Characteristics and mortality risk of children with life-threatening influenza infection admitted to paediatric intensive care in England 2003-2015

Severe Influenza Virus and Respiratory Syncytial Virus Infections in Intensive Care Over the Last 15 Years

INTRODUCTION

Influenza virus is a common agent of pediatric infections. Most cases are mild, but severe illness and death can occur. We aimed to analyze severe cases associated the influenza virus and compare it with respiratory syncytial virus (RSV).

METHODS

This is a retrospective study of 0-17-year-old patients admitted to the intensive care unit (ICU) of Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra (Pediatric Hospital, Coimbra Hospital and University Center), a tertiary pediatric hospital in Coimbra, Portugal, over the last 15 years (2008-2022) due to influenza virus infection. Clinical presentation, severity, and evolution were analyzed. A comparison of children with RSV infection admitted in the same period was performed.

RESULTS

We identified 47 cases of influenza virus infection (34% coinfection with other viruses), median age of 2.3 years (interquartile range (IQR) 6.1), and 38% had comorbidities. The median admissions were three/year (maximum 11 in 2019). Influenza A was identified in 96%. Ninety-six percent had respiratory symptoms, 38% had neurologic symptoms, and 28% had sepsis. The main reason for admission was respiratory failure (68%). The mean pediatric index of mortality 2 (PIM2) at admission was 9±15.9%. Ventilatory support was necessary in 66%, vasoactive support in 19%, and blood products in 17%. The median length of stay was four days (IQR 5). There were four (8.5%) deaths. During the same study period, there were 171 RSV-related admissions. When comparing influenza (group A, without RSV coinfection) and RSV (group B), the first had a higher PIM2 on admission, greater need of ventilatory support, more complications, and higher mortality (p=0.001).

CONCLUSIONS

The number of influenza virus infections admitted to ICU was much lower than RSV. However, influenza was more severe and associated with all deaths registered.

The convergent evolution of influenza A virus: Implications, therapeutic strategies and what we need to know

Influenza virus infection, more commonly known as the 'cold flu', is an etiological agent that gives rise to recurrent annual flu and many pandemics. Dated back to the 1918- Spanish Flu, the influenza infection has caused the loss of many human lives and significantly impacted the economy and daily lives. Influenza virus can be classified into four different genera: influenza A-D, with the former two, influenza A and B, relevant to humans. The capacity of antigenic drift and shift in Influenza A has given rise to many novel variants, rendering vaccines and antiviral therapies useless. In light of the emergence of a novel betacoronavirus, the SARS-CoV-2, unravelling the underpinning mechanisms that support the recurrent influenza epidemics and pandemics is essential. Given the symptom similarities between influenza and covid infection, it is crucial to reiterate what we know about the influenza infection. This review aims to describe the origin and evolution of influenza infection. Apart from that, the risk factors entail the implication of co-infections, especially regarding the COVID-19 pandemic is further discussed. In addition, antiviral strategies, including the potential of drug repositioning, are discussed in this context. The diagnostic approach is also critically discussed in an effort to understand better and prepare for upcoming variants and potential influenza pandemics in the future. Lastly, this review encapsulates the challenges in curbing the influenza spread and provides insights for future directions in influenza management.

The influence of disparities on intensive care outcomes in children with respiratory diseases: A systematic review

CONTEXT

The negative effects of socioeconomic, environmental and ethnic inequalities on childhood respiratory diseases are known in the development of persistent asthma and can result in adverse outcomes. However, little is known about the effects of these disparities on pediatric intensive care unit (PICU) outcomes in respiratory diseases.

OBJECTIVE

The purpose of this systematic review is to evaluate the literature on disparities in socioeconomic, environmental and ethnic determinants and PICU outcomes. We hypothesize that these disparities negatively influence the outcomes of children's respiratory diseases at the PICU.

METHODS

A literature search (in PubMed, Embase.com and Web of Science Core Collection) was performed up to September 30, 2022. Two authors extracted the data and independently evaluated the risk of bias with appropriate assessment methods. Articles were included if the patients were below 18 years of age (excluding neonatal intensive care unit admissions), they concerned respiratory diseases and incorporated socioeconomic, ethnic or environmental disparities.

RESULTS

Eight thousand seven hundred fourty-six references were reviewed, and 15 articles were included; seven articles on the effect of socioeconomic status, five articles on ethnicity, one on the effect of sex and lastly two on environmental factors. All articles but one showed an unfavorable outcome at the PICU.

CONCLUSION

Disparities in socioeconomic (such as a low-income household, public health insurance), ethnic and environmental factors (such as exposure to tobacco smoke and diet) have been assessed as risk factors for the severity of children's respiratory diseases and can negatively influence the outcomes of these children admitted and treated at the PICU.

The burden of viral infections in pediatric intensive care unit between endemic and pandemic coronavirus infections: A tertiary care center experience

Objectives

To measure the prevalence of viral infections, length of stay (LOS), and outcome in children admitted to the pediatric intensive care unit (PICU) during the period preceding the COVID-19 pandemic in a MERS-CoV endemic country.

Methods

A retrospective chart review of children 0–14 years old admitted to PICU with a viral infection.

Results

Of 1736 patients, 164 patients (9.45%) had a positive viral infection. The annual prevalence trended downward over a three-year period, from 11.7% to 7.3%. The median PICU LOS was 11.6 days. Viral infections were responsible for 1904.4 (21.94%) PICU patient-days. Mechanical ventilation was used in 91.5% of patients, including noninvasive and invasive modes. Comorbidities were significantly associated with intubation (P-value = 0.025). Patients infected with multiple viruses had median pediatric index of mortality 2 (PIM 2) scores of 4, as compared to 1 for patients with single virus infections (p < 0.001), and a median PICU LOS of 12 days, compared to 4 in the single-virus group (p < 0.001). Overall, mortality associated with viral infections in PICU was 7 (4.3%). Patients with viral infections having multiple organ failure were significantly more likely to die in the PICU (p = 0.001).

Conclusion

Viral infections are responsible for one-fifth of PICU patient-days, with a high demand for mechanical ventilation. Patients with multiple viral infections had longer LOS, and higher PIM 2 scores. The downward trend in the yearly rate of PICU admissions for viral infections between the end of the MERS-CoV outbreak and the start of the COVID-19 pandemic may suggest viral interference that warrants further investigations.

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.

Risk factors in pediatric hospitalization for influenza A and B during the seven seasons immediately before the COVID-19 era in Japan

INTRODUCTION

The risk factors in pediatric influenza immediately before the COVID-19 era are not well understood. This study aims to evaluate the risk factors for hospitalization in pediatric influenza A and B for the recent seasons.

METHODS

Children with a fever of ≥38 °C and laboratory-confirmed influenza at 20 hospitals in outpatient settings in Japan in the 2013/14 to 2019/20 seasons were retrospectively reviewed. Possible risk factors, including gender, age, comorbidities, nursery school or kindergarten attendance, earlier diagnosis, no immunization, lower regional temperature, earlier season, and period of onset, were evaluated using binary logistic regression methods.

RESULTS

A total of 13,040 (type A, 8861; B, 4179) children were evaluated. Significant risk factors (p < 0.05) in multivariate analyses were young age, lower regional temperature, earlier season, respiratory illness (adjusted odds ratio [aOR]:2.76, 95% confidence interval [CI]:1.84-4.13), abnormal behavior and/or unusual speech (aOR:2.78, 95% CI:1.61-4.80), and seizures at onset (aOR:16.8, 95% CI:12.1-23.3) for influenza A; and young age, lower regional temperature, respiratory illness (aOR:1.99, 95% CI:1.00-3.95), history of febrile seizures (aOR:1.73, 95% CI:1.01-2.99), and seizures at onset (aOR:9.74, 95% CI:5.44-17.4) for influenza B.

CONCLUSIONS

In addition to previously known factors, including young age, seizures, and respiratory illness, abnormal behavior and/or unusual speech and lower regional temperature are new factors. Negative immunization status was not a risk factor for hospitalization. A better understanding of risk factors may help improve the determination of indications for hospitalization during the future co-circulation of influenza and COVID-19.

Racial, ethnic, and socioeconomic disparities in paediatric critical care in the USA

In an era of tremendous medical advancements, it is important to characterise and address inequities in the provision of health care and in outcomes. There is a large body of evidence describing such disparities by race or ethnicity and socioeconomic position in critically ill adults; however, this important issue has received less attention in children and adolescents (aged ≤21 years). This Review presents a summary of the available evidence on disparities in outcomes in paediatric critical illness in the USA as a result of racism and socioeconomic privilege. The majority of evidence of racial and socioeconomic disparities in paediatric critical care originates from the USA and is retrospective, with only one prospective intervention-based study. Although there is mixed evidence of disparities by race or ethnicity and socioeconomic position in general paediatric intensive care unit admissions and outcomes in the USA, there are striking trends within some disease processes. Notably, there is evidence of disparities in management and outcomes for out-of-hospital cardiac arrest, asthma, severe trauma, sepsis, and oncology, and in families' perceptions of care. Furthermore, there is clear evidence that critical care research is limited by under-enrolment of participants from minority race or ethnicity groups. We advocate for rigorous research standards and increases in the recruitment and enrolment of a diverse range of participants in paediatric critical care research to better understand the disparities observed, including the effects of racism and poverty. A clearer understanding of when, where, and how such disparities affect patients will better enable the development of effective strategies to inform practice, interventions, and policy.

Estimated impact of maternal vaccination on global paediatric influenza-related in-hospital mortality: A retrospective case series

BACKGROUND

Influenza virus infection is an important cause of under-five mortality. Maternal vaccination protects children younger than 3 months of age from influenza infection. However, it is unknown to what extent paediatric influenza-related mortality may be prevented by a maternal vaccine since global age-stratified mortality data are lacking.

METHODS

We invited clinicians and researchers to share clinical and demographic characteristics from children younger than 5 years who died with laboratory-confirmed influenza infection between January 1, 1995 and March 31, 2020. We evaluated the potential impact of maternal vaccination by estimating the number of children younger than 3 months with in-hospital influenza-related death using published global mortality estimates.

FINDINGS

We included 314 children from 31 countries. Comorbidities were present in 166 (53%) children and 41 (13%) children were born prematurely. Median age at death was 8·6 (IQR 4·5-16·6), 11·5 (IQR 4·3-24·0), and 15·5 (IQR 7·4-27·0) months for children from low- and lower-middle-income countries (LMICs), upper-middle-income countries (UMICs), and high-income countries (HICs), respectively. The proportion of children younger than 3 months at time of death was 17% in LMICs, 12% in UMICs, and 7% in HICs. We estimated that 3339 annual influenza-related in-hospital deaths occur in the first 3 months of life globally.

INTERPRETATION

In our study, less than 20% of children is younger than 3 months at time of influenza-related death. Although maternal influenza vaccination may impact maternal and infant influenza disease burden, additional immunisation strategies are needed to prevent global influenza-related childhood mortality. The missing data, global coverage, and data quality in this study should be taken into consideration for further interpretation of the results.

FUNDING

Bill & Melinda Gates Foundation.

Contemplating on the Etiology of COVID-19 Severity and Mortality Sex Differences

COVID-19 displays a sex-biased behavior with a higher rate of intensity and mortality in men. In that sense, COVID-19 deflects-off the typical trend of many viral infections which are characterized by a higher rate of intensity and prevalence in males, yet a higher female mortality rate. Severity and mortality rates of COVID-19 are associated with several underlying diseases, which exhibit significant self-sufficient male-biased dimorphism, thus are at times hypothesized to be the ones responsible to tilt mortality balance toward higher men death in COVID-19. Yet, similar comorbidities prevail in other viral infections, raising curiosity to what makes COVID-19 unique? The answer may lay in the involvement of renin-angiotensin system and ACE2 receptor in COVID-19 progression, 2 players which are significant contributors to the fatality of COVID-19. A structured difference is evident in the expression and function of RAS and ACE2 between the sexes, presumably tipping over mortality rate tendency toward male-risk factor.

A paediatric influenza update 100 years after the Skyros island Spanish flu outbreak

This year marks the 100th anniversary of the 1918 Spanish flu outbreak on the Greek Aegean Sea island of Skyros, which devastated its population in less than 30 days. According to Constantinos Faltaits's annals published in 1919, the influenza attack on the island of Skyros commenced acutely ‘like a thunderbolt’ on the 27th of October, 1918 and was exceptionally severe and fatal. At that time, the viral cause of the influenza had not been detected, while the total number of victims of the Spanish flu outbreak has been estimated to have surpassed 50 million, worldwide. Almost one century after this Aegean Sea island's tragedy, the ‘4th Workshop on Paediatric Virology’, organised on the 22nd of September, 2018 in Athens, Greece, was dedicated to the 100 years of the ‘Spanish’ flu pandemic. This review article highlights the plenary and key lectures presented at the workshop on the recent advances on the epidemiology, clinical management and prevention of influenza in childhood.

Impact of the introduction of a universal childhood influenza vaccination programme on influenza-related admissions to paediatric intensive care units in England

Introduction

A universal childhood influenza vaccination programme was introduced in the UK in September 2013. We examine the impact of the gradual introduction of this programme on influenza-related paediatric intensive care unit (PICU) admission rates in England.

Methods

We extracted data on all influenza-related admissions to PICUs in England in resident children aged 0–15 years old between October 2003 and March 2017 from the Paediatric Intensive Care Audit Network (PICANet) database. We estimated influenza-associated PICU admission rates per 100 000 children by age group, sex and winter season (October to March), and used Poisson regression models to estimate incidence rate ratios (IRRs) in the winter seasons since the introduction of universal childhood vaccination compared with the two winters before the introduction of the programme (2011–2013).

Results

We identified 929 influenza-related PICU admissions among 873 children. 48.3% of admissions were among children aged less than 2 years old. The influenza-associated PICU admission rate was 1.32 per 100 000 children (95% CI 1.23 to 1.40). We identified a significant increase in influenza PICU admissions in the winters following the introduction of the universal childhood vaccination programme compared with the winters of 2010/2011–2012/2013 among children aged <5 years old: IRR 1.58 (1.05, 2.37) in children <1 year, 2.71 (1.43, 5.17) in 1 year-olds and 1.98 (1.18, 3.31) in children 2–4 years old. No significant difference was found among children aged 5–15 years.

Conclusion

The universal childhood influenza vaccination has not yet reduced the influenza-associated burden on PICUs in England during its early phase of introduction. Monitoring of influenza PICU admission rates needs to continue in England to assess the long-term impact of universal paediatric influenza vaccination. Linkage between PICANet and national infection surveillance databases would better enable such monitoring.