Strongyloides tumefaciens

Strongyloides tumefaciens

<p align="CENTER"><span style="font-size: medium;"><i><b>Strongyloides tumefaciens</b></i></span><span style="font-size: medium;"><b> Price and Dikmans 1941</b></span></p> <p align="CENTER"><span style="font-size: medium;"><b>(Figures 4-05 through 4-08)</b></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>tumefaciens</i></span><span style="font-size: medium;"> to reflect the tumor-like nodules induced by the parasite.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>SYNONYMS:</b></span><span style="font-size: medium;"> None.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HISTORY:</b></span><span style="font-size: medium;"> Price and Dikmans first reported lesions caused by this parasite in 1929 from a cat from Louisiana. They provided a description of the lesions and worms from the original cat and an additional case from Florida in 1941 and named the parasite </span><span style="font-size: medium;"><i>Strongyloides tumefaciens</i></span><span style="font-size: medium;">.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>GEOGRAPHIC DISTRIBUTION: </b></span><span style="font-size: medium;"><i> Strongyloides tumefaciens</i></span><span style="font-size: medium;"> has been found in a small number of domestic cats from the Southeastern United States in Louisiana, Florida, Texas, and Georgia (Price and Dikmans, 1941; Malone et al., 1977; Lindsay et al., 1987). It also has been observed in 2 wild cats, </span><span style="font-size: medium;"><i>Felis chaus</i></span><span style="font-size: medium;">, in India (Dubey and Pande, 1964). A </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> sp., most likely </span><span style="font-size: medium;"><i>S</i></span><span style="font-size: medium;">. </span><span style="font-size: medium;"><i>tumefaciens</i></span><span style="font-size: medium;">, has been observed in 3 Florida bobcats, </span><span style="font-size: medium;"><i>Felis rufus,</i></span><span style="font-size: medium;"> and a Florida panther, </span><span style="font-size: medium;"><i>Felis concolor coryi,</i></span><span style="font-size: medium;"> (Forrester, 1992).</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LOCATION IN HOST:</b></span><span style="font-size: medium;"> Adult </span><span style="font-size: medium;"><i>Strongyloides tumefaciens</i></span><span style="font-size: medium;">, eggs, and larvae are found in grossly visible tumor-like nodules in the large intestine. Migrating larvae may be observed in various tissues during migration to the large intestine. </span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>IDENTIFICATION</b></span><span style="font-size: medium;">: Parthenogenic females os </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>tumefaciens</i></span><span style="font-size: medium;"> dissected from formalin fixed nodules are about 5 mm long (Price and Dikmans, 1941); the species of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> present in the small intestine of the cat tend to be around 3.5 mm or less in length. Eggs from females of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"><i>tumefaciens</i></span><span style="font-size: medium;"> are embryonated and measure 114 to 124 by 62 to 68 µm. Fecal cultures of larvae at room temperature will result in third-stage larvae that have a “split tail” appearance (typical for </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> sp.) and a filariform esophagus (Malone et al., 1977). </span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LIFE CYCLE:</b></span><span style="font-size: medium;"> The life cycle is unknown. Infections are probably acquired by oral ingestion or skin penetration by third stage larvae. Parthenogenic females are found in grossly visible tumor-like nodules in the large intestine. Eggs and larvae are also present in the nodules. Eggs hatch in the nodules and larvae are excreted in the feces. No parasitic males exist.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>CLINICAL PRESENTATION AND PATHOGENESIS:</b></span><span style="font-size: medium;"> Abdominal palpation of cats with </span><span style="font-size: medium;"><i>S. tumefaciens</i></span><span style="font-size: medium;"> may reveal a firm and fibrotic colon (Malone et al., 1997). </span><span style="font-size: medium;"><i>Strongyloides tumefaciens</i></span><span style="font-size: medium;"> produces characteristic tumor-like nodules in the large intestine. Grossly, white, glistening nodules present on the mucosal surface are elevated 1 to 3 mm above the mucosa and are 2 to 3 mm in diameter (Fig 4-05). These nodules may be visualized on colonoscopy. A central depression may also be present. Microscopically, hyperplastic nodules of crypt epithelium are present in the submucosa (Fig 4-06). A connective tissue capsule surrounds the nodules. The mucosal epithelium covering the nodules may be degenerative and infiltrated by neutrophils and lymphocytes. Parthenogenic females are present and confined to the nodules (Fig 4-07). Eggs can be observed within the females and free in the nodules (Fig 4-08). Rhabditiform larvae can be found in the nodules, in adjacent submucosal tissues and free in the lumen.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>TREATMENT:</b></span><span style="font-size: medium;"> Thiabendazole is effective in treating cats with </span><span style="font-size: medium;"><i>S. tumefaciens</i></span><span style="font-size: medium;"> when administered orally at 125 mg daily for 3 days (Malone et al., 1977). The feces become normal and larvae are eliminated by day 4 post-treatment.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARD TO HUMANS:</b></span><span style="font-size: medium;"> Unknown. </span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARD TO OTHER ANIMALS:</b></span><span style="font-size: medium;"> Unknown. A similar lesion containing </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> was observed in the jejunum of a chimpanzee (Blacklock and Adler, 1922).</span></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>REFERENCES:</b></span></p> <p align="JUSTIFY"><span style="font-size: medium;">Blacklock B, Adler S. 1922. The pathological effects produced by </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;"> in a chimpanzee. Ann. Trop. Med. Parasitol. 16: 383-290.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Dubey JP, Pande BP. 1964. On helminthic lesions encountered in the alimentary canal of the Indian wild cat (</span><span style="font-size: medium;"><i>Felis chaus</i></span><span style="font-size: medium;">). Agra Univ. J. Res. Sci. 13:169-184.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Forrester DJ. 1992. </span><span style="font-size: medium;"><i>Parasites and Diseases of Wild Mammals in Florida</i></span><span style="font-size: medium;">. University of Florida Press, Gainesville, Fla. pp.174-203.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Lindsay DS, Blagburn BL, Stuart BP, Gosser HS. . 1987. </span><span style="font-size: medium;"><i>Strongyloides tumefaciens</i></span><span style="font-size: medium;"> infection in a cat. Compan. Anim. Pract. 1:12-13.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Malone J. B., A. B. Butterfield, J. C. Williams, B. P. Stuart, and H. Travasos. 1977. </span><span style="font-size: medium;"><i>Strongloides tumefaciens</i></span><span style="font-size: medium;"> in cats. J. Am. Vet. Med. Assoc. 171:278-280.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Price EW, Dikmans G. 1929. Multiple adenomata of the large intestine of a cat caused by a species of </span><span style="font-size: medium;"><i>Strongyloides</i></span><span style="font-size: medium;">. J. Parasitol 16: 104.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Price EW, Dikmans G. 1941. Adenomatous tumors in the large intestine of a cats caused by </span><span style="font-size: medium;"><i>Strongloides tumefaciens</i></span><span style="font-size: medium;">, n. sp. Proc. Helminthol. Soc. Wash 8:41-44. </span></p> &nbsp; <p align="JUSTIFY"><span style="font-size: medium;">Figure 4-05. </span><span style="font-size: medium;"><i>Strongyloides tumefasciens</i></span><span style="font-size: medium;">. Transverse section through a nodule in the colon of a cat showing the hyperplatic mucosa and muscularis containing numerous worms.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Figure 4-06</span><span style="font-size: medium;"><i>. Stongyloides tumefasciens</i></span><span style="font-size: medium;">. Transverse section showing several sections through the parthenogentic female.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Figure 4-07. </span><span style="font-size: medium;"><i>Strongyloides tumefasciens</i></span><span style="font-size: medium;">. Section through a female worm at the level of the ovary.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Figure 4-08. </span><span style="font-size: medium;"><i>Strongyloides tumefasciens. </i></span><span style="font-size: medium;"> Section through the worm at the level of the uterus. Also present are laid eggs in various states of development.</span></p>