Spirometra mansonoides

Spirometra mansonoides

<p align="CENTER"><span style="color: #000000"><span style="font-size: large"><i><b>Spirometra </b></i></span></span><span style="color: #000000"><span style="font-size: large"><i><b>mansonoides</b></i></span></span><span style="color: #000000"><span style="font-size: large"><b> Mueller, 1935</b></span></span></p> <p align="CENTER"><span style="color: #000000"><span style="font-size: large"><b>Figures 3-4 and 3-5</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>Spiro</i></span></span><span style="color: #000000"><span style="font-size: medium"> = spiral and </span></span><span style="color: #000000"><span style="font-size: medium"><i>metra</i></span></span><span style="color: #000000"><span style="font-size: medium"> = uterus (referring to the spiral-shaped uterus as opposed to the rosette-shaped uterus in </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</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>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> because it was "like” </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansoni</i></span></span><span style="color: #000000"><span style="font-size: medium"> the synonym that Mueller used as representing </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinaceieuropaei</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>SYNONYMS:</b></span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium">, Mueller, 1935.</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"> Faust et al. (1929) created a subgenus called Spirometra within the genus Diphyllobothrium. Mueller (1935) described </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> using specimens recovered from dogs and cats in the area around Syracuse, New York, USA. In 1937, Mueller raised </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> to generic rank, and hence, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> became </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra mansonoides</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>GEOGRAPHIC DISTRIBUTION: </b></span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> is considered a parasite of the eastern United States that extends into parts of South America where it has been reported from Colombia, Ecuador, and Brazil (Fernandez TE, 1978; Lillis and Burrows, 1964; Mueller et al., 1975; Ogassawara and Benassi, 1980.).</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"> The adults of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> are found within the small intestine of the feline host.</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"> Mueller (1935) provided the original description of this tapeworm. At that time he stated that the maximum length of the strobila was 60 cm with a maximum width of 7 mm. Following almost forty years of study, he later determined that in a large dog, this tapeworm may attain a length of 1.5 meters with a maximum width of a centimeter or more (Mueller, 1974). The margins of this tapeworm are serrate. The strobila appears to be delicate in the neck region and robust posteriorly. Like the adult </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>latum</i></span></span><span style="color: #000000"><span style="font-size: medium">, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> selectively absorb large quantities of vitamin B12 (Marchiondo et al., 1989). This absorption gives the adult tapeworms a characteristic pinkish color (Mueller, 1974). This tapeworm is unique due to the fact that while attached in the host's intestine, the mature proglottids often separate along the longitudinal axis for a short distance; the tapeworm will appear to become "unzipped," hence its common name, the zipper tapeworm (Hendrix, personal observation).</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"> The scolex of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> lacks suckers but instead possesses two shallow longitudinal grooves called bothria (Mueller, 1935). It varies in diameter from 0.2 mm to almost 0.5 mm with bothria approximately 1.0 mm in length. The bothria are shallow, broad and flat bottomed. Each proglottid of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> possesses a centrally located spiraled uterus and associated uterine pore through which eggs are released (Fig. 3-4). The uterus is composed of two sections: an anterior series of heavy "outer" coils and an posterior series of narrow "inner" coils. These two regions are joined by a narrow duct that will accommodate only three or four eggs. The uterine and genital apertures open on the ventral surface of the proglottid. These tapeworms characteristically release the eggs until they become exhausted of their uterine contents. Segments are not discharged into the feces until groups of segments have shed all their eggs and are passed as "spent” segments (Kirkpatrick and Sharninghausen, 1983). The uterus in the proglottids of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> terminates in the anterior of the proglottid in a distinct "U”-shaped uterus packed full of eggs. This distinct uterine formation does not occur in </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinaceieuropaei</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 egg of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> resembles the egg of a digenetic trematode, that is, it is oval, yellow-brown and possesses a distinct operculum at one pole of the shell (Fig. 3-5). The eggs have dimensions that average 60 µm by 36 µm. </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> eggs have an asymmetric appearance and tend to be pointed at one end. There may be a slight bump on the abopercular end. The eggs are unembryonated when passed in the feces. It is possible that cats will go for extended periods with negative fecal samples that will be followed by periods when eggs are present in the feces.</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"> Domestic and wild felids serve as the principal definitive hosts for Spirometra mansonoides, although dogs and racoons may harbor the adult cestodes; Mueller believes the natural host in the Americas was probably the bobcat, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Lynx </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>rufus</i></span></span><span style="color: #000000"><span style="font-size: medium">. Unembryonated eggs pass through the uterine pore of each of the adult cestode's gravid proglottids. The eggs are discharged to the external environment with the cat's feces. Eggs can be stored at 4C for at least a year without any significant decreases in viability. In the presence of aeration at room temperature, the eggs develop to the infective stage and can then be stored at 4C for at least a year. Eggs are induced to hatch by exposure to direct sunlight and cold temperature shock. In fresh water, the first developmental stage, the ciliated coracidium emerges from the egg and is eaten by the first intermediate host, a freshwater crustacean of the genus </span></span><span style="color: #000000"><span style="font-size: medium"><i>Cyclops</i></span></span><span style="color: #000000"><span style="font-size: medium">. The second developmental stage, the procercoid, develops within the copepod. When the procercoid is ingested by the second intermediate host, a frog, water snake or rodent, the procercoid develops into a plerocercoid or sparganum, the third developmental stage. These white, ribbon-like spargana are found primarily in subcutaneous sites. Cats become infected with </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> by preying on frogs, water snakes, fish, birds or rodents containing the infective plerocercoids. Within ten to thirty days, the tapeworm develops to the mature stage in the cat's small intestine. Some of the plerocercoids may develop in the wall of the intestine and Mueller hypothesized that they may eventually migrate back into the lumen of the gut to begin an infection with the adult tapeworm. The adult tapeworm may survive for as long as 3.5 years in the cat (Mueller, 1974).</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"> Cats can be infected with the larval form of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> (described below under feline sparganosis.)</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"> Most of the reports of infection with </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> species in domestic cats have been from results from parasitologic surveys or from results of fecal assays. Muller (1938) described the signs of infection with adult worms in cats as causing marked signs. Infected animal loose weight but remain hungry. The wall of the intestine of the infected cat became thickened, particularly in the layers of circular muscles. If a cat is given an anthelminthic, recovery is rapid, unless animals have been infected for long periods causing stunted growth in which cases deworming fails to result in the animals reaching target weights. If nursing kittens become infected, there is a marked retardation in growth. Muller believed that a severe anemia developed in infected cats, but no specific parameters were reported to substantiate this claim. One cat infected with adult </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> in the United States did exhibit an intermittent watery diarrhea of two months duration which resolved following therapy (Kirkpatrick and Sharninghausen, 1983). </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"> It is expected that treatment of cats with </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> with praziquantel at the elevated dosage of 30 to 35 mg/kg body weight would cause the elimination of these parasites as they do </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinaceieuropaei</i></span></span><span style="color: #000000"><span style="font-size: medium"> (Fukase et al., 1992).</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"> The </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> in a domestic cat reported by Kirkpatrick and Sharninghausen (1983) was likely to be </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium">. This tapeworm was refractory to treatment with albendazole (25 mg/kg BID for 6 consecutive days) and with 1500 mg of niclosamide following an overnight fast. A single treatment of the cat with 100 mg of bunamidine HCl appeared to remove the worms from this cat based on postmortem performed a month later after death due to other causes. Bunamidine (Scolaban) is administered orally to cats at a rate of 25 to 50 mg/kg body weight up to a maximum of 600 mg. The tablets should not be broken, crushed, mixed with food or dissolved in liquid because bunamidine irritates the oral mucosa. Bunamidine should be administered on an empty stomach and food should be withheld for 3 hours following medication. Treatment with bunamidine should not be repeated within 14 days. It should not be concurrently administered with butamisole (Stiquin), to unweaned kittens, or to cats with cardiac or hepatic disease. Cats should not be allowed to exercise or become excited immediately after treatment with bunamidine. Vomiting, diarrhea, and ventricular fibrillation are the most frequent side effects (Sakamoto, 1977).</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 when they eat water snakes, tadpoles, other amphibians, and small mammals, e.g. rats and mice containing the infective plerocercoid stage. Domestic and wild felids serve as the principal definitive hosts for </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium">, although dogs and racoons may harbor the adult cestodes (Mueller, 1974). In a survey of animals from Louisiana in the United States, plerocercoids were found in two amphibian, eight reptilian and three mammalian species. The mammalian species included the opossum, the racoon, and the grey fox (Corkum, 1966). </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"> The egg passes in the feces of the cat is not directly infectious to other hosts, the, the hazard to other animals is mainly in the form of the plerocercoid that can be obtained from the drinking of water containing copepods infected with the procercoid stage.</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">The procercoids of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> are of public health significance as a cause of sparganosis in human beings in the United States; most of the American cases in humans have occurred in the southeastern United States. Mueller and Coulston (1941) had spargana from experimentally infected mice surgically implanted in their arms to show that the sparganum of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> was capable of persisting in humans. The introduced spargana were about 2 mm long, and when the larvae were recovered from the investigators three to four months later, the spargana were 12 to 60 mm long. One was fed to a cat, and the cat developed a patent infection. Mueller et al. (1963 a&amp;b) reported on the first naturally acquired human case of sparganosis in the United States. There have been rare cases of sparganosis that are apparently of the </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinaceieuropaei</i></span></span><span style="color: #000000"><span style="font-size: medium"> type and a second form of proliferating sparganosis reported from humans in Florida, but these seem to be the exception rather than the majority of cases. Muller (1974) believes that the characters of the plerocercoid stage is rather characteristic for the two species: that of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> is thin and elongate while that of the </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinaceieuropaei</i></span></span><span style="color: #000000"><span style="font-size: medium"> type is massive and rather fragile; the growth factors produced by the two species also appear to have different effects on mice and rats (Mueller, 1972) There have been over fifty cases of human sparganosis reported in the United States, and for further information the readers are referred to Taylor (1976) and the texts by Beaver et al., 1984 and Gutierrez, 1990. </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"> At no time should cats be allowed to ingest frogs, water snakes or rodents. Such habits may lead to infections with the infective plerocercoid stages of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium">. Cats should not be allowed to roam freely or to scavenge carcasses. Predation and carrion feeding may lead to parasitism if prey animals such as frogs, water snakes, rodents or their carcasses contain the infective plerocercoid stages (Hendrix and Blagburn, 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"> Beaver PC, RC Jung, EW Cupp. 1984. </span></span><span style="color: #000000"><span style="font-size: medium"><span style="text-decoration: underline">Clinical Parasitology, 9</span></span></span><span style="color: #000000">^{<span style="font-size: medium"><span style="text-decoration: underline">th</span></span>}</span><span style="color: #000000"><span style="font-size: medium"><span style="text-decoration: underline"> edition.</span></span></span><span style="color: #000000"><span style="font-size: medium"> Lea &amp; Febiger, Philadelphia, USA.; </span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Corkum KC. 1966. Sparganosis in some vertebrates of Louisiana and observations and observations on a human infection. J Parasitol 52:444-448.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Faust EC, Campbell HE, Kellogg CR. 1929. Morphological and biological studies on the species of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</i></span></span><span style="color: #000000"><span style="font-size: medium"> in China. Am J Hyg 9:560-583.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Fernandez TE. 1978. Reporte del </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</i></span></span><span style="color: #000000"><span style="font-size: medium"> (</span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium">) en el Ecuador. Rev Ecuator Hig Med Trop 31:93-97.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Fukase T, Suzuki M, Igawa H, Chinone S, Akihama S, Itagaki H. 1992. Anthelmintic effect of an injectable formulation of praziquantel against cestodes in dogs and cats. J Jap Vet Med Assoc 45:408-413.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Gutierrez Y. 1990. </span></span><span style="color: #000000"><span style="font-size: medium"><span style="text-decoration: underline">Diagnostic Pathology of Parasitic Infections with Clinical Correlations.</span></span></span><span style="color: #000000"><span style="font-size: medium"> Lea &amp; Febiger, Philadelphia, USA. 532 pages.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Hendrix CM and Blagburn BL. 1983. Common gastrointestinal parasites. Vet Clin N Am: Sm An Prac 13:627-645.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Kirkpatrick CE and Sharninghausen F. 1983. </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"> sp in a domestic cat in Pennsylvania. J Am Vet Med Assoc 183:111-112.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Lillis WG and Burrows RB. 1964. Natural infections of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> in New Jersey cats. J Parasitol 50:680.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Marchiondo AA, Weinstein PP, Mueller JF. 1989. Significance of the distribution of </span></span><span style="color: #000000">^{<span style="font-size: medium">57</span>}</span><span style="color: #000000"><span style="font-size: medium">Co-Vitamin B</span></span><span style="color: #000000">_{<span style="font-size: medium">12</span>}</span><span style="color: #000000"><span style="font-size: medium"> in </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> (Cestoidea) during growth and differentiation in mammalian intermediate and definitive hosts. Int J Parasitol 19:119-124.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF. 1935. A </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</i></span></span><span style="color: #000000"><span style="font-size: medium"> from cats and dogs in the Syracuse region. J Parasitol 21:114-122.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF. 1937. A repartition of the genus </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</i></span></span><span style="color: #000000"><span style="font-size: medium">. J Parasitol 23:308-310.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF. 1938. The life history of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium</i></span></span><span style="font-size: medium"><em><span style="color: #000000"> mansonoides </span></em></span><span style="color: #000000"><span style="font-size: medium"><i>Mueller</i></span></span><span style="color: #000000"><span style="font-size: medium">, 1935, and some considerations with regard to sparganosis in the United States. Am J Trop Med 18:41-58.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF. 1972. Failure of oriental spargana to immunize the hypophysectomized rat against the sparganum growth factor of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium">. J Parasitol 58:872-875.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF. 1974. The biology of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium">. J Parasitol 60:3-14.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF, Coulston F. 1941. Experimental human infection with the sparganum larva of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> (Mueller, 1935). Am J Trop Med 21:399-425.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF, Hart EP, Walsh WP. 1963a. First reported case of naturally-occurring human sparganosis in New York State. NY State J Med 63:715-718.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF, Hart EP, Walsh WP. 1963b. Human sparganosis in the United States J Parasitol 49:294-296.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Mueller JF, Miranda Fróes O, Fernández T. 1975. On the occurrence of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra</i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> in South America. J Parasitol 61:774-775.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Ogassawara S, Benassi S. 1980. </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> Mueller, 1935, em animal da especie felina no estado de Sao Paulo. Arq Inst Biol Sao Paulo 47:43-46.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Sakamoto T. 1977. The anthelmintic efficacy of Droncit on adult tapeworms of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Hydatigera </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>taeniaeformis</i></span></span><span style="color: #000000"><span style="font-size: medium">, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Mesocestoides</i></span></span><span style="color: #000000"><span style="font-size: medium"><i>corti</i></span></span><span style="color: #000000"><span style="font-size: medium">, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Echinococcus </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>multilocularis</i></span></span><span style="color: #000000"><span style="font-size: medium">, </span></span><span style="color: #000000"><span style="font-size: medium"><i>Diphyllobothrium </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>erinacei</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>D</i></span></span><span style="color: #000000"><span style="font-size: medium">. </span></span><span style="color: #000000"><span style="font-size: medium"><i>latum</i></span></span><span style="color: #000000"><span style="font-size: medium">. Vet Med Rev 1:64-74. </span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium">Taylor RL. 1976. Sparganosis in the United States. Am J Cl Path 66:560-564.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"><b>FIGURES:</b></span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"><b>Figure 3-4.</b></span></span><span style="color: #000000"><span style="font-size: medium"> Gravid segment of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> showing the compact anterior of the uterus in this genus.</span></span></p> <p align="JUSTIFY"><span style="color: #000000"><span style="font-size: medium"><b>Figure 3-5.</b></span></span><span style="color: #000000"><span style="font-size: medium"> Egg of </span></span><span style="color: #000000"><span style="font-size: medium"><i>Spirometra </i></span></span><span style="color: #000000"><span style="font-size: medium"><i>mansonoides</i></span></span><span style="color: #000000"><span style="font-size: medium"> (Specimen courtesy of Dr. Raab, Florida, USA).</span></span></p>