Paragonimus mexicanus

Paragonimus mexicanus

<p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: large;"><i><b>Paragonimus mexicanus</b></i></span></span><span style="color: #000000;"><span style="font-size: large;"><b> Miyazaki and Ishii, 1968</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>Para</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = side-by-side and </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>gonimus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> = gonads along with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>mexicanus </i></span></span><span style="color: #000000;"><span style="font-size: medium;">referring to the geographical location of this parasite.</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>Paragonimus peruvianus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Miyazaki, Ibanez, and Miranda, 1968; </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Paragonimus ecuadorensis</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> Voelker and Arzube, 1979.</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 found in an opossum, </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;">, captured in Mexico. It has been found in other animals and in humans. </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;"> Mexico, Central America, and the western coast of South America, including Ecuador and Peru.</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;"> In cysts in the lungs.</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>Paragonimus mexicanus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> are similar to the other species of </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;"> possessing single cuticular spines (Tongu</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;">., 1995).</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;"> The eggs of the American species of </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;">, other than those of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Paragonimus kellicotti</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, have eggshells that are undulated rather than smooth. The size of the eggs average 79 by 48 µm. In other aspects the eggs are quite similar morphologically to the other species. </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 first intermediate hosts of this parasite are species of snails of the genus </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Aroapyrgus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. The second intermediate hosts are fresh-water crabs of the genera </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Pseudothelphusa</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Ptychophallus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">, </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Potamocarcinum</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>Hypolobocerca</i></span></span><span style="color: #000000;"><span style="font-size: medium;">. In the crab, the metacercaria has no cyst stage and it moves freely about in the liver tissue of the crab. This species has been shown to have metacercarial stages that persist in the tissues of rats as paratenic hosts and which are capable of developing to the adult stage upon the ingestion of the rats by cats. (Miyazaki, 1991). </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;"> Clinical signs similar to those of </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Paragonimus kellicotti</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>TREATMENT:</b></span></span><span style="color: #000000;"><span style="font-size: medium;"> Probably praziquantel.</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;"> Numerous mammals are capable of being infected with </span></span><span style="color: #000000;"><span style="font-size: medium;"><i>Paragonimus mexicanus</i></span></span><span style="color: #000000;"><span style="font-size: medium;">; including: cats, jaguars, dogs, foxes, raccoon, coatimundis, skunks, and three species of opossums.</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;"> Other animals appear likely to develop infection and disease similar to that seen in the ct, but only if they ingest the infected crayfish. Thus, the infected cat is not a direct threat to other uninfected 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;"> Human infections with this parasite have been reported in Mexico, Central America, Ecuador, and Peru, where people are known to eat raw crabs (Brenes</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).</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;">Brenes RR, Little MD, Raudales O, Múñoz G, Ponce C. 1983. Cutaneous paragonimiasis in man in Honduras. Am J Trop Med Hyg 32:376-378.</span></span></p> <p align="JUSTIFY"><span style="color: #000000;"><span style="font-size: medium;">Tongu Y, Hata H, Orido Y, Pinto MR, Lamoth-Argumedo R, Yokogawa M, Tsuji M. 1995. Morphological observations of </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;"><i>mexicanus</i></span></span><span style="color: #000000;"><span style="font-size: medium;"> from Guatemala. Jap[ J Parasitol 44:365-370.</span></span></p>