Patients with malaria infection typically present with non-specific symptoms such as fever, chills, sweats, headache, and myalgia.
In Western countries, almost all malaria occurs in travellers; therefore, the diagnosis may be missed if a history of travel is not elicited.
Examination of a Giemsa-stained blood film remains the diagnostic test of choice.
Once the diagnosis of malaria is confirmed, treatment should be started urgently, as a delay may be associated with disease progression and complications.
Management should be undertaken in conjunction with an infectious diseases specialist.
Vaccination is recommended in children living in regions with moderate to high malaria transmission.
Malaria is a parasitic infection caused by protozoa of the genus Plasmodium. Five species are known to infect humans; Plasmodium falciparum is the most life-threatening. It is naturally transmitted to humans through a bite by an infected female Anopheles mosquito but may potentially be transmitted by blood transfusion or organ transplantation. It is widely distributed throughout tropical and subtropical regions, and the main burden of disease falls on these areas. Travellers account for the majority of disease in Western countries.
History and exam
Key diagnostic factors
- presence of risk factors for acquiring malaria
- presence of risk factors for severe disease
- fever or history of fever
Other diagnostic factors
- nausea and vomiting
- abdominal pain
- altered level of consciousness
- travel to endemic area
- inadequate or absent chemoprophylaxis
- insecticide-treated bed net not used in endemic area
- settled migrants returning from travel to endemic area of origin
- low host immunity (for severe disease)
- pregnancy (for severe disease)
- age <5 years (for severe disease)
- immunocompromise (for severe disease)
- older age (for severe disease)
- iron administration (children)
1st investigations to order
- Giemsa-stained thick and thin blood smears
- rapid diagnostic tests (RDTs)
- clotting profile
- serum electrolytes, urea and creatinine
- serum LFTs
- serum blood glucose
- arterial blood gas
Investigations to consider
- polymerase chain reaction (PCR) blood for malaria
- chest x-ray
- blood culture
- urine culture
- sputum culture
- lumbar puncture
- HIV test
- PCR nasopharyngeal swabs for influenza
- CT head
- loop-mediated isothermal amplification
Plasmodium falciparum: uncomplicated disease, able to take oral medication initially
Plasmodium falciparum: severe disease or unable to take oral medication initially
Plasmodium malariae or Plasmodium knowlesi
Plasmodium falciparum: recurrent infection
Ron Behrens, MD, FRCP
Honorary Consultant in Tropical and Travel Medicine
Hospitals for Tropical Diseases
London School of Hygiene and Tropical Medicine
RB has acted as a paid expert to the courts on malaria prophylaxis. RB has received fees on the Travel Health advisory board for Emergent BioSolutions. RB had prepared education material for the Royal College of Physicians and Surgeons of Glasgow. RB is an author of a number of references cited in this topic.
Dr Ron Behrens would like to gratefully acknowledge Mariyam Mirfenderesky, Dr Signe Maj Sorensen, Dr Joanna Allen, Dr Simon Warren, and Dr Behzad Nadjm, previous contributors to this topic.
MM, SMS, JA, and SW declare that they have no competing interests. BN is an author of a reference cited in this topic.
Blaise Genton, MD
Head of the Travel Clinic
Consultant of Tropical and Travel Medicine
Swiss Tropical and Public Health Institute
BG has received a research grant from Novartis Pharma to assess the impact of the introduction of artemether-lumefantrine (Novartis) as first-line treatment for uncomplicated malaria on mortality of children under 5 years old in 2 districts in Tanzania and travel grants from Novartis Pharma to present the results of the study above. BG is an author of a reference cited in this topic.
David Sullivan, MD
Malaria Research Institute and Department of Molecular Microbiology and Immunology
Johns Hopkins Bloomberg School of Public Health
DS has received royalties from antigen provision for a diagnostic test to Inverness. DS with Johns Hopkins University has patents on diagnostic tests that do not require blood.
Walther H. Wernsdorfer, MD
Institute of Specific Prophylaxis and Tropical Medicine
Medical University of Vienna
WHW declares that he has no competing interests.
- Dengue fever
- Zika virus infection
- Chikungunya virus
- WHO Guidelines for malaria
- Malaria prevention guidelines for travellers from the UK
Malaria preventionMore Patient leaflets
Diagnostic lumbar puncture in adults: animated demonstrationMore videos
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer