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.

Parasitological confirmation of diagnosis

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.

Parasite-based diagnosis for all age groups

The number of countries that have adopted and implemented policies for the parasite-based diagnosis of malaria is increasing. Of the 97 countries with ongoing malaria transmission, 96 have adopted a policy to test all patients with suspected malaria before treating with antimalarial medicines. In 88 countries, diagnostic testing is free of charge in the public sector.

The proportion of patients suspected of having malaria who receive a malaria diagnostic test has increased substantially since 2010, when WHO recommended testing of all suspected malaria cases. In 2013, 62% of patients with suspected malaria in public health facilities in the WHO African Region received a diagnostic test, compared to 40% in 2010.

The volume of RDT sales to the public and private sectors of endemic countries increased from 46 million in 2008 to 319 million in 2013. The number of patients tested by microscopic examination increased to 197 million in 2013, with India accounting for over 120 million slide examinations.

Last updated: 25 March 2015

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