Preliminary observations on infection of brackish and fresh water fish by heterophyid encysted metacercariae in Egypt

Abstract

The infection status with heterophyids in the second intermediate host fish obtained from brackish and fresh water resources in Dakahlia governorate, northern Egypt was investigated. Encysted metacercariae (EMC) in the fish species Mugil cephalus, Mugil capito, Mugil auratus, Tilapia nilotica, and Tilapia zilli from brackish water and T. nilotica and T. zilli from fresh water were isolated by artificial digestion method and identified by microscopic examination. Morphometric analysis of EMC isolated from these fishes identified seven phenotypically distinct groups. No significant morphologic differences were detected between EMC of the same group obtained from different fish species. The adult flukes recovered from seven groups of puppies separately infected with distinct EMC groups were compatible with seven species belong to six genera of Heterophyidae namely Heterophyes heterophyes, Heterophyes aequalis, Pygidiopsis genata, Haplorchis yokogawi, Prohemostomum vivax, Phagicola ascolonga, and Stictodora tridactyla. EMC of these seven heterophyid species were detected in all examined brackish water fishes. On the other hand, only EMC of P. genata, H. yokogawi, and P. ascolonga were detected in fresh water fishes, T. nilotica and T. zilli. These results indicate that heterophyid infections occur in brackish and fresh water fishes in northern Egypt, where the parasites are indigenous.

Prevalence of heterophyiosis in Tilapia fish and humans in Northern Egypt

“…This suggests that the type of water seems to play an important role in infection of fish by certain types of heterophyid parasites. These results are in agreement with previous studies (Makhlouf et al 1987;Mahdy et al 1995;Elsheikha and Elshazly 2008b). The recovered heterophyid species in the examined fish have zoonotic importance to Egyptians who reside in the Nile Delta of Egypt.…”

“…Different types of metacercariae were segregated and collected from the sediment using a binocular stereo microscope. Recovered metacercariae were categorized according to their phenotypic features into distinct groups before they were administered to the dogs as described (Paperna 1980;Elsheikha and Elshazly 2008b).…”

Review of Parasitic Zoonoses in Egypt

“…Infected fish is the main source of infection. Heterophyid infections occur in brackish and fresh water fish in northern Egypt, where the parasites are indigenous [66]. The highest intensity of infection has been detected among fishermen (33.8%) [67] and local residents in northern Egypt (13.3%) [68].…”

“…Many heterophyids have been identified from fish. Adult heterophyids from Heterophyes heterophyes , H. aequalis , Pygidiopsis genata , Haplorchis yokogawai , Prohemostomum vivax , Phagicola ascolonga , and Stictodora tridactyla were recovered from encysted metacercaria-fed puppies [66, 68, 69]. The prevalence of H. heterophyes was 3% amongstray cats in Kafr Elsheikh province in the northern region of the Delta [25].…”

Molecular characterization of Stictodora tridactyla (Trematoda: Heterophyidae) from Kuwait Bay using rDNA ITS and mtCO1

“…In addition to their effects on public health, these fish parasites form a great threat to the aquaculture fish industry (Dzikowski et al 2004;Thien et al 2007;Díaz et al 2008;Clausen et al 2014). The infection is transmitted to man through the ingestion of raw or uncooked fish which harbor heterophyid metacercariae (Fried et al 2004;Chai et al 2005;Kim et al 2006;Elsheikha and Elshazly 2008;Thaenkham et al 2011;Cho et al 2014;Chontananarth et al 2014;Clausen et al 2014).…”