULTS

Demographics associated with the lowest continuity quartile included white race (adjusted odds ratio [aOR] 1.43; 95% confidence interval [CI] 1.25-1.64), Medicaid insurance (aOR 1.41; 95% CI 1.23-1.61), and asthma (aOR 1.59; 95% CI 1.30-1.93). Lower continuity was associated with more ambulatory care-sensitive hospitalizations (adjusted incidence rate ratio 2.74; 95% CI 1.49-5.03), ambulatory sick visits (adjusted incidence rate ratio 1.08; 95% CI 1.05-1.11), and lower odds of lead screening (aOR 0.61; 95% CI 0.46-0.79). These associations were stronger for children with chronic conditions. Continuity measured during well visits was not associated with outcomes.

CONCLUSIONS

Continuity may improve care quality and prevent high-cost health encounters, especially for children with chronic conditions. Novel solutions are needed to improve continuity in the medical home.

Use of a Digital Health Application for Influenza Surveillance in China

OBJECTIVES

To examine whether a commercial digital health application could support influenza surveillance in China.

METHODS

We retrieved data from the Thermia online and mobile educational tool, which allows parents to monitor their children's fever and infectious febrile illnesses including influenza. We modeled monthly aggregated influenza-like illness case counts from Thermia users over time and compared them against influenza monthly case counts obtained from the National Health and Family Planning Commission of the People's Republic of China by using time series regression analysis. We retrieved 44 999 observations from January 2014 through July 2016 from Thermia China.

RESULTS

Thermia appeared to predict influenza outbreaks 1 month earlier than the National Health and Family Planning Commission influenza surveillance system (P = .046). Being younger, not having up-to-date immunizations, and having an underlying health condition were associated with participant-reported influenza-like illness.

CONCLUSIONS

Digital health applications could supplement traditional influenza surveillance systems in China by providing access to consumers' symptom reporting. Growing popularity and use of commercial digital health applications in China potentially affords opportunities to support disease detection and monitoring and rapid treatment mobilization.

Characterization and circulation of seasonal influenza viruses in Madrid, 2010-2016

Influenza virus infection is a major health care burden and is associated with significant morbidity and mortality. The 2009 influenza pandemic highlighted the importance of influenza surveillance. The objective of this study was to assess the epidemiology and activity of influenza A and B viruses in adults and children in the post-pandemic period with a special focus on the pediatric population. We performed a retrospective descriptive study involving adults and children with influenza-like illness at the Clinico San Carlos Hospital (Madrid, Spain) over six influenza seasons, between August 2010 and April 2016. Respiratory specimens were collected from 3131 patients and routinely processed for influenza diagnosis. Epidemiological analysis was performed in terms of gender, age, and seasonal distribution. Globally, Influenza A and B viruses were detected in the respiratory specimens of 696 (22.2%) of the 3131 studied population. Among all influenza positive specimens, 142 (20.4%) were influenza A(H1N1)pdm09, 61 (8.8%) were influenza A(H3N2), 321 (46.1%) were untypeable influenza A viruses and 166 (23.9%) were influenza B. Co-infection by both influenza A and B viruses was detected in six patients (0.9%). Meanwhile, co-infection with other non-influenza respiratory viruses was identified in 5 children and 20 adults. Influenza A(H1N1)pdm09 virus activity has been significantly high since the 2009 pandemic and has gradually replaced the previously circulating seasonal influenza A(H1N1) virus. Moreover, influenza A(H3N2) virus activity remained at low levels during the last winter season while influenza B virus isolates increased significantly over the past 2 years.

Morbidity, Mortality, and Seasonality of Influenza Hospitalizations in Egypt, November 2007-November 2014

BACKGROUND

Influenza typically comprises a substantial portion of acute respiratory infections, a leading cause of mortality worldwide. However, influenza epidemiology data are lacking in Egypt. We describe seven years of Egypt's influenza hospitalizations from a multi-site influenza surveillance system.

METHODS

Syndromic case definitions identified individuals with severe acute respiratory infection (SARI) admitted to eight hospitals in Egypt. Standardized demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, and influenza A specimens subtyped.

RESULTS

From November 2007-November 2014, 2,936/17,441 (17%) SARI cases were influenza-positive. Influenza-positive patients were more likely to be older, female, pregnant, and have chronic condition(s) (all p<0.05). Among them, 53 (2%) died, and death was associated with older age, five or more days from symptom onset to hospitalization, chronic condition(s), and influenza A (all p<0.05). An annual seasonal influenza pattern occurred from July-June. Each season, the proportion of the season's influenza-positive cases peaked during November-May (19-41%).

CONCLUSIONS

In Egypt, influenza causes considerable morbidity and mortality and influenza SARI hospitalization patterns mirror those of the Northern Hemisphere. Additional assessment of influenza epidemiology in Egypt may better guide disease control activities and vaccine policy.

A randomized, double-blind, placebo-controlled trial evaluating the safety of early oseltamivir treatment among children 0-9 years of age hospitalized with influenza in El Salvador and Panama

BACKGROUND

Oseltamivir reduces symptom duration among children with uncomplicated influenza, but few data exist on treatment efficacy and tolerability among hospitalized children, particularly among infants aged <1 year. We evaluated tolerability and efficacy of oseltamivir treatment of children aged 0-9 years hospitalized with influenza.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial at tertiary care hospitals in El Salvador and Panama. Primary outcomes were length of hospitalization and increased work of breathing. Children were eligible if hospitalized <7 days after symptom onset with cough or sore throat plus tachypnea. Children were randomized 1:1 to receive oseltamivir or placebo; had swabs collected at enrollment for influenza RT-PCR testing; were assessed at enrollment and every 12 h for work of breathing; and were followed for adverse events through 7 days after discharge. Analyses were intention-to-treat.

RESULTS

Overall, 683 children were randomized (oseltamivir, n = 341, placebo n = 342). Fifty-three percent were aged <1 year and 30 had influenza (oseltamivir, n = 19; placebo, n = 11). The study was terminated early after enrollment of 21% of the sample size due to lower than anticipated participant accrual. Using Kaplan-Meier analysis, there was no significant difference in median length of hospitalization (3 days, IQR 2-4 vs. 5 days, IQR 3-7, p = 0.22) and increased work of breathing (36 h, IQR 24-72 vs. 96 h, IQR 13-108, p = 0.14) between oseltamivir versus placebo recipients. There was no difference in adverse events between groups.

CONCLUSION

Oseltamivir treatment was well tolerated among hospitalized children, including among infants aged <1 year.

Prevention and Control of Seasonal Influenza with Vaccines

This report updates the 2015-16 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep 2015;64:818-25). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For the 2016-17 influenza season, inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in a trivalent formulation (RIV3). In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013-14 and 2015-16 seasons, for the 2016-17 season, ACIP makes the interim recommendation that live attenuated influenza vaccine (LAIV4) should not be used. Vaccine virus strains included in the 2016-17 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent vaccines will include an additional influenza B virus strain, a B/Phuket/3073/2013-like virus (Yamagata lineage).Recommendations for use of different vaccine types and specific populations are discussed. A licensed, age-appropriate vaccine should be used. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. Information in this report reflects discussions during public meetings of ACIP held on October 21, 2015; February 24, 2016; and June 22, 2016. These recommendations apply to all licensed influenza vaccines used within Food and Drug Administration-licensed indications, including those licensed after the publication date of this report. Updates and other information are available at CDC's influenza website (http://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information.

Uptake of childhood influenza vaccine from 2012-2013 to 2014-2015 in the UK and the implications for high-risk children: a retrospective observational cohort study

OBJECTIVES

To evaluate changes in influenza vaccination rates in healthy and at-risk children following the implementation of the UK's childhood influenza immunisation programme.

DESIGN

Observational cohort study before and after initiation of the UK's childhood influenza immunisation programme over three influenza seasons (2012-2013, 2013-2014 and 2014-2015) using data from the Clinical Practice Research Datalink (CPRD).

SETTING

More than 500 primary care practices in the UK.

POPULATION

All individuals aged 2-17 years on 1 September, with at least 12 months of medical history documented in CPRD were retained in the analysis.

INTERVENTION

Starting in 2013-2014, all children aged 2 and 3 years were offered influenza vaccination through general practice, and primary school-aged children were offered influenza vaccination in selected counties in England (described as pilot regions). The vaccination programme was extended to all children aged 4 years in England in 2014-2015.

MAIN OUTCOME MEASURE

Cumulative vaccination rate from 1 September to 28 February of the next calendar year as assessed by a time-to-event statistical model (vaccination uptake). Age group, sex, region and type of high-risk medical condition were assessed as predictors.

RESULTS

Vaccination uptake increased considerably from 2012-2013 to 2013-2014 in targeted children aged 2-3 years, both in children with a high-risk medical condition (from 40.7% to 61.1%) and those without (from 1.0% to 43.0%). Vaccination rates increased also, though less markedly, in older children. In 2014-2015, vaccination rates remained higher than 40% in healthy children aged 2-3 years, although they decreased slightly from 2013-2014 (from 43.0% to 41.8%). Vaccination rates in older healthy children continued to increase, driven primarily by an increase in children aged 4 years to 31.3% in 2014-2015.

CONCLUSIONS

The introduction of a universal childhood vaccination policy in the UK increased vaccination rates for targeted children, including those with high-risk conditions.

Strategies to identify and stratify children with special health care needs in outpatient general pediatrics settings

Developing improved systems of care for children with special health care needs (CSHCN) requires accurate identification and stratification of this population. This study was designed to assess the ability of a brief screener to identify and stratify CSHCN in a primary care clinic to focus future quality improvement initiatives and allocate resources. All families presenting for health maintenance visits or acute care appointments at an academic primary care clinic between September 5, 2012 and September 28, 2012 were asked to complete the CSHCN Screener(©). This panel of patients was compared to registries previously created by: (1) retrospective chart reviews using published lists of International Statistical Classification of Diseases and Related Health Problems (ICD9) codes for CSHCN and (2) direct physician referral to a clinic case manager providing care coordination services to CSHCN. Screeners identified 246 CSHCN (16.8 % of unique completed screeners). Scores ranged from 0 to 5; higher scores indicate higher levels of complexity. Patients with positive screens had a mean score of 2.4. Patients previously identified by retrospective ICD9 search who completed a screener had a mean score of 1.6 with nearly one-half having negative screens. Patients previously identified by physician referral who completed a screener had a mean score of 2.7 with nearly one-half having scores of 4 or 5. The CSHCN Screener(©) can be utilized in an academic primary care clinic to prospectively identify CSHCN and potentially offers a more clinically meaningful method of identification given its inherent ability to stratify this population based on complexity of medical needs.

Evaluation of the Alere i Influenza A&B assay for rapid identification of influenza A and influenza B viruses

The Alere i Influenza A&B assay is a novel isothermal nucleic acid amplification assay capable of detecting and differentiating influenza A and B viruses in approximately 15 min with minimal hands-on time. This study was conducted in order to assess the performance of the Alere i Influenza A&B assay compared to molecular techniques, considered to be gold standard methods, to evaluate the results. A total of 119 nasopharyngeal swabs collected from inpatients with influenza-like illness were included in the study using both archived and prospectively collected samples from adults and children. Prospectively collected samples were also compared to the Alere BinaxNOW® Influenza A & B Card. The overall sensitivity for detection of influenza A and B viruses compared to those of molecular techniques were 65.96 % and 53.33 % respectively, while the specificity was 98.51 % and 95.96 %. Compared to the Alere BinaxNOW® Influenza A & B Card, the Alere i assay is considerably more sensitive for detection of influenza A and B viruses, although both tests demonstrated excellent specificity for diagnosis of influenza viruses.

Seasonal Patterns of Asthma in Children and Adolescents Presenting at Emergency Departments in Korea

Purpose

Seasonal variations in asthma-related hospitalizations and emergency department visits have long been recognized. This study aimed to investigate the seasonal patterns of asthma in children and adolescents who presented at emergency departments in Korea.

Methods

We analyzed the National Emergency Department Information System records from 117 emergency departments in Korea that comprised all of the patients with asthma who were aged 3-18 years and who presented at the emergency departments from 2007 to 2012. The children and adolescents were divided into 3 groups based on their ages, namely, 3-6 years, 7-12 years, and 13-18 years. The data were tabulated, and graphs were created to show the seasonal trends in the monthly numbers of emergency department visits as a consequence of asthma.

Results

A total of 41,128 subjects were identified, and the male-to-female ratio was 1:0.5. General ward admissions comprised 42.6% (n=17,524 patients) of the emergency department visits, and intensive care unit admissions comprised 0.8% (n=335 patients) of the emergency department visits. The monthly numbers of emergency department visits for asthma varied according to the season, with high peaks during fall, which was from September to November, and low levels in summer, which was from June to August.

Conclusions

Important differences in the seasonal patterns of emergency department visits for asthma were evident in children and adolescents. Identifying seasonal trends in asthma-related emergency department visits may help determine the causes and reduce the likelihood of asthma exacerbation.

Improving influenza vaccination in chronically ill children using a tertiary-care based vaccination clinic: Is there a role for the live-attenuated influenza vaccine (LAIV)?

BACKGROUND

Children with underlying medical conditions should receive influenza vaccine (IV) yearly; yet this remains sub-optimal. We aimed to describe our experience with a tertiary-care hospital-based influenza vaccination clinic for this at-risk population.

METHODS

From October to December 2012, 2013, and 2014, we ran an influenza vaccination clinic at the Montreal Children's Hospital, where children with high-risk conditions come for their follow-up. Both injectable IV (IIV) and live-attenuated IV (LAIV) were offered free of charge to patients and their household contacts. Upon vaccination, parents were asked to fill a pre-piloted questionnaire.

RESULTS

We vaccinated a total of 2640 high-risk children and 1912 household members during the three influenza vaccination seasons. In 2012 and 2013, 631 and 630 patients with chronic illnesses were vaccinated, compared to 1379 in 2014. Caregivers preferred LAIV primarily because no needle was involved (49.0%) and because it was perceived as less painful (46.9%). LAIV was administered to 69% (2012), 55% (2013) and 47% (2014) of high-risk children. The main reason for not receiving LAIV was because it was contra-indicated. A small fraction of children previously vaccinated with LAIV who did not present any contraindication to LAIV opted for IIV: 12/101 (11.8%) in 2013 and 16/272 (5.9%) in 2014. In 2014, this was mainly due to a previous negative experience with LAIV (11/16).

CONCLUSION

Having an influenza vaccination clinic on site at a tertiary care hospital, where children come for their scheduled visits, facilitates yearly influenza vaccination in children with chronic illnesses. LAIV is preferred by caregivers and patients, when not contraindicated.

Continued high incidence of children with severe influenza A(H1N1)pdm09 admitted to paediatric intensive care units in Germany during the first three post-pandemic influenza seasons, 2010/11-2012/13

BACKGROUND

Previous influenza surveillance at paediatric intensive care units (PICUs) in Germany indicated increased incidence of PICU admissions for the pandemic influenza subtype A(H1N1)pdm09. We investigated incidence and clinical characteristics of influenza in children admitted to PICUs during the first three post-pandemic influenza seasons, using active screening.

METHODS

We conducted a prospective surveillance study in 24 PICUs in Bavaria (Germany) from October 2010 to September 2013. Influenza cases among children between 1 month and 16 years of age admitted to these PICUs with acute respiratory infection were confirmed by PCR analysis of respiratory secretions.

RESULTS

A total of 24/7/20 influenza-associated PICU admissions were recorded in the post-pandemic seasons 1/2/3; incidence estimates per 100,000 children were 1.72/0.76/1.80, respectively. Of all 51 patients, 80% had influenza A, including 65% with A(H1N1)pdm09. Influenza A(H1N1)pdm09 was almost absent in season 2 (incidence 0.11), but dominated PICU admissions in seasons 1 (incidence 1.35) and 3 (incidence 1.17). Clinical data was available for 47 influenza patients; median age was 4.8 years (IQR 1.6-11.0). The most frequent diagnoses were influenza-associated pneumonia (62%), bronchitis/bronchiolitis (32%), secondary bacterial pneumonia (26 %), and ARDS (21%). Thirty-six patients (77 %) had underlying medical conditions. Median duration of PICU stay was 3 days (IQR 1-11). Forty-seven per cent of patients received mechanical ventilation, and one patient (2%) extracorporeal membrane oxygenation; 19% were treated with oseltamivir. Five children (11%) had pulmonary sequelae. Five children (11%) died; all had underlying chronic conditions and were infected with A(H1N1)pdm09. In season 3, patients with A(H1N1)pdm09 were younger than in season 1 (p = 0.020), were diagnosed more often with bronchitis/bronchiolitis (p = 0.004), and were admitted to a PICU later after the onset of influenza symptoms (p = 0.041).

CONCLUSIONS

Active screening showed a continued high incidence of A(H1N1)pdm09-associated PICU admissions in the post-pandemic seasons 1 and 3, and indicated possible underestimation of incidence in previous German studies. The age shift of severe A(H1N1)pdm09 towards younger children may be explained by increasing immunity in the older paediatric population. The high proportion of patients with underlying chronic conditions indicates the importance of consistent implementation of the current influenza vaccination recommendations for risk groups in Germany.

Comparative acceptance of pertussis and influenza immunization among health-care personnel

BACKGROUND

Pertussis and influenza immunization in health-care professionals (HCP) has been shown to lead to significant reduction of nosocomial infections. Parallel campaigns of pertussis and seasonal influenza immunization gave us a unique opportunity to compare attitudes towards influenza and pertussis immunization among HCP and to determine acceptance rates for both or either one of the two immunizations or refusal of both.

METHODS

A questionnaire was sent to HCP to anonymously obtain demographic data, profession, numbers of previous influenza immunizations, acceptance of influenza immunization in the current 2012/13 season, pertussis immunization currently or within the last 10 years, and reasons for acceptance or decline of pertussis and influenza vaccination.

RESULTS

Of 638 HCP with patient contact, 314 (49%) responded and 303 (47%) were included in the analysis. Immunization acceptance rates were 33% for influenza, 57% for pertussis; 24% accepted both immunizations and 34% none of both. Acceptance of influenza immunization was significantly higher in those with one or more previous influenza vaccinations (p<0.005). Among 130 HCP who declined pertussis immunization, missed opportunity (28%) was the dominant reason. Of 204 HCP who declined influenza immunization, the most frequently stated reason was "lack of influenza immunization is not considered an issue" (36%).

CONCLUSIONS

Misconceptions about the efficacy and necessity of pertussis and especially influenza immunization continue to prevail among HCP. Active promotion, personal encouragement, providing more immunization opportunities and other incentives are measures that should be considered to increase the rate of immunization among HCP.