Malaria

Detail extracted from CKS, How should I assess a person with suspected Malaria?

Suspect malaria in anyone who has returned from or previously visited an area endemic for malaria, who is unwell, or has a fever or history of fever, regardless of malaria chemoprophylaxis — specific country information can be found on the UK Health Security Agency website.

• • Almost all cases of P. falciparum malaria present within 6 months of exposure and most within 2–3 months.
  • Infection with other malaria species, such as P. ovale and P. vivax may present months or years after exposure due to reactivation of hypnozoites (a dormant liver stage).
  • Presentation may be delayed in people who have taken chemoprophylaxis.
  • Most missed cases of malaria are wrongly diagnosed as non-specific viral infections, influenza, gastroenteritis, and hepatitis.

Clinical features of malaria include

• • Fever (often 39°C or higher), sweats, and/or chills — absence of fever should not remove the suspicion of malaria.
  • Headache.
  • General malaise, lethargy, and fatigue — somnolence is more common in children than in adults.
  • Anorexia, gastrointestinal disturbance (such as nausea, abdominal pain, vomiting, diarrhoea), and jaundice.
  • Poor feeding in children.
  • Myalgia and arthralgia.
  • Sore throat, cough, lower respiratory tract symptoms, and respiratory distress.
  • Confusion.
  • Hepatomegaly, splenomegaly, and somnolence are more common on examination in children.

Take a history asking about

• • Symptoms of malaria (such as fever, sweats, chills, malaise, myalgia, headache, vomiting, diarrhoea, and cough) and timing of onset.
  • Travel history including:
    • Country and area of travel.
    • Stopovers and other countries transited through.
    • Date of return.
    • Type of travel and activities while abroad — people returning from visiting friends and family in endemic areas are more at risk of malaria than tourists.
  • Possible differential diagnoses:
    • Viral haemorrhagic fever (VHF) such as Ebola, Lassa fever, or Marburg  — further assessment must be in line with Public Health England guidelines on Management of Hazard Group 4 viral haemorrhagic fevers and similar human infectious diseases of high consequence.
  • Preventative measures such as:
    • Malaria chemoprophylaxis (drug, dose, adherence, and cessation) — full adherence to appropriate prophylaxis does not guarantee protection against malaria.
    • Precautions taken against biting insects for example insecticide-impregnated bednets and repellent.
    • Travel immunizations against other travel related infections such as yellow fever.
  • Risk of severe malaria:
    • Severe malaria is more likely in children, pregnant women, older people, and immunocompromised people (for example those with splenectomy or HIV/AIDS).

Arrange appropriate investigations

• • Malaria is a medical emergency and if suspected, a blood test to confirm the diagnosis must be carried out without delay.
  • Diagnosis of malaria is only possible with microscopy of thick and thin blood films (the gold standard) or an antigen detection test.
    • Most people will need immediate referral to secondary care (an Infectious Disease or appropriate Medical Assessment Unit) to allow testing with a same-day result

• • Following discussion with the medical registrar / infectious diseases team, in hours,  a decision is made to test for Malaria in the community and not to admit (usual practice is to admit)
    • Please send  a purple top bottle and request a thick and thin film
    • Document on the form that this test is for malaria and where the patient has travelled to with the relevant dates
    • The bloods should be sent to the lab urgently
    • Follow the blood taking and follow up procedure 

Addition information from UK health security agency available here