Parasitological confirmation of the diagnosis of malaria is recommended. This should be provided by microscopy or, where not available, RDTs. Low to moderate transmission settings8 include many urban areas in Africa, and the low transmission season in areas with seasonal malaria.
8 Transmission intensity is conventionally expressed in terms of EIR (see section 2). There is as yet no consensus on criteria for determining the thresholds between high, and low to moderate transmission settings. Suggested criteria include: the proportion of all children under 5 years of age with patent parasitaemia, and the incidence of individuals with the spleen palpable below the umbilicus in children aged 2-9 years. The IMCI guidelines recommend that areas in which fewer than 5% of young children with fever have malaria parasitaemia should be considered as low-transmission settings.
In settings where malaria incidence is very low, parasitological diagnosis for all fever cases may lead to considerable expenditure to detect only a few patients who are actually suffering from malaria. In such settings, health workers should be trained to identify, through the history, patients that have been exposed to malaria risk before they conduct a parasitological test.