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    Fever in returned traveller
    Febrile child

    Key points

    1. Most influenza in healthy children is self-limiting and uncomplicated
    2. Some chronic illnesses predispose children to higher risk of severe disease, but up to half of severe cases occur in previously well children
    3. In hospitalised children with severe disease, antiviral treatment should be commenced empirically if less than 48 hours since the onset
    4. In an unwell child, presence of influenza does not exclude co-existing serious bacterial infection


    • Incubation period is 1–4 days (average 2 days)
    • Hand and respiratory hygiene (eg covering the mouth when coughing) reduce transmission
    • Infectious period is from 24 hours prior to onset of symptoms for 4–7 days of illness. This can be prolonged in young children or those with immunodeficiency


    Clinical features of uncomplicated influenza

    • Fever (one third of children have fever without other symptoms)
    • Rigors or chills
    • Respiratory symptoms: rhinorrhoea, sore throat, cough, croup, otitis media
    • Headache
    • Myalgia, arthralgia
    • Lethargy, malaise
    • Less common: conjunctivitis, abdominal pain, nausea and vomiting

    Younger children may be:

    • less likely to have respiratory features
    • more likely to have febrile seizures
    • more likely to have gastrointestinal features
    • more likely to have severe disease – see Febrile child

    Complications of severe influenza

    • Pneumonia
    • Secondary bacterial infection especially S. aureus and S. pneumoniae
    • Respiratory failure
    • Neurological complications
      • Encephalopathy / encephalitis
      • Aseptic meningitis
      • Guillain-Barre Syndrome
      • Cerebellar ataxia
    • Myositis and rhabdomyolysis
    • Myocarditis and pericarditis
    • Reye syndrome (associated with aspirin use) 

    Risk factors for severe disease – consider treatment (see flowchart)

    • Severe chronic disease, particularly:
      • neurological
      • respiratory
      • cardiac
      • haematological eg sickle cell disease
    • Genetic condition eg trisomy 21
    • Premature infant
    • Immunosuppression


    Immunisation status does not affect the management of children with suspected influenza


    • Consider testing where confirmation is likely to influence treatment decisions - see flowchart
    • Detection of influenza virus by nucleic acid (PCR) testing from appropriate respiratory specimen (nasal or throat swab or nasopharyngeal aspirate)


    Supportive care eg hydration and/or respiratory support

    Admitted children should be isolated (or cohorted) - discuss with hospital infection control


      Clinical features at presentation - indications for treatment

      Severe respiratory (eg pneumonia), neurological (eg encephalitis), cardiac (eg myocarditis, pericarditis), muscle (eg rhadomyolysis) or multi-organ failure

      Antiviral treatment

      • Oseltamivir, zanamivir and peramivir are neuraminidase inhibitors that reduce influenza virus replication
        • Oseltamivir is usually first line therapy (oral or nasogastric)
      • Treatment may have a modest effect in terms of reducing duration of symptoms (1 day on average) and may prevent more severe disease
      • Treatment is most effective if started within 48 hours of onset of illness
      • Neuraminidase inhibitors have no role in treating other viral infections


      • Oral capsule 30 mg, 45 mg, 75 mg or oral suspension 6 mg/mL
      • Capsule contents may be dissolved in water (for use immediately)
      • Side effects:
        • headache
        • nausea and vomiting (reduce by giving with food), twice as likely to have vomiting (from 4% to 8% of unwell children)
      • For use in renal impairment – seek advice

      Oseltamivir dosage

      Weight Doses (oral) Duration
      Birth (term)–12 months 3 mg/kg/dose bd  5 days
      1–18 years
      <15 kg 30 mg bd 
      15–23 kg 45 mg bd 
      23–40 kg 60 mg bd 
      >40 kg 75 mg bd 
      Birth (term)–12 months 3 mg/kg/dose daily 10 days
      1–18 years
      <15 kg 30 mg daily
      15–23 kg 45 mg daily
      23–40 kg 60 mg daily
      >40 kg 75 mg daily

      *doses based on AMH


      • Seek specialist advice – for inpatient use only
      • Only children over 2 years
      • IV preparation – used when enteral route not appropriate

      Consider consultation with local paediatric team when

      Child has suspected influenza and risk factors 

      Consider transfer when

      • Child requiring care above the level of comfort of the local hospital
      • Child has severe disease

      For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services 

      Consider discharge when:

      Child is well and education provided to monitor for complications 

      Parent information

      RCH Kids Health Info Fact Sheet 
      NSW Children’s Hospital Fact Sheets  

      Additional notes

      Influenza vaccine

      • The best available preventative measure against influenza
      • Recommended for all people aged >6 months annually
        • Strongly recommended and funded for children ≥6 months and <5 years
        • Strongly recommended and funded for all children with Aboriginal or Torres Strait Islander background, children with risk factors for severe influenza and pregnant women
      • More information is available from the Australian Immunisation Handbook and the ATAGI annual position statement.

      Prophylaxis of contacts

      In hospital contact:

      • significant exposure is classified as being within 1 metre >15 mins without personal protective equipment

      After significant exposure, suggest oseltamivir (prophylaxis) for children and family members if:

      • they have risk factors
      • household contacts have risk factors
      • household contacts are:
        • aged ≥65 years 
        • women who are pregnant or within 2 weeks after delivery

      Last updated September, 2019

    • Reference List

      1. Blyth, C et al. Influenza Epidemiology, Vaccine Coverage and Vaccine Effectiveness in Children Admitted to Sentinel Australian Hospitals in 2017: Results from the PAEDS-FluCAN Collaboration. Clin Infect Dis. 2019. 68(6):940-948.
      2. Chaves, S et al.The Burden of Influenza Hospitalizations in Infants From 2003 to 2012, United States. The Pediatric Infectious Disease Journal. 2014. 33(9).  
      3. Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza, IDSA. Retrieved from (viewed July 2019).
      4. Committee on Infectious Diseases, American Academy of Pediatrics. Recommendations for Prevention and Control of Influenza in Children, 2018-2019. PEDIATRICS. 2018. 142(4).
      5. Gill, P et al. Identification of children at risk of influenza-related complications in primary and ambulatory care: a systematic review and meta-analysis. Lancet Respir Med. 2015; 3: 139–49.
      6. Jefferson T et al. Neuraminidase inhibitors for preventing and treating influenza in adults and children. Cochrane Database of Systematic Reviews. 2014.
      7. Jefferson, T et al. Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments. BMJ 2014. 348.
      8. McVernon J. Controversies in medicine: the rise and fall of the challenge to Tamiflu, The Conversation. Retrieved from (viewed 28 July 2019).
      9. Muthuri, S et al. Impact of neuraminidase inhibitor treatment on outcomes of public health importance during the 2009-2010 influenza A (H1N1) pandemic: a systematic review and meta-analysis in hospitalized patients. J Infect Dis.2013.207(4):553-63.
      10. NICE Guideline: Amantadine, oseltamivir and zanamivir for the treatment of influenza. Retrieved from (viewed 15 July 2019).
      11. Poehling, K et al. The Burden of Influenza in Young Children, 2004–2009. PEDIATRICS. 2013. 131(2).  
      12. Red Book. 2015. American Academy of Pediatrics. Retrieved from (viewed July 2019).
      13. Kmietowicz Z. WHO downgrades oseltamivir on drugs list after reviewing evidence. BMJ. 2017. 357.
      14. Seasonal influenza in children: Clinical features and diagnosis, UpToDate Retrieved from (viewed 6 June 2019).
      15. Silvennoinen, H et al. Clinical Presentation of Influenza in Unselected Children Treated as Outpatients. The Pediatric Infectious Disease Journal. 2009. 28(5).
      16. Upton D. The use of antiviral drugs for influenza: Guidance for practitioners. Retrieved from (viewed 15 July 2019).
      17. Wilson, E et al. Starship Guideline: Influenza. Retrieved from (viewed 15 July 2019).