Diplopylidium nölleri (Skrjabin, 1924) Lopez-Neyra, 1927
ETYMOLOGY:Diplo = double and pylidium = openings along with nölleri for Dr. Nöller.
SYNONYMS: Witenberg (1932) reviewed the genus Diplopylidium, and he recognized four species of which only two were considered as parasites of the domestic cat. The synonyms Witenberg recognized for Diplopylidiumnölleri were: Diplopylidiummonoophoroides (Lopez-Neyra, 1927) Witenberg, 1932.
HISTORY:Diplopylidiumnölleri was originally described as Progynopylidiumnölleri by Skrjabin (1924) from a cat in Turkestan. The genus Diplopylidium, first described by Beddard in 1913, had priority over that proposed by Skrjabin. The name proposed for the genus by Skrjabin similarly recognized the same generic condition of this worm’s morphology.
GEOGRAPHIC DISTRIBUTION:Diplopylidiumnölleri has been reported from the Middle East and southern Europe (Abdul-Salam & Baker, 1990; Burgu et al, 1985; El-Shabrawy and Imam, 1978; Gadale et al., 1989; Haralampides, 1977; Ismail et al, 1983; Witenberg, 1932). In some cases Diplopylidiumnölleri was found very commonly being reported by Haralampides (1977) in 71 or 123 cats in Greece and by El-Shabrawy & Imam in 24 of 66 cats in Egypt. In Jordan, Ismail et al. (1983) report that 96 of 123 cats had Dipylidiumcaninum, 32 cats had Diplopylidiumacanthotetra, and 24 cats had Diplopylidiumnölleri. Geckos have been found infected with cysticercoids in Tanzania (Simonsen & Sarda, 1985).
LOCATION IN HOST: The adult Diplopylidiumnölleri is in found in the small intestine of the feline host. Ismail et al. (1983) state that Diplopylidiumnölleri is in usually found in the very posterior of the small intestine, while Diplopylidiumacanthotetra is in found at the end of the first third of the small intestine. Dipylidiumcaninum was found in the posterior two-thirds of the small intestine, overlapping the posterior range of Diplopylidiumacanthotetra and extending through the range of Diplopylidiumnölleri. Taeniataeniaeformis was found by these authors mainly in the first third of the small intestine.
IDENTIFICATION: When compared to Dipylidium and Joyeuxiella species, Diplopylidium is in the smallest, only 4-12 cm, of these types of tapeworms found in the cat. It holdfast possesses four suckers and a retractable rostellum armed with thorn-like hooks. The proglottids are shaped like cucumber seeds, possessing two complete sets of genital organs and bilateral genital pores. The genital pores of Diplopylidium lie anterior to the middle of the proglottid. Each egg capsule contains a single egg. Diplopylidiumnölleri is in characterized by having a long neck and hooks on the scolex that are smaller than 0.05 mm and those of Diplopylidiumacanthotetra. The posterior, gravid segments of fresh specimens of Diplopylidium nölleri have a dark reddish brown coloration that distinguishes this parasite from specimens for Diplopylidiumacanthotetra, Dipylidiumcaninum, and Joyeuxiella spp. that may be found within the intestine of a cat.
LIFE CYCLE: Very little has been described relative to the biology of this parasite. The cat sheds segments into the environment which contain eggs that are infectious. It is in believed that the first intermediate host is in some form of coprophagous insect, but this has never actually been proven for any member of this genus. The second intermediate hosts are cysticercoids (small solid-bodied tapeworm larvae with an inverted scolex) that are found in reptiles. Cats become infected by the ingestion of the second intermediate host. Popov (1935) described the life cycle of a species of Diplopylidium, that he described as Diplopylidiumskrjabini. Two cats were infected with cysticercoids recovered from lizards, and six weeks later, they were found to harbor adult tapeworms in their intestines. At this time the adults were 4 to 5 cm long, and the posterior segments were darkly colored, being red rather than brown. It is in very likely that these represent the same species as Diplopylidiumnölleri.
CLINICAL PRESENTATION AND PATHOGENESIS: There have been no descriptions of signs in cats infected with Diplopylidiumnölleri., so it is thought to be asymptomatic.
DIAGNOSIS: Methods for the diagnosis of infection with this tapeworm other than at necropsy have not been described in any detail. It would seem likely that proglottids are passed in the feces of the cat as occurs with Dipylidium, and it may bee that occasionally free egg capsules containing a single egg may be observed in fecal samples. Each proglottid of Diplopylidiumnölleri possesses two genital pores for fertilization. The egg with its capsule is in best demonstrated by taking a gravid proglottid and teasing it open in a small amount of physiologic saline or tap water to disperse the characteristic egg capsule with its single egg (Georgi, 1987).
TREATMENT: Praziquantel (Droncit) administered at 25 mg per animal at 6-week intervals has proven to be effective against Joyeuxiella (Blagburn and Todd, 1986), a tapeworm in the same family as Diplopylidiumnölleri.
EPIZOOTIOLOGY: Cats become infected by ingesting reptiles in dwellings and yards. Some surveys have shown that up to 16 of 55 examined geckos have cysticercoids in their body cavity (Simonsen & Sarda, 1985).
HAZARDS TO OTHER ANIMALS: There probably is in no significant hazard from an infected cat because the larvae must pass through a first intermediate host, probably an arthropod. Thus, cats probably pose no significant hazard to other animals. Of course, as the number of pet reptiles increases, and because the first host is in not known, there is in the possibility of increasing the potential of having large numbers of infected arthropods present in areas where both cats and reptiles share the same living quarters. Dogs can be infected with this parasite (Illescas-Gomez et al., 1989).
HAZARDS TO HUMANS: The authors were unable to ascertain any public health significance potential similar to that which would be observed with Dipylidiumcaninum.
CONTROL/PREVENTION: Cats should not be allowed to roam freely or to scavenge carcasses. Predation may lead to infection with Diplopylidiumnölleri if prey animals or carcasses containing cysticercoids (Hendrix and Blagburn, 1983).
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