[Malaria--rapid diagnostic tests and emergency self-medication]

Abstract

WHO recommendations have adopted the option of stand-by emergency treatment (SBT) for travellers to areas where malaria is endemic and medical attention may not be obtained within 24 hours after onset of symptoms. Indication and choice of drugs for SBT depend on use and kind of a chemoprophylactic regimen, situation of plasmodial resistance at the destination, and contraindications and tolerability in the individual traveller. However, the diagnosis of malaria on clinical grounds alone is unreliable, and fever occurs frequently during travel to malaria endemic areas from various reasons. The possibility of malaria has to be considered in all cases of unexplained fever that starts after the 7th day of stay in an endemic area. Studies in European travellers have shown that only 0.5-1.4% of all travellers to whom SBT medication has been prescribed, will finally use it. SBT use in febrile travellers (8.1-10.4% of all travellers) has been 4.9-17%, but plasmodial infection could be confirmed retrospectively in 10.8-16.7% of SBT-users only. The recent introduction of rapid diagnostic tests (RDT) for malaria has provided a potential tool to self-diagnose and treat a possible malaria attack when medical attention or microscopic diagnosis is not available. However, the utilisation of currently available RTDs by travellers has been shown to be technically problematic. Healthy volunteers were able to learn how to perform the tests, especially when standard written instructions were supplemented with verbal information (75 vs. 90% successful performance). But their interpretation of test results was unsatisfactory, with a high rate of false-negatives (14.1%). In another study in febrile European tourists in Kenya, only 68% of patients were able to perform the RDTs correctly, and 10 out of 11 with microscopically confirmed malaria failed to diagnose themselves accurately. Thus, besides appropriate training before departure, technical improvements are required before such RDT kits can be recommended for self-use by travellers.