Influenza and the rates of hospitalization for respiratory disease among infants and young children

Clinical Profile, Intensive Care Needs and Predictors of Outcome Among Children Admitted with Non-COVID Severe Acute Respiratory Illness (SARI) During the Pandemic

OBJECTIVES

To study the epidemiology of non-coronavirus disease-2019 (non-COVID-19) respiratory viral infections with respect to their clinical profile, intensive care needs and predictors of outcome once the non-pharmacological interventions (NPI) during the coronavirus disease-2019 (COVID-19) pandemic were relaxed.

METHODS

Retrospective analysis of children with Severe Acute Respiratory Illness (SARI) who were SARS-CoV-2 negative, admitted to the Pediatric Emergency/Intensive Care Unit (PICU) from July 2021 through October 2021 was conducted.

RESULTS

One hundred and thirty nine children with median age of 11 (4-28.5) mo were included. Besides respiratory symptoms in all, diarrhea was reported in 90 (64.7%) children. Nearly half (n = 66; 47%) presented in hypoxemic respiratory failure (SpO2 <88%). Fifty-two (37.4%) children had co-morbidities, commonest being congenital heart disease in 12 (23.1%). Baseline parameters revealed leukopenia (specifically lymphopenia) 39 (28%), elevated aspartate transaminase [Serum glutamic-oxaloacetic transaminase (SGOT)] in 108 (77.6%), elevated N-acetyl-cysteine-activated creatinine kinase (CK-NAC) 23 (79%) and lactate dehydrogenase (LDH) 15 (88%). Intensive care needs included mechanical ventilation 51 (36.6%), vasoactive support 34 (24.5%), and renal replacement therapy 10 (7.1%). Forty-two (30.2%) children developed multi-organ dysfunction syndrome (MODS). One hundred and three (74.1%) children were discharged, 31 (22.3%) died, and 5 (3.6%) left against medical advice. On multivariate regression analysis, elevated liver enzymes (>5 times normal), hypoxemic respiratory failure at admission, hypotensive shock and MODS predicted mortality.

CONCLUSIONS

A surge in non-COVID SARI was observed once lockdown measures were relaxed. Nearly 1/3rd progressed to multi-organ failure and died. Elevated liver enzymes, hypoxemic respiratory failure at admission, hypotensive shock and MODS predicted death.

Characteristics and Outcomes of Pregnant Women Hospitalized With Laboratory-Confirmed Respiratory Syncytial Virus Before and During the COVID-19 Pandemic

Background

Respiratory syncytial virus (RSV) can cause severe disease among infants and older adults. Less is known about RSV among pregnant women.

Methods

To analyze hospitalizations with laboratory-confirmed RSV among women aged 18 to 49 years, we used data from the RSV Hospitalization Surveillance Network (RSV-NET), a multistate population-based surveillance system. Specifically, we compared characteristics and outcomes among (1) pregnant and nonpregnant women during the pre-COVID-19 pandemic period (2014-2018), (2) pregnant women with respiratory symptoms during the prepandemic and pandemic periods (2021-2023), and (3) pregnant women with and without respiratory symptoms in the pandemic period. Using multivariable logistic regression, we examined whether pregnancy was a risk factor for severe outcomes (intensive care unit admission or in-hospital death) among women aged 18 to 49 years who were hospitalized with RSV prepandemic.

Results

Prepandemic, 387 women aged 18 to 49 years were hospitalized with RSV. Of those, 350 (90.4%) had respiratory symptoms, among whom 33 (9.4%) were pregnant. Five (15.2%) pregnant women and 74 (23.3%) nonpregnant women were admitted to the intensive care unit; no pregnant women and 5 (1.6%) nonpregnant women died. Among 279 hospitalized pregnant women, 41 were identified prepandemic and 238 during the pandemic: 80.5% and 35.3% had respiratory symptoms, respectively (P < .001). Pregnant women were more likely to deliver during their RSV-associated hospitalization during the pandemic vs the prepandemic period (73.1% vs 43.9%, P < .001).

Conclusions

Few pregnant women had severe RSV disease, and pregnancy was not a risk factor for a severe outcome. More asymptomatic pregnant women were identified during the pandemic, likely due to changes in testing practices for RSV.

Sickness absence and disability pension three years before and seven years after first childbirth: A Swedish population-based cohort study

AIMS

There is a widely held belief, in Sweden and internationally, that women with children are more likely to be on sickness absence (SA) than their nulliparous counterparts. However, empirical findings in the field are limited and inconsistent. We aimed to explore initially nulliparous women's patterns of SA and disability pension (DP) three years before and seven years after 2009, by later parity.

METHODS

We conducted a longitudinal cohort study of nulliparous women in Sweden on 31 December 2009 (N=426,918). We compared crude and standardized numbers of SA/DP net days in the three years before (Y-3 to Y-1) and the seven years (Y+1 to Y+7) after the date of the first birth in 2010 or 2 July 2010 in the following three groups: (1) women with no childbirth during the seven-year follow-up and an additional nine months (i.e. 7.8 years), (2) women with a first childbirth in 2010 and no additional childbirth during the next 7.8 years, and (3) women with their first childbirth in 2010 and minimum one more during the next 7.8 years.

RESULTS

Women remaining nulliparous had consistently more standardized mean SA/DP days than women giving birth. Compared with women with one birth, women with several births had similar mean numbers of standardized SA/DP days during Y-3 and Y-2, more during Y+1 to Y+3 and fewer during Y+4 to Y+7.

CONCLUSIONS

In contrast to the widely held societal belief, we found that in all years women who gave birth had fewer SA/DP days than those remaining nulliparous.

Risk factors for hospitalization and pneumonia development of pediatric patients with seasonal influenza during February-April 2023

Objectives

In China influenza remains a low activity for continuous 3 years due to COVID-19 controls. We here sought to study the clinical characteristics and risk factors of the influenza infection among children after the mandatory COVID-19 restrictions were lifted.

Methods

We included 1,006 pediatric patients with influenza A virus (IAV) infection, enrolled in one tertiary hospital in Zhenjiang, Jiangsu Province, China, during February to April 2023. Patients were divided into the outpatient (n = 798) and inpatient (n = 208) groups, and their baseline characteristics were compared between two groups to conclude the risk factors for pediatric hospitalization. Separately, pediatric inpatients (n = 208) were further divided into the pneumonia and non-pneumonia groups with comparison of their clinical characteristics, including their laboratory test results and representative radiological features, to derive the key determinants for pneumonia development after hospitalization.

Results

Compared to outpatients, IAV-infected pediatric inpatients exhibited younger age, higher female: male ratio, more co-infection of influenza B virus (IBV) and hematological abnormality. Multivariate regression analysis determined the independent risk factors of hospitalization to be the clinical symptom of abdominal pain (OR = 2.63, [95% CI, 1.05-6.57], p = 0.039), co-infection of IBV (OR = 44.33, [95% CI, 25.10-78.30], p = 0.001), elevated levels of lymphocytes (OR = 2.24, [95% CI,1.65-3.05], p = 0.001) and c-reactive proteins (CRPs) (OR = 1.06, [95% CI, 1.03-1.08], p = 0.001) upon hospital admission. Furthermore, the cough symptom (OR = 17.39, [95% CI, 3.51-86.13], p = 0.001) and hospitalization length (OR = 1.36, [95% CI, 1.12-1.67], p = 0.002) were determined to be risk factors of pneumonia acquirement for pediatric inpatients.

Conclusion

While the abdominal pain, viral co-infection and some hematological abnormality mainly contribute to hospitalization of pediatric patients with IAV infection, the length of hospital stay and clinical sign of coughing upon hospital admission constitute the key determinants for nosocomial pneumonia development.

Emergency departments: An underutilized resource to address pediatric influenza vaccine coverage

BACKGROUND

Emergency department (ED) based influenza vaccine (IV) programs have been successful in adults; however, little is known about pediatric ED IV programs in terms of prevalence, feasibility, or successful implementation.

AIMS

To describe the reach and effectiveness of IV practices in pediatric EDs, and identify IV facilitators and barriers.

METHODS

We assessed, via cross-sectional survey of pediatric ED physicians, number of EDs offering IV to children, vaccines administered annually, and perceived facilitators/barriers to vaccination. The proportion of EDs offering IV is reported. Chi-square tests compared facilitators and barriers among high performers (≥50 IV/year), low performers (<50 IV/yr), and non-vaccinators. We calculated an area of missed effect for the number of children who could be vaccinated if non-vaccinating EDs offered IV.

RESULTS

Among 492 physicians from 166 EDs, 142 responded (representing 61 (37.3 %) EDs). Most EDs were in large, urban, academic, freestanding children's hospitals (Table 1). Only twenty-six EDs (44.3 %) offer ≥ 1 IV/yr. Seventeen (65.4 %) were low performers, five (19.2 %) high performers, and four (15.4 %) were model programs. High/model performers used establish workflows more commonly than lower performers (78 % vs. 33 %), although this was not statistically significant (p = 0.077). Common facilitators included: strong provider and administration buy-in, electronic health record facilitation, storage/accessibility, and having a leadership team/champion (Fig. 1). Non-vaccinators commonly perceived lack of these factors as barriers. Many (24/61, 39.3 %) EDs expressed interested in establishing or growing IV programs. Up to 18,250 unvaccinated children could receive IV annually if non-vaccinating EDs offered IV during influenza season.

CONCLUSIONS

Over half of EDs participating in the Pediatric Emergency Medicine Collaborative Research Committee do not currently offer pediatric IV. Addressing identified barriers/facilitators to develop IV programs in EDs has potential to improve vaccination rates, especially among minority and underserved children.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Platelet count and risk of severe illness in hospitalised children with Influenza-Like illness

AIM

To examine the clinical significance of thrombocytosis (platelets > 500 × 109 /L) in admitted children with an influenza-like illness.

METHODS

We performed a database analysis consisting of patients evaluated at our medical centers with an influenza-like illness between 2009 and 2013. We included paediatric patients and examined the association between platelet count, respiratory viral infections, and admission outcomes (hospital length of stay and admission to the paediatric intensive care unit) using regression models adjusting for multiple variables.

RESULTS

A total of 5171 children were included in the study cohort (median age 0.8 years; interquartile range, 0.2-1.8; 58% male). Younger age, and not the type of viral infection, was associated with a high platelet count (p < 0.001). Elevated platelet count independently predicted admission outcomes (p ≤ 0.05). The presence of thrombocytosis was associated with an increased risk for a prolonged length of stay (odds ratio = 1.2; 95% Confidence interval = 1.1 to 1.4; p = 0.003) and admission to the paediatric intensive care unit (odds ratio = 1.5; 95% Confidence interval = 1.1 to 2.0; p = 0.002).

CONCLUSION

In children admitted with an influenza-like illness, a high platelet count is an independent predictor of admission outcomes. Platelet count may be used to improve risk assessment and management decisions in these paediatric patients.

Maternal and Newborn Hospital Outcomes of Perinatal SARS-CoV-2 Infection: A National Registry

OBJECTIVES:

The American Academy of Pediatrics National Registry for the Surveillance and Epidemiology of Perinatal coronavirus disease 2019 (COVID-19) (NPC-19) was developed to provide information on the effects of perinatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS:

National Registry for the Surveillance and Epidemiology of Perinatal COVID-19 participating centers entered maternal and newborn data for pregnant persons who tested positive for SARS-CoV-2 infection between 14 days before and 10 days after delivery. Incidence of and morbidities associated with maternal and newborn SARS-CoV-2 infection were assessed.

RESULTS:

From April 6, 2020 to March 19, 2021, 242 centers in the United States centers reported data for 7524 pregnant persons; at the time of delivery, 78.1% of these persons were asymptomatic, 18.2% were symptomatic but not hospitalized specifically for COVID-19, 3.4% were hospitalized for COVID-19 treatment, and 18 (0.2%) died in the hospital of COVID-related complications. Among 7648 newborns, 6486 (84.8%) were tested for SARS-CoV-2, and 144 (2.2%) were positive; the highest rate of newborn infection was observed when mothers first tested positive in the immediate postpartum period (17 of 125, 13.6%). No newborn deaths were attributable to SARS-CoV-2 infection. Overall, 15.6% of newborns were preterm: among tested newborns, 30.1% of polymerase chain reaction-positive and 16.2% of polymerase chain reaction-negative were born preterm (P &lt; .001). Need for mechanical ventilation did not differ by newborn SARS-CoV-2 test result, but those with positive tests were more likely to be admitted to a NICU.

CONCLUSIONS:

Early in the pandemic, SARS-CoV-2 infection was acquired by newborns at variable rates and without apparent short-term effects. During a period that preceded widespread availability of vaccines, we observed higher than expected numbers of preterm births and maternal in-hospital deaths.

Motivational interviewing for maternal Immunizations: Intervention development

BACKGROUND AND OBJECTIVE

Vaccine uptake during pregnancy remains low. Our objectives were to describe 1) development and adaptation of a clinician communication training intervention for maternal immunizations and 2) obstetrics and gynecology (ob-gyn) clinician and staff perspectives on the intervention and fit for the prenatal care context.

METHODS

Design of the Motivational Interviewing for Maternal Immunizations (MI4MI) intervention was based on similar communication training interventions for pediatric settings and included presumptive initiation of vaccine recommendations ("You're due for two vaccines today") combined with motivational interviewing (MI) for hesitant patients. Interviews and focus group discussions were conducted with ob-gyn clinicians and staff in five Colorado clinics including settings with obstetric physicians, certified nurse midwives (CNMs), and clinician-trainees. Participants were asked about adapting training to the ob-gyn setting and their implementation experiences. Feedback was incorporated through iterative changes to training components.

RESULTS

Interview and focus group discussion results from participants before (n = 3), during (n = 11) and after (n = 25) implementation guided intervention development and adaptation. Three virtual, asynchronous training components were created: a video and two interactive modules. This virtual format was favored due to challenges attending group meetings; however, participants noted opportunities to practice skills through role-play were lacking. Training modules were adapted to include common challenging vaccine conversations and live-action videos. Participants liked interactive training components and use of adult learning strategies. Some participants initially resisted the presumptive approach but later found it useful after applying it in their practices. Overall, participants reported that MI4MI training fit well with the prenatal context and recommended more inclusion of non-clinician staff.

CONCLUSIONS

MI4MI training was viewed as relevant and useful for ob-gyn clinicians and staff. Suggestions included making training more interactive, and including more complex scenarios and non-clinician staff.

Influenza is More Severe than Our Newest Enemy (COVID-19) in Hospitalized Children: Experience from a Tertiary Center

Understanding differences in terms of clinical phenotypes and outcomes of coronavirus disease 2019 (COVID‐19) compared with influenza is vital to optimizing the management of patients and planning healthcare. Herein, we aimed to investigate the clinical differences and outcomes in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and influenza. We performed a retrospective study of hospitalized children who were positive for SARS‐CoV‐2 between March 2020 and March 2021 and for influenza between January 2016 and February 2020 in respiratory samples. The primary outcome of this study was pediatric intensive care unit (PICU) admission, and the secondary outcome was the need for respiratory support. A total of 74 patients with influenza and 71 who were positive for SARS‐CoV‐2 were included. The distribution among the sexes was similar, but patients with COVID‐19 were older than patients with influenza (96 vs. 12, p < 0.001). In terms of underlying chronic diseases, the frequency was 26.7% in the COVID‐19 group and 54% in the influenza group (p = 0.001). The comparison of symptoms revealed that fatigue, headache, nausea, vomiting, and abdominal pain occurred more frequently with COVID‐19 (for all p < 0.05) and runny nose with influenza (p = 0.002). The frequency of admission to the PICU was relatively higher (18.9%) in the influenza group than with COVID‐19 (2.8%) with a significant ratio (p = 0.001), secondary bacterial infections were observed more frequently in the influenza group (20.2% vs. 4.2%, p = 0.003). Some 88.7% of patients with COVID‐19 did not need respiratory support, whereas 59.4% of patients with influenza did require respiratory support (p < 0.001). This study noted that influenza caused more frequent admissions to the PICU and a greater need for respiratory support in hospitalized pediatric patients than COVID‐19.

Incidence of lower respiratory tract infection and associated viruses in a birth cohort in the Philippines

Background

Lower respiratory tract infection (LRTI) is an important cause of morbidity and mortality in infants and young children. However, the etiological role of viruses and the timing of developing LRTI are not well defined.

Methods

We analyzed the data of a prospective cohort study in the Philippines as a birth cohort. We detected LRTI among children who visited healthcare facilities with respiratory symptom, and collected nasopharyngeal swabs for virus detection. We analyzed the incidence rates (IRs) and cumulative proportion of LRTI and severe LRTI by age group and each virus detected.

Results

A total of 350 LRTI episodes were observed from 473 child-years yielded from 419 children. The IRs of LRTI were 70.8, 70.7, and 80.8 per 100 child-years for 0–5, 6–11, and 12–23 months of age, respectively. By 12 months of age, 45% of children developed LRTI at least once. Rhinovirus and respiratory syncytial virus were the most frequently detected viruses in all age groups. However, the IRs of influenza virus were low especially at 0–5 months of age.

Conclusions

We identified various patterns of age-specific IRs of LRTI and severe LRTI for different viruses, which should be considered to establish more effective interventions including vaccinations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07289-3.

The burden of hospital-attended influenza in Norwegian children

BACKGROUND

Norwegian health authorities do not recommend universal pediatric vaccination against seasonal influenza. We aimed to estimate the incidence of influenza by age and underlying medical conditions in hospitalized Norwegian children aged <18 years.

METHODS

Active surveillance for influenza in children <18 years was implemented in five hospitals during 2015-18. Children with respiratory symptoms and/or fever were prospectively enrolled and tested for influenza. Surveillance data were linked to health registry data to estimate the national burden of influenza in hospitals.

RESULTS

In 309 (10%) out of 3,010 hospital contacts, the child tested positive for influenza, corresponding to an average incidence of 0.96 hospital-attended influenza cases per 1,000 children <18 years of age. Children <1 year of age (3.8 per 1,000 children) and children with underlying medical conditions (17 per 1,000 children with bronchopulmonary dysplasia) had the highest average incidence. Among <1 year old children, 3% tested positive for influenza, compared to 25% for children aged 6-17. Few children were vaccinated against influenza.

CONCLUSIONS

Children <1 year of age and children with underlying medical conditions had a higher incidence of influenza requiring hospital treatment compared to the general population. Effective interventions against seasonal influenza for children in Norway should be considered.

Adjuvanted trivalent influenza vaccine versus quadrivalent inactivated influenza vaccine in Hutterite Children: A randomized clinical trial

BACKGROUND

Children play an important role in the transmission of influenza. The best choice of vaccine to achieve both direct and indirect protection is uncertain. The objective of the study was to test whether vaccinating children with MF59 adjuvanted trivalent influenza vaccine (aTIV) can reduce influenza in children and their extended households compared to inactivated quadrivalent vaccine (QIV).

METHODS

We conducted a cluster randomized trial in 42 Hutterite colonies in Alberta and Saskatchewan. Colonies were randomized such that children were assigned in a blinded manner to receive aTIV (0.25 ml of pediatric aTIV for ages 6 months to < 36 months or 0.5 ml for ages ≥ 36 months to 6 years) or 0.5 ml of QIV. Participants included 424 children aged 6 months to 6 years who received the study vaccine and 1246 family cluster members who did not receive the study vaccine. The primary outcome was confirmed influenza A and B infection using a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay. An intent to treat analysis was used. Data were collected from January 2017 to June 2019.

RESULTS

The mean percentage of children who received study vaccine was 62% for aTIV colonies and 74% for QIV colonies. There were 66 (3.4%) with RT-PCR confirmed influenza A and B in the aTIV colonies (children and family clusters) versus 93 (4.4%) in the QIV colonies, hazard ratio (HR) 0.78 (95 %CI 0.36-1.71). Of these, 48 (2.5%) in the aTIV colonies and 76 (3.6%) in the QIV colonies had influenza A, HR 0.69, (95 %CI 0.29-1.66) while 18 (0.9%) and 17 (0.8%) in the aTIV versus QIV colonies respectively had influenza B, HR 1.22, (95 %CI 0.20-7.41). In children who received study vaccine, there were 5 Influenza A infections in the aTIV colonies (1.1%) compared to 30 (5.8%) in the QIV colonies, relative efficacy of 80%, HR 0.20, (95 %CI 0.06-0.66). Adverse events were significantly more common among children who received aTIV. No serious vaccine adverse events were reported.

CONCLUSION

Vaccinating children with aTIV compared to QIV resulted in similar community RT-PCR confirmed influenza illness and led to significant protection against influenza A in children.

Burden of influenza disease in children under 2 years of age hospitalized between 2011 and 2020 in France

BACKGROUND

Although influenza viruses cause significant morbidity and mortality worldwide, the impact of these infections on children in France and in other European countries has not been extensively characterized. The primary objective of the present study was to describe the burden of influenza disease on hospitalized children under 2 years of age in France, using data from the national hospital discharge summary database (Programme de Médicalisation des Systèmes d'Information, PMSI).

METHODS

In a retrospective study of hospital admissions for influenza among children under the age of 2 in France, we extracted and analyzed hospital administrative data from the PMSI database (from January 1, 2011, to December 31, 2020).

RESULTS

From 2011 to 2020, 28,507 children under the age of 2 were admitted to hospital with a primary or secondary diagnosis of influenza infection. The hospital admission rate was 205 per 100,000 for children under the age of 2, 276 per 100,000 for children under the age of 12 months, and 135 per 100,000 for children aged between 12 and 23 months. Children under 6 months of age were the most affected (45.4%). An underlying condition was identified for 9.4% of the children, and 2.2% of the children were admitted to the intensive care unit. The death rate was 0.12 per 100,000 for children under 2, 0.11 per 100,000 for children under 12 months, and 0.16 per 100,000 for children aged between 12 and 23 months.

CONCLUSIONS

In France, the burden of influenza disease is significant in children under the age of 2.

The limited value of triage vital signs in predicting influenza infection in children aged 5 years and under in the emergency department: A single-center retrospective cross-sectional study

Diagnosing influenza in children aged 5 years and under can be challenging because of their difficulty in verbalizing symptoms. This study aimed to explore the value of the triage heart rate (HR), respiratory rate (RR), and temperature, either alone or when combined with individual symptoms and signs, in predicting influenza infection in this age group.This was a retrospective study covering 4 influenza seasons from 2017 to 2019 in an emergency department (ED) in Hong Kong. We recruited patients ≤5 years of age who had an reverse transcription polymerase chain reaction influenza test within 48 hours of ED presentation. The diagnostic performance of the triage HR, RR, and temperature was evaluated as dichotomized or categorized values with diagnostic odds ratios (DORs) calculated based on different age-appropriate thresholds. Linear discriminant analysis was performed to assess the combined discriminatory effect of age, HR, RR, and temperature as continuous variables.Of 322 patients (median age 26 months), 99 had influenza A and 13 had influenza B infection. For HR and RR dichotomized based on age-appropriate thresholds, the DORs ranged from 1.16 to 1.54 and 0.78 to 1.53, respectively. A triage temperature ≥39.0 °C had the highest DOR (3.32) among different degrees of elevation of temperature. The diagnostic criteria that were based on the presence of fever and cough and/or rhinitis symptoms had a higher DOR compared with the Centers for Disease Control and Prevention influenza-like illness criteria (4.42 vs 2.41). However, combining HR, RR, or temperature with such diagnostic criteria added very little to the diagnostic performance. The linear discriminant analysis model had a high specificity of 92.5%, but the sensitivity (18.3%) was too low for clinical use.Triage HR, RR, and temperature had limited value in the diagnosis of influenza in children ≤5 years of age in the ED. Fever and cough and/or rhinitis symptoms had a better diagnostic performance than the Centers for Disease Control and Prevention influenza-like illness criteria in predicting influenza in this age group.

A Paper-Based IL-6 Test Strip Coupled With a Spectrum-Based Optical Reader for Differentiating Influenza Severity in Children

Influenza virus infection is a major worldwide public health problem. Influenza virus infections are associated with a high hospitalization rate in children between the ages of 5 and 14. The predominant reason for poor influenza prognosis is the lack of any effective means for early diagnosis. Early diagnosis of severe illness is critical to improving patient outcome, and could be especially useful in areas with limited medical resources. Accurate, inexpensive, and easy-to-use diagnostic tools could improve early diagnosis and patient outcome, and reduce overall healthcare costs. We developed an interleukin-6 paper-based test strip that used colloidal gold-conjugated antibodies to detect human interleukin-6 protein. These complexes were captured on a paper-based test strip patterned with perpendicular T lines that were pre-coated with anti-human interleukin-6 antibodies. Applied serum samples interacted with these antibodies and presented as colored bands that could be read using a spectrum-based optical reader. The full-spectrum of the reflected light interleukin-6 protein signal could be obtained from the spectral optics module, and the standard could be used to quantitatively analyze interleukin 6 level in serum. We retrospectively evaluated 10 children (23 serum samples) with severe influenza virus infections, 26 children (26 serum samples) with mild influenza virus infections, and 10 healthy children (10 serum samples). Our system, the combined use of a paper-based test strip and a spectrum-based optical reader, provided both qualitative and quantitative information. When used with the optical reader, the detection limit was improved from a qualitative, naked-eye level of 400 pg/ml to a quantitative, optical reader level of 76.85 pg/ml. After monitoring serum interleukin-6 level via our system, we found a high correlation between our system results and those obtainable using a conventional sandwich enzyme-linked immunosorbent assay method (Rho = 0.706, p < 0.001). The sensitivity and specificity for differentiating between severe and mild influenza using our combined method (test strip coupled with optical reader) were 78.3 and 50.0%, respectively. When interleukin-6 was combined with serum C-reaction protein, the sensitivity and specificity were 85.7 and 95.5%, and the receiver operating characteristic area-under-the-curve was quite high (AUC = 0.911, p < 0.001). The potential advantages of our system, i.e., a paper-based test strip coupled with a spectrum-based optical reader, are as follows: 1) simple user operation; 2) rapid turnaround times–within 20 min; 3) high detection performance; and, 4) low-cost fabrication.

Antiviral Use in Canadian Children Hospitalized for Influenza

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A study on catalytic and non-catalytic sites of H5N1 and H1N1 neuraminidase as the target for chalcone inhibitors

The H1N1 pandemic in 2009 and the H5N1 outbreak in 2005 have shocked the world as millions of people were infected and hundreds of thousands died due to the infections by the influenza virus. Oseltamivir, the most common drug to block the viral life cycle by inhibiting neuraminidase (NA) enzyme, has been less effective in some resistant cases due to the virus mutation. Presently, the binding of 10 chalcone derivatives towards H5N1 and H1N1 NAs in the non-catalytic and catalytic sites was studied using molecular docking. The in silico study was also conducted for its drug-like likeness such as Lipinski Rule, mutagenicity, toxicity and pharmacokinetic profiles. The result demonstrates that two chalcones (1c and 2b) have the potential for future NA inhibitor development. Compound 1c inhibits H5N1 NA and H1N1 NA with IC₅₀ of 27.63 µM and 28.11 µM, respectively, whereas compound 2b inhibits NAs with IC₅₀ of 87.54 µM and 73.17 µM for H5N1 and H1N1, respectively. The in silico drug-like likeness prediction reveals that 1c is 62% better than 2b (58%) in meeting the criteria. The results suggested that 1c and 2b have potencies to be developed as non-competitive inhibitors of neuraminidase for the future development of anti-influenza drugs.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s13765-021-00639-w.

The contrasting relationships of relative humidity with influenza A and B in a humid subtropical region

Influenza is an acute respiratory disease that seriously threatens public health. The occurrence of influenza has been proved to be related to a variety of meteorological factors. However, less attention has been paid to the effect of relative humidity (RH) on different types of influenza, especially in subtropical regions. Daily data on laboratory-confirmed influenza cases, weather variables, and air pollutants in Hefei covering the 2014-2019 period were collected. The seasonality and trend of daily influenza cases were explored by the time series seasonal decomposition method. Generalized linear model was fitted in conjunction with distributed lag nonlinear model to quantify the associations of RH with influenza A and influenza B. Subgroup analyses were conducted by sex, age (0-4, 5-17, and ≥18 years), and season (cold and warm seasons). A total of 5238 influenza cases including 2847 influenza A cases and 2391 influenza B cases were recorded. The epidemic of influenza presented a distinct seasonal pattern, and the number of daily influenza cases increased steadily since 2016. High RH was related to an increased risk of influenza A (maximum RR = 1.683, 95%CI: 1.365-2.076), especially among males, females, and school-age children. Low RH was associated with an increased risk of influenza B (maximum RR = 1.252, 95%CI: 1.169-1.340). The contrasting relationships of RH with influenza A and B remained significant in cold seasons. High RH and low RH were significantly associated with the increased risk of influenza A and B, respectively. The findings of our study may provide clues for proposing new effective interventions.

Lung surgery in children and their post-operative risk of respiratory infection

PURPOSE

Pediatric surgeons at our institution are often asked by families about a theoretical increased risk of severe common upper respiratory infections in children status post lung resection. No data exist on this topic. We, therefore, aimed to examine the risk of severe respiratory infection in children after pulmonary resection.

METHODS

A chart review was conducted on all pediatric patients who underwent pulmonary resection between August 1st, 2009 and January 31st, 2019. Collected data included patient characteristics, operation, complications and any admission for respiratory infection.

RESULTS

Fifty-seven patients met inclusion criteria. Resections included lobectomy (45.6%), segmentectomy (14.0%), and wedge resection (40.4%). Twelve (21.1%) were immunocompromised and 6 (10.5%) had post-operative complications. Within 1 year of surgery, 2 (3.5%) patients were hospitalized for a viral upper respiratory illness (URI), 1 (1.8%) for bacterial pneumonia, and none due to influenza.

CONCLUSION

In the general pediatric population, the risk of admission for respiratory illness is 3-21%. At this institution, overall risk of respiratory infection after lung resection appears comparable to baseline community risk. Our findings could aid counseling pediatric patients and their families regarding the 1-year risk of infection after lung resection.

Long-term cigarette smoke exposure dysregulates pulmonary T cell response and IFN-γ protection to influenza virus in mouse

BACKGROUND

Influenza is a highly contagious, acute, febrile respiratory infection caused by a negative-sense, single-stranded RNA virus, which belongs in the Orthomyxoviridae family. Cigarette smoke (CS) exposure worsens influenza infection in terms of frequency and severity in both human and animal models.

METHODS

C57BL/6 mice with or without CS exposure for 6 weeks were inoculated intranasally with a single, non-lethal dose of the influenza A virus (IAV) A/Puerto Rico/8/1934 (PR8) strain. At 7 and 10 days after infection, lung and mediastinal lymph nodes (MLN) cells were collected to determine the numbers of total CD4 + and CD8 + T cells, and IAV-specific CD4 + and CD8 + T cells, using flow cytometry. Bronchoalveolar lavage fluid (BALF) was also collected to determine IFN-γ levels and total protein concentration.

RESULTS

Although long-term CS exposure suppressed early pulmonary IAV-antigen specific CD8 + and CD4 + T cell numbers and IFN-γ production in response to IAV infection on day 7 post-infection, CS enhanced numbers of these cells and IFN-γ production on day 10. The changes of total protein concentration in BALF are consistent with the changes in the IFN-γ amounts between day 7 and 10, which suggested that excessive IFN-γ impaired barrier function and caused lung injury at the later stage of infection.

CONCLUSIONS

Our results demonstrated that prior CS exposure caused a biphasic T cell and IFN-γ response to subsequent infection with influenza in the lung. Specifically, the number of IAV antigen-specific T cells on day 10 was greatly increased by CS exposure even though CS decreased the number of the same group of cells on day 7. The result suggested that CS affected the kinetics of the T cell response to IAV, which was suppressed at an early stage and exaggerated at a later stage. This study is the first to describe the different effect of long-term CS on T cell responses to IAV at early and late stages of infection in vivo.

Population child health: understanding and addressing complex health needs

Advances in paediatric care mean that more children with complex medical problems (heart disease, neurodevelopmental problems and so on) are surviving their early years. This has important implications for the design and delivery of healthcare given their extensive multidisciplinary requirements and susceptibility to poor outcomes when not optimally managed. Importantly, their medical needs must also be understood and addressed within the context of the child and family's life circumstances. There is growing recognition that many other factors contribute to a child's complex health needs (CHNs), for example, family problems, fragmentation of health and care provision, psychological difficulties or social issues.To facilitate proactive care for these patients, we must develop accurate ways to identify them. Whole Systems Integrated Care-an online platform that integrates routinely collected data from primary and secondary care-offers an example of how to do this. An algorithm applied to this data identifies children with CHNs from the entire patient population. When tested in a large inner-city GP practice, this analysis shows good concordance with clinical opinion and identifies complex children in the population to a much higher proportion than expected. Ongoing refinement of these data-driven processes will allow accurate quantification and identification of need in local populations, thus aiding the development of tailored services.

Influenza vaccination and healthcare workers: barriers and predisposing factors

BACKGROUND AND AIM OF THE WORK

Influenza is a disease that affects a large part of the world's population annually, with major health, social and economic impacts. Active immunisation practices have always been recommended to counter influenza, especially for people at risk. The recommendations of major health agencies strongly advise influenza vaccination for all healthcare workers, mostly for those in contact with at-risk or immunocompromised individuals. Yet, the influenza vaccination coverage among healthcare workers remains rather low worldwide. This review explore barriers and the facilitators of health care professional toward influenza's vaccination.

METHODS

Narrative review  consulting the databases: PubMed, CINAHL by combining keywords health care worker, flu, influenza, vaccination, barrier, resistence, hesitangy, between November 2019 and February 2020 Results. From the 1031 records initially, twenty-two primary studies were included in this narrative review. Our results show that the identified facilitators are: desire for self-protection, protection for loved ones and community. Instead, the barriers to vaccination identified are: fear of contracting influenza from the vaccination itself; not considering themselves at risk; to believing believe that their immune system is capable of managing a trivial disease; disease considered trivial, laziness; false beliefs.

DISCUSSION AND CONCLUSION

Adherence rate on influenza vaccination among health professionals is quite low. The interventions that make it "complex and traceable" flu vaccination refusal increase adherence to this type of vaccination. The results show that current vaccination campaigns do not increase the rate of adherence by healthcare workers. Identifying the predisposing factors and barriers to such vaccination can help to create, develop and test targeted educational programmes.

Relative Effectiveness of Influenza Vaccines Among the United States Elderly, 2018-2019

BACKGROUND

Studies among individuals ages ≥65 years have found a moderately higher relative vaccine effectiveness (RVE) for the high-dose (HD) influenza vaccine compared with standard-dose (SD) products for most seasons. Studies during the A(H3N2)-dominated 2017-2018 season showed slightly higher RVE for the cell-cultured vaccine compared with SD egg-based vaccines. We investigated the RVE of influenza vaccines among Medicare beneficiaries ages ≥65 years during the 2018-2019 season.

METHODS

This is a retrospective cohort study using inverse probability of treatment weighting and Poisson regression to evaluate RVE in preventing influenza hospital encounters.

RESULTS

Among 12 777 214 beneficiaries, the egg-based adjuvanted (RVE, 7.7%; 95% confidence interval [CI], 3.9%-11.4%) and HD (RVE, 4.9%; 95% CI, 1.7%-8.1%) vaccines were marginally more effective than the egg-based quadrivalent vaccines. The cell-cultured quadrivalent vaccine was not significantly more effective than the egg-based quadrivalent vaccine (RVE, 2.5%; 95% CI, -2.4% to 7.3%).

CONCLUSIONS

We did not find major effectiveness differences between licensed vaccines used among the elderly during the 2018-2019 season. Consistent with prior research, we found that the egg-based adjuvanted and HD vaccines were slightly more effective than the egg-based quadrivalent vaccines.

Outcome predictors of influenza for hospitalization and mortality in children

Severity of disease caused by influenza virus and the influencing factors that may be different. Moreover, the disease course actually may not be determined specifically in children because of lower seroprotection rates of children. Herein, the results clinic and outcome data of children with influenza from Turkey were reported. We present here the results from 2013 to 2017. Nasopharyngeal swab samples of the children with influenza were investigated via multiplex polymerase chain reaction. A total of 348 children were diagnosed with influenza; 143 (41.1%) were influenza A, 85 (24.4%) were influenza B, and 120 (34.5%) were mixt infection with other respiratory viruses. Fifty‐four percent of children admitted to intensive care unit (ICU) were under 2 years of age (p = .001). Having an underlying disease was detected as the main predictor for both hospitalization and ICU stay according to multiple logistic regression analysis (odds ratio [OR], 11.784: 95% confidence interval [CI], 5.212–26.643; p = .001 and OR, 4.972: 95% CI, 2.331–10.605; p = .001, respectively). Neurological symptoms most frequently seen in cases who died (44.4%; p = .02). Lymphopenia was relatively higher (55.6%) and thrombocytopenia was most frequently seen in cases who died (77.8%) with a significant ratio (p = .001). Underlying diseases was found a risk factor for influenza being hospitalized and being admitted to ICU. Children under 2 years of age and with underlying diseases should be vaccinated particularly in countries where the influenza vaccination is still not routinely implemented in the immunization schedule.

Highlights Underlying diseases is a risk factor for influenza to be hospitalized and admitted to ICU. Influenza vaccination is of great importance to prevent life‐threatening complications of influenza, particularly in children require ICU admission. The possibility to reduce the outpatient visit number by vaccination has a great impact on disease burden in addition to the underestimated crucial social benefits, as well.

The burden of influenza and other respiratory viruses in hospitalized infants and children in a university hospital, Jordan

Background

Acute lower respiratory infection (ALRI) is a major cause of morbidity and mortality worldwide in young children and is predominately caused by viral respiratory pathogens. This study aims to identify the viral etiologies of ALRI in hospitalized children in Jordan University Hospital and compare the clinical characteristics of influenza virus infection with other respiratory viruses.

Methods

A retrospective viral surveillance study that included 152 children below 15 years of age admitted with ALRI from December 2018 through April 2019 was conducted. We recorded results of real-time reverse transcriptasepolymerase chain reaction (RT-PCR) for common respiratory viruses. Clinical and demographic information of the study population was collected from patients' electronic medical records.

Results

152 patients were identified with a median age of 1 year (mean was 2.1 years). Ninety-five patients (62.5%) were males. One or more viral respiratory pathogens were detected in 145 (95.3%) children. Respiratory syncytial virus was the most detected virus in 68 patients (44.8%). Influenza virus was detected in 25 patients (16.4%). Children with influenza infection had more fever and lower leukocyte count compared to children infected with other viruses. The severity of the ALRI correlated significantly with several factors, including age less than six months and the presence of neuromuscular disease (p<0.05).

Conclusion

Viral detection was common among children admitted with ALRI. Viruses, including influenza, are recognized as significant contributors to the morbidity associated with ALRI. More attention is needed on strategies for the prevention and detection of viral ALRI in developing countries.

Elevation of creatine kinase is associated with acute kidney injury in hospitalized patients infected with seasonal influenza virus

BACKGROUND

Although acute kidney injury (AKI) is known as a potential complication of influenza infections, there is limited information concerning the association between influenza and AKI. The aim of this study is to evaluate the incidence, the mortality, and risk factors of AKI in hospitalized patients by seasonal influenza viral infections.

METHODS

We performed a single center, retrospective observational study. 123 patients admitted to Iwata City Hospital due to influenza for 3 seasons were included. We examined the association between the incidence of AKI and clinical parameters using Spearman's correlation analyses, receiver-operating characteristic (ROC) curves, and multivariate logistic regression analyses.

RESULTS

Of 123 patients, AKI developed in 46 patients (37.4%). Patients with AKI showed higher serum creatine kinase (CK, P < 0.001), higher creatinine (Cr, P < 0.001), and higher C-reactive protein (CRP) levels (P < 0.001) at admission and higher mortality rate (P < 0.05) compared with patients without AKI. The severity of kidney injuries was well correlated with serum CK levels (P < 0.001). By ROC curve analysis, 186 U/L was the most predictive value of CK levels for AKI (sensitivity, 0.674; specificity, 0.688; and area under the curve [AUC], 0.714). Multivariate logistic regression analyses revealed that elevated CK levels (> 186 U/L) were significantly associated with AKI (P < 0.01).

CONCLUSIONS

The incidence of AKI and the mortality were high in hospitalized patients infected with seasonal influenza. The slight elevation of CK levels (> 186 U/L) at admission was associated with the development of AKI.

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.

Motivational Interviewing for Maternal Immunisation (MI4MI) study: a protocol for an implementation study of a clinician vaccine communication intervention for prenatal care settings

INTRODUCTION

Vaccination against influenza and pertussis in pregnancy offers a 'two-for-one' opportunity to protect mother and child. Pregnant patients have increased risk of severe disease from influenza and newborns have increased risk of severe disease from both influenza and pertussis. Obstetricians need communication tools to support their self-efficacy and effectiveness in communicating the importance of immunisation during pregnancy and ultimately improving maternal vaccination rates.

METHODS AND ANALYSIS

We describe the protocol for a pragmatic study testing the feasibility and potential impact of a clinician communication strategy on maternal vaccination uptake. This study will be conducted in five prenatal care settings in Colorado, USA. The Motivational Interviewing for Maternal Immunisation strategy involves training prenatal care providers to use motivational interviewing in the vaccine conversation with pregnant patients. Our primary outcomes will be the adoption and implementation of the intervention measured using the Enhanced RE-AIM/Practical Robust Implementation and Sustainability Model for dissemination and implementation. Secondary outcomes will include provider time spent, fidelity to Motivational Interviewing and self-efficacy measured through audio recorded visits and provider surveys, patients' visit experience based on audio recorded visits and follow-up interviews, and maternal vaccine uptake as measured through chart reviews.

ETHICS AND DISSEMINATION

This study is approved by the following institutional review boards: Colorado Multiple Institutional Review Board. Results will be disseminated through peer-reviewed manuscripts and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04302675.

The Differences in Viral Etiologies between Children with and without Severe Disability Admitted to the Pediatric Intensive Care Unit with Acute Respiratory Illness

Objectives The objectives of this study were to evaluate the differences in the viral etiologies and variability in the clinical course between children with and without severe disability (SD) admitted to the pediatric intensive care unit (PICU) with acute respiratory illness (ARI).

Methods The medical records of patients admitted to our PICU between June 2017 and July 2019 were retrospectively reviewed for viral etiology and clinical course.

Results Forty-eight of 136 patients included in the study had SD. The rates of requiring positive pressure ventilation (43.5% vs. 20.5%) or inotropic support (39.9% vs. 15.9%), and the median length of stay (11 [10] vs. 5 [8]) were significantly higher in children with SD (p < 0.01, each). Influenza infection was significantly higher in children with SD (20.8% vs. 2.3%; p < 0.01) whereas respiratory syncytial virus (RSV) infection was more common in children without SD (47.7% vs. 4.2%; p < 0.01). There was no statistically significant difference in terms of other viruses between study groups.

Conclusion In this present study, influenza was an important pathogen for children with SD, while RSV was the main cause of ARI-associated PICU admission in children without SD. By focusing on increasing the rate of immunization against influenza in children with SD and their caregivers the burden of influenza-associated PICU admissions could be decreased.

Burden of influenza during the first year of life

Background

Every year, influenza viruses infect millions of children and cause an enormous burden of disease. Young children are at the highest risk for influenza‐attributable hospitalizations. Nevertheless, most young children are treated as outpatients, and limited data are available on the burden of influenza in these children.

Methods

We carried out a prospective cohort study and followed 431 infants born in June‐August 2017 for 10 months from September 1, 2017, to June 30, 2018. The parents filled out daily symptom diaries and were instructed to bring their child for clinical examination at our study clinic each time the child had fever or any signs or symptoms of respiratory tract infection. During each visit, we obtained nasopharyngeal swab specimens for determination of the viral etiology of the illness.

Results

A total of 55 episodes of laboratory‐confirmed influenza were diagnosed among the 408 actively participating children, which corresponds to an annual incidence rate of 135/1000 children (95% Cl, 102‐175). Excluding five children with double viral infection, acute otitis media developed as a complication of influenza in 23 (46%) children. One (2%) child with influenza was hospitalized because of febrile convulsion. The effectiveness of influenza vaccination was 48% (95% CI, −29%‐80%).

Conclusions

The burden of influenza during the first year of life is heavy in the outpatient setting where most infants with influenza are managed. Effective strategies for the prevention of influenza particularly in infants under 6 months of age are needed to diminish the burden of disease in this age group.

Challenges for the Newborn Following Influenza Virus Infection and Prospects for an Effective Vaccine

Newborns are at significantly increased risk of severe disease following infection with influenza virus. This is the collective result of their naïve status, altered immune responsiveness, and the lack of a vaccine that is effective in these individuals. Numerous studies have revealed impairments in both the innate and adaptive arms of the immune system of newborns. The consequence of these alterations is a quantitative and qualitative decrease in both antibody and T cell responses. This review summarizes the hurdles newborns experience in mounting an effective response that can clear influenza virus and limit disease following infection. In addition, the challenges, as well as the opportunities, for developing vaccines that can elicit protective responses in these at risk individuals are discussed.

Challenges for the Newborn Immune Response to Respiratory Virus Infection and Vaccination

The initial months of life reflect an extremely challenging time for newborns as a naïve immune system is bombarded with a large array of pathogens, commensals, and other foreign entities. In many instances, the immune response of young infants is dampened or altered, resulting in increased susceptibility and disease following infection. This is the result of both qualitative and quantitative changes in the response of multiple cell types across the immune system. Here we provide a review of the challenges associated with the newborn response to respiratory viral pathogens as well as the hurdles and advances for vaccine-mediated protection.

Comparative Severity of Influenza A and B Infections in Hospitalized Children

BACKGROUND

Influenza A viruses are conventionally thought to cause more severe illnesses than B viruses, but few studies with long observation periods have compared the clinical severity of A and B infections in hospitalized children.

METHODS

We analyzed the clinical presentation, outcomes and management of all children <16 years of age admitted to Turku University Hospital, Finland, with virologically confirmed influenza A or B infection during the 14-year period of 1 July 2004 to 30 June 2018. All comparisons between influenza A and B were performed both within predefined age groups (0-2, 3-9 and 10-15 years) and in all age groups combined.

RESULTS

Among 391 children hospitalized with influenza A or B infection, influenza A was diagnosed in 279 (71.4%) and influenza B in 112 (28.6%) children. Overall, there were no significant differences in any clinical features or outcomes, management, treatment at intensive care unit or length of stay between children with influenza A and B, whether analyzed by age group or among all children. As indicators of the most severe clinical presentations, blood cultures were obtained from 101 (36.2%) children with influenza A and 39 (34.8%) with influenza B (P = 0.80), and lumbar puncture was performed to 16 (5.7%) children with influenza A and 11 (9.8%) children with influenza B (P = 0.15).

CONCLUSIONS

The clinical severity of influenza A and B infections is similar in children. For optimal protection against severe influenza illnesses, the use of quadrivalent vaccines containing both lineages of B viruses seems warranted in children.

Relative Effectiveness of Cell-Cultured and Egg-Based Influenza Vaccines Among Elderly Persons in the United States, 2017-2018

BACKGROUND

The low influenza vaccine effectiveness (VE) observed during the A(H3N2)-dominated 2017-2018 season may be due to vaccine virus adaptation to growth in eggs. We compared the effectiveness of cell-cultured and egg-based vaccines among Medicare beneficiaries.

METHODS

Retrospective cohort study on Medicare beneficiaries aged ≥65 years who received an influenza vaccine (cell-cultured, egg-based quadrivalent; egg-based high-dose, adjuvanted, or standard-dose trivalent) during the 2017-2018 season. We used Poisson regression to evaluate relative VE (RVE) in preventing influenza-related hospital encounters.

RESULTS

Of >13 million beneficiaries, RVE for cell-cultured vaccines relative to egg-based quadrivalent vaccines was 10% (95% confidence interval [CI], 7%-13%). In a midseason interim analysis, this estimate was 16.5% (95% CI, 10.3%-22.2%). In a 5-way comparison, cell-cultured (RVE, 11%; 95% CI, 8%-14%) and egg-based high-dose (RVE, 9%; 95% CI, 7%-11%) vaccines were more effective than egg-based quadrivalent vaccines.

CONCLUSIONS

The modest VE difference between cell-cultured and egg-based vaccines only partially explains the low overall VE reported by the Centers for Disease Control and Prevention, suggesting that egg adaptation was not the main contributor to the low VE found among individuals aged ≥65 years. The midseason interim analysis we performed demonstrates that our methods can be used to evaluate VE actively during the influenza season.

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

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

Influenza-related hospitalizations due to acute lower respiratory tract infections in a tertiary care children's hospital in Turkey

BACKGROUND

The influenza virus is a significant cause of acute lower respiratory tract infections (LRTI) requiring hospitalization in childhood and leads to severe morbidity and mortality, especially in certain risk groups.

OBJECTIVES

The study aims to evaluate acute LRTI due to influenza in a tertiary care hospital and the risk factors for hospitalization among Turkish children.

STUDY DESIGN

Children between 1 month and 18 years of age who were hospitalized at Dr. Behçet Uz Children's Hospital between January 2016 and March 2018 with lower respiratory tract infection that tested positive for influenza by PCR were included. Children with viral coinfections were excluded. Patient files were retrospectively scanned from the hospital computerized system in terms of age, underlying diseases, whether antiviral therapy was used, and length of hospital stay. Statistical analysis was performed using SPSS statistical software.

RESULTS

The study included 131 patients with a median age of 2 years (1 month-15 years). Sixty-seven (51,1%) patients were younger than two years. Influenza A was isolated in 129 patients and B in 2 patients. Fifty-two patients (39,7%) had underlying medical conditions, and the most common one was malignancies (12/52, 23%). This was followed by neurodevelopmental diseases (9/52, 17,3%), prematurity (9/52 patients, 17,3%), primary immunodeficiency (8/52, 15,4%), asthma (7/52, 13,4%), Down syndrome (4/52, 7,7%), chronic renal disease (2/52, 3,8%) and congenital heart diseases (1/52, 1,9%). The mean length of stay (LOS) was 12,3 ± 9,5 days (2-60 days). The LOS was found to be statistically longer (15,2 ± 12,1 days, 3-60 days) in patients with an underlying disease compared to previously healthy patients (10,4 ± 6,7 days, 2-35 days) (p = 0.01).

CONCLUSIONS

Hospitalization due to influenza-related acute LRTI is not an issue only for patients with an underlying medical condition. Vaccination should be considered not only for those with underlying medical conditions but also for healthy children.

Characterisation of respiratory syncytial virus activity in children and adults presenting with acute respiratory illness at primary care clinics in Singapore, 2014-2018

BACKGROUND

Respiratory syncytial virus (RSV) is an important respiratory pathogen that affects people of all ages.

OBJECTIVES

We examined the patterns of RSV circulation in 2014-2018, and investigated their age-specific differences in tropical Singapore.

METHODS

Nasopharyngeal and/or throat swabs were taken from outpatient attendees for the national influenza virological surveillance among those who presented with acute respiratory illness in the community. Specimens tested negative for influenza were then tested for RSV and other respiratory pathogens.

RESULTS

Among 8436 influenza-negative specimens tested during the five-year period, 5.8% (95% confidence interval 5.3%-6.3%) were positive for RSV. The peak of RSV activity occurred around middle of the year. The age-specific proportion of RSV detections showed a reverse J-shaped pattern; RSV positivity was the highest in young children ≤2 years of age (10.9%), followed by those aged 3-5 years (6.4%) and persons aged ≥65 years (5.3%), while the nadir was observed in the age group of 15-24 years (1.2%). RSV type A was predominantly circulating in children ≤5 years of age from 2014 to 2015 and 2017, whereas in 2016, they were more affected by type B.

CONCLUSION

Respiratory syncytial virus was more frequently detected among the two age groups that have been recommended for influenza vaccination; persons ≥65 years of age and children 6 months to <5 years of age. Characterisation of RSV activity in the community helps to better inform public health policies for effective prevention and control interventions.

Quadrivalent Influenza Vaccine Prevents Illness and Reduces Healthcare Utilization Across Diverse Geographic Regions During Five Influenza Seasons: A Randomized Clinical Trial

BACKGROUND

We evaluated an inactivated quadrivalent influenza vaccine (IIV4) in children 6-35 months of age in a phase III, observer-blind trial.

METHODS

The aim of this analysis was to estimate vaccine efficacy (VE) in preventing laboratory-confirmed influenza in each of 5 independent seasonal cohorts (2011-2014), as well as vaccine impact on healthcare utilization in 3 study regions (Europe/Mediterranean, Asia-Pacific and Central America). Healthy children were randomized 1:1 to IIV4 or control vaccines. VE was estimated against influenza confirmed by reverse transcription polymerase chain reaction on nasal swabs. Cultured isolates were characterized as antigenically matched/mismatched to vaccine strains.

RESULTS

The total vaccinated cohort included 12,018 children (N = 1777, 2526, 1564, 1501 and 4650 in cohorts 1-5, respectively). For reverse transcription polymerase chain reaction confirmed influenza of any severity (all strains combined), VE in cohorts 1-5 was 57.8%, 52.9%, 73.4%, 30.3% and 41.4%, respectively, with the lower limit of the 95% confidence interval >0 for all estimates. The proportion of vaccine match for all strains combined in each cohort was 0.9%, 79.3%, 72.5%, 24.1% and 28.6%, respectively. Antibiotic use associated with influenza illness was reduced with IIV4 by 71% in Europe, 36% in Asia Pacific and 59% in Central America.

CONCLUSIONS

IIV4 prevented influenza in children 6-35 months of age in each of 5 separate influenza seasons in diverse geographical regions. A possible interaction between VE, degree of vaccine match and socioeconomic status was observed. The IIV4 attenuated the severity of breakthrough influenza illness and reduced healthcare utilization, particularly antibiotic use.

Estimated Burden of Community-Onset Respiratory Syncytial Virus-Associated Hospitalizations Among Children Aged <2 Years in the United States, 2014-15

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospitalizations in young children. We estimated the burden of community-onset RSV-associated hospitalizations among US children aged <2 years by extrapolating rates of RSV-confirmed hospitalizations in 4 surveillance states and using probabilistic multipliers to adjust for ascertainment biases.

METHODS

From October 2014 through April 2015, clinician-ordered RSV tests identified laboratory-confirmed RSV hospitalizations among children aged <2 years at 4 influenza hospitalization surveillance network sites. Surveillance populations were used to estimate age-specific rates of RSV-associated hospitalization, after adjusting for detection probabilities. We extrapolated these rates using US census data.

RESULTS

We identified 1554 RSV-associated hospitalizations in children aged <2 years. Of these, 27% were admitted to an intensive care unit, 6% needed mechanical ventilation, and 5 died. Most cases (1047/1554; 67%) had no underlying condition. Adjusted age-specific RSV hospitalization rates per 100 000 population were 1970 (95% confidence interval [CI],1787 to 2177), 897 (95% CI, 761 to 1073), 531 (95% CI, 459 to 624), and 358 (95% CI, 317 to 405) for ages 0-2, 3-5, 6-11, and 12-23 months, respectively. Extrapolating to the US population, an estimated 49 509-59 867 community-onset RSV-associated hospitalizations among children aged <2 years occurred during the 2014-2015 season.

CONCLUSIONS

Our findings highlight the importance of RSV as a cause of hospitalization, especially among children aged <2 months. Our approach to estimating RSV-related hospitalizations could be used to provide a US baseline for assessing the impact of future interventions.

Age-Stratified Risk of Critical Illness in Young Children Presenting to the Emergency Department with Suspected Influenza

OBJECTIVE

To investigate the risk of critical illness by age group among young children without a chronic condition presenting to the emergency department (ED) with suspected influenza.

STUDY DESIGN

Retrospective study of patients aged <2 years presenting to the ED with suspected influenza (defined by diagnostic codes for influenza or influenza-like illness) from 2009 to 2017 in 49 hospitals in the Pediatric Health Information System. Patients with chronic conditions were excluded. The main clinical outcomes were intensive care unit (ICU) admission, ventilatory support, vasopressor administration, and mortality, which were compared independently by age group (<3 months, 3 to <6 months, 6 to <12 months, and 12 to <24 months). To compare outcomes by age, we estimated the prevalence of each outcome by age group after fitting logistic regression models to control for demographic differences between groups.

RESULTS

A total of 55 986 children were studied. Overall admission and ICU admission rates were 20% and 2%, respectively. After adjustment for demographic variables, infants aged <3 months had higher rates of ICU admission (2.7%; 95% CI, 2.0%-3.3%; P < .001 compared with other age groups) and ventilatory support (2.5%; 95% CI, 1.9%-3.2%; P < .001 compared with other age groups); however, there were no differences in vasopressor administration. The overall case fatality rate was low (0.007%) and thus could not be compared across age groups.

CONCLUSIONS

Infants aged <3 months with suspected influenza are at greatest risk for critical illness. Although critical illness is uncommon, these findings should be incorporated into acute management decisions, including the need for specified outpatient follow-up or hospitalization, and public health efforts should focus on prevention and disease-modifying interventions in this high-risk population.

Evaluation of a New Clinical Endpoint for Moderate to Severe Influenza Disease in Children: A Prospective Cohort Study

BACKGROUND

A moderate to severe (M/S) influenza clinical endpoint has been proposed in children, defined as fever >39°C, otitis media, lower respiratory tract infection, or serious extrapulmonary manifestations. The objective of the study was to evaluate the M/S measure against clinically relevant outcomes including hospitalization, emergency room visits, antimicrobial use, and child/parental absenteeism.

METHODS

We conducted a prospective observational study of children aged 6 months-8 years at the Children's Hospital Colorado emergency department (ED) and urgent care site during 2016-2017 and 2017-2018. Children with influenza-like illness (ILI) underwent influenza testing by polymerase chain reaction (PCR); children who tested positive and a subset of matched test-negative controls underwent follow-up at 2 weeks. The primary outcome was the proportion of children who were hospitalized. Secondary outcomes included recurrent ED visits, antimicrobial use, hospital charges, and child/parental absenteeism within 14 days.

RESULTS

Among 1478 children enrolled with ILI, 411 (28%) tested positive for influenza by PCR. Of children with influenza illness, 313 (76%) met the M/S definition. Children with M/S influenza were younger (3.8 years vs 4.8 years), infected with influenza A (59% vs 44%), and more frequently hospitalized (unadjusted risk difference [RD], 6.3%; 95% confidence interval [CI], 2.1-10.4; P = .03) and treated with antibiotics (unadjusted RD, 13.3%; 95% CI, 4.3-22.4; P < .01) compared to those with mild disease.

CONCLUSIONS

Children with M/S influenza have a higher risk of hospitalization and antibiotic use compared with mild disease. This proposed definition may be a useful clinical endpoint to study the public health and clinical impact of influenza interventions in children.

CLINICAL TRIALS REGISTRATION

NCT02979626.

Nanobody-based sandwich reporter system for living cell sensing influenza A virus infection

The influenza epidemic is a huge burden to public health. Current influenza vaccines provide limited protection against new variants due to frequent mutation of the virus. The continual emergence of novel variants necessitates the method rapidly monitoring influenza virus infection in experimental systems. Although several replication-competent reporter viruses carrying fluorescent proteins or small luciferase have been generated in previous studies, visualizing influenza virus infection via such strategy requires reverse genetic modification for each viral strain which is usually time-consuming and inconvenient. Here, we created a novel influenza A nucleoprotein (NP) dependent reporter gene transcription activation module using NP-specific nanobodies. Our results demonstrated the modular design allowed reporter genes (mNeonGreen fluorescent protein and Gaussia luciferase) specifically expressing to detect intracellular NP protein, and therefore acts as a universal biosensor to monitor infection of various influenza A subtypes in living cells. The new system may provide a powerful tool to analyze influenza A infections at the cellular level to facilitate new antiviral drug discovery. Moreover, this approach may easily extend to develop live-cell biosensors for other viruses.

Obstetrician-Gynecologists' Strategies to Address Vaccine Refusal Among Pregnant Women

OBJECTIVE

To describe 1) obstetrician-gynecologists' (ob-gyns') perceptions of the frequency of vaccine refusal among pregnant patients and perceived reasons for refusal and 2) ob-gyns' strategies used when encountering vaccine refusal and perceived effectiveness of those strategies.

METHODS

We conducted an email and mail survey among a nationally representative network of ob-gyns from March 2016 to June 2016.

RESULTS

The response rate was 69% (331/477). Health care providers perceived that pregnant women more commonly refused influenza vaccine than tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine: 62% of respondents reported 10% or greater of pregnant women they care for in a typical month refused influenza vaccine compared with 32% reporting this for Tdap vaccine. The most commonly reported reasons for vaccine refusal were patients' belief that influenza vaccine makes them sick (48%), belief they are unlikely to get a vaccine-preventable disease (38%), general worries about vaccines (32%), desire to maintain a natural pregnancy (31%), and concern that their child could develop autism as a result of maternal vaccination (25%). The most commonly reported strategies ob-gyns used to address refusal were stating that it is safe to receive vaccines in pregnancy (96%), explaining that not getting the vaccine puts the fetus or newborn at risk (90%), or that not getting the vaccine puts the pregnant woman's health at risk (84%). The strategy perceived as most effective was stating that not getting vaccinated puts the fetus or newborn at risk.

CONCLUSION

Ob-gyns perceive vaccine refusal among pregnant women as common and refusal of influenza vaccine as more common than refusal of Tdap vaccine. Emphasizing the risk of disease to the fetus or newborn may be an effective strategy to increase vaccine uptake.

The burden and clinical manifestation of hospitalized influenza among different pediatric age-groups in the tropics

Introduction

In tropical Singapore, influenza occurs all year‐round. This study of influenza‐confirmed hospitalized pediatric patients compared clinical characteristics and complications by age‐group and differences between influenza A and B.

Methods

This was a retrospective study of pediatric inpatients from January 2013 to December 2014. Patients were grouped into: <6 months, 6 months to <5 years, 5‐ to <10‐year and ≥10 years. Complications were classified into neurologic, pulmonary, and other. We also calculated the incidence of hospitalized influenza cases per 100 000 age‐related population.

Results

There were a total of 1272 patients with a median age of 37 months. The highest hospitalization rates were in the <6 months age‐group. Majority (75.2%) had no comorbidity; 25.6% had complications: neurologic 11.9%, pulmonary 9.6%, other 4.1%. Patients with other complications were older, male, and had the highest influenza B rates and the longest length of stay. Influenza A comprised 76.9% of cases and had higher complication rates especially neurologic, compared to influenza B. Influenza B patients were older and were more likely to develop other complications. The 6‐month to <5‐year‐age‐group had the highest complication rate (30.6%), especially neurologic. However, ≥10 years old had the highest other complications, ICU/ high‐dependency admissions and influenza B Victoria rates.

Conclusions

Infants <6 months had the highest hospitalization rates for influenza. The 6‐month to <5‐year‐age‐group had the highest complication rate especially neurologic. Influenza A patients were younger, had higher seizure rates and complications compared to influenza B.

Efficacy of a Web-Based Intervention to Increase Uptake of Maternal Vaccines: An RCT

INTRODUCTION

Tetanus, diphtheria, and acellular pertussis (Tdap) and influenza vaccines are recommended for pregnant women in each pregnancy, yet uptake is suboptimal. This study tested the efficacy of an online vaccine resource in increasing uptake of Tdap and influenza vaccines among pregnant women.

STUDY DESIGN

RCT.

SETTING/PARTICIPANTS

This study was conducted among women in the third trimester of pregnancy in an integrated healthcare system in Colorado in September 2013-July 2016, with data analysis in 2017-2018.

INTERVENTION

Women were randomly assigned to 1 of 3 arms: website with vaccine information and interactive social media components, website with vaccine information only, or usual care. Participants in the website with vaccine information and interactive social media components and website with vaccine information only arms had access to the same base vaccine content. The website with vaccine information and interactive social media components also included a blog, discussion forum, and "Ask a Question" portal.

MAIN OUTCOME MEASURES

Tdap and influenza vaccination. These outcomes were analyzed separately.

RESULTS

For influenza (n=289), women in both the website with vaccine information and interactive social media components (OR=2.19, 95% CI=1.06, 4.53) and website with vaccine information only (OR=2.20, 95% CI=1.03, 4.69) arms had higher vaccine uptake than the usual care arm. The proportions of women receiving the influenza vaccine were 57%, 55%, and 36% in the website with vaccine information and interactive social media components, website with vaccine information only, and usual care arms, respectively. For Tdap (n=173), there were no significant differences in vaccine uptake between study arms. The proportions of women receiving Tdap were 71%, 69%, and 68% in the website with vaccine information and interactive social media components, website with vaccine information only, and usual care arms, respectively.

CONCLUSIONS

Web-based vaccination information sent to pregnant women can positively influence maternal influenza vaccine uptake. Because of potential scalability, the impact of robust vaccination information websites should be studied in other settings.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT01873040.

Estimating Influenza-associated Mortality in Korea: The 2009-2016 Seasons

OBJECTIVES

Estimating influenza-associated mortality is important since seasonal influenza affects persons of all ages, causing severe illness or death. This study aimed to estimate influenza-associated mortality, considering both periodic changes and age-specific mortality by influenza subtypes.

METHODS

Using the Microdata Integrated Service from Statistics Korea, we collected weekly mortality data including cause of death. Laboratory surveillance data of respiratory viruses from 2009 to 2016 were obtained from the Korea Centers for Disease Control and Prevention. After adjusting for the annual age-specific population size, we used a negative binomial regression model by age group and influenza subtype.

RESULTS

Overall, 1 859 890 deaths were observed and the average rate of influenza virus positivity was 14.7% (standard deviation [SD], 5.8), with the following subtype distribution: A(H1N1), 5.0% (SD, 5.8); A(H3N2), 4.4% (SD, 3.4); and B, 5.3% (SD, 3.7). As a result, among individuals under 65 years old, 6774 (0.51%) all-cause deaths, 2521 (3.05%) respiratory or circulatory deaths, and 1048 (18.23%) influenza or pneumonia deaths were estimated. Among those 65 years of age or older, 30 414 (2.27%) all-cause deaths, 16 411 (3.42%) respiratory or circulatory deaths, and 4906 (6.87%) influenza or pneumonia deaths were estimated. Influenza A(H3N2) virus was the major contributor to influenza-associated all-cause and respiratory or circulatory deaths in both age groups. However, influenza A(H1N1) virus-associated influenza or pneumonia deaths were more common in those under 65 years old.

CONCLUSIONS

Influenza-associated mortality was substantial during this period, especially in the elderly. By subtype, influenza A(H3N2) virus made the largest contribution to influenza-associated mortality.