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Guidelines for the treatment of malaria – 2 edition

In children under five years of age, the WHO/United Nations Children’s Fund (UNICEF)
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strategy for Integrated Management of Childhood Illness (IMCI) practical algorithms
for management of the sick child should be used to ensure full assessment and appropriate
case management of children at the first-level health facilities.

6.2 parasitological diagnosis
The changing epidemiology of malaria and the introduction of ACTs have increased the
urgency of improving the specificity of malaria diagnosis. Parasitological diagnosis has
the following advantages:
■ improved patient care in parasite-positive patients;
■ identification of parasite-negative patients in whom another diagnosis must be sought;
■ prevention of unnecessary use of antimalarials, reducing frequency of adverse effects,
especially in those who do not need the medicines, and drug pressure selecting for
resistant parasites;
■ improved malaria case detection and reporting;
■ confirmation of treatment failures.

The two methods in routine use for parasitological diagnosis are light microscopy and
rapid diagnostic tests (RDTs). The latter detect parasite-specific antigens or enzymes and
some have a certain ability to differentiate species. Deployment of microscopy and RDTs
must be accompanied by quality assurance. Antimalarial treatment should be limited to
test positive cases and negative cases should be reassessed for other common causes of
fever. The benefit of parasitological diagnosis depends entirely on health-care providers
adhering to the results in managing the patient, except where the severity of the disease
justifies the use of antimalarials in test negative cases, considering the possible small risk
of false negative tests. The risk of false negative microscopy is higher if the patient has
received a recent dose of an artemisinin derivative.
The results of parasitological diagnosis should be available within a short time (less than
two hours) of the patient presenting. In the absence or delay of parasitological diagnosis,
patients with suspected severe malaria, and other high risk groups, should be treated
immediately on clinical grounds.

6.2.1 The choice between rapid diagnostic tests and microscopy

The choice between RDTs and microscopy depends on local circumstances, including
the skills available, patient case-load, epidemiology of malaria and the possible use of
microscopy for the diagnosis of other diseases. Where the case-load of fever patients is
high, microscopy is likely to be less expensive than RDTs, but may be less operationally

5 Integrated management of childhood illness for high HIV settings: chart booklet. Geneva, World Health Organization, 2008
http://www.who.int/child_adolescent_health/documents/9789241597388/en/index.html, accessed 29 Oct. 2009.
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