ABSTRACT
TJINTAMOEBA histolytica and Cryptosporidium parvum are pathogenic protomJj zoa that are transmitted by the fecal-oral route. Infection occurs by ingestion of environmentally resistant cyst forms of the parasites in contaminated food or water. Neither parasite can grow or multiply in food or water and requires a host to complete its life cycle. E. histolytica infection, or amebiasis, is now an uncommon cause of disease in developed countries but is still a threat in many developing nations that have areas with poor sanitation and unclean water. Cryptosporidiosis is an example of an emerging disease. The parasite has long been known to cause disease in farm animals but has only been recognized as a human pathogen since the early 1980s. Cryptosporidiosis is also common in developing nations but is now recognized as one of the leading causes of waterborne disease outbreaks in the United States.
