As severe malaria is the progression of uncomplicated malaria, its diagnosis is similar to that of uncomplicated malaria plus observations of danger signs.
As noted in WHO's Management of Severe Malaria, the most important element in the clinical diagnosis of malaria is a high index of suspicion.
Gold standard: microscopy
- Where microscopy is unavailable or unfeasible, a rapid diagnostic test (RDT) should be used.
In the absence of diagnostic facilities, a patient diagnosed with severe malaria based on clinical suspicion should be started on antimalarial treatment without delay, while other diagnoses are also considered.
Monitoring of parasitaemia at least every 12h is important during the first 2–3 days of treatment in order to assess parasite response to the antimalarial medicine, especially in South-East Asia where resistance to artemisinin and the partner drugs is emerging.
Obtaining a parasitological diagnosis does not resolve the diagnostic problem, especially in high transmission areas, where asymptomatic parasitaemia is common and may be incidental in any severe illnesses.
Attention should be paid to:
- Residence and travel history indicative of exposure, or the possibility of "airport malaria" (exposure in non-endemic areas)
- Possibility of induced malaria (through transfusion, transplantation or use of contaminated needles)
- Diseases presenting similar symptoms that are also common in malaria-endemic countries
- In children, convulsions due to malaria must be differentiated from febrile convulsions