Haplorchis yokogawai

Haplorchis yokogawai

<p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><i><b>Haplorchis yokogawai</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> (Katsuta, 1932) Chen, 1936</b></span></span></p> <p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><b>(Figure 2-22)</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>yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = for Dr. Yokogawa</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>Monorchotrema yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Katsuta, 1932; </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>Monorchotrema taihokui</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Africa and Garcia, 1935; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis vagabundi</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Baugh, 1963).</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 specimens collected from dogs, cats, and human beings that were experimentally infected (Katsuta, 1932).</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 throughout Asia and the Mediterranean. It has been reported from cats in Taiwan, China, Java, Egypt, and Hawaii, from avian hosts in India, and from the cat, a water rat (</span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Hydromys chorogaster</i></span></span><span style="color: #000000;"><span style="font-size: medium;">) and a whistling eagle (</span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haliastur sphenurus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">) in Australia (Pearson, 1964).</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, within the first half.</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;"><i>Haplorchis yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> differs from the 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;"> found in the cat in that the ventral sucker is covered with a small number of very small spines rather than with hooks as in </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;"> or a few large spines as in </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;">.</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 yokogawi</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> is a small fluke that is rather wide, 0.23 to 0.34 mm long by 0.2 to 0.28 mm wide. The eggs measure 29 to 30 µm by 13 to 17 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 the feeding of infected brackish-water mullet to human beings (Katsuta, 1932). The metacercariae are encysted in the scales, gills, and fins of mullet, but not in the muscles. The snail host in Hawaii is </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Stenomelania newcombi</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> where two generations of rediae develop in the digestive gland of the snail (Martin, 1958). The cercariae have a very long flagellum and lateral fins near the body. When experimentally infected fish were fed to cats, the adult worms were found to contain eggs within 10 days after infection (Martin, 1958)</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. The fact that the eggs are carried to ectopic locations in humans (see "Hazards to Humans”) would suggest that similar events could occur in other hosts including the cat.</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 normal natural hosts are probably piscivorous birds.</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, by the ingestion of the infected fish intermediate hosts. Eggs of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Haplorchis yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> have been found in cardiac lesions of persons with cardiac failure and in the epicardiac layer of the heart (Africa</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;">., 1936).</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;">Africa JE, de Leon W,. Garcia EY. 1937. Heterophyidiasis. VI. Two more case of heart failure associated with the presence of eggs in sclerosed veins. J Philip Is Med Assoc 17:605-609.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Katsuta I. 1931. Studies on trematodes whose second intermediate hosts are fishes from the brackish waters of Formosa. III. On a new trematode </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Monorchotrema</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> of which the mullet is the second intermediate host. J med Assoc Formosa 31:25-26.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Martin WE. 1958. The life histories of some Hawaiian Heterophyid trematodes. J Parasitol 44:305-323.</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 2-22.</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>yokogawai</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> recovered from the intestine of a cat in Cairo, Egypt.</span></span></p>