Haplorchis pumilio

Haplorchis pumilio

<p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><i><b>Haplorchis pumilio</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> (Looss, 1896) Looss, 1899</b></span></span></p> <p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><b>(Figure 2-21)</b></span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>ETYMOLOGY:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = single testis and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pumilio</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = a dwarf</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>SYNONYMS:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Monostomum pumilio</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Looss, 1896; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Monorchotrema taihokui</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Nishigori, 1924; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis taihokui</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Yamaguti, 1958; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis milvi</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Gohar, 1934; and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Kasr aini</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Khalil, 1932.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>HISTORY:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> This fluke was originally described from a pelican, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Pelecanus onocrotalus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, and a kite, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Milvus migrans</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in Cairo Egypt. </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis pumilio</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> has been described from numerous hosts as a new species, it has also been confused with other species, i.e., </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis taichui</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, and with parasites in other genera, i.e., </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Stellantochasmus falcatus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> (Pearson, 1964).</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>GEOGRAPHIC DISTRIBUTION:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> This trematode has a wide distribution. It has been reported from Egypt, Israel, Tunisia, China, Taiwan, India, and Australia.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>LOCATION IN HOST:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Small intestine.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>PARASITE IDENTIFICATION:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> The genus </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> (as is the related </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Procerovum</i></span></span><span style="color: #000000;"><span style="font-size: medium;">) is characterized by possession of a single testis. The ventral sucker is posterior to the bifurcation of the intestine and contains the typical sucker/genital complex. </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> can be differentiated from </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Procerovum</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> by the in the possession in the latter of a very muscular wall on the seminal vesicle, called an expulsor, that runs along the intestinal cecum on the left side.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"> The species </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis pumilio</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> is a small fluke, 0.25 to 7.2 mm long by 0.1 to 0.19 mm wide. It differs from other species of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in that the anterior edge of the ventral sucker is not lined with spines but with what has been called bars that number from 32 to 40. The eggs measure 29 to 32 µm by 15.5 to 17.5 µm.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>LIFE CYCLE:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> The life cycle has elucidated by feeding kittens fresh-water fish, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Gambusia</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, infected with cercariae that had developed in the snail </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Pirenella conica</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> (Kuntz and Chandler, 1956).</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>CLINICAL PRESENTATION AND PATHOGENESIS:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Not reported so thought to be asymptomatic.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>TREATMENT:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Probably praziquantel, but not reported.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>EPIZOOTIOLOGY:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Cats probably become infected by eating raw fish. Other animals that have been found naturally infected include among others, pelicans, kites, dogs, fox </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Vulpes vulpes</i></span></span><span style="color: #000000;"><span style="font-size: medium;">), shrew (</span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Crocidura olivieri</i></span></span><span style="color: #000000;"><span style="font-size: medium;">), gulls, and human beings.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>HAZARD TO OTHER ANIMALS:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> None known; however, due to the requirements for two intermediate hosts, it is unlikely that an infected cat would pose a direct threat to other animals.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>HAZARD TO HUMANS:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Humans have been infected, probably by the ingestion of the infected fish intermediate hosts.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>CONTROL/PREVENTION:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> The prevention of the ingestion of raw fish.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>REFERENCES:</b></span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Kuntz RE, Chandler AC. 1956. Studies on Egyptian trematodes with special reference to the Heterophyids of mammals. I. Adult flukes, with descriptions of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Phagicola</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>longicollis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> n. sp., </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Cynodiplostomum</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>namrui</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> n.sp., and a </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Stephanoprora</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> from cats. J Parasitol. 42:445-459.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Pearson JC. 1964. A revision of the subfamily Haplorchiinae Looss, 1899 (Trematoda: Heterophyidae). Parasitology 54:601-676.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>Figure 2-21.</b></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pumilio</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> from the small intestine of a domestic cat in Cairo, Egypt. Note the large single testis in the posterior of the body.</span></span></p>