Heterophyes heterophyes

Heterophyes heterophyes

<p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><i><b>Heterophyes heterophyes</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> (von Siebold, 1852) Stiles and Hassal, 1900</b></span></span></p> <p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><b>(Figure 2-25)</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 early in the study of trematodes to distinguish it from another fluke </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Paragonimus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> by Cobbold in 1866).</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 aegyptiaca</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Cobbold, 1866; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Mesogonimus heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Railliet, 1890; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Coenogonimus heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Looss, 1900; and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Cotylogonimus heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Lühe, 1900. In the orient, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes nocens</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Onji and Nishio, 1915 was described, but it is now considered a subspecies of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;">.</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 collected in 1851 by Bilharz from a human being in Egypt; the fluke was named </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Distoma heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> by von Siebold. The first report in cats is that of Looss (1902).</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 been reported from Egypt, Israel, Kuwait, Greece, Turkey, and Spain (probably throughout the Mediterranean); as the subspecies </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes heterophyes nocens</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, it has been reported from cats in Japan (Miyazaki, 1991). It has also been reported on rare occasions from west Africa and India (Malek, 1980).</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;"> Middle and upper portion, jejunum and duodenum of the small intestine (Tarachewski, 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 the genus </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;"> have a large genital sucker. The adult trematodes are found embedded in the villi, and measure about 1 mm by 0.5 mm. The spines on the genital sucker of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Heterophyes heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> number 50 to 80 and are digitate, looking like small leafless trees. The eggs are yellow brown in color, contain a miracidium, and have an average size of 27 µm by 16 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 in Egypt involves the snail </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Pironella conica</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> and the brackish-water fish host </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Mugil cephalus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. In Asia, the life cycle involves snails, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Certhideopsilla cingulata</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, that live in the mouths of rivers and various brackish-water fish hosts, including </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Mugil cephalus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Liza haematocheila</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Acanthogobius flavimanus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Glossogobius</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>giuris</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>Tridentiger obscurus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. The metacercariae are found within the muscle of the fish hosts.</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;"> An examination of the histopathology of the intestine of infected cats revealed that the parasites were closely associated with the villi (Hamdy and Nicola, 1980). At the sites of infection, the villi were swollen, the columnar epithelium was destroyed, and there was swelling of the underlying submucosa. There was a local cellular reaction and the Peyer's patches were hyperplastic. Immature flukes were found in lymphoid follicles and in Peyer's patches. Mature flukes were also found within mesenteric lymph nodes. However, no clinical signs were described. </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 as do other piscivorous animals.</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;"> Numerous humans have been infected with this parasite. In 1933, Khalil found 53 of 60 school children infected in an area close to the Suez Canal; in 1983, it was found in 14 of 65 cats in Egypt (Abo-Shady</span></span><span style="color: #000000;"><span style="font-size: medium;"><i> et al</i></span></span><span style="color: #000000;"><span style="font-size: medium;">., 1983). Infection rates in Japan have also reached levels as high as 30%; however, more recently, infection levels in humans in Japan are less than 1%.</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;">Abo-Shady AF, Ali MM, Abdel-Magied S. 1983. Helminth parasites of cats in Dakahlia, egypt. J Egypt Soc PArasitol 13:129-133,</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Hamdy EI, Nicola E. 1980. On the histopathology of the small intestine in animals experimentally infected with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>H. heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. J Egypt Med Assoc 63:179-184.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Looss A. 1902. Notizen zur Helminthologie egyptens. V. Eine Revision der Fasciolidengattung </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;"> Cobb. Centralblatt bakt. Orig. I. 32:886-891.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Malek E.A. 1980. </span></span><span style="color: #000000;"><span style="font-size: medium;"><span style="text-decoration: underline;">Snail-Transmitted Parasitic Diseases. Volumes I and II. </span></span></span><span style="color: #000000;"><span style="font-size: medium;"> 334 &amp; 324 pages. CRC Press, Boca Raton, FL. USA.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Miyazaki I. 1991. </span></span><span style="color: #000000;"><span style="font-size: medium;"><span style="text-decoration: underline;">Helminthic Zoonoses.</span></span></span><span style="color: #000000;"><span style="font-size: medium;"> 494 pages. International Medical Foundation of Japan. Fukuoka, Japan.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Tarachewski H. 1987. Experiments on habitat selection 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;"> species in different definitive hosts. J Helminthol 61:33-42.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"><b>Figure 2-25. </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>heterophyes</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> recovered from the from the intestine of a cat in Egypt. In this figure, it is difficult to appreciate the genital sucker except as a darkened area to the right and slightly posteriad to the ventral sucker.</span></span></p>