Malaria

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  • See also

     Fever in the recently returned traveller

    Key points

    1. Malaria should be suspected in children with any febrile illness if they have travelled to a region where malaria is endemic (see map below)
    2. Artemether-lumefantrine is the treatment of choice for uncomplicated Plasmodium falciparum malaria
    3. Infection with P. vivax, P. ovale (or an unknown species) must be treated with primaquine to prevent relapse
    4. G6PD screening must be done before Primaquine is commenced

    Background

    • Malaria is a parasitic infection transmitted by Anopheles mosquitoes
    • The 5 species that infect humans are Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi
    • Severe malaria is largely caused by P. falciparum, although children with P. vivax and P. knowlesi malaria can also present seriously ill
    • Incubation period for P. falciparum infection is usually 14 days (range 7-30)
    • P. vivax and P. ovale produce liver hypnozoite forms which can cause relapse of the illness months to years later
    • Uncomplicated malaria is defined as confirmed parasitological diagnosis of malaria without signs of severity (organ dysfunction)
    • Young children (especially <5 years) can deteriorate rapidly and are more likely to have severe and cerebral malaria than adults

    Assessment

    History

    • Fever
    • Initial symptoms non-specific – include chills, sweating, abdominal pain, vomiting, diarrhoea, headache, myalgia
    • Malaria prophylaxis – medication, duration, adherence
    • Travel history (see map and Additional notes)

    Malaria

    Examination

    Pallor
    Splenomegaly
    Impaired consciousness
    Seizures
    Respiratory distress
    Shock
    Jaundice
    Spontaneous bleeding

    Management

    Investigations

    • Thick and thin film
    • Malaria antigen/ICT (rapid immunochromatographic assay) - detects P. falciparum with >90% sensitivity - insensitive for other species or low level of parasitaemia
    • Both tests are required: 1 ml blood in EDTA tube is sufficient for both 

    Note: A single negative film or antigen does not exclude malaria - thick and thin films should be repeated with fever spikes until positive test or 3 negative films

    Other investigations
    Consider (depending on likelihood of malaria and severity)

    • FBE, UEC, LFT
    • Blood glucose
    • Blood cultures
    • Blood gas
    • Coagulation profile
    • Group and hold
    • G6PD screen (if considering Primaquine)
    • CXR
    • Consider septic screen if unwell

    Assessment of severity

    Haemolytic anaemia
    Hypoglycaemia
    Metabolic acidosis
    Increased serum lactate
    Haemoglobinuria
    Parasitaemia >2%
    Renal impairment
    Pulmonary oedema
    Coagulopathy

    Treatment

    In an unwell child, assume P. falciparum is present as mixed infection is relatively common

    Uncomplicated malaria

    Species

    Medication & Dose

    Comment

    P. falciparum or unidentified species

    Artemether-lumefantrine (1 tablet = 20 mg artemether/120 mg lumefantrine)
    5-14 kg: 1 tablet 
    15-24 kg: 2 tablets 
    25-34 kg: 3 tablets 
    >35 kg: 4 tablets (adult dose) orally with fatty food, full-fat milk, or breastmilk
    At 0, 8, 24, 36, 48 and 60 hours 

    Discuss alternatives with Infectious Disease if Artemether-lumefantrine not available

    Outpatient management may be suitable if adherence to antimalarials can be assured

    P. vivax, P. ovale, P. malariae, and P. knowlesi

    All regions except if suspected chloroquine-resistant P. vivax ( see below)

    Doses are expressed in chloroquine base
    Chloroquine (1 tablet = 155 mg base = 250 mg chloroquine phosphate)
    10 mg/kg (max 620 mg) orally at 0 hours, then 
    5 mg/kg (max 310 mg) orally at 6, 24, and 48 hours 
    and follow up with
    Primaquine for P. vivax or P. ovale or unknown species

    Chloroquine is available in Australia through Special Access Scheme.

    Round dose to the nearest ¼ tablet

    Hydroxycholoroquine or artemether-lumefantrine are alternatives

    Exclude G6PD deficiency before starting Primaquine - if deficient, consult Infectious Diseases 

    P. vivax malaria with known chloroquine resistance

    Artemether-lumefantrine as above for uncomplicated P. falciparum  
    and

    Primaquine ( see below)

     

                         

    Severe malaria

    Severe malaria  
    Any species
    or 
    inability to tolerate oral therapy

    Artesunate 2.4 mg/kg IV/IM (bolus dose over 1-2 minutes) on admission 

    Repeat at 12 hours and 24 hours, then once daily until oral therapy tolerated (complete full oral course as above)

    Available through  Special Access Scheme

    Maintain strict fluid balance - avoid fluid overload - cerebral/pulmonary oedema

    Complex administration – please contact pharmacy

     

    When patient is able to tolerate oral therapy, change to Artemether-lumefantrine (dosage as above)

    Discuss alternatives with Infectious Disease if Artemether-lumefantrine not available

     

    Species

    Primaquine dose (for children >6 months of age)

    Doses are expressed in terms of primaquine base;
    7.5 mg primaquine base is equivalent to 13.2 mg primaquine phosphate

    Tablet strength = 7.5 mg

    Exclude G6PD deficiency before starting Primaquine

    P. vivax

    0.5 mg/kg (max 30 mg) orally daily with food for 14 days (or divided 12 hourly if causing nausea)

    P. ovale

    0.5 mg/kg (max 30 mg) orally daily with food for 14 days

    Species unknown

    0.5 mg/kg (max 30 mg) orally daily with food for 14 days (or divided 12 hourly if causing nausea)

    G6PD deficiency

    Consult Infectious Diseases

     

    Consider consultation with local paediatric team when

    • Any child presents with suspected malaria 
    • Consider consultation with Infectious Diseases team

    Consider transfer when

    • Any child with features of severe malaria
    • Child requiring care beyond the comfort level of the hospital

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

    Consider discharge when

    • Afebrile for 24 hours
    • Able to tolerate oral medications
    • Decreasing parasite counts 

    Additional notes

    Travel Health PR - Malaria
    World Health Organisation - Malaria
    Centers for Disease Control and Prevention - Malaria

    Last updated July 2020

  • Reference List

    1. Baron, EL et al 2015, Diagnosis of Malaria. Retrieved from UpToDate, https://www.uptodate.com/contents/diagnosis-of-malaria (viewed April 2020)
    2. Breman, JG et al 2016, Clinical manifestations of malaria in nonpregnant adults and children. Retrieved from UpToDate, https://www.uptodate.com/contents/malaria-clinical-manifestations-and-diagnosis-in-nonpregnant- adults-and-children (viewed April 2020)
    3. eTG complete [digital], 2019, Malaria. Retrieved from Therapeutic Guidelines Limited, https://tgldcdp.tg.org.au.acs.hcn.com.au/viewTopic?topicfile=malaria&guidelineName=Antibiotic&topicNavigation=navigateTopic#toc_d1e47 (viewed April 2020)
    4. Medecins sans Frontieres 2020, In Medecins sans Frontieres Clinical guidelines: Diagnosis and Treatment Manual. Retrieved from Medecins sans Frontieres, Paris,  https://medicalguidelines.msf.org/viewport/CG/english/malaria-16689758.html (viewed April 2020)
    5. Weiss, DJ et al 2019, 'Mapping the global prevalence, incidence, and mortality of Plasmodium falciparum, 2000-17: a spatial and temporal modelling study', Lancet, vol.394, no. 10195, pp. 322‐331 https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)31097-9/fulltext/