Paeds · infectious-diseases
Influenza and antiviral treatment
Also known as Seasonal influenza in children · Flu (paediatric) · Influenza A and B in children · Oseltamivir and baloxavir treatment of influenza · Paediatric influenza pneumonia and encephalopathy
Fellowship topic on influenza and antiviral treatment in children: the influenza A and B viruses and their seasonal epidemiology; abrupt febrile presentation and the atypical infant and high-risk presentations; viral and secondary bacterial pneumonia, encephalopathy and the other complications; PCR and rapid testing interpreted in context; stepwise management from supportive care of the hospitalised child through early oseltamivir and baloxavir, who to treat and when; post-exposure prophylaxis; and annual plus maternal vaccination as the prevention backbone — with ANZ, UK, US and Canada guidance.
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Target exams
Red flags
- An infant with influenza and respiratory distress, apnoea, poor feeding or a sepsis-like picture — deteriorates quickly and needs admission and early antiviral treatment
- Secondary deterioration after initial improvement — new fever, worsening breathlessness or sepsis signals secondary bacterial pneumonia, a leading cause of influenza death
- Altered consciousness, seizures or behavioural change during influenza — influenza-associated encephalopathy, which can be rapidly progressive and fatal
- Myocarditis signs — tachycardia out of proportion to fever, poor perfusion, hepatomegaly or arrhythmia in a febrile child with influenza
- A child with a high-risk condition (chronic lung, cardiac, neurologic, immunocompromise, < 2 years) — treat early with antivirals; do not wait for confirmation
- Severe myositis with an inability to walk, or rhabdomyolysis with dark urine — escalate fluid and monitoring
Life stages
Care settings
Clinical exam formats
Board mappings
- General Paediatrics and Infectious Diseases: influenza — clinical presentation, complications and antiviral treatment in children
- Immunisation: the annual childhood influenza schedule and the maternal-vaccination programme
- Renewed curriculum — Infectious diseases: influenza diagnosis, antiviral use (oseltamivir and baloxavir), prophylaxis and notification
- Community and population child health: seasonal vaccination strategy, high-risk groups and outbreak response
- General Paediatrics: influenza — assessment and antiviral treatment of the febrile child and the sick infant
- Public health: droplet precautions, exclusion and post-exposure prophylaxis of high-risk contacts
- Long Case / Structured discussion: the hospitalised child with influenza and complications — diagnosis, antiviral treatment, supportive care and prevention
- Communication station: explaining influenza, antiviral treatment and vaccination to a family
- Level 2 / 3 — Infection: influenza as a vaccine-preventable respiratory infection; diagnosis, antiviral treatment and complications
- Public health and immunisation: the annual influenza vaccine, the two-dose first season, and maternal vaccination
- Foundation of Practice (FOP): influenza presentation, complications and the high-risk groups in children
- Applied Knowledge in Practice (AKP): oseltamivir and baloxavir treatment, prophylaxis and immunisation strategy
- History-taking and management: the febrile child with influenza and the sick infant
- Communication: explaining influenza, antiviral treatment and vaccination to a family
- General Pediatrics Content Outline — influenza: diagnosis, antiviral treatment, complications and prevention
- Infectious Diseases: influenza A/B, PCR testing, oseltamivir and baloxavir, and post-exposure prophylaxis
- Bright Futures / immunisation: the annual influenza vaccine from 6 months and maternal vaccination
- Patient Care: diagnosis and stepwise antiviral management of influenza across age groups and severities
- Systems-Based Practice and Population Health: droplet precautions, exclusion, prophylaxis and the immunisation programme
- Medical Knowledge: influenza pathophysiology, antiviral mechanisms and complications
- Medical Expert: influenza diagnosis, antiviral treatment and complications
- Health Advocate and Collaborator: immunisation, maternal vaccination, prophylaxis and public-health coordination
- Communicator: explaining influenza, antiviral treatment and prevention to families
Two ends of the same virus
Older, healthy child
Infant or high-risk child
Fever with cough in season → test with PCR when it changes management, but Lower your threshold to treat the Unwell, hospitalised, infant under two, and any child with a high-risk condition. Early oseltamivir helps most in the first 48 hours, but treat severe disease regardless of duration — the antiviral is cheap, the complications are not. [2] [6]
Overview & Definition
Picture a three-year-old brought to the emergency department in mid-winter with a high fever, a dry cough and aching legs, who has been well until that morning. The suddenness is the clue — influenza does not creep in the way a common cold does, it arrives all at once. Recognising that pattern, and knowing when to escalate from reassurance to antiviral treatment, is the skill this topic builds. [2] [3]
Influenza is an acute infection of the respiratory tract caused by influenza A or B viruses (family Orthomyxoviridae), spread by respiratory droplets and by contact with contaminated surfaces. It causes recurrent seasonal winter epidemics and, periodically, pandemics. In older children and adults it is a self-limiting febrile illness; in infants and in children with chronic medical conditions it is a leading cause of hospitalisation, intensive-care admission and death. [2] [3]
The clinician's task has three parts. The first is to recognise influenza and triage severity — who can be managed at home and who is heading for the ward or the intensive-care unit. The second is to treat early with antivirals in the right patients, alongside supportive care and active management of complications. The third is prevention through annual vaccination, maternal vaccination and infection control, because the child who never reaches hospital is child immunisation programme has protected. [3] [10]
References11ShowHide
- [1]Whitley RJ; Hayden FG; Reisinger KS; et al Oral oseltamivir treatment of influenza in children. Pediatr Infect Dis J, 2001.PMID 11224828
- [2]Jain S; Kamimoto L; Bramley AM; et al Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009. N Engl J Med, 2009.PMID 19815859
- [3]Bhat N; Wright JG; Broder KR; et al Influenza-associated deaths among children in the United States, 2003-2004. N Engl J Med, 2005.PMID 16354892
- [4]Randolph AG; Vaughn F; Sullivan R; et al Critically ill children during the 2009-2010 influenza pandemic in the United States. Pediatrics, 2011.PMID 22065262
- [5]Dobson J; Whitley RJ; Pocock S; et al Oseltamivir treatment for influenza in adults: a meta-analysis of randomised controlled trials. Lancet, 2015.PMID 25640810
- [6]Heinonen S; Silvennoinen H; Lehtinen P; et al Early oseltamivir treatment of influenza in children 1-3 years of age: a randomized controlled trial. Clin Infect Dis, 2010.PMID 20815736
- [7]Hayden FG; Sugaya N; Hirotsu N; et al Baloxavir Marboxil for Uncomplicated Influenza in Adults and Adolescents. N Engl J Med, 2018.PMID 30184455
- [8]Kimberlin DW; Acosta EP; Prichard MN; et al Oseltamivir pharmacokinetics, dosing, and resistance among children aged <2 years with influenza. J Infect Dis, 2013.PMID 23230059
- [9]Ishiguro N; Morioka I; Nakano T; et al Clinical and Virologic Outcomes of Baloxavir Compared with Oseltamivir in Pediatric Patients with Influenza in Japan. Infect Dis Ther, 2025.PMID 40155497
- [10]Omer SB; Clark DR; Madhi SA; et al Efficacy, duration of protection, birth outcomes, and infant growth associated with influenza vaccination in pregnancy: a pooled analysis of three randomised controlled trials. Lancet Respir Med, 2020.PMID 32526188
- [11]Omer SB; Clark DR; Aqil AR; et al Maternal Influenza Immunization and Prevention of Severe Clinical Pneumonia in Young Infants: Analysis of Randomized Controlled Trials Conducted in Nepal, Mali and South Africa. Pediatr Infect Dis J, 2018.PMID 29443825