Spirometra erinacei tapeworm Spirometra erinacei is reported for the first time in New Zealand, in a feral cat. The tapeworm is likely to in a feral cat be established here but with low prevalence. Definitive Early in 2004, two approximately 20 cm segments of a tapeworm, hosts, which in New Zealand are probably cats and subsequently identified as Spirometra erinacei, were recovered from dogs, rarely show clinical signs. There is zoonotic a feral cat. This was the first recorded finding of this parasite in potential through ingesting infected intermediate hosts. New Zealand.1

also present in cats in New Zealand(3). Pseudophyllidean tapeworms possess a scolex (or holdfast) that, instead of suckers and hooks, bears only two muscular grooves. Cyclophyllidean tapeworms generally retain their eggs within the uterus of the proglottids. Mobile gravid proglottids are passed intact into the environment and eggs are released as the segments disintegrate. As observed on this occasion, pseudophyllidean cestodes release eggs while proglottids are still attached to the strobila. Empty proglottids are then shed from the worm but before they do so they may begin to break up, with the terminal portion of the worm separating along the midline. This gives rise to one of the common names for these Figure 1: Section of tapeworm (Spirometra erinacei) recovered from the small intestine of a feral cat. The genital pore is visible in the centre of cestodes, ‘zipper worms’. the proglottids (arrows) The lifecycles of pseudophyllidean cestodes are tied to fresh water. Figure 2: Unembryonated tapeworm Two stages of development must occur sequentially in intermediate (Spirometra erinacei) egg recovered after the overnight incubation of proglottids in hosts before the definitive host can be infected. Eggs are initially water. Each egg measured approximately unembryonated. In oxygenated water, the embryo or coracidium 60 x 40 mm develops and hatches. This motile stage is then consumed by The cat had been trapped in the (aquatic invertebrates), which are the first intermediate Manawatu area. Two sections of worm host and within which the procercoid stage develops inside the were detected in its small intestine during body cavity. In the case of Spirometra spp, potentially any vertebrate postmortem examination. Neither had a , with the possible exception of fish, can act as the second scolex, and it is possible they were parts of the same cestode. The intermediate host, allowing the procercoid to develop into the individual proglottids were up to 7 mm wide and only 2-3 mm in plerocercoid. The plerocercoid can reach 5-10 cm in length and is length, each with a central uterine pore (Figure 1). The tapeworm slender and ribbon-like. For S erinacei, the main second (4) segments were kept overnight immersed in water in petri dishes. intermediate hosts are believed to be amphibians , although Eggs released were collected and examined. The eggs measured reptiles (such as water snakes) and mammals commonly harbour approximately 60 by 40 µm, and each had a single operculum plerocercoids. To complete the lifecycle, the second intermediate (Figure 2). Colonic contents collected during postmortem host is ingested by the definitive host – cats, dogs and foxes in the examination also yielded eggs, which floated in 33% zinc sulphate. case of S erinacei – in which the mature adult cestode can establish within 6-28 days. The morphology of the proglottids and eggs placed this tapeworm in the Spirometra. Within this genus several species have When predatory other than the definitive host consume been recorded in cats(1). A section of the organism was submitted prey harbouring the plerocercoid stage, the plerocercoid may for expert identification (by Dr Robin Gasser, University of re-establish in the new host. Plerocercoid infections can therefore Melbourne). Analysis was based on sequencing DNA from the be acquired either through ingesting water containing infected cytochrome c oxidase subunit 1 gene (pcox1)(2). DNA of the New copepods or following predation on animals harbouring Zealand tapeworm included all the base changes characteristic of plerocercoids. the feline Spirometra erinacei present in Australia. Plerocercoids were previously called spargana (singular sparganum) Spirometra erinacei is a tapeworm in the pseudophyllidean order and human disease associated with plerocercoids is still commonly and therefore differs in many ways from the cyclophyllidean referred to as . Sparganosis occurs infrequently in tapeworms Taenia taeniaeformis and Dipylidium caninum that are Australia, the US, Europe and Asia associated with several

1 Since this article was originally written, a further three Spirometra tapeworms have been found in a second cat.

page 18 Surveillance 31(4) 2004 Spirometra spp and acquired from eating feral pig meat (and other methods using saturated salt or 33% zinc sulphate should suffice. meats), ingesting copepods in drinking water and the practice in Treatments aimed at removing other cestodes, such as praziquantel Asia of using frog tissue in poultices applied to skin wounds. In at 5 mg/kg, may not be effective at eliminating S erinacei. In fact infected individuals, spargana may be present in the subcutaneous the dose of praziquantel may need to be as high as 35 mg/kg(7). tissues or between the muscles of the limbs or body wall. In some Spirometra erinacei poses a slight risk to human health but an instances they may penetrate the periorbital area, the CNS and the infected dog or cat poses no direct threat. The risk of human thoracic and abdominal cavities. Human infections are generally infection is eliminated by drinking filtered or boiled water and by asymptomatic, and clinical signs occur only if surrounding tissue adequate cooking of meat. becomes inflamed. Signs may include localised swelling, pain, erythema, urticaria, pyrexia and eosinophilia. If treatment is References required, the plerocercoid is usually removed surgically although (1) Hendrix CM. Helminthic infections of the feline small and large intestines: diagnosis and treatment. Veterinary Medicine 90, 456-72, 1995. medical treatment can be attempted. (2) Zhu XQ, Beveridge I, Berger L, Barton D, Gasser RB. Single-strand conformation polymorphism-based analysis reveals genetic variation within Spirometra erinacei is present in parts of Asia and throughout Spirometra erinacei (: ) from Australia. Molecular and Australia. In Australia it is common in cats (especially rural), wild Cellular Probes 16, 159-65, 2002.

(4)(5)(6) (3) McKenna PB. Checklist of helminth parasites of terrestrial mammals in New dogs and foxes but it has low prevalence in domestic dogs. Zealand. New Zealand Journal of Zoology 24, 277-90, 1997. Plerocercoids are frequently found in feral pigs in Australia(4), and (4) Dunsmore JD, Shaw SE. Clinical Parasitology of Dogs. Pp 64-6. The pose some risk for humans consuming poorly cooked meat. The University of Sydney Post Graduate Foundation in Veterinary Science, 1990. (5) Shaw J, Dunsmore J, Jakob-Hoff R. Prevalence of some gastrointestinal number of cases of human sparganosis in Australia appears low. parasites in cats in the Perth area. Australian Veterinary Journal 60, 151-2, 1983. The finding of S erinacei in a feral cat in New Zealand suggests the (6) Brown B, Copeman DB. Zoonotic importance of parasites in wild dogs caught parasite is established here, but its prevalence is likely to be low. in the vicinity of Townsville. Australian Veterinary Journal 81, 700-2, 2003. It will probably be most common in feral and rural cats and least (7) Fukase T, Suzuki M, Ogawa H, Chinone S, Akihama S, Itagaki H. Anthelmintic effect of an injectable formulation of praziquantel against cestodes in common in urban cats and dogs. Its distribution in New Zealand dogs and cats. Journal of the Japan Veterinary Medical Association 45, will depend on the presence of suitable intermediate hosts 408-13, 1992. (particularly frogs), suitable wet habitats and access to these areas Ian Scott by cats or dogs. There are a number of introduced and indigenous Institute of Veterinary, Animal and Biomedical Sciences species of frog, gecko, skink, small mammal and bird potentially Massey University involved in transmission. It is possible that spargana are present Private Bag 11 222 here in feral pigs, although it is likely to be uncommon. There may Palmerston North also be some risk of infection for farmed outdoor pigs. Email: [email protected]

From a veterinary viewpoint, S erinacei is of little clinical Claudia Ugarte significance to dogs and cats, although some studies suggest Institute of Food, Nutrition and Human Health it is more pathogenic than its cyclophyllidean counterparts. Massey University Diagnosis will probably rest on the finding of the operculate eggs Private Bag 11 222 (see Figure 2) in faecal samples. For this, standard flotation Palmerston North

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