The present study spotted some light on human fascioliasis in Kafr El-Sheikh Governorate in the west of the Nile Delta in Egypt, its species, its intermediate host (IMH) snail and tried to answer previous questions about development of Fasciola (F.) species in new snail hosts other than that known for animal fascioliasis in Egypt. The study recorded a percentage of infection by Fasciola eggs reached up to 6.02% in 1810 randomly collected human stool samples from 6 climatically selected sites in this governorate using fluke-finder technique. The incidence was high in Sedi Salem and Motobus than in the other study sites. Micrometry measuring of 100 eggs from each locality showed that egg size cannot be used as a main criterion in differentiation between F. hepatica and gigantica. Wide range of egg size varied between 130-162.5 µ X 75-87.5 µ with a mean length and width of 144.24 ± 11.33 µ X 80± 6.55µ, was recorded. Upon dissection of 1972 Lymnaea (L.) cailliaudi, 268 L. alexandrina, 502 Bulinus species, 11316 Biomphalaria alexandrina, 1398 Cleopatra species, 8520 Physa acuta, 420 Melania tuberculata, 2132 Vivipara (Bellamya) unicolar, 144 Neritina nilotica and 1570 Planorbis philippi, Fasciola parthenitae were not detected in snails other than L. cailliaudi (the known IMH of Fasciola in Egypt). The results proved that there is no accommodation has occurred in any of the surrounding snails to transmit Fasciola to man. The present study proved that human fascioliasis in the study sites was due to Fasciola gigantica not F. hepatica. This appeared in its tendency to develop in L. cailliaudi not in other tested snails with successive radial generations as that described previously for F. gigantica. Moreover, early mature flukes extracted from laboratory infected rabbits by the produced encysted metacercariae had the characteristic features described previously for F. gigantica.

Fascioliasis is an important disease caused by Fasciola hepatica and Fasciola gigantica. The distributions of both species overlap in many areas of Asia and Africa including Egypt. Fifty adult Fasciola worms were collected from livers of cattle and sheep slaughtered in abattoirs, Cairo, Egypt. They were subjected to morphological and metric assessment of external features of fresh adults, morphological and metric assessment of internal anatomy of stained mounted worms, determination of electrophorezed bands of crude adult homogenates using SDS-PAGE, and molecular characterization of species-specific DNA segments using RFLP-PCR. It was found that the correlation between conventional morphology and its morphotype was statistically significant (P value = 0.00). Using SDS-PAGE, 13 bands were detected among both genotypes of Fasciola (35.7, 33.6, 32.4, 29.3, 27.5, 26, 24.4, 23, 21.45, 19, 16.75, 12.5, and 9.1 kDa).The most prevalent bands were that with a molecular weight of 29.3, 26, and 19 kDa. Bands detected were common for both species, but protein bands could not distinguish between F. hepatica and F. gigantica. The result of PCR for the amplification of the selected 28S rDNA fragment with the designed primer set yielded 618 bp long PCR products for F. hepatica and F. gigantica. Different band patterns generated after digestion of the 618 bp segment by the enzyme AvaII obtained with F. hepatica showed segments of the length 529, 62, 27 bp, while with F. gigantica 322, 269, 27 bp bands were obtained. Genotyping revealed no equivocal results. The conventional morphological parameters for species determination of Fasciola spp. endemic in Egypt were evaluated versus protein bands characterization and genotyping. It was concluded that conventional morphological and metric assessments were not useful for differentiation between F. gigantica and F. hepatica due to extensive overlap in the relative ranges. Similar conclusion was reached concerning protein band characterization where the patterns of protein banding were mostly similar. In contrast, genotyping using RFLP-PCR gave consistent results and clear differentiation between the two species. Considering the implications of proper speciation of endemic parasites on clinical evaluation, therapy, epidemiology, and control measures, speciation of parasites is currently revised on molecular basis. The presently used molecular tool is therefore recommended for further study to help draw a proper map for geographical distribution of Fasciola species.

Fascioliasis is now recognized as an emerging zoonotic disease in Egypt. Diagnosis in suspected patients still needs some degree of accuracy. In the present study, three Fasciola gigantica execratory secretory (ES) protein bands of molecular weight (MW) ranging from 14 to 20 kDa, 25 to 32 kDa and 45 to 65 kDa were eluted after fractionation of the parasite antigen using SDS-PAGE. The extracted kDa protein bands were concentrated and evaluated in diagnosis of Fasciola infection. Moreover the level of their cross reaction with other parasitic infections in infected and suspected patients of known parasite eggs/gram stool was evaluated using the dot-ELISA technique. Protein bands in the range of 14-20 kDa and that of 25-32 kDa were markedly specific and sensitive in diagnosis of different levels of anti-Fasciola antibodies (Ab) in sera of infected cases. These two groups of bands were able to exclude cross-reaction between anti-Fasciola Ab and other parasites recorded in stool of selected patients suffering from Schistosoma mansoni, Ascaris, and Giardia, either in single or mixed conditions with Fasciola eggs. While that of 45-65 kDa appeared less specific than the other previously mentioned bands. Protein bands in the range of 25-32 kDa appeared more sensitive than the other protein bands in detection of anti-Fasciola Ab at higher serum dilutions. The Dot-ELISA technique was proved to be more economic and easy in application. The dotted very small amount of antigens can be stored in a freezer and used at request in diagnosis of large numbers of samples. ª 2014 Production and hosting by Elsevier B.V. on behalf of Faculty of Veterinary Medicine, Cairo University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/3.0/).

No abstract

No abstract