Cryptosporidiosis in Perspective

This chapter focuses on cryptosporidiosis in perspective. The significance of cryptosporidiosis in humans, however, depends on the severity of the disease it produces and the incidence in population, both of which are unknown. The frequency of cryptosporidiosis is highest in children aged between six months and three years. The chapter discusses these epidemiological observations and more accurate information regarding the morphology and the life-cycle of Cryptosporidium. Detailed studies on the life-cycle and the ultrastructure have provided a better understanding of the biology of the parasite and have highlighted its unique characteristics. Of these, the existence of sporulated, thin-walled oocysts, and their independence of reducing conditions for excystation are of major importance and may explain the occurrence of autoinfection and persistent infection. Cryptosporidium has numerous characteristics that set it apart from the rest of that subclass. The parasite's ability to maintain persistent infection in certain individuals and its astonishingly stubborn resistance to chemotherapy are serious medical problems that need to be addressed in the future.