New Hosts for Trematodes of the Genus Heterophyes in Egypt

Abstract

Trematodes of the genus Heterophyes Cobbold, 1866, have been known to be endemic in the Nile Delta for many years. More than 100 years have passed since Heterophyes heterophyes (v. Siebold, 1852) was first reported as an intestinal parasite of Egyptians, yet less is known of the epidemiology of Heterophyes than of any other human helminth parasite in Egypt. Early descriptions of species of this genus were provided by Looss (1894, 1896, 1902), who described 8 species and 2 subspecies from Egyptian hosts. Later, Witenberg (1929), after revising the family HETEROPHYIDAE, discarded a number of species of doubtful validity from the genus Heterophyes and recognized only 3 species as being valid, namely: H. heterophyes (v. Siebold, 1852), H. dispar Looss, 1902, and H. aequalis Looss, 1902. Khalil (1937), in his description of the life history of Heterophyes heterophyes, named a brackish-water snail, Pirenella conica, as the first intermediate host, several species of fishes, Mugil spp. and Tilapia spp., as the second intermediate host and man, dog and cat as the final host. In 1953, a survey of trematodes of the genus Heterophyes of Egyptian birds and mammals was begun in this laboratory. The present paper gives the results of that survey and reports new definitive hosts for each of the 3 species of Heterophyes studied. MATERIALS AND METHODS