Towards a research agenda for global malaria elimination

Excerpt

For the past twenty years, many scientific papers on malaria have begun with statements such as 'there are an estimated three billion people at risk of the disease'; or '300–600 million episodes of clinical falciparum malaria occur each year, killing between one and three million individuals annually'; or 'the global burden of malaria exceeds 40 million disability-adjusted life years' [1, 2]. These figures may once have been a credible approximation, but need to be looked at today with considerable scepticism, even when they appear in official statements. Indeed, figures of malaria incidence/prevalence or of disease burden, are mostly based on reports of 'presumptive diagnosis', the accuracy of which is 50% at best and less than 5% in situations of low endemicity. Figures relating to malaria mortality are even less reliable, because the exact cause of death is always difficult to determine, even in hospital settings [3]. Recent studies of severe malaria in children in Malawi and in Kenya suggest that, in at least 25% of cases, the WHO definition of severe malaria is unable to exclude concomitant bacterial or viral infections, which may actually be responsible for the fatal outcome [4]. The field reality is worse, when one considers that many malaria cases occur in remote areas, where the resources for making adequate diagnosis are not available. …