الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Fasciola is essentially a parasite of herbivorous animals. However, in the I ast two decades human fasc i ol i as i s became a world wide problem. In Egypt, the disease was considered endemic in some areas like Abis in Behe i ra prov i nce. F. ~i~antica was the species common in Egypt wh i le L heQat i ca was I oca I i zed to the Oases. However, reports mentioned the prevalence of ~ hepatica in human infections. The par t played by Lymnaea sna i Is, the molluscan inter mediate hosts, is of considerable importance in transmission of the parasite and even in the evolution of new fluke species. The aim of the present work was to clarify the relation Fasciola the parasite, its definitive hosts and its intermediate host(s) in Abis area. Field and experimental wrks complemented each others in the study. MATERIAL AND METHODS This work was carried out in Abis I1 vi Ilage. Stud i es on the human hos t A random sample of 371 individuals were enrol led in the Stool specimens were collected and examined micro scopically after the Kato thick smear technique. The intensity infection was determined. The positive specimens were further processed by sa I i ne sedimentation and eggs were by the micrometer. . Fascio1 ; as is among livestock 153 animals were examined for fasciol iasis. Stool samples were examined and Fasciola eggs were measured. .’1 I~tudi es on the Lymnaea snai 1 intermedi ate hos t During Apri I and May 1990, in a pilot study, a I I wa t e r ~od i e s in Ab i s I I village were searched for the presence of snails particularly Lymnaea species. According to the results, 116 permanent stat ions, were fixed, for monthly survey. The collected Lymnaea snails were examined for trematode infection ~y two methods: shedding of cercariae and dissection. All I t rema todes obta i ned were exam i ned, i dent i f i ed and drawn camera I uc i da. Breeding and Maintenance of L. cailliaudi in the laboratory Breeding was run in aquaria under normal laboratory illumination and at a temperature of 22 - 26°C. The followi ng parameters were studied: 1) The number of egg masses deposited, 2) The number. of egg ce 11 si egg ma ss, 3) The i n cub a t ion and hat chi n g per i 0 d s, 4) The ~rowt h curve of Lymnaea snai Is, and the age at egg depo sition, and 5) The death rc{te. Maintenance of the 1 i fe cycl e of Fasciola ap. in the laboratory a. Collection and cultivation of I ivinQ eQQs: Adu It flukes were obtained from the liver of slaughtered an i ma I s and classified into F. hepatica and F. QiQantica depend i ng on the morphological characters. Fasciola eggs were teased from their uteri. They were incubated in dechlorinated tap water in the dark until they became mature. . ’0. Ha t chi n Q 0 f the m i r a cid i a : Mass hatching of the miracidia was effected by exposure of the embryonated eggs to light. In feet ion 0 f the s n a i I s -- i J1~~ I ab 0 rat 0 r y : Young I abora tory h call1iaudi snails with a shell height of 3-5 mm were used for’I aboratory infect ion. Each sna i I was exposed to 5-7 m i rac i d i a. Wh i te mi ce and rabbits were infected w i tll metacercariae obta i ned from field collected snaiIs. They were autopsied 7-12 weeks later. RESULTS AND DISCUSSION ~~cioliasis in the definitive hosts In the human host, the preva I ence of fasciolias i s was ~,3 . All age groups were found infected, the highest rates Ilere in the extremes of age. This might be due to their ~reater exposure and/or the i r lower immun i ty. i;asciola was determined depending on egg size.