Parasitic infections

Red flags

Consider urgent referral for patients with the following:

  • Red flags occur from complications of dehydration from gastroenteritis, from extensive secondary bacterial infection and from the presence of parasites in vital organs
  • Dehydration from gastroenteritis
  • Marked anaemia
  • Deteriorating renal function
  • Abnormal LFT
  • Extensive crusting and secondary infection of the skin associated with scabies
  • Altered conscious level
  • Tapeworm cysts in liver, brain, myositis
  • Visual problems (toxocara)
  • Myocarditis (toxocara)

Features that may lead to more urgent categorisation

  • Hepatic cysts

Parasitic infections are common in Australia and simple infections include:

  • Skin and hair
    • Head and body lice
    • Pubic lice
    • Scabies
  • Gastrointenstinal
    • Intestinal helminth (whipworm, threadworm, hookworm, tapeworm)
    • Giardia lamblia
    • Blastocystis, Dientamoeba fragilis
  • Other
    • Cysticercosis
    • Toxoplasmosis
    • Toxocara

Other important information for referring practitioners

Lifestyle changes

  • Encourage good personal hygiene habits especially after toileting and food preparation
  • Encourage regular worming of pets

Medical management

Pediculosis (head and body lice)

  • Use hair conditioner & comb through, immersing the comb in hot water will kill lice and eggs
  • If using anti lice shampoo ensure complete treatment of all parts of the scalp and retreat 1 week later. Use nit comb to remove all eggs (nits).
    • Main treatment compounds are:
      • Pyrethrins
      • Perimethrin and bioallethrin
      • Organophosphates (malathion or malison)
      • Herbal and essential oils


  • If neglected can lead to extensive secondary infection and serious health consequences, especially in remote communities. Consider urgent referral.
  • Consider this diagnosis for unexplained dermatitis of recent onset, recurrent impetigo with itch, unexplained pruritis
  • Look for typical burrows, consider skin scrapings
  • Used scabicidal cream from neck down and treat all family members, even if asymptomatic
  • Use permethrin cream and leave on for 24 hrs. Other treatments are:
    • Benzoyl benzoate (irritating)
    • Gamma benzene hexachloride (potential neurotoxin)
    • Ivermectin (potential side effects in young and very elderly)
  • Repeat in 1 week
  • Wash all clothes and bedding in hot water and iron or heat dry
  • Treat pruritis with emollients and steroid creams and treat secondary infection
  • Reassure that pruritis takes up to 4 weeks to settle


  • Helminth infection
    • Suspect threadworm if unexplained pruritis ani
    • A wide range of antihelminthics are available over the counter, these are:
      • Mebendazole, Pyrantel, (OTC)
      • Albendazole (tapeworm and hydatid) PBS listed
      • Ivermectin (strongyloidiasis and onchocerciasis) PBS listed
      • Praziquantel (Brachylaima cribbi from snails ingestion) is prescription only not PBS listed
  • Giardia, blastocystis, dientamoeba
    • Suspect if persistent diarrhoea or intermittent diarrhoea
    • Diagnose on stool microscopy or PCR
      • The multiplex PCR assay currently available produces many positives for blastocystis and dientamoeba, the significance of which remains unclear
    • Treat with Metronidazole or Tinidazole
    • Often resolves without treatment

Referral requirements

A referral may be rejected without the following information.

  • Reason for referral e.g. multiple treatment failures
  • Presence of any red flags
  • Duration of infection and symptoms
  • Main symptoms and signs
  • Microscopy/pcr evidence of infection
  • Microscopy and culture of secondary infection in case of extensive scabies

Additional referral information (useful for processing the referral)

  • Liver ultrasound if hepatic cysts present

Out of catchment

Metro North Health is responsible for providing public health services to the people who reside within its boundaries. Special consideration is made for patients requiring tertiary care or services that are not provided by their local Hospital and Health Service. If your patient lives outside the Metro North Health area and you wish to refer them to one of our services, inclusion of information regarding their particular medical and social factors will assist with the triaging of your referral.

  • Impact on employment
  • Impact on education
  • Impact on home
  • Impact on activities of daily living
  • Impact on ability to care for others
  • Impact on personal frailty or safety
  • Identifies as Aboriginal and/or Torres Strait Islander
  • To establish a diagnosis
  • For treatment or intervention
  • For advice and management
  • For specialist to take over management
  • Reassurance for GP/second opinion
  • For a specified test/investigation the GP can’t order, or the patient can’t afford or access
  • Reassurance for the patient/family
  • For other reason (e.g. rapidly accelerating disease progression)
  • Clinical judgement indicates a referral for specialist review is necessary
  • Presenting symptoms (evolution and duration)
  • Physical findings
  • Details of previous treatment (including systemic and topical medications prescribed) including the course and outcome of the treatment
  • Body mass index (BMI)
  • Details of any associated medical conditions which may affect the condition or its treatment (e.g. diabetes), noting these must be stable and controlled prior to referral
  • Current medications and dosages
  • Drug allergies
  • Alcohol, tobacco and other drugs use
  • Full name (including aliases)
  • Date of birth
  • Residential and postal address
  • Telephone contact number/s – home, mobile and alternative
  • Medicare number (where eligible)
  • Name of the parent or caregiver (if appropriate)
  • Preferred language and interpreter requirements
  • Identifies as Aboriginal and/or Torres Strait Islander
  • Full name
  • Full address
  • Contact details – telephone, fax, email
  • Provider number
  • Date of referral
  • Signature
  • Willingness to have surgery (where surgery is a likely intervention)
  • Choice to be treated as a public or private patient
  • Compensable status (e.g. DVA, Work Cover, Motor Vehicle Insurance, etc.)
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