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Clinical Practice Guidelines

Prolonged fever

  • See also

    Febrile child 

    Fever in the recently returned traveller 

    Sepsis: assessment and management 

    Kawasaki disease

    Key points

    1. Infection is the most common cause of prolonged fever. However, malignancy, rheumatological disorders and other inflammatory conditions should also be considered
    2. Detailed history taking and serial examination are essential in the workup
    3. A tiered diagnostic approach helps minimise unnecessary investigations and should be guided by the child's clinical presentation
    4. If the child is stable, observation and investigation prior to commencing antibiotics is preferred

    Background

    • In this guideline, prolonged fever refers to a fever of ≥38.0°C lasting more than 7 days without an identifiable source
    • Investigations may be postponed for 10-14 days in previously healthy, immunised, otherwise well looking children, who are not returned international travellers
    • The following are outside the scope of this guideline:

    Assessment

    History

    • Immune status: immunocompetent vs immunocompromised
    • Ethnicity and background: Aboriginal and/or Torres Strait Islander status, country of birth, vaccination history
    • Fever details: onset, duration, pattern
    • Resolved or transient symptoms: rash, conjunctivitis, sore throat, skin infections
    • Systemic symptoms: weight loss, night sweats, bruising/bleeding, joint pain or swelling
    • Environmental and exposure history
      • Property type (urban vs rural)
      • Drinking water source (town vs tank) and water exposure (floods, swimming)
      • Soil ingestion (intentional or unintentional eg toddler age-group, children with pica)
      • Consumption of unpasteurised animal milk or imported foods/substances
      • Contact with pets/animals (at home or outside the home)
      • Exposure to arthropod bites
    • Travel history (domestic or international): timeframe of travel, destinations visited, activities undertaken and preventative measures taken
    • Medications: recent antibiotics, steroids, possibility of drug-induced fever
    • Infection history: previous similar episodes of symptoms, previous significant microbiology if available including multi-resistant organisms
    • Family history: acute rheumatic fever (ARF), rheumatic heart disease (RHD), hereditary cancer syndromes, rheumatological conditions, autoimmune disorders or recurrent fever syndromes
    • Sexual history: sexually transmitted infections should be considered

    Examination

    • Neurological: change in personality, unexplained lethargy or confusion, meningism or focal neurological findings
    • Cardiac: new murmur may suggest endocarditis
    • Respiratory: subtle reduced air entry or respiratory distress
    • Abdominal: tenderness or mass
    • Lymphadenopathy or hepatosplenomegaly
    • Musculoskeletal: inability to weight bear, focal bony tenderness, or joint pain or swelling
    • Skin and mucosa: rash, purpura, cellulitis, hidden tick or eschar, mucosal or oral changes like conjunctival injection or strawberry tongue
    • Ear, nose and throat: sinus, mastoid or dental infection
    • Signs of systemic inflammatory conditions: consider clinical criteria of Kawasaki Disease including incomplete, acute rheumatic fever (ARF), juvenile idiopathic arthritis (JIA) and systemic lupus erythematosus (SLE)

    Management

    Investigations

    Prolonged fever flow chart

    Tiered investigations to consider in the diagnostic approach of a child with prolonged fever

    Tier 1 investigations
    Bloods
    • FBE
    • UEC and LFTs
    • CRP, ESR
    • Ferritin, LDH
    • Serial blood cultures, initially at least two sets
    • Collect spare serum and plasma specimens for storage for "add-on" investigations as required
    Other investigations
    • Nasopharyngeal swab for respiratory virus and Mycoplasma pneumoniae polymerase chain reaction (PCR)
    • Urinalysis and MCS
    • Chest radiograph (CXR)
    • Faecal PCR +/- MCS and ova, cyst and parasite examination (if diarrhoea)
    • CSF analysis (if clinical concerns of CNS infection)
    Note
    • Review relevant endemic infections and exposures table below and investigate accordingly
    Tier 2 investigations
    Bloods
    • Repeat FBE and film, LDH and urea
    • Serology for
      • Epstein Barr virus
      • Cytomegalovirus +/- IgG avidity (if IgM detected)
      • Group A Streptococcus (ASOT, anti-DNAse)
      • Bartonella henselae
      • Toxoplasma gondii
    Other investigations
    • Throat swab MCS
    • Nasopharyngeal swab and faecal PCR for enterovirus and adenovirus
    • US abdomen
    • Consideration of further imaging: targeted imaging is preferred in patients with focal findings
    • Reconsider CSF analysis if not already completed and clinical concerns of CNS infection
    Note
    • Review Tier 1 investigations results
    • Review relevant endemic infections and exposures table below and investigate accordingly
    Tier 3 investigations
    Bloods
    • Serology for
      • Hepatitis ABCE +/- PCR in child with deranged LFTs; withhold hep B serology in vaccinated child
      • HIV
      • Syphilis
    • If close contact of tuberculosis (TB) or travel to endemic areas: Interferon-gamma release assay (IGRA) +/- TB PCR (eg Xpert TB/Rif Ultra)
    • Anti-nuclear antibodies (ANA), double stranded DNA (dsDNA), extractable nuclear antigen (ENA), anti-neutrophil cytoplasmic antibodies (c-ANCA, p-ANCA) and rheumatic factor (RF)
    • Consideration of tumour markers, lymph node biopsy and/or bone marrow aspirate
    Other investigations
    • If close contact of TB or travel to endemic areas: mycobacterial culture on induced sputum or early morning gastric aspirate or stool (if sputum/aspirate is not feasible)
    • Faecal-occult blood test (FOBT)
    • Echocardiogram
    • Consideration of further imaging: targeted imaging is preferred in patients with focal findings
    • CSF analysis (if not already completed)
    Note
    • Review Tier 1 and 2 investigations results
    • Review relevant endemic infections and exposures table below and investigate accordingly

    Interpret investigation results in the context of the clinical presentation, considering both the limitations of the test and recognising that positive tests (eg for respiratory viruses) may not fully account for the severity or duration of a child's illness

    Endemic infectious diseases and exposures to consider

    • Carefully review the timing of the exposure, the expected incubation period and the onset of illness. This informs the likelihood of the diagnosis and the appropriate timing of investigations
    • Nucleic acid amplification tests, most commonly polymerase chain reaction (PCR), are most helpful in the first 1-2 weeks of infection (in the seronegative window period)
    • Serology is most useful when collected early in illness and again at 7-21 day intervals. Serial samples should be tested in parallel to be able to demonstrate seroconversion
    • Endemic regions are indicative and may shift over time due to globalisation, climate change and other dynamic factors influencing disease epidemiology

    Endemic infections and exposures: Domestic, farm or wild animals

    Exposure Disease pathogen Endemic region Incubation period Clinical features Bloods Other investigations
    Contaminated food

    Contact with unusual pets (eg turtles)    		 Nontyphoidal salmonellosis

    Salmonella enterica    		 National

    6 to 72 hours    		 Enterocolitis, bacteraemia, focal infection Blood culture Stool for PCR and MCS
    Cats Cat scratch disease

    Bartonella henselae    		 National

    3 to 30 days    		 Localised cutaneous and lymph node disease, disseminated disease (liver, spleen, eye, musculoskeletal or nervous system) Serology Sample for PCR and culture (skin swab, aspirate, tissue)
    Cats
    Dogs
    Contaminated dirt being ingested    		 Toxocariasis (Visceral and ocular larva migrans)

    Toxocara canis

    Toxocara cati

    National


    Weeks to years

    		 Visceral: eosinophilia, hepatomegaly
    Ocular: visual loss, eye pain, white pupil, strabismus    		 Serology Ophthalmology review (if eye symptoms)
    Rats Rat bite fever

    Streptobacillus moniliformis    		 National

    3 to 10 days    		 Myalgia, migratory polyarthralgia, arthritis, rash (hands/feet) Blood culture Sample for MCS (skin swab, joint aspirate)
    Snails, slugs
    Unwashed vegetables

    Contaminated dirt being ingested    		 Eosinophilic meningitis

    Angiostrongylus cantonensis    		 Eastern Australia

    2 to 35 days    		 Eosinophilic meningoencephalitis Serology CSF for eosinophils, PCR and IgG antibodies
    Pigs (pig hunting, pig dogs or undercooked feral pig meat) Brucellosis

    Brucella suis    		 QLD, NSW

    5 to 60 days    		 Night sweats, malaise, arthralgia, hepatosplenomegaly, lymphadenopathy Blood culture

    PCR
    Serology    		 Notify pathology prior to sending samples
    Birds

    Contaminated aerosols being inhaled    		 Psittacosis (Ornithosis)

    Chlamydia psittaci    		 VIC, NSW

    5 to 21 days    		 Asymptomatic, flu-like illness, severe atypical pneumonia Serology Respiratory sample for PCR (nasopharyngeal swab, sputum or BAL)
    Cattle, sheep, goats or macropods

    Contaminated aerosols being inhaled    		 Q fever

    Coxiella burnetii    		 QLD, NSW, VIC

    2 to 3 weeks    		 Acute: flu-like illness, pneumonia, hepatitis, lymphopenia, thrombocytopenia
    Chronic: endocarditis, osteomyelitis    		 PCR (days 1-14)

    Serology (from day 7)
    Ringtail possums Tularemia

    Francisella tularensis subsp. holarctica (type B)    		 TAS, NSW

    1 to 14 days    		 Ulcer and regional lymphadenopathy (ulceroglandular syndrome) Blood culture

    PCR

    Serology    		 Sample for PCR and culture (skin swab, aspirate, tissue)

    Notify pathology prior to sending samples

    Endemic infections and exposures: Insect bites

    Exposure Disease pathogen

    Endemic region

    Incubation period

    		 Clinical features Bloods Other investigations
    Fleas, mites (chiggers) and ticks Murine typhus

    Rickettsia typhi

    Rickettsia felis    		 National

    2 to 14 days    		 Papule at bite site becomes an eschar (scab), headache, myalgia, lymphadenopathy, rash PCR

    Serology    		 Sample for PCR (skin swab, tissue)
    Scrub typhus

    Orientia tsutsugamushi    		 North QLD, Litchfield, NT, Kimberly, WA

    2 to 14 days
    Queensland tick typhus (spotted fever)

    Rickettsia australis    		 Eastern Australia

    2 to 14 days
    Flinders Island spotted fever

    Rickettsia honei    		 Flinders Island, TAS

    2 to 14 days
    Mosquitoes Barmah Forest virus

    		 National

    3 to 11 days    		 Arthralgia, arthritis, prolonged fatigue/malaise PCR (limited availability)

    Serology

    Ross River Fever

    Ross river virus
    Dengue

    Dengue virus

    Serotypes 1-4    		 North QLD

    3 to 14 days    		 Headache, retro-orbital pain, myalgia, rash, haemorrhagic fever/shock PCR and NS1 antigen (days 0-9)

    Serology
    Japanese encephalitis

    Japanese encephalitis virus (JEV) 
    		 NSW, VIC, SA, QLD

    5 to 15 days    		 Headache, myalgia, rash, encephalitis  PCR +/- culture (acute illness)

    Serology     		 CSF for PCR and serology

    Urine for PCR

    Note provisional diagnosis on pathology form to inform serology 

    Murray Valley encephalitis

    Murray Valley encephalitis virus 

    		 NSW, VIC, WA, NT

    5 to 28 days 

    Endemic infections and exposures: Contaminated water including after wet weather/flooding events

    Exposure Disease pathogen Endemic region Incubation period Clinical features Bloods Other investigations
    Contaminated water/soil Melioidosis

    Burkholderia pseudomallei    		 Northern Australia

    1 to 21 days    		 Subclinical, localised (pneumonia, skin lesions), disseminated (sepsis, internal abscesses, septic arthritis, osteomyelitis, parotitis, central nervous system disease) Blood culture

    Serology (limited value in endemic areas)    		 Sample for MCS (respiratory secretions, urine, CSF, wound sample)

    Note provisional diagnosis on pathology form for specific media
    Contaminated freshwater/soil
    Water activities (eg white-water rafting)
    Animal urine (eg rats)    		 Leptospirosis

    Leptospira sp.    		 QLD, NSW, VIC

    5 to 14 days    		 Subclinical, myalgia (calves and lower back), conjunctival suffusion, headache, disseminated (jaundice, renal failure) Blood culture (<10 days)

    PCR (<7 days)

    Leptospira IgM and Leptospira microscopic agglutination test (MAT) (>7 days)    		 Note provisional diagnosis on pathology form for specific media

    Treatment

    • Any febrile child who appears seriously unwell should be managed as suspected sepsis (see Sepsis)
    • If the child is stable, observation and investigation prior to commencing antibiotics is preferred
    • Specific treatment should be guided by clinical condition and investigation results
    • Antimicrobial recommendations may vary according to local antimicrobial susceptibility patterns, please refer to local guidelines
    • Provide antipyretics for comfort and ensure hydration

    Consider consultation with local paediatric team when

    All children with prolonged fever should be discussed with local paediatric team

    Consider transfer when

    The child requires care above the level of comfort of the local hospital or further inpatient sub-specialty opinion +/- management is required

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

    Consider discharge when

    • The child has been afebrile for >24-48 hours and showing clinical improvement
    • The diagnosis of the underlying cause of prolonged fever has been made, appropriate treatment (if required) has been commenced, and the child can be managed in the outpatient setting

    Parent information

    Fever fact sheets

    NSW 

    QLD 

    South Australia 

    Victoria 

    Western Australia

    Additional notes

    Australian guideline for prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease

    Last updated October 2025

    Reference List

    • Rupasinghe H, et al. Prolonged Fever in Children: An Inpatient Diagnostic Framework for Infections in Australia. J Paediatr Child Health. 2025 Mar 13. doi: 10.1111/jpc.70027. Epub ahead of print. PMID: 40083136.