Aberrant sparganosis in cat caused by Spirometra mansoni (Cestoda: Diphyllobothriidae): a case report.

BACKGROUND: Sparganosis is a rare zoonotic disease caused by plerocercoid larvae of the genera Spirometra or Sparganum (Cestoda: Diphyllobothriidae). The larvae of Spirometra generally do not undergo asexual reproduction, whereas those of Sparganum can induce proliferative lesions in infected tissues. This paper presents an unusual case of proliferative sparganosis due to infection with Spirometra mansoni in a cat, normally considered a definitive host of the species. CASE PRESENTATION: A 9-year-old male domestic cat was presented with a mass on the right side of the face that underwent progressive enlargement for 1 month. The morphological and histopathological examinations revealed multiple asexual proliferative cestode larvae in the lesions, suggestive of proliferative sparganosis. Next-generation sequencing analysis of formalin-fixed and paraffin-embedded specimens of surgically excised tissue indicated that the worm was Spirometra mansoni. CONCLUSION: Although S. mansoni a common tapeworm species found in the small intestine of domestic cats and dogs in Japan, proliferative sparganosis is extremely rare. This is the first confirmed case of proliferative sparganosis due to infection with S. mansoni in cat.

Molecular identification of sparganum of Spirometra mansoni isolated from the abdominal cavity of a domestic cat in Vietnam.

Cats normally play a role of the definitive host in which the plerocercoid (sparganum), the second larval form of Spirometra spp., develops into an adult in the intestines. However, some cases of cats with visceral or subcutaneous sparganosis were sporadically reported worldwide. We herein documented the discovery of a sparganum in abdominal cavity of a domestic cat during a surgery of dystocia. The larva was molecularly identified as Spirometra mansoni, belonging to Type I, that was recently misidentified to be S. erinaceieuropaei in several Asian countries. This is the first report for sparganum of S. mansoni in the cat. The future study is necessary to provide further insights into the species of Spirometra causing sparganosis and spirometrosis in humans and other animals.

Description of Spirometra asiana sp. nov. (Cestoda: Diphyllobothriidae) found in wild boars and hound dogs in Japan.

According to the latest taxonomy of Spirometra species, six species (lineages) have been tentatively classified as valid. These species are Spirometra erinaceieuropaei, S. folium, S. mansoni, undescribed Spirometra sp. 1, and S. decipiens complex 1 and 2. Among these species, the undescribed species was first discovered as plerocercoid larvae in wild boars in Japan and further studies have confirmed that this species is a new taxon belonging to the genus Spirometra. Here, we describe Spirometra asiana sp. nov., which is difficult to distinguish morphologically from known Spirometra species. However, it is genetically easily distinct from other Spirometra species, thus facilitating identification. We also emphasize that S. mansoni and S. asiana, but not S. erinaceieuropaei, are etiological agents that cause human sparganosis and/or spirometrosis in Asia.

Genetic interrelationships of Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidea), the causative agent of sparganosis in Europe.

The geographic distribution of Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidea), the causative agent of food/water-borne sparganosis, is restricted to Europe, where infected canids, felids, mustelids, suids, and reptiles have been documented from Poland, Ukraine, Belarus, Russia, Serbia, Estonia, Latvia, and Finland. The main objective of the current study was to map the molecular divergence of S. erinaceieuropaei from Finland using the complete sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1 mtDNA). Seven cox1 haplotypes were determined in 15 tapeworms from Eurasian lynx (Lynx lynx) from three localities in southern Finland. In addition, the first inter-population study of S. erinaceieuropaei based on currently obtained data on cox1 from Finland and previously published data from Finland, Latvia, Ukraine, and Poland, was performed. The haplotype network showed a star-like pattern without specific subdivision of lineages according to the locality. Samples from Finland, Latvia, and Poland shared several haplotypes and formed the common Baltic lineage. The haplotype of S. erinaceieuropaei from Ukraine was unique and placed on a separate mutational pathway, suggesting a different lineage of the parasite.

TITLE: Interrelations génétiques de Spirometra erinaceieuropaei (Cestoda, Diphyllobothriidea), l'agent causal de la sparganose en Europe. ABSTRACT: La distribution géographique de Spirometra erinaceieuropaei (Cestoda : Diphyllobothriidea), l'agent causal de la sparganose d'origine alimentaire/hydrique, est limitée à l'Europe, où des canidés, félidés, mustélidés, suidés et reptiles infectés ont été documentés en Pologne, Ukraine, Biélorussie, Russie, Serbie, Estonie, Lettonie et Finlande. L'objectif principal de la présente étude était de cartographier la divergence moléculaire de S. erinaceieuropaei de Finlande à l'aide des séquences complètes du gène mitochondrial de la sous-unité 1 de la cytochrome c oxydase (ADNmt cox1). Sept haplotypes cox1 ont été déterminés chez quinze cestodes du Lynx d'Eurasie (Lynx lynx) de trois localités du sud de la Finlande. En outre, la première étude inter-populationnelle de S. erinaceieuropaei basée sur les données actuellement obtenues sur cox1 de Finlande et sur des données précédemment publiées de Finlande, Lettonie, Ukraine et Pologne, a été réalisée. Le réseau d'haplotypes a montré un motif en étoile sans subdivision spécifique des lignées selon la localité. Des échantillons de Finlande, Lettonie et Pologne partagent plusieurs haplotypes et forment la lignée commune de la Baltique. L'haplotype de S. erinaceieuropaei d'Ukraine est unique et placé sur une voie de mutation distincte suggérant une lignée différente du parasite.

First Clinical Cases of Spirometrosis in Two Cats in Korea.

This study reports the first two clinical cases of spirometrosis caused by Spirometra sp. in cats in Korea. In these two cases, the cats vomited, and long proglottids of tapeworm were recovered. The sick cats presented with anorexia and lethargy. However, they unexpectedly showed no diarrhea, which is the main symptom of spirometrosis. Based on a fecal floatation test as well as morphological and molecular analyses, the parasite was diagnosed as Spirometra sp. The 2 cases were treated with praziquantel. This study suggests regular monitoring of health and deworming in companion animals, even when animals are well cared for, with regular preventive medication. Additionally, spirometrosis should be considered in the differential diagnosis in cases of gastrointestinal symptoms in Spirometra endemic areas.

The first records of Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidae), a causative agent of human sparganosis, in Latvian wildlife.

Diphyllobothriid tapeworms of the genus Spirometra are causative agents of sparganosis, food-borne zoonotic parasitic disease. They have been recorded in broad spectrum of hosts, including humans, in all continents except Antarctica. Spirometra tapeworms have been intensively studied in several Asian countries; however, they have been rather neglected in Europe. The aim of this study was to provide a pilot screening of Spirometra spp. in Latvia, where data on sparganosis are not available. Tapeworms morphologically identified as diphyllobothriid species were isolated from grey wolves Canis lupus and Eurasian lynxes Lynx lynx from Latvia during the hunting periods 2013-2019. The parasites were subjected to molecular genotyping using sequences of the partial large (LSU rDNA; 615 bp) and small (SSU rDNA; 720 bp) subunits of the nuclear ribosomal RNA gene and complete (1566 bp) cytochrome c oxidase subunit I gene of the mitochondrial DNA (cox1 mtDNA). Analyses of both ribosomal subunits of 13 tapeworms revealed no intraspecific variation within the respective rDNA subunits. On the other hand, sequence analysis of mitochondrial cox1 revealed intraspecific polymorphism displayed by 12 cox1 haplotypes. Comparison of the current data with sequences of the corresponding DNA regions deposited in the GenBank revealed 99.3-99.5% (LSU rDNA), 99.2% (SSU rDNA) and 99.6-100% (cox1 mtDNA) identity of studied tapeworms with Spirometra erinaceieuropaei, which provided the first confirmation of this diphyllobothriid tapeworm in Latvia. Since S. erinaceieuropaei is probably prevalent in Latvian wildlife and may also occur in other potential host species, further studies are needed in order to acquire complex data on its geographic distribution and transmission in the natural environment of Latvia, as well as on the spectrum of its intermediate, paratenic, and definitive hosts.

Multispecies reservoir of Spirometra erinaceieuropaei (Cestoda: Diphyllobothridae) in carnivore communities in north-eastern Poland.

BACKGROUND: Spirometra erinaceieuropaei is a diphylobothriid tapeworm with a complex life-cycle including definitive, intermediate and paratenic (transport) hosts. Multiple routes of parasite transmission often make it impossible to determine what type of host a specific infected animal is considered to be. Spargana larvae cause sparganosis, a severe food- and water-borne disease mainly found in Asia. In Poland, Spirometra sp. was reported in large carnivores in Bialowieza Primeval Forest for the first time in the 1940s and was recently confirmed as S. erinaceieuropaei in several mammals and snakes using molecular methods. METHODS: In total, 583 carcasses of 9 carnivore species were necropsied between 2013 and 2019 in north-eastern (NE) Poland. The larvae of S. erinaceieuropaei (spargana) were isolated from subcutaneous tissue, counted, and preserved for genetic analyses. We calculated the prevalence and intensity of infection. To assess spatial variation in S. erinaceieuropaei infection probability in NE Poland, we applied a generalized additive model (GAM) with binomial error distribution. To confirm the species affiliation of isolated larvae, we amplified a partial fragment of the 18S rRNA gene (240 bp in length). RESULTS: Spirometra larvae were found in the subcutaneous tissue of 172 animals of 7 species and confirmed genetically as S. erinaceieuropaei. The overall prevalence in all studied hosts was 29.5% with a mean infection intensity of 14.1 ± 33.8 larvae per individual. Native European badgers and invasive raccoon dogs were characterized by the highest prevalence. An analysis of parasite spread showed a spatially diversified probability of infection with the highest values occurring in the biodiversity hot spot, Bialowieza Primeval Forest. CONCLUSIONS: Our study revealed that various mammal species (both native and non-native) can serve as S. erinaceieuropaei reservoirs. The frequency and level of infection may differ between selected hosts and likely depend on host diversity and habitat structure in a given area. Further studies are needed to assess the distribution of the parasite throughout Europe and the environmental and biological factors influencing infection severity in wild mammals.

Low prevalence of spargana infection in farmed frogs in the Yangtze River Delta of China.

Frogs are the main source of infection for human sparganosis. In this study, the prevalence and pathogenicity of plerocercoid larvae (sparganum) in frogs collected from the Yangtze River Delta in East China were investigated. A total of 386 frogs belonging to five species were purchased from farmers' markets across all three provincial level areas in the Yangtze River Delta region. The overall prevalence was 4.9% (19/386), and 39 spargana were detected visually, with the intensity ranging from 1 to 11. The spargana infection rate was 7.7% (11/143) in Jiangsu Province and 4.4% (8/181) in Shanghai City, while no spargana infection was detected in Zhejiang Province. In five tested frog species, only Rana nigromaculata and R. limnocharis were found to harbor spargana infection, with a prevalence of 7.7% (13/168) and 6.3% (6/95), respectively. There was no significant difference among the months of the experimental period, July to September. The spargana mostly parasitized the muscle tissues of frogs, especially in the hind legs. All the spargana were identified by molecular analysis based on cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, and all plerocercoids were Spirometra erinaceieuropaei. Nine mice were infected orally with 1 to 3 scoleces, and 77.8% (14/18) of plerocercoids were found in mice at the 30th day post infection. No obvious clinical symptoms were observed in the mice; however, histopathological analysis showed an inflammatory cellular response in all tissues except intestinal tissue. Hematologic analysis showed an increased number of white blood cells (WBCs) at the 18th day post infection. These results indicated that R. nigromaculata and R. limnocharis are a potential source of zoonotic sparganosis in the Yangtze River Delta of China, and farmed frogs may substantially reduce zoonotic risk as compared to eating wild frogs. Our findings will provide data for frog food safety and prevention and control of sparganosis in the region.

Prevalence and molecular characterization of Spirometra erinaceieuropaei spargana in snakes in Hunan Province, China.

Sparganosis is an important foodborne parasitic zoonosis; however, few reports on the prevalence of snake-infecting plerocercoids from Hunan province in China are available. Therefore, we investigated the prevalence of spargana infection in wild snakes from this region in 2018, and identified an astonishing prevalence rate of 91.7% (344/375). Spargana parasites were found in 99.1% of Zaocys dhumnades, 94.1% of Elaphe carinata and 86.7% of Elaphe taeniura. Parasites exhibited various distributions: 50% were located in muscular tissue, 32.1% in subcutaneous tissue and 17.9% in the coelomic cavity. To identify the specific status of spargana collected from wild snakes, partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequences were amplified, sequenced and analysed. Sequence variations for cox1 among all the examined plerocercoids ranged between 0.0 and 2.9%, with 21 variable sites identified (4.71%, 21/446). Phylogenetic analyses identified that all plerocercoids isolated from Hunan province were Spirometra erinaceieuropaei. This is the first report of S. erinaceieuropaei infection in snakes in Hunan province. The risks and harms of sparganosis should be publicized, and illegal wildlife trade should be controlled.

The first case of genetically confirmed sparganosis (Spirometra erinaceieuropaei) in European reptiles.

Sparganosis is a zoonosis caused by the spargana (larvae) of Spirometra sp. (Diphyllobothriidae). Reptiles are particularly important vectors for the transmission of this parasite in Asia; however, their role in sparganosis spread in European wildlife is unrecognized. We investigated the infection of reptiles with Spirometra sp. in NE Poland, where several mammalian hosts have been identified recently and in the past. Of the 59 dead reptiles, plerocercoids were found in two grass snakes (Natrix natrix) from the Bialowieza Primeval Forest (BPF). The Spirometra erinaceieuropaei species was genetically confirmed using the evolutionary conserved nuclear 18S rRNA gene, and then compared to GenBank deposits. The sequences were identical to previously investigated Spirometra sp. found in Eurasian badger and wild boar from BPF. Our finding is the first genetically confirmed record of Spirometra sp. in reptiles in Europe. Since reptiles are often a component of mammalian diet, they can be a source of Spirometra tapeworm infection in European wildlife; however, further studies are needed to investigate the prevalence of infection in reptiles and other non-mammalian hosts.

A simplified method to estimate Diphyllobothrium spp. infection in salmonids.

Some fish parasites constitute severe management problems as they may cause mortality of their fish host or are important zoonoses of humans. Parasite assessments are therefore critical to keep track of infections. If conventional sampling techniques can be simplified, parasite assessments might be easier to obtain, less time-consuming and more extensive. In this study, we compare the assessed number of Diphyllobothrium spp. cysts (CYST) with the counted number of Diphyllobothrium spp. plerocercoid larvae recovered using a conventional digestive technique (LARV). The aim was to determine the potential of using CYST as a simplified methodology for assessing Diphyllobothrium spp. infection in salmonids. In total, 365 brown trout and 424 Arctic charr were sampled from nine lakes in subarctic Norway. Strong correlation, significant linear relationship and large amount of explained variation were found between log10 CYST and log10 LARV in both fish species. The method had a slight, but not significant tendency to work better in charr compared to trout. In addition, absolute difference between CYST and LARV increased at parasite intensities >100 indicating that the method has reduced functionality when estimating parasite intensity in heavily infected salmonid populations. However, overall, using this simplified and less time-consuming methodology, a good indication of Diphyllobothrium spp. intensity, abundance and prevalence was obtained. We suggest that this method provides a sound proxy of the Diphyllobothrium spp. burden and have the potential to be used in parasite assessment during fish monitoring and fisheries management surveys, particularly if the time and resources for detailed parasite studies are not available.

Sparganosis in wild boar (Sus scrofa) - Implications for veterinarians, hunters, and consumers.

From February to March 2016 we found plerocercoids of Spirometra sp. in four wild boar hunted in Bialowieza Primeval Forest, north-eastern Poland. Plerocercoids were located subcutaneously and in muscle tissue. A sequence of a nuclear 18S rRNA gene was used for genetic specification of the samples. The analyzed gene fragment showed 100% identity with the Spirometra erinacei sequence. Thus, the emerge of human sparganosis due to consumption of undercooked or smoked wild boar meat is likely in the areas where wild boar is an approved food source, especially in the absence of routine guidelines for vets. It has become a priority to inform the public about possibilities and consequences of this zoonosis.

Mass Death of Predatory Carp, Chanodichthys erythropterus, Induced by Plerocercoid Larvae of Ligula intestinalis (Cestoda: Diphyllobothriidae).

We describe here the mass death of predatory carp, Chanodichthys erythropterus, in Korea induced by plerocercoid larvae of Ligula intestinalis as a result of host manipulation. The carcasses of fish with ligulid larvae were first found in the river-edge areas of Chilgok-bo in Nakdong-gang (River), Korea at early February 2016. This ecological phenomena also occurred in the adjacent areas of 3 dams of Nakdong-gang, i.e., Gangjeong-bo, Dalseong-bo, and Hapcheon-Changnyeong-bo. Total 1,173 fish carcasses were collected from the 4 regions. To examine the cause of death, we captured 10 wondering carp in the river-edge areas of Hapcheon-Changnyeong-bo with a landing net. They were 24.0-28.5 cm in length and 147-257 g in weight, and had 2-11 plerocercoid larvae in the abdominal cavity. Their digestive organs were slender and empty, and reproductive organs were not observed at all. The plerocercoid larvae occupied almost all spaces of the abdominal cavity under the air bladders. The proportion of larvae per fish was 14.6-32.1% of body weight. The larvae were ivory-white, 21.5-63.0 cm long, and 6.0-13.8 g in weight. We suggest that the preference for the river-edge in infected fish during winter is a modified behavioral response by host manipulation of the tapeworm larvae. The life cycle of this tapeworm seems to be successfully continued as the infected fish can be easily eaten by avian definitive hosts.

Levels of sparganum infections and phylogenetic analysis of the tapeworm Spirometra erinaceieuropaei sparganum in wild frogs from Henan Province in central China.

Sparganosis is a serious food-borne parasitic zoonosis caused by infection with Spirometra spargana. The prevalence of sparganum infection in wild frogs (Rana nigromaculata, R. limmochari, R. temporaria and Bufo gargarizans) was investigated in Henan Province of central China during 2008-2012. Of 3482 caught wild frogs, 565 (16.23%) were found to be infected with plerocercoids (spargana) of the genus Spirometra. Spargana were found in 14.85% (320/2155) of R. nigromaculata, 20.82% (233/1119) of R. limmochari and 10.91% (12/110) of R. temporaria frogs. However, no sparganum was found in B. gargarizans. To investigate the phylogenetic position of collected spargana, three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunits 1 and 3 (cox1 and cox3), and NADH dehydrogenase subunit 4 (nad4), were amplified, sequenced and analysed. Sequences of cox1, cox3 and pnad4 were 417, 390 and 578 bp in length, respectively. The base composition of cox1, cox3 and pnad4 were generally AT rich with a mean of 63.5%, 68.3% and 67% AT, respectively. Phylogenetic analysis showed that all the sparganum isolates in Henan Province represented Spirometra erinaceieuropaei and were a well-supported clade. These findings demonstrated clearly the usefulness of the three mtDNA sequences for molecular identification and population genetics studies of S. erinaceieuropaei spargana of human and animal health significance.

Acanthocephalan infection and sparganosis in a green tree snake (Dendrelaphis punctulata).

Acanthocephalan and spargana parasites were identified within a body wall mass during exploratory surgery in a wild green tree snake. Acanthocephalan parasites have not previously been reported in this species. Surgical excision, the treatment of choice, could not be achieved because of the extensive infiltration of the coelomic cavity.

Subcutaneous sparganosis, a zoonotic cestodiasis, in two cats.

Sparganosis is a zoonotic cestodiasis of human beings and animals caused by plerocercoid or second-stage larvae (sparganum) of pseudophyllidean tapeworms in host tissues. Cats are among definitive hosts in which the larva develops to adult stage in the intestines. Reports on larval infection involving various tissues and organs in cats are scarce. Rare single case reports of visceral sparganosis in cats are previously documented. The present report documents an unusual subcutaneous sparganosis in 2 Domestic Shorthair cats from southern Georgia. Veterinary clinicians should consider sparganosis as differential diagnosis for subcutaneous cyst-like masses in cats. As infected animals and animal tissues are sources of human infection, sparganosis warrants public awareness and due precaution to avoid human infection.

The first report of sparganosis (Spirometra sp.) in Eurasian badger (Meles meles).

Spirometra sp. is a diphyllobothriid cestode which reproduces mainly in cat-like carnivores and canids. Several animal species that are not definitive hosts function as paratenic hosts, in which plerocercoids migrate to other tissues causing sparganosis. In this paper we describe the first case of sparganosis (Spirometra sp.) in Eurasian badger (Meles meles). It was found in an adult female Eurasian badger killed on the road in the Bialowieza Primeval Forest (north-eastern Poland) in April 2013. At necropsy, 128 complete and 40 fragments of plerocercoids (spargana) were found and were located subcutaneously, mainly on the hind legs and along the spine. The average length of spargana was 87±38mm. No adult Spirometra sp. tapeworms were found in the animal intestine, indicating that the investigated badger was a paratenic host for Spirometra sp. Analysis of 18S rRNA gene sequences combined with morphological examination confirmed affiliation of the concerned plerocercoids to genus Spirometra.

Spargana in a weasel, Mustela sibirica manchurica, and a wild boar, Sus scrofa, from Gangwon-do, Korea.

To know the status of sparganum (plerocercoid of Spirometra erinacei) infection in the Korean wild life, several species of wild animals were captured in Gangwon-do and examined for their status of infection with spargana. From February to December 2011, a total of 62 wild boars, 5 badgers, 1 weasel, 1 Siberian chipmunk, and 53 wild rodents were captured, and their whole muscles were examined with naked eyes for the presence of spargana worms. From the weasel and 1 wild boar, a total of 5 spargana specimens were extracted. The weasel was for the first time recorded as an intermediate or paratenic/transport host of S. erinacei in Korea, and both the weasel (Mustela sibirica manchurica) and wild boar (Sus scrofa) were added to the list of wild animals carrying spargana.

Disseminated sparganosis in a cynomolgus macaque (Macaca fascicularis).

An adult male cynomolgus macaque (Macaca fascicularis) from Mauritius arrived at our facility in France after a 1-year period of quarantine in Spain. Clinical examination soon after arrival revealed the presence of numerous firm cutaneous and subcutaneous nodules (0.1-0.5 cm diameter) in the scrotal and inguinal areas, and persistent mild eosinophilia. On necropsy examination additional similar nodules were found in the peritoneum and abdominal wall, omentum and mesentery. Microscopical examination revealed disseminated eosinophilic granulomas containing tapeworm larvae identified as Spirometra erinaceieuropaei by direct sequencing of the cox1 gene.

[Investigation on prevalence of Spirometra mansoni sparganum infection in frogs from Henan Province].

OBJECTIVE: To understand the prevalence of Spirometra mansoni sparganum infection in frogs from Henan Province and analyze the risk of people suffering from sparganum infection. METHODS: The spargana were examined in the muscle of frogs collected from 12 sites of 5 regions in Henan Province, and the amount of spargana and their location were recorded. RESULTS: The natural infection rate of Spirometra mansoni spargana in frogs was 26.63% (306/1 149). There were totally 1 897 spargana found in those frogs, and the average was 6.2 per frog. The infection rate of pond frogs was higher than that of toad, the difference was statically significant (chi2 = 30.42, P < 0.01). The natural infection rate of pond frogs in the nearby patients' residence was higher than that of pond frogs collected from the other sites, and the natural infection rate of frogs was lower in the west region of Henan than that in the other areas. The muscles of hind legs of the frogs was the most common parasitic location compared with other parts of the frogs, and the ratio was 73.74% (1 365/1 851). CONCLUSION: The frogs living in the nature are widely infected with Spirometra mansoni spargana in Henan Province, and the comprehensive measures should be taken for the prevention and control of sparganosis mansoni.