Critical influenza virus infection
Related Experiment Video
Updated: Oct 13, 2026
Imaging Cell Interaction in Tracheal Mucosa During Influenza Virus Infection Using Two-photon Intravital Microscopy
Published on: August 17, 2018
C Kappagoda1, D Isaacs, C Mellis
1Department of Immunology and Infectious Diseases, Royal Alexandra Hospital for Children, Westmead and The University of Sydney, New South Wales, Australia.
Insights
Children with chronic underlying conditions face a higher risk of death from critical influenza infections. This retrospective study highlights the significant mortality associated with severe influenza in this vulnerable pediatric population.
Area of Science:
- Pediatric Infectious Diseases
- Critical Care Medicine
- Epidemiology
Background:
- Influenza virus infections can lead to severe illness in children.
- Chronic underlying diseases may increase the risk of critical influenza outcomes.
- Understanding mortality risks is crucial for managing pediatric influenza cases.
Purpose of the Study:
- To assess the mortality risk of influenza infection in children with chronic underlying diseases.
- To identify factors associated with severe influenza outcomes in pediatric patients.
- To evaluate the impact of chronic conditions on influenza-related deaths.
Main Methods:
- Retrospective study of 27 children with critical influenza A or B infection over 18 years.
- Inclusion criteria: intensive care unit admission or death, excluding laryngotracheobronchitis (LTB).
- Influenza diagnosis confirmed by viral culture or immunofluorescence; LTB cases analyzed separately.
Main Results:
- Overall mortality for critical influenza was 33% (9 out of 27 children).
- Children with chronic underlying disease had a higher mortality rate (46%) compared to those without (21%).
- Nosocomial influenza infection accounted for 26% of critical cases, indicating hospital-acquired infections are a concern.
Conclusions:
- Critical, life-threatening influenza is uncommon but carries a high mortality rate, especially in children with chronic conditions.
- Chronic underlying diseases significantly increase the risk of death from severe influenza.
- Nosocomial influenza infections are a notable cause of critical illness and intensive care admissions in children.
Objective:
To determine the risk of death from influenza infection in children with chronic underlying disease.
Methodology:
An 18-year retrospective study of children with 'critical' influenza A or B virus infection, defined as requiring admission to intensive care or resulting in death, but excluding laryngotracheobronchitis (LTB). Influenza infection was diagnosed by viral culture and/or immunofluorescence of respiratory secretions. Patients with LTB were analysed separately.
Results:
There were 27 cases of critical influenza virus infection over the study period, comprising 26 admissions to the intensive care unit (excluding LTB) and one death on the general wards. Thirteen (48%) of the 27 children had chronic underlying disease. In addition, 12 children with LTB were admitted to the intensive care unit. The LTB children were older and less likely to have chronic underlying disease. Nosocomial infection caused seven (26%) of the 27 critical infections. Nine (33%) of the 27 children with critical influenza died. Six (46%) of 13 children with chronic underlying disease and influenza admitted to intensive care died, compared with three of 14 (21%) without any underlying disease (odds ratio = 3.1, 95% confidence interval 0.6-14.0).
Conclusions:
Critical life-threatening influenza virus infection was uncommon, but the mortality was high (33%), particularly in children with chronic underlying disease. Nosocomial infection with influenza was an important cause of admission to intensive care.
Related Concept Videos
01:27Influenza
01:25Inhibitors Of Virion Release
01:29Respiratory Syncytial Virus Disease
01:29Coronavirus
01:26Stages of Infection