Overview of diagnostic testing
Early and accurate diagnosis of malaria is essential for effective disease management and malaria surveillance. High-quality malaria diagnosis is important in all settings as misdiagnosis can result in significant morbidity and mortality.
WHO recommends prompt parasitological confirmation of diagnosis either by microscopy or malaria rapid diagnostic test (RDT) in all patients with suspected malaria before treatment is administered. The choice of method depends on local circumstances, including patient case-load, epidemiology of malaria, and availability of skilled laboratory technicians.
Parasite-based diagnostic testing of malaria improves the management of patients with febrile illnesses, particularly by helping to identify patients who do not have malaria and need different treatment. It may also help reduce the emergence and spread of drug resistance by reserving antimalarials for those who actually have malaria.
The benefit of parasitological diagnosis is dependent on health-care providers adhering to the test results in managing the patient. Where quality-assured parasitological diagnosis is promptly available, and in the absence of signs of severe disease, antimalarial treatment should be limited to test-positive cases while negative cases should be assessed for other causes of fever.
The number of countries that have adopted and implemented policies for the parasite-based diagnosis of malaria is increasing. In 2011, 41 of 44 malaria-endemic countries in the WHO African Region and 46 of 55 countries in other WHO Regions reported having adopted a policy of providing parasitological diagnosis for all age groups.
The percentage of reported malaria cases receiving a parasitological test increased from 20% in 2005 to 47% in 2011 in the WHO African Region, and from 68% to 77% globally. However, in 2011, the number of ACT treatments distributed in Africa was still more than double the total number of diagnostic tests performed, indicating that many patients still receive treatment without confirmatory diagnosis.
Last update: 6 March 2013
- Guidelines for the treatment of malaria, second edition (2010)
- Universal access to malaria diagnostic testing: an operational manual (2011)
- Information note on recommended selection criteria for procurement of malaria rapid diagnostic tests (RDTs) (2012)
- Good practices for selecting and procuring rapid diagnostic tests for malaria (2011)
- Malaria microscopy quality assurance manual - version 1 (2009)
- Bench aAids for malaria microscopy (2009)