ABSTRACT
Apart from those infections transmitted by arthropod vectors, virtually all human parasitoses may be acquired orally. Even organisms that normally penetrate skin, such as schisto-some cercariae and hookworm larvae, can establish infection after being ingested in drinking water or on contaminated food, although for them this portal hardly constitutes a significant route of transmission. Other fecally dispersed parasites, including the cysts of Giardia and Entamoeba, oocysts of Cryptosporidium, Cyclospora and other less common coccidia, and the eggs of geohelminths, may be transported mechanically on food or in drinking water, but they do not occur within the substance of unprocessed food.
