Epstein-Barr virus is a ubiquitous human herpes virus that is widespread in all human populations. The position ofEBV: Host balance can be assessed in a quantitative way by looking at correlates between the level ofvirus infection in latently infected PBMC as measured by quantitative, realtime PCR, and the strength ofthe CD8+ T cell response to lytic and latent cycle antigens, measured by ELIspot assays of epitope-induced IFN-A. release. EBV and Plasmodium falciparum malaria infections have overlapping distributions, and are thought to be co-factors in the aetiology of endemicBurkitt's lymphoma, the commonest 'childhood malignancy in sub-Saharan Africa. How these two pathogens interact to drive the emergence ofthe malignant B cell clone remains unknown. The aim of this study was to look EBV: Malaria interactions in at-risk children who have been infected with EBV early in life, with specific focus on the effect ofacute malaria on EBV: Host balance in Gambian children. Using the prevailing level ofEBV-specific immunity in healthy adults in Birmingham and in the Gambia as baseline comparisons, this study has shown that there is a dramatic increase in EBV . genome load in Gambian children with acute malaria infection, without a corresponding increase in the EBV-specific immunity. This provides an important step in understanding how these two pathogens might interact to result in disease.