The leech is, apparently, an exceptionally rare foreign body. In Greece some pertinent cases have been reported by Douvlaris,1 by Polyzoidis,2 and by Pessach.3 In the present report we shall describe the largest series of cases in which leeches were found in the upper respiratory tract of humans. The large number of our cases may be explained by the special conditions of the water supply of the particular geographical area from which our patients came. (This is a low land in the center of Greece, to the north of Athens.)
Before we enter into the description of our cases, it might be expedient to review briefly the vital characteristics (biology) of the roundworms that are known under the name of leeches.
The leeches belong to the zoological phylum of Annelida (ringed worms), and more specifically to the order of Hirudinea. They have a flattened body, composed of