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.

Presence of Spirometra mansoni, Causative Agent of Sparganosis, in South America.

We report molecular identification of an adult Spirometra mansoni tapeworm retrieved from a crab-eating fox (Cerdocyon thous) in Colombia, confirming presence of this parasite in South America. This tapeworm is the causative agent of human sparganosis, commonly reported from Southeast Asia, and represents the second congeneric species with known zoonotic potential in the Americas.

Surgical treatment of a patient with live intracranial sparganosis for 17 years.

BACKGROUND: The incidence of sparganosis, especially intracranial live sparganosis is very low in China. Due to the lack of typical clinical manifestations, it is difficult to make a clear preoperative diagnosis of the disease, which often leads to delays the disease and serious consequences. CASE PRESENTATION: A 23-year-old man presented with a 17-year history of intermittent seizures and right extremity numbness and weakness. Magnetic resonance imaging (MRI) showed patchy, nodular and line-like enhancement. Enzyme-linked immunosorbent assay (ELISA) detected positive antibodies to Spirometra mansoni in peripheral blood and cerebrospinal fluid (CSF). In addition, during the operation, an ivory-colored live sparganosis was removed under the precise positioning of neuronavigation, and the patient was diagnosed with cerebral sparganosis. The patient began praziquantel and sodium valproate treatment after the operation, and was followed up for 3 months. There was no recurrence of epilepsy, and the weakness and numbness of the right limb improved. CONCLUSION: Nonspecific clinical manifestations often make the diagnosis of cerebral sparganosis difficult, and a comprehensive diagnosis should be made based on epidemiological history, clinical manifestations, ELISA results and imaging findings. Surgery is the preferred method for the treatment of cerebral sparganosis, and more satisfactory results can be achieved under the precise positioning of neuronavigation.

A Case of Ocular Sparganosis in China: Episode of Migration from Muscle Cone to Subconjunctiva.

To improve our understanding of the migration of sparganum in humans, we report a case of ocular sparganosis having the migratory episode from the muscle cone to the subconjunctiva. A 34-year-old woman was admitted to the Hospital of Anhui Medical University (Hefei, China), in December 2019. She presented with conjunctival hemorrhage and recurrent pain in the left eye. A foreign body was found in the muscle cone of the eye. Two months later, a ribbon-like white material was found under the conjunctiva on slit-lamp examination. A long and slender, actively moving parasite was extracted by surgery. The extracted worm was approximately 8 cm long and 2 mm wide. The worm was whitish, wrinkled, ribbon shaped, and had a slightly enlarged scolex. The worm sample was morphologically identified as a plerocercoid larva (sparganum) of the Spirometra tapeworm. Her conjunctival blood suffusion and eye pain ceased within 1 week after operation. She has been in good health without any symptoms during the 2-year follow-up. A case of ocular sparganosis, in which larval worm migrated from the muscle cone to the subconjunctiva is reported from China.

Sparganosis (Spirometra) in Europe in the Molecular Era.

Sparganosis is a relatively neglected foodborne and waterborne disease caused by species of the tapeworm genus Spirometra, the global distribution of which has not been sufficiently recognized. Known mainly as a zoonosis of East Asia, its species are native to all inhabited continents including Europe. Spirometra has been reported from numerous wildlife species from 17 European countries, and a critical review confirmed 17 autochthonous and 8 imported human clinical cases. We present the first molecular evidence of the coincident presence of 2 species in Europe and review the current distribution to raise awareness of the parasite in this region. Spirometra erinaceieuropaei is restricted to Europe and Spirometra mansoni represents a lineage distributed mainly across Asia and Oceania that reaches Europe. The parasite is common in Eastern Europe and its distribution has potential to expand along with its invasive or migrating mammal hosts, spreading the risks of human infection.

Identification of an enolase gene and its physiological role in Spirometra mansoni.

Enolase is a crucial enzyme involved in the glycolytic pathway and gluconeogenesis in parasites. It also has been reported to function as a plasminogen receptor and may be involved in tissue invasion. In this study, the biochemical properties of the enolase of Spirometra mansoni (Smenolase) were investigated. The Smenolase gene was found to cluster closely with the enolase genes of Clonorchis sinensis and Echinococcus granulosus, and some functional motifs were identified as conserved. Smenolase was confirmed to be a component of the secretory/excretory products (ESPs) and a circulating antigen of spargana. Recombinant Smenolase expressed in vitro was able to bind to human plasminogen. Smenolase was detected in the eggs, testicles, and vitellaria of adult worms and the tegument of spargana. The transcription level of Smenolase was highest at the gravid proglottid stage. When spargana were cultured with glucose of different concentration in vitro, it was observed that the expression levels of Smenolase in the low-glucose groups were consistent with that of Smenolase in vivo. These results indicate that Smenolase is a critical enzyme involved in supplying energy to support the development and reproduction of the parasite, and it may also play a role in sparganum invasion.

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.

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.

Mitochondrial Genome of Spirometra theileri Compared with Other Spirometra Species.

This study was carried out to provide information on the taxonomic classification and analysis of mitochondrial genomes of Spirometra theileri. One strobila of S. theileri was collected from the intestine of an African leopard (Panthera pardus) in the Maswa Game Reserve, Tanzania. The complete mtDNA sequence of S. theileri was 13,685 bp encoding 36 genes including 12 protein genes, 22 tRNAs and 2 rRNAs with absence of atp8. Divergences of 12 protein-coding genes were as follow: 14.9% between S. theileri and S. erinaceieuropaei, 14.7% between S. theileri and S. decipiens, and 14.5% between S. theileri with S. ranarum. Divergences of 12 proteins of S. theileri and S. erinaceieuropaei ranged from 2.3% in cox1 to 15.7% in nad5, while S. theileri varied from S. decipiens and S. ranarum by 1.3% in cox1 to 15.7% in nad3. Phylogenetic relationship of S. theileri with eucestodes inferred using the maximum likelihood and Bayesian inferences exhibited identical tree topologies. A clade composed of S. decipiens and S. ranarum formed a sister species to S. erinaceieuropaei, and S. theileri formed a sister species to all species in this clade. Within the diphyllobothridean clade, Dibothriocephalus, Diphyllobothrium and Spirometra formed a monophyletic group, and sister genera were well supported.

Proteomic and Immunological Identification of Diagnostic Antigens from Spirometra erinaceieuropaei Plerocercoid.

Human sparganosis is a food-borne parasitic disease caused by the plerocercoids of Spirometra species. Clinical diagnosis of sparganosis is crucial for effective treatment, thus it is important to identify sensitive and specific antigens of plerocercoids. The aim of the current study was to identify and characterize the immunogenic proteins of Spirometra erinaceieuropaei plerocercoids that were recognized by patient sera. Crude soluble extract of the plerocercoids were separated using 2-dimensional gel electrophoresis coupled with immunoblot and mass spectrometry analysis. Based on immunoblotting patterns and mass spectrometry results, 8 antigenic proteins were identified from the plerocercoid. Among the proteins, cysteine protease protein might be developed as an antigen for diagnosis of sparganosis.

Morphological and Molecular Identification of Spirometra Tapeworms (Cestoda: Diphyllobothriidae) from Carnivorous Mammals in the Serengeti and Selous Ecosystems of Tanzania.

Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri (MK955901), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania.

Ocular Sparganosis: The First Report of Spirometra ranarum in Thailand.

A 22-year-old Thai man from the Northeast region presented with acute eye swelling, itching, and discharge on his left eye. He was suspected of having gnathostomiasis and treated with albendazole and prednisolone for 3 weeks. Nine months later, he was treated with high-dose oral prednisolone for the preliminary and differential diagnoses with thyroid-associated orbitopathy and lymphoma. He had been administered prednisolone intermittently over a few years. Then he developed a painless movable mass at the left upper eyelid and recurrent pseudotumor oculi was suspected. The surgical removal of the mass was performed. A white pseudosegmented worm revealed a definite diagnosis of ocular sparganosis by a plerocercoid larva. Molecular diagnosis of the causative species was made based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Proper technique of extraction and amplification of short fragments DNA from formalin-fixed paraffin-embedded tissue successfully identified parasite species. The result from the sequencing of the PCR-amplified cox1 fragments in this study showed 99.0% sequence homology to Spirometra ranarum. This is the first report of S. ranarum in Thailand.

A Retrieved Sparganum of Spirometra erinaceieuropaei from a Korean Man during Mechanical Thrombectomy.

Human sparganosis is a zoonotic disease caused by infection and migration of the plerocercoid of Spirometra spp. Although sparganosis were reported from most parts of the body, the sparganum parasitizing inside cerebral artery is remarkably uncommon. We report a case of cerebral intravascular sparganosis in an elderly patient with acute ischemic stroke who was diagnosed by retrieving sparganum during mechanical thrombectomy. Finally, the parasites were identified as Spirometra erinaceieuropaei using multiplex PCR and cox1 gene sequencing.

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.

A case report: 1-year follow-up of cerebral sparganosis mansoni with a stroke-like onset.

BACKGROUND: Sparganosis mansoni is a parasitic disease caused by infection with the larvae of Spirometra spp. tapeworms. Its clinical manifestations and severity depend on the migration and the location of the parasites. The proportion of cerebral sparganosis in all Spirometra mansoni infections is 13.5% in Thailand and 12.4% in China. In the clinical setting, cerebral sparganosis is often misdiagnosed due to atypical characteristics, irregular intracranial location, and atypical epidemiology. CASE PRESENTATION: The patient in the case study suffered from an acute paroxysmal attack of lateral numbness, accompanied with focal epilepsy. He was admitted to the neurology department as a stroke patient but was later diagnosed with cerebral sparganosis mansoni following lab and radiology investigations. He was fully recovered and free of Spirometra mansoni one year after initial consultation following several courses of oral praziquantel. The current report focuses on the diagnosis, treatment and follow up of this patient. CONCLUSIONS: A case of cerebral sparganosis mansoni with a stroke-like onsetsuggests that in the clinical diagnosis, neurologists should pay attention to brain lesions and look out for the possibility of neuroparasitic infections when dealing with patients with stroke-like onset accompanied by epilepsy. Detections of relevant antibodies in blood and cerebrospinal fluid may be necessary. The combination of the epidemiological history, clinical manifestations, detection of parasite antibody, head radiology, pathological biopsy, and identification of parasites will help us in diagnosis and differential diagnosis.

Cerebral sparganosis presenting with atypical postcontrast magnetic resonance imaging findings: a case report and literature review.

BACKGROUND: Sparganosis, a rare and severe parasitic infection caused by the larvae of Spirometra species or simply sparganum, generally involves subcutaneous tissue or muscle. But occasionally, sparganum can also invade the human brain, resulting in cerebral sparganosis. CASE PRESENTATION: A 33-year-old woman presented with a 10-day history of headache. Postcontrast magnetic resonance imaging (MRI) revealed an irregular lesion with enhancement and the tunnel-shaped focus extending to the contralateral hemiphere. Cerebrospinal fluid (CSF) analysis disclosed pleocytosis (166 cells/µL) and an elevated protein concentration (0.742 g/L). Enzyme-linked immunosorbent assay (ELISA) revealed positive sparganum-specific antibody in both blood and CSF. Finally, the diagnosis of cerebral sparganosis was comfirmed. She received praziquantel treatment and got a favorable outcome during six-month follow-up. CONCLUSIONS: Irregular enhancement and the tunnel sign that extends to the contralateral hemisphere on postconstrast MRI are unusual presentations of cerebral sparganosis. ELISA for sparganum-specific antibody can help confirm the diagnosis. Although surgery is the preferred treatment for cerebral sparganosis, praziquantel might also achieve satisfying outcomes.

A case of mammary sparganosis due to infection with Spirometra mansoni.

The authors report the case of a 56-year-old woman with mammary sparganosis due to infection with a plerocercoid tapeworm larva of Spirometra mansoni. Magnetic resonance imaging revealed an area of heterogeneous density in outer upper quadrant of the right breast, with a high likelihood of malignancy. During surgery for the removal of a granuloma, the parasite was discovered and excised. The authors review the pathological and imaging features of mammary sparganosis.

Genetic Identification of Spirometra erinaceieuropaei Spargana in Liaoning and Hubei Provinces, PR China.

Spargana were collected from human and frogs in Liaoning and Hubei Provinces, China. PCR amplification and direct sequencing of A cox1 fragment was PCR-amplified from genomic DNA extracted from 7 specimens (5 from humans and 2 from frogs). The cox1 fragment (390 bp) showed 97-100% similarity to the reference sequence of S. erinaceieuropaei and 88-89% to the reference sequence of S. decipiens. There were 1-12 bases different between these worms, but no obvious genetic variation (0-3.3%) to the references. There was little difference of cox1 gene between sparganum samples of humans and frogs (1-3%). This study is the first report on S. erinaceieuropaei spargana from humans in Liaoning and Hubei Provinces.

Mitochondrial DNA Sequence Variability of Spirometra Species in Asian Countries.

Mitochondrial DNA sequence variability of Spirometra erinaceieuropaei in GenBank was observed by reinvestigation of mitochondrial cox1 and cytb sequences. The DNA sequences were analyzed in this study, comprising complete DNA sequences of cox1 (n=239) and cytb (n=213) genes. The 10 complete mitochondrial DNA sequences of Spirometra species were compared with those of Korea, China and Japan. The sequences were analyzed for nucleotide composition, conserved sites, variable sites, singleton sites and parsimony-informative sites. Phylogenetic analyses was done using neighbor joining, maximum parsimony, Bayesian inference and maximum-likelihood on cox1 and cytb sequences of Spirometra species. These polymorphic sites identified 148 (cox1) and 83 (cytb) haplotypes within 239 and 213 isolates from 3 Asian countries. Phylogenetic tree topologies were presented high-level confidence values for the 2 major branches of 2 Spirometra species containing S. erinaceieuropaei and S. decipiens, and S. decipiens sub-clades including all sequences registered as S. erinaceieuropaei in cox1 and cytb genes. These results indicated that mitochondrial haplotypes of S. erinaceieuropaei and S. decipiens were found in the 3 Asian countries.

Subcutaneous Sparganosis on Abdomen Mimicking Multiple Lipomas.

Human sparganosis is a food-borne zoonosis mainly caused by the plerocercoid belonging to the genus Spirometra. The most common clinical sign of sparganosis is a subcutaneous mass in the trunk including abdominal or chest wall. The mass may be mistaken for a malignant tumor, thereby causing difficulty in terms of diagnosis and treatment. A 66-year-old woman visited our clinic for the removal of a lipoma-like mass. It was movable, hard, and painless. We identified 2 white mass, measuring 0.2×4 cm and 0.2×1 cm. Pathologic findings indicated the white mass was a sparganum. She recalled having eaten a raw frog approximately 60 years before. A 35-year-old who lived North Korea was also presented to our clinic with an asymptomatic nodule on her abdomen. Intraoperatively, we found sparganum approximately 24 cm size. Subcutaneous masses are associated with clinical signs of inflammation or they may mimic a soft tissue neoplasm. While the incidence rate of sparganosis has decreased with economic development and advancements in sanitation, surgeons still encounter patients with sparganosis in the clinical setting. Therefore, a careful history is required in order to diagnose sparganosis.