Infectious diseases, particularly parasitic infections, play a major role in the overall world's health and economy. As travel increases, we anticipate seeing many more people who may be infected with parasites that may not be endemic to the specific area where they live. During the past few years, the United States has seen a number of outbreaks with Cyclospora cayetanensis, a coccidian parasite that has been linked to the importation of fresh produce (primarily raspberries, fresh basil, and baby lettuce mixtures) into the United States. Continued vector and disease control efforts will remain on the high priority list, especially when seen within the context of global health.
Also, we continue to see the compromised patient population increase, due to age, intentional immunosuppression (transplantation), underlying disease and chemotherapy. As this population grows, we anticipate the identification of additional etiologic agents of disease, some of which will most probably be human parasites.
Recently, two organisms have been linked to human disease and have been categorized as "emerging infections." These are Cyclospora cayetanensis, a coccidian similar to Cryptosporidium spp. and the Microsporidia. Currently, there are eight genera and 13 species of Microsporidia that have been identified as causing human disease.