Infectious Disease

Malaria

A mosquito-borne Plasmodium infection in which travel history, species and severity determine how quickly treatment must begin.

In a nutshell

Malaria is an emergency diagnosis after relevant travel. P. falciparum can deteriorate rapidly; P. vivax and P. ovale can relapse from hypnozoites. Urgent films, species and severity assessment determine treatment.

Classic presentation

Fever, sweats or chills, headache, malaise, myalgia or gastrointestinal symptoms after travel to a malaria-risk area; the fever may be non-periodic and symptoms may occur months after travel.

Key points

Consider malaria in every ill patient returning from the tropics within the previous year, especially the previous 3 months.
Send urgent thick and thin films; one negative film or RDT does not exclude malaria, so repeat films daily for 3 days if suspicion remains.
Severe or complicated malaria requires urgent hospital and specialist management with parenteral treatment; IV artesunate is the UK treatment of choice for severe malaria.
Use species-, geography- and patient-specific UKMEAG/BNF treatment advice; do not use a prophylaxis regimen as treatment.
P. vivax and P. ovale need a liver-stage treatment decision for radical cure; check G6PD before primaquine.
Malaria is statutorily notifiable, and confirmed cases require the relevant UKHSA/MRL reporting pathway.
Prevention requires destination-specific chemoprophylaxis plus bite avoidance; prophylaxis does not rule out malaria after return.

First-line investigation

Urgent EDTA venous blood for thick and thin films, with species and parasitaemia; add RDT as an adjunct and repeat films daily for 3 days when the initial result is negative but suspicion persists.

Management

Recognise the emergency

After relevant tropical travel, assess urgently, take ABCDE observations and glucose, and send malaria films without waiting for a fever spike.^5,6

Test and classify

Use urgent thick and thin films for species and parasitaemia; repeat daily for 3 days after a negative result if suspicion remains, while assessing severe features.^5,1

Treat according to species and severity

Use current UKMEAG treatment guidance and BNF; uncomplicated disease needs appropriate oral species-specific treatment, whereas severe disease needs urgent parenteral therapy and hospital monitoring.^2,4

Support severe malaria

Escalate immediately for impaired consciousness, seizures, respiratory distress, shock, hypoglycaemia, severe anaemia, acidosis, bleeding or kidney injury; IV artesunate is the UK treatment of choice for severe malaria.^1,2,4

Prevent relapse and reinfection

For vivax or ovale, check G6PD before a radical-cure decision; for future travel combine current destination-specific chemoprophylaxis with bite avoidance and safety-net any post-travel fever.^3,8,6,4

Exam traps

A single negative blood film does not rule out malaria.
Do not wait for a fever spike or classic periodicity before taking blood.
Falciparum or mixed infection with falciparum can deteriorate quickly even when symptoms initially appear non-specific.
Vivax or ovale relapse reflects dormant hypnozoites and requires a separate radical-cure decision; check G6PD before primaquine.
A prior or completed prophylaxis course does not exclude malaria and should not delay testing.

Illustrations

Thin blood film in malariaMicroscopy image showing Plasmodium parasites within red blood cells on a thin film.Dr Graham Beards, Wikimedia Commons · CC-BY-SA-4.0

Cerebral malaria mechanismDiagram of parasitised red cell sequestration obstructing cerebral microvasculature in severe falciparum malaria.PassFinals · original

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.