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Guidelines for the treatment of malaria – 2 edition

10. mixed malaria infections

Mixed malaria infections are common. In Thailand, despite low levels of malaria
transmission, one third of patients with acute P. falciparum infection are co-infected with
P. vivax; and 8% of patients with acute vivax malaria have simultaneous P. falciparum
infection. Mixed infections are underestimated by routine microscopy. Cryptic
P. falciparum infections can be revealed in approximately 75% of cases by the RDTs
based on the HRP2 antigen, but such antigen tests are much less useful (because of
their lower sensitivity) in detecting cryptic vivax malaria. ACTs are effective against all
malaria species, and they are the treatment of choice. Radical treatment with primaquine
should be given to patients with confirmed P. vivax and P. ovale infections, except in high
transmission settings where the risk of re-infection is high.

11. complex emerGencies and epidemics

When large numbers of people are displaced within malaria endemic areas, there is a
risk of severe malaria epidemics (especially when people living in an area with little or
no malaria transmission move to an endemic area, e.g. displacement from highland to
lowland areas). The lack of protective immunity, concentration of people in exposed
settings, breakdown in public health and preventive activities, difficulties in accessing
effective treatment, concomitant infections and malnutrition all render populations
vulnerable to epidemic malaria. Such circumstances are also ideal for the development
of parasite resistance to antimalarials. For these reasons, particular efforts must be made
to deliver, free-of-charge, effective antimalarial treatment to the populations at risk. The
principles below are applicable to epidemics and to all complex emergencies occurring in
areas with malaria risk, where appropriate case management should be key.

11.1 diagnosis

11.1.1 Use of microscopy

In the acute phase of epidemic and complex emergency situations, facilities for laboratory
diagnosis are usually either unavailable, destroyed, or so overwhelmed with the case-
load that parasite-based diagnosis before treatment in all fever cases is impossible. In

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