Heterophyes aequalis

Heterophyes aequalis

<p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><i><b>Heterophyes aequalis</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> Looss, 1902</b></span></span></p> <p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><b>(Figure 2-26)</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>Hetero</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = different and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>phyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = form (named to distinguish it from along with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>aequalis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = equal, referring to the equivalent sizes of the ventral and oral suckers when compared to </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes dispar</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> which was named at the same time and which supposedly had a ventral sucker much larger in diameter than the oral sucker.</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>Heterophyes dispar</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Looss, 1902 (according to Kuntz and Chandler, 1956).</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 species was originally described from naturally infected cats in Egypt.</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;"> Egypt and Israel.</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, mainly the terminal portion of the intestinal tract (Taraschewski, 1987).</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;"> Specimens of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes aequalis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> are characterized by having a few, 15 to 35, rodlets surrounding the genital sucker </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>versus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> the 50 to 80 digitate rodlets present on that of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. The flukes from cats range in size from 0.5 to 1.4 (rarely 1.6) mm with a width of 0.25 to 0.5 mm. The ventral sucker is typically 0.06 to 0.18 mm in diameter. The yellowish-brown shelled eggs are 23-25 µm long by 14-16 µm wide.</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 involves metacercariae encysted in </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Mugil, Epinephelus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Tapia</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Lichia</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Barbus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> fish. Cats become infected by the ingestion of these marine, brackish-water, or fresh-water fish.</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 but 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 become infected by eating raw fish. Other hosts that ingest infected raw fish are also likely to become infected. The host that has been described for this parasite is the cat with adults sometimes being found in dogs.</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 probably could be infected 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>Figure 2-26.</b></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>aequalis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> recovered from a cat in Cairo, Egypt. The separate genital sucker on this species is more apparent than in the figure showing </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;">.</span></span></p>