u‰‰ŽาF Basil Gramaticos ŽiƒpƒŠ‘ๆ‚V‘ๅŠw‹ณŽ๖j “๚ŽžF‚P‚PŒŽ@‚X“๚i‹เj@Œ฿Œใ‚SŽž‚R‚O•ช‚ฉ‚็ ๊ŠF ยŽRŠw‰@‘ๅŠw@—HŠw•”i‘Š–อŒดƒLƒƒƒ“ƒpƒXj‚k“‚UŠK@‚k‚U‚O‚RŽบ ‘่–ฺF uEpidemic dynamics: a physicist's viewv —vŽ|F @We shall present a review of our results on various epidemic models. Our starting will be the Kermack-McKendrick deterministic model. We will introduce a discrete time version of the model as well as its ultradiscrete (cellular-automaton) extension. Based on this discrete version we shall analyse a model where the epidemic may appear in successive waves and even become endemic. An simple model for the spread of AIDS will also be analysed. The analysis of this model shows that within the basic assuptions a) an epidemic is unavoidable and b) the number of survivors is in general non-zero. Finally we shall present a model for nonendemic epidemics and show that epidemics with different dynamics may lead to the same result concerning the number of non-infected individuals. The case of carrier-induced epidemics will also be examined and their dynamics analysed. --------------------------------- ‹ครF@ยŽRŠw‰@‘ๅŠw@—HŠw‰๏