Amphimerus pseudofelineus

Amphimerus pseudofelineus

<p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><i><b>Amphimerus pseudofelineus</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> (Ward, 1901) Barker, 1911</b></span></span></p> <p align="CENTER"><span style="color: #000000;"><span style="font-size: large;"><b>(Figure 2-37)</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>Amphi</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = on both sides and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>merus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = part (referring to the break in the vitellaria) along with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudo </i></span></span><span style="color: #000000;"><span style="font-size: medium;">= false and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>felineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = cat host; differentiating it from </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis felineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> which had already been described from cats in Europe.</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>Opisthorchis guyaquilensis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Rodriguez</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;">, 1949</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 trematode was originally described from a cat in Nebraska, USA. Barker (1911) differentiated the genus </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> from that of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, and he transferred the species </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> to the new genus.</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;"> The Americas; besides the original description from Nebraska, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> has been described from cats from Illinois, Michigan, and experimentally from Manitoba, Canada. Human infections with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis guyaquilensis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in Ecuador were later identified as </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus psuedofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. Miyazaki (1991) states that about 10 species have been found in the america, and that all may potentially infect human. In a similar fashion, it may be that all are capable of occurring in cats.</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;"> Gall bladder and bile ducts; occasionally in the 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;"><i>Amphimerus pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> adults are very similar to those of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis.</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> The major difference is that the vitelline glands situated along the side of the body are divided on each side into anterior and posterior clusters at the level of the ovary. Also, the vitellaria extend more posteriad within the lateral field.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"> The adults measure about 16 to 24 mm in length. The eggs are similar to those of other opisthorchids measuring 27 by 15 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 been incompletely described (Evans, 1963). A cat was fed 700 grams of fresh-water fish fillets from suckers, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Catostomus commersonii</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, collected from lake Manitoba. The examination of the cat 51 days after the last feeding revealed the </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> within the bile ducts.</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;"> Infection of cats can result in severe cirrhosis of the liver ultimately resulting in death (Levine</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;">., 1956; Rothenbacher and Lindquist, 1963). In chronic cases the liver can be enlarged with a granular appearing surface. Cut sections of the liver appear fibrotic with a distinct yellow-brown mottling. The larger bile ducts may contain a dark-brown exudate. Bile duct epithelium becomes thickened and fibrotic. Clinical signs reflect progression in liver dsyfunction with anorexia, weight loss, diarrhea, periodic vomiting, and icterus, with hepatomegally initially, then microhepatica.</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;"> Praziquantel is likely to prove successful in eliminating these trematodes.</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 are not the only hosts of this parasite. It has also been reported from coyotes in the USA and as </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis guayaquilensis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in dogs in Ecuador and in cats and opossums, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Didelphis marsupialis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in Panama. A related species, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus lancea</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, has been reported from fresh-water porpoises in Brazilian waters.</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. </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;"> There have been records of human infections with this parasite in Ecuador where 4% of the human beings and 3% of the dogs in a village were found to be infected (Rodriguez</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;">., 1949). It is believed that the infections were obtained by the ingestion of raw fish.</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;"> Prevent the ingestion of infected lizards, toads, and frogs.</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;">Barker FD. 1911. The trematode genus </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> R. Blanchard, 1895. Studies Zool Lab Univ Nebraska 103:513-561.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Evans WS. 1963. </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> (Ward, 1901) (Digenea: Opisthorchidae) and its second intermediate host in manitoba. Can J Zool 41:649-651.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Levine ND, Beamer PD, Maksic D. 1956. Hepatitis due to </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> in a cat. J Parasitol 42(suppl):37.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Rodriguez JD, Gomez LF, and Montalvan CJA. 1949. El </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>guayaquilensis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> (una nueva especie de </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Opisthorchis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> encontrada en el Ecuador). Rev Ecua Hig Med Trop. 6:11-24.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Rothenbacher H, Lindquist WD. 1963. Liver cirrhosis and pancreatitis in a cat infected with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. JAVMA 143:1099-1105.</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;"><b>Figure 2-37. </b></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Amphimerus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"><i>pseudofelineus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> recovered from the bile duct of a cat in Temple, Texas, USA, by Dr. DM Bandy.</span></span></p>