Name: Elhassan, Ibrahim Home Country: Sudan Research Country: Sudan Project Period: 1992-1995   Title Plasmodium falciparum malaria in an area of seasonal and unstable malaria transmission: an immuno-epidemiological survey Abstract Malaria is a serious health problem in the tropical and subtropical countries. As the antimalarial control activities become more difficult, an effective malaria vaccine is needed. The main obstacles facing the development of an effective anti-malaria vaccine is our lack of knowledge concerning the exact mechanisms of acquired immunity to human malaria. This emphasizes the need of a better understanding of the immune responses by people living in the endemic areas, and comparing the development of immunity acquired by individuals living in different epidemiological settings. In the present study we have characterized the geographical, parasitological, immunological and epidemiological features of the study area which can be described as an area of seasonal and unstable malaria transmission. It was concluded that about two third of blood stage P. falciparum infections appear to have subclinical course, in this area of highly seasonal and unstable malaria transmission. This conclusion is in disagreement with the conventional assumption that infection will generally be followed by clinical disease in areas of low transmission. Acute P. falciparum malaria is associated with the inability of peripheral T cells to respond to related and unrelated antigens in vitro. Two theories have been proposed to explain this phenomenon. These are immunosuppression and reallocation theories. In the present study we have found that plasma level s of T cell activation markers (sCD4, sCD8, ß82-m) and inflammation markers (ELAM-1, ICAM-1 and VCAM-1) are significantly increase during P. falciparum infection. In addition, we have found that the disease induced depletion of T cells which induced high expression of the LF A-l antigen, particularly in CD4+ subsets. The results obtained may provide further evidence for the reallocation of T cell to inflamed endothelium in the internal organs in acute P. falciparum    Involved research institution(s) Centre for Medical Parasitology, University of Copenhagen   Supervisor(s) Thor Theander & Lars Hviid Correspondence