Parasitism in man-made ecosystems

Like free organisms, parasites and pathogens have the ability to colonize and evolve in new environments. Technical and surgical developments (e.g., air conditioning, catheters, fibroscopy, etc.) and medical advances (e.g., organ transplants associated with antirejection medicine, immunosuppressing drugs, etc.) are generating new environments in hospital ecosystems, which are now colonized by new parasite and pathogen flocks. Elsewhere, agricultural processes have widely disturbed ecological parameters in natural ecosystems; they are responsible for the introduction of new parasites and pathogens species, and for changes in host-parasite interactions. This chapter discusses some of these phenomena and processes in man-made ecosystems.