A preliminary study on dicrocoeliasis in Egypt, with a general review.

Dicrocoelium dendriticum (D. dendriticum) is a lancet-shape liver fluke that affects sheep and mammals including man. Human and animal infections have been world widely reported particularly in some of the Eastern Mediterranean sheep raising countries. Infection is acquired by eating the second intermediate host (17 species of ants) with raw fruits, vegetables, herbs or even with the drinking water. As for the first intermediate host, there is about 54 different species of land snails. In spite of the fact that both the first and second intermediate hosts of D. dendriticum are available in Egypt, data about human and animal dicrocoeliasis is lacking. This investigation is a preliminary study to report on the presence of D. dendriticum (in sheep, goats and man in North Sinai Governorate) in Egypt.

Morphologic and biochemical changes caused by experimentally induced dicroceliosis in hamsters (Mesocricetus auratus).

BACKGROUND AND PURPOSE: The aim of the study reported here was to investigate the pathomorphologic changes caused by experimentally induced dicroceliosis and their correlation with hepatobiliary function. METHODS: Studies were carried out at days 80 and 120 after oral inoculation of hamsters with 40 metacercariae of Dicrocoelium dendriticum. RESULTS: The parasite-induced pathologic changes were assessed by presence of fluke eggs in feces, increased plasma alanine transaminase and aspartate transaminase activities and morphologic alterations. Dicroceliosis was characterized by bile ductular proliferation and enlargement of the bile duct surface area caused by hyperplastic cholangitis in septal bile ducts. The liver from infected animals contained portal tracts infiltrated with small to moderate numbers of lymphocytes, macrophages, and eosinophils. Simultaneously, there was an increase in portal tract collagen that extended to the interlobular septa and caused pressure atrophy of the hepatic parenchyma. The concentration of thiobarbituric acid-reactive substances and the ratio of oxidized to reduced glutathione, measured as markers of oxidative stress, were significantly increased. CONCLUSIONS: The presence of oxidative alterations could be related to the morphologic evidence of chronic inflammatory response as well as to liver cellular injury indicated by cellular swelling, and increased presence of peroxisomes and lysosomes.

Enhanced bile formation induced by experimental dicrocoeliosis in the hamster.

The purpose of this investigation was to determine the effects of experimental dicrocoeliosis on bile formation in the hamster. Studies were carried out at 120 days after infection with an oral dose of 40 metacercariae of Dicrocoelium dendriticum. A significant elevation in bile flow (+20%) and in the biliary output of glutathione (+34%), bile acid (+59%), cholesterol (+108%), phospholipids (+99%) and alkaline phosphatase (+36%) was observed in the infected animals. The bile-to-plasma [14C] mannitol ratio increased to values greater than 1 and there was a reduced contribution (-26%) of biliary tree to bile formation. Those data suggest that enhancement in choleresis had a canalicular origin. The presence of oxidative stress, evidenced by the increased oxidized/reduced glutathione ratio and TBARS concentrations, may contribute to the elevated glutathione efflux into bile. Enhancement in bile acid output was not due to qualitative or quantitative changes in bile acid metabolism, as indicated by the absence of significant modification in liver cholesterol 7alpha-hydroxylase activity and bile acid profile in bile. Increase in the ability of the canalicular membrane to export bile acids was not involved, since maximal secretion rate for exogenously administered taurocholate was decreased. When bile flow, bile acid and biliary lipid secretion was determined in colchicine-pretreated animals differences between control and infected animals were abolished, suggesting that stimulation of the transcytotic vesicle pathway plays an important role in the alteration of the biliary function caused by dicrocoeliosis.

Effects of experimental dicrocoeliosis on oxidative drug metabolism in hamster liver.

The purpose of this investigation was to determine the effects of experimental dicrocoeliosis on the hepatic oxidative drug-metabolizing system in hamsters. Studies were carried out 80 and 120 days after infestation with an oral dose of 40 metacercariae of Dicrocoelium dendriticum. The parasitic pathology was ascertained by detection of the fluke eggs in faeces, increased serum alanine aminotransferase and aspartate aminotransferase activities, and postmortem and histological findings. Cytochrome P-450 concentration, aniline hydroxylase activity and ethoxycoumarin O-deethylase activity were significantly decreased in both groups of infected animals. Aminopyrine N-demethylase activity and erythromycin N-demethylase activity were only reduced 120 days after infection. Effects on drug metabolizing enzymes were unrelated to changes in the physical state of the microsomal membrane, as assessed by measurement of fluorescence polarization. The results of this study indicate that the capacity of the liver for handling drugs and xenobiotics may be impaired as a consequence of dicrocoeliosis.

Human dicrocoeliasis. Report on 208 cases from Saudi Arabia.

In 3 years, Dicrocoelium dendriticum ova were detected in 208 patients at the Armed Forces Hospital, Riyadh, Saudi Arabia during 1984-1986. At least 7 of these patients had a true infection and at least 34 patients had spurious infection as they gave a history of eating raw liver. 23% of the 208 patients were under 14 years of age. The peak incidence was between October and November in each of the 3 years. 134 of these patients were symptomatic. 16 patients had disturbed liver functions and 13 had eosinophilia. 10 patients had gall bladder or biliary tree disease and in at least 2 of which it was due to D. dendriticum. Malabsorption occurred in one patient. Praziquantel was used in 9 patients and was successful in treating 4 of these patients.