Strongyloides planiceps

Strongyloides planiceps

<p align="CENTER"><span style="font-size: medium;"><i><b>Strongyloides planiceps</b></i></span><span style="font-size: medium;"><b> Rogers, 1943</b></span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>SYNONYMS</b></span><span style="font-size: medium;">: </span><span style="font-size: medium;"><i>Strongyloides cati</i></span><span style="font-size: medium;"> Rogers, 1939</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>ETYMOLOGY:</b></span><span style="font-size: medium;"><i> Strongyl </i></span><span style="font-size: medium;">= round and</span><span style="font-size: medium;"><i> oides </i></span><span style="font-size: medium;">= like for the genus and </span><span style="font-size: medium;"><i>planiceps</i></span><span style="font-size: medium;"> for the species name of the Rusty tiger cat, </span><span style="font-size: medium;"><i>Felis planiceps</i></span><span style="font-size: medium;">, the host from which the parasite was isolated by R. T. Leiper in 1927.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>GEOGRAPHIC DISTRIBUTION</b></span><span style="font-size: medium;">: </span><span style="font-size: medium;"><i>Strongyloides planiceps</i></span><span style="font-size: medium;"> was originally described from Malaya (Rogers, 1943) and subsequent found in wild carnivores and occasionally domestic cats in Japan (Horie et al., 1981; Fukase et al., 1985). It has been observed several times in cats from Japan. It has not been observed in the United States.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LOCATION IN HOST:</b></span><span style="font-size: medium;"><i>Strongyloides planiceps</i></span><span style="font-size: medium;"> is present in the anterior portion of the small intestine.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>IDENTIFICATION:</b></span><span style="font-size: medium;"> Parasitic females are 2.4-3.3 mm long (mean, 2.8 mm); the ovaries of the female have a spiral appearance. Partially embryonated eggs measuring 58-64 by 32-40 µm (mean, 61 by 35 µm) are excreted in the feces. Infections with </span><span style="font-size: medium;"><i>Strongyloides planiceps</i></span><span style="font-size: medium;"> can be identified by finding embryonated eggs in fecal smears or fecal flotations. Fresh samples should examined to avoid confusion with hookworm eggs. The tip of the tail of the parasitic female of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>planiceps</i></span><span style="font-size: medium;"> abruptly narrows to a blunt end, while that of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;"> is longer and narrows more slowly to the tip of the tail (Horie et al., 1981).</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LIFE CYCLE:</b></span><span style="font-size: medium;"> Cats become infected by oral ingestion of infective larvae or by skin penetration (Rogers, 1939). Larvae can be found in the lungs by four days after infection, and young parthenogenic adult females can be found in the small intestine 6 days after skin penetration. Eggs are excreted in the feces 10 to 11 days after infection.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>CLINICAL PRESENTATION AND PATHOGENESIS:</b></span><span style="font-size: medium;"> There has been no description of clinical signs in infected cats. It is possible that large numbers are capable of causing disease, but this is likely to require careful research in which this species is examined in cats known to be free of other helminths, particularly, </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;">.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>TREATMENT:</b></span><span style="font-size: medium;"> This is likely to be similar to that reported for </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;">. It is expected that therapeutic doses of ivermectin may also be efficacious.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>EPIZOOTIOLOGY:</b></span><span style="font-size: medium;"> This parasite is probably as common in its range in dogs as it is in cats (Fukase et al., (1985). These authors report finding this parasite in 4 of 420 dogs, 4 of 105 domestic cats, 26 of 40 raccoon dogs (</span><span style="font-size: medium;"><i>Nyctereutes</i></span><span style="font-size: medium;"><i>procyonoides</i></span><span style="font-size: medium;"><i>viverrinus</i></span><span style="font-size: medium;">) and 2 of 5 Japanese weasels (</span><span style="font-size: medium;"><i>Mustela</i></span><span style="font-size: medium;"><i>sibirica</i></span><span style="font-size: medium;"><i>itatsi</i></span><span style="font-size: medium;">). Cats can become infected either by the oral inoculation of larvae or by skin penetration, and it would appear that where the range of cats overlaps that of wildlife reservoir hosts that cats will be at risk of infection with this parasite.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARD TO HUMANS:</b></span><span style="font-size: medium;"> There are no records of this parasite in humans.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARD TO OTHER ANIMALS:</b></span><span style="font-size: medium;"><i>Strongyloides planiceps</i></span><span style="font-size: medium;"> is found in wildlife in areas of the world where it is present. It has been reported from dogs, raccoon dogs, Japanese weasels, and the rusty tiger cat in Malaysia. It appears that a red fox from Hokkaido Japan was also infected with this parasite (Fukase et al., 1985).</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>REFERENCES:</b></span></p> <p align="JUSTIFY"><span style="font-size: medium;">Fukase T, Chinone S, Itagaki H. 1985. </span><span style="font-size: medium;"><i>Strongyloides planiceps</i></span><span style="font-size: medium;"> (Nematoda; Strongyloididae) in some wild carnivores. Jpn. J. Vet. Sci. 47:627-632.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Horie M, Noda R, Higashino J. 1981. Studies on </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> sp. isolated from a cat and raccoon dog. Jpn. J. Parasitol. 30: 215-230.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Rogers WP. 1939. A new species of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> from the cat. J. Helminthol. 17: 229-238.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Rogers WP. 1943. </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>planiceps</i></span><span style="font-size: medium;">, new name for </span><span style="font-size: medium;"><i>S. cati</i></span><span style="font-size: medium;"> Rogers. J. Parasitol. 29: 160.</span></p>