Sparganosis in mainland China

A hepatic sparganosis misdiagnosed as intrahepatic mass-forming cholangiocarcinoma: a case report and literature review

Hepatic sparganosis (HS) is extremely rare and has not been previously reported in Eastern China. We report the diagnosis and treatment of a patient with HS from Xuzhou City, Jiangsu Province, China. The patient was admitted due to an acute biliary tract infection, and the symptoms improved after treatment at the Gastroenterology Department. During an ultrasound examination on admission, an abnormal echo was incidentally discovered at the junction of the left and right lobes of the liver. Thereafter, upper abdominal computed tomography (CT) and magnetic resonance imaging (MRI) non-contrast and contrast-enhanced examinations, and serum tumor biomarker examination were completed. After a multidisciplinary treatment (MDT) discussion at the Department of Hepatobiliary Surgery, the patient was diagnosed with intrahepatic mass-type cholangiocarcinoma (IMCC) and surgery was recommended. The patient underwent surgical treatment, and postoperative pathology revealed HS. No signs of intrahepatic recurrence were observed during the 1-year follow-up period.

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.

The serum IgG antibody level as a biomarker for clinical outcome in patients with cerebral sparganosis after treatment

Introduction

Cerebral sparganosis is a rare parasitic infection of the brain tissue. The remission of MRI change and clinical symptom has been used to evaluate the therapeutic effect. However, there is no study to correlate the serum IgG antibody level of sparganum to the prognosis of disease after treatment.

Methods

87 patients with cerebral sparganosis were collected from three medical centers. Clinical symptoms and MRI changes were evaluated at 12 months after initial treatment, and serum IgG antibody level of sparganum was evaluated at 2, 6, and 12 months after treatment. The positive cut-off value was based on 2.1 times the optical density (OD) of negative control. The index value was defined as the sample OD divided by the cut-off value.

Results

Among the 87 patients after treatment, 71 patients had good clinical outcomes, and 16 had poor clinical outcomes. The area under the curve (AUC) showed that the index value measured at 12 months after treatment had the best prediction effect, with a value of 2.014. In the good-outcome group, the index values were less than 2.014 in all 71 patients, and only 8 patients had mildly enhanced residual lesions on MRI. In the poor-outcome group, the index values were more than 2.014 in all 16 patients, and all patients still showed significantly enhanced lesions on MRI. Compared with poor-outcome patients, only 2 patients with good outcomes had disease recurrence after treatment.

Discussion

This study provided evidence that the serum IgG antibody level of sparganum was a promising biomarker to evaluate the prognosis of patients with cerebral sparganosis after treatment.

Epidemiology, Diagnosis, and Prevention of Sparganosis in Asia

Sparganosis is a zoonotic parasitic disease caused by the larvae (spargana) of the genus Spirometra, which is widely distributed globally and threatens human health. More than 60 species of Spirometra have already been identified, and over 2000 cases have been reported. This review summarizes the prevalence of humans, frogs, snakes, and other animals with spargana. Furthermore, the infection mode, distribution, and site are summarized and analyzed. We also describe the epidemiology, molecular diagnosis, and other aspects which are of considerable significance to preventing sparganum.

Molecular Characterization and Phylogenetic Analysis of Spirometra Tapeworms from Snakes in Hunan Province

Sparganosis is a neglected zoonotic parasitic disease that poses huge threats to humans worldwide. Snakes play an important role in sparganosis transmission because they are the most common second intermediate hosts for Spirometra parasites. However, the population genetics of Spirometra isolates from snakes is currently not well studied in China. The present study was performed to explore the molecular characteristics and phylogenetic analysis of Spirometra tapeworms from different species of snakes in Hunan Province. This study obtained 49 Spirometra isolates from 15 geographical areas in Hunan Province, Central China. Subsequently, the 18S and 28S ribosomal DNA (rDNA) fragments were amplified from the isolated parasites, and their sequences were analyzed to assess their genetic diversity. Phylogenetic analyses were performed using the maximum likelihood algorithm. The results showed that sequence variations among these isolates were 0–2.3% and 0–0.1% for 18S and 28S rDNA, respectively. The phylogenetic analysis showed that all Spirometra isolates from Hunan Province were clustered into the same branch with Spirometra erinaceieuropaei isolated from other areas (China, Vietnam, Australia). Moreover, the phylogenetic trees revealed that Spirometra is closely related to Adenocephalus, Pyramicocephalus, Ligula, Dibothriocephalus, Schistocephalus, and Diphyllobothrium. The Spirometra isolates of different hosts/regions in Hunan Province are not host segregated or geographically isolated, and support for the taxonomic status of Spirometra tapeworms in China has been added. These results provide reference values for future accurate identification and taxonomic status of Spirometra tapeworms in China.

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.

A case of breast sparganosis: with an emphasis on ultrasonographic findings

Sparganosis is a rare disease caused by the infestation of the plerocercoid tapeworm larva of the genus Spirometra. Human sparganosis is most commonly encountered in subcutaneous fat areas of the abdomen, limbs, and genitourinary tract. Breast sparganosis occur very rarely, accounting for less than 2% of total human sparganosis cases. Because of the disease's rarity, clinical suspicion is essential to reach the diagnosis of breast sparganosis. We present a case of mammary sparganosis in a 58 year-old woman on the ultrasonographic findings. The patient had a painless breast lump with a history of drinking impure water. On ultrasonography (US), we noted four masses, the largest lesion was suspected as sparganosis, and others tended to be benign lesions. The patient was treated following excisions by a US guided Vacuum-assisted breast biopsy system (VABB). The final diagnosis of all lesions was sparganosis.

Lesionectomy for cerebral sparganosis and concomitant epilepsy: A case series of 15 patients

OBJECTIVE

To report the clinical characteristics and surgical outcomes of patients with cerebral sparganosis and concomitant epilepsy.

METHODS

We retrospectively collected the clinical data of all patients with cerebral sparganosis and concomitant epilepsy who underwent lesionectomy as treatment at Xiangya Hospital, Central South University between January 2015 and August 2019. Seizure outcomes were evaluated according to the International League Against Epilepsy (ILAE) classification. ILAE classes 1 and 2 were defined as favorable seizure outcomes, whereas ILAE classes 3-6 were defined as unfavorable seizure outcomes.

RESULTS

Fifteen patients with cerebral sparganosis and concomitant epilepsy who underwent lesionectomy as treatment met the inclusion criteria. Live worms were surgical removed in 80 % of patients. With a mean follow-up of 2.4 ± 1.1 years, 66.7 % of patients demonstrated favorable seizure outcomes, with improvement of symptoms other than seizures. Longer seizure duration associated with unfavorable seizure outcomes.

CONCLUSIONS

Lesionectomy is an effective treatment for patients with cerebral sparganosis and concomitant epilepsy. Early surgical treatment may offer more benefits to such patients.

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.

A case of human breast sparganosis diagnosed as Spirometra Type I by molecular analysis in Japan

A 92-year-old Japanese woman presented with a mass in the left breast, and sparganosis was suspected by biopsy of the mass. The mass disappeared once, but it reappeared at the same site one year later. For a definitive diagnosis, the mass was surgically removed, and a sparganum-like worm was detected. The causative agent was confirmed as Spirometra Type I (most probably Spirometra mansoni) by mitochondrial DNA analysis. The serological examination also proved the case as sparganosis. Considering the presence of two Spirometra species (Type I and II) in Asia, particularly Japan, molecular analysis of the causative agents is highly recommended to understand the epidemiology, infection sources, and pathogenicity in humans in both species, if the parasite specimens are available.

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.

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 Białowieża 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, Białowieża 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.

First identification and molecular phylogeny of Sparganum proliferum from endangered felid (Panthera onca) and other wild definitive hosts in one of the regions with highest worldwide biodiversity

After decades of being neglected, broad tapeworms now attract growing attention thanks to the increasing number of reports from humans but also thanks to many advancements achieved by application of molecular methods in diagnosis and epidemiological studies. Regarding sparganosis, unfortunately general uniformity of most species, their high intraspecific variability and lack of agreement among researchers has led to confusion about the classification of Spirometra/Sparganum species. For the first time we determined adult, eggs and plerocercoid life cycle stages and the molecular phylogeny of Sparganum proliferum obtained from endangered wild felids (Panthera onca, Leopardus pardalis, Leopardus guttulus and Herpailurus yagoauroundi) in one of the largest continuous remnants of worldwide biodiversity, the Atlantic Forest from South America. Our results showed that at least 57% of total species of wild felids in this natural area could act as definitive hosts of Sparganum proliferum. We conclude that the availability of more morphological characteristics are needed in order to secure reliable characterization and diagnosis of sparganosis. The integration of these data with molecular analysis of mitochondrial DNA sequences will be useful for species discrimination.

Spirometra species from Asia: Genetic diversity and taxonomic challenges

Despite considerable controversy concerning the taxonomy of species within the genus Spirometra, human sparganosis and spirometrosis mainly in Asia and Europe has long been confidently ascribed to Spirometra erinaceieuropaei. Recently, the mitochondrial genomes of purported "S. erinaceieuropaei", "Spirometra decipiens" and "Spirometra ranarum" from Asia have been determined. However, it has been pointed out that the morphological criteria used for identifying these species are unsuitable and thus these identifications are questionable. In the present study, therefore, Spirometra samples from Asia were re-examined based on mitochondrial cytochrome c oxidase subunit 1 gene sequences and the identification of these species was discussed. Haplotype network and phylogenetic analyses revealed that: i) two distinct Spirometra species, Type I and Type II, are present in Asia and neither of which is close to likely European "S. erinaceieuropaei"; ii) Type I is genetically diverse and widely distributed, however Type II is known so far from Japan and Korea; iii) "S. decipiens" and "S. ranarum" reported from Asia are conspecific with Type I; iv) Type I is probably conspecific with Spirometra mansoni, and Type II may represent an undescribed species.

Larval Gnathostomes and Spargana in Chinese Edible Frogs, Hoplobatrachus rugulosus, from Myanmar: Potential Risk of Human Infection

Chinese edible frogs, Hoplobatrachus rugulosus, were examined to estimate the potential risks of human gnathostomiasis and sparganosis in Myanmar. A total of 20 frogs were purchased in a local market of Yangon and examined with naked eyes and the artificial digestion method after skin peeling in June 2018 and June 2019. Larvae of gnathostomes and Spirometra (=spargana) were detected in 15 (75.0%) and 15 (75.0%) frogs with average intensities of 10.5 and 6.3 larvae per infected frog, respectively. Gnathostome larvae were 2.75–3.80 (av. 3.30) mm long and 0.29–0.36 (0.33) mm wide. They had a characteristic head bulb with 4 rows of hooklets, a muscular long esophagus, and 2 pairs of cervical sac. The mean number of hooklets were 41, 44, 47, and 50 on the 1st, 2nd, 3rd, and 4th row, respectively. Collected spargana were actively moving, particularly with the scolex part, and have ivory-white color and variable in size. Conclusively, it has been first confirmed that Chinese edible frogs, H. rugulosus, are highly infected with larval gnathostomes and spargana in this study. Consuming these frogs is considered a potential risk of human gnathostomiasis and sparganosis in Myanmar.

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.

Recurrent eosinophilic pleuritis caused by sparganum infection: A case report and review of the literature

RATIONALE

Sparganosis is an infectious disease caused by a larval tapeworm of the genus Spirometra, which commonly invades subcutaneous tissues. Pulmonary and pleural involvement due to sparganum has been rarely reported previously.

PATIENT CONCERNS

We herein described a case of recurrent eosinophilic pleuritis in a 24-year-old woman. She was admitted with persistent cough and shortness of breath for more than 1 month. Initial chest computed tomography scan suggested right pleural effusion and diffuse pleural thickening. Slightly elevated eosinophil counts were found in both the peripheral blood and pleural fluid. She underwent right pleurectomy but histological examination failed to obtain an etiological diagnosis. Moreover, eosinophilic pleural effusion re-appeared in the contralateral thoracic cavity one month later. After re-admission, we reviewed her medical history meticulously and found she had a history of ingesting raw snake gallbladders before hospitalization. The final diagnosis was confirmed by the markedly positive reaction against sparganum antigen in both serum and pleural fluid sample.

DIAGNOSIS

Eosinophilic pleuritis caused by sparganum infection.

INTERVENTIONS

After the diagnosis, the patient was treated with praziquantel at 75 mg/kg/d for 3 days.

OUTCOMES

Pleural effusion absorbed completely and eosinophil count in peripheral blood returned to normal range. No evidence of recurrent pleural effusion had been observed in over one year of follow-up.

LESSONS

Clinicians need to be aware the possibility of sparganum infection in cases of eosinophilic pleuritis. The specific enzyme-linked immunosorbent assay remains a useful method in acquiring a rapid diagnosis, especially when histological examination is unable to detect the larvae in the thoracic cavity.

Protein phosphorylation networks in spargana of Spirometra erinaceieuropaei revealed by phosphoproteomic analysis

Background

Sparganosis caused by Spirometra erinaceieuropaei spargana is a zoonotic parasitic infection that has been reported in many countries, including China, Japan, Thailand and Korea, as well as European countries and the USA. The biological and clinical significance of the parasite have previously been reported. Although the genomic and transcriptomic analysis of S. erinaceieuropaei provided insightful views about the development and pathogenesis of this species, little knowledge has been acquired in terms of post-translational regulation that is essential for parasite growth, development and reproduction. Here, we performed site-specific phosphoproteomic profiling, with an aim to obtain primary information about the global phosphorylation status of spargana.

Results

A total of 3228 phosphopeptides and 3461 phosphorylation sites were identified in 1758 spargana proteins. The annotated phosphoproteins were involved in a variety of biological pathways, including cellular (28%), metabolic (20%) and single-organism (17%) processes. The functional enrichment of phosphopeptides by Gene Ontology analysis indicated that most spargana phosphoproteins were related to the cytoskeleton cellular compartment, signaling molecular function, and a variety of biological processes, including a molecular function regulator, guanyl-nucleotide exchange factor activity, protein kinase activities, and calcium ion binding. The highly enriched pathways of phosphorylation proteins include the phosphatidylinositol signaling system, phagosome, endocytosis, inositol phosphate metabolism, terpenoid backbone biosynthesis, and peroxisome. Domain analysis identified an EF-hand domain and pleckstrin homology domain among the key domains.

Conclusions

To our knowledge, this study performed the first global phosphoproteomic analysis of S. erinaceieuropaei. The dataset reported herein provides a valuable resource for future studies on the signaling pathways of this important zoonotic parasite.

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 medical relevance of Spirometra tapeworm infection in Indonesian Bronzeback snakes (Dendrelaphis pictus): A neglected zoonotic disease

Aim:

Spirometra parasites cause sparganosis, a zoonotic disease, especially in reptiles and humans. This study aimed to report on the prevalence and effects of Spirometra parasites infection on public health and provide a scientific foundation for its prevention.

Materials and Methods:

A total of 378 living Indonesian wild-caught and captive-bred Bronzeback snakes (Dendrelaphis pictus) were selected. The snakes were euthanized using ethyl ether anesthesia before checking for Spirometra parasites. The numbers of Spirometra located in the muscle tissue, subcutaneous tissue, and coelom (including the viscera) were each counted to investigate the distribution of Spirometra inside the snake body cavity.

Results:

The total prevalence in the sample was 50.85%. The prevalence values in wild-caught and captive-bred snakes were 70.7% and 48.7%, respectively. More than half (56.6%) of the Spirometra parasites were located in the muscular tissue, while 29.5% were in the subcutaneous tissue and 13.8% were in the coelomic cavity.

Conclusion:

Wild-caught Indonesian Bronzeback snakes, which are sold as food in markets, and captive-bred snakes, which are collected as exotic pets in Indonesia, have similar opportunities to transmit the Spirometra parasite and cause global health problems due to their high prevalence.

Diagnosis and surgical management of orbital sparganosis

PURPOSE/BACKGROUND

Orbital sparganosis represents an extremely rare condition with only a few cases being reported in literature. Here we describe cases of orbital sparganosis, including their etiology, clinical findings, and surgical outcomes.

PATIENTS AND METHODS

A retrospective review was performed on patients with orbital sparganosis, who were treated at Zhongshan Ophthalmic Center, of Sun Yat-sen University, China between 2000 and 2012.

RESULTS

Five patients (three males and two females, one right orbit and four left orbits) were identified. Their mean age was 14.8 years (range = 6-33 years). Four cases were contracted from eating raw snakes and fishes, or placing poultices of frog on open wounds. All cases showed a swelling and/or redness of the eyelid and conjunctiva, and a migrating inflammation was present in one of the cases. High levels of blood eosinophils were observed in three of these cases. Of the two patients examined using computed tomography, one showed a diffuse soft tissue infiltration and a punctate calcification, while one of the three patients examined using magnetic resonance imaging displayed an annular "tunnel sign" within the lesion. All patients underwent an anterior orbitotomy and the entire worm was removed with no surgical complications.

CONCLUSIONS

Orbital sparganosis should be highly suspected in patients with a history of eating raw snakes and frogs, a migrating orbital inflammation and the presence of eosinophilia. Orbital imaging examinations play an important role in the diagnosis of orbital sparganosis. Surgical removal of the entire worm is required.

Follow-up study of high-dose praziquantel therapy for cerebral sparganosis

Background

Cerebral sparganosis is the most serious complication of human sparganosis. Currently, there is no standard for the treatment of inoperable patients. Conventional-dose praziquantel therapy is the most reported treatment. However, the therapeutic outcomes are not very effective. High-dose praziquantel therapy is a useful therapeutic choice for many parasitic diseases that is well tolerated by patients, but it has not been sufficiently evaluated for cerebral sparganosis. This study aims to observe the prognoses following high-dose praziquantel therapy in inoperable patients and the roles of MRI and peripheral eosinophil absolute counts during follow-up.

Methodology

Baseline and follow-up epidemiological, clinical, radiological and therapeutic data related to 10 inoperable patients with cerebral sparganosis that were treated with repeated courses of high-dose praziquantel therapy, with each course consisting of 25 mg/kg thrice daily for 10 days were assessed, followed by analyses of the prognoses, MRI findings and peripheral eosinophil absolute counts.

Principal findings

Baseline clinical data: the clinical symptoms recorded included seizures, hemiparesis, headache, vomiting and altered mental status. Peripheral blood eosinophilia was found in 3 patients. The baseline radiological findings were as follows. Motile lesions were observed in 10 patients, including aggregated ring-like enhancements, tunnel signs, serpiginous and irregular enhancements. Nine of the 10 patients had varying degrees of white matter degeneration, cortical atrophy and ipsilateral ventricle dilation. The follow-up clinical data were as follows. Clinical symptom relief was found in 8 patients, symptoms were eliminated in 1 patient, and symptoms showed no change from baseline in 1 patient. Peripheral blood eosinophilia was found in 2 patients. The follow-up radiological findings were as follows. Motile lesions that were transformed into stable, chronic lesions were found in 8 patients, and motile lesions that were eliminated completely were found in 2 patients.

Conclusions

High-dose praziquantel therapy for cerebral sparganosis is effective. The radiological outcomes of motile lesions are an important indicator during the treatment process, especially during follow-ups after clinical symptoms have improved. Peripheral eosinophil absolute counts cannot be used as an effective prognostic indicator.

Sparganosis is a rare parasitic disease with a high prevalence in East Asia. Because of limited radiological technology and clinical experience, the prevalence of cerebral sparganosis is likely underestimated in developing countries. Cerebral sparganosis is the most serious complication of human sparganosis. Currently, it is generally believed that the most effective treatment for cerebral sparganosis is surgical treatment. However, the choice of treatment is a challenge for inoperable patients, including those with multifocal lesions or lesions in deep structures or important functional areas and those refusing invasive treatment due to personal willingness. Currently, there is no standard for the treatment of inoperable patients. In addition, anthelmintic treatment for sparganosis has rarely been reported in the literature. High-dose praziquantel therapy is a useful therapeutic choice for many cerebral parasitic diseases, including neurocysticercosis, and is well tolerated for patients, but it has not been sufficiently evaluated for the treatment of cerebral sparganosis. This study aims to describe the clinical, radiological and therapeutic data following high-dose praziquantel therapy for ten inoperable patients. All patients reached clinical cure after one to five courses. These results suggest that high-dose praziquantel therapy for cerebral sparganosis could achieve favorable outcomes and that MRI plays an important role in follow-up, especially when clinical symptoms have improved.

Efficacy comparison between long-term high-dose praziquantel and surgical therapy for cerebral sparganosis: A multicenter retrospective cohort study

Background

Sparganosis is a parasitic infection caused by the plerocercoid larvae of Spirometra mansoni in East and Southeast Asia. The plerocercoid larvae sometimes invade the encephalon, resulting in severe cerebral sparganosis. Surgical removal of the larvae is considered a standard therapy for cerebral sparganosis. In contrast, the efficacy and safety of long-term, high-dose praziquantel treatment for cerebral sparganosis have not been explored.

Methodology/Principal findings

In this multicenter retrospective study, we assessed the records of 96 patients with cerebral sparganosis who consulted at three medical centers from 2013 to 2017. Forty-two patients underwent surgical lesion removal, and the other 54 patients received long-term, high-dose praziquantel (50 mg/kg/day for 10 days, repeated at monthly intervals). The primary outcome was the complete disappearance of active lesions on cerebral magnetic resonance imaging. The secondary outcomes included the modified Rankin scale score at 90 days, incidence of seizure, eosinophil count, and serological Spirometra. mansoni antibody titer. The efficacy of praziquantel treatment was similar to that of surgical lesion removal for cerebral sparganosis with respect to both the primary outcome and secondary outcomes. Although binary logistic regression models also supported the primary outcome after adjustment for age, sex, lesion location, and loss to follow-up, some unavoidable confounders might have biased the statistical power. No significant clinical complications or laboratory side effects occurred in the praziquantel group with the exception of a relatively benign allergic reaction.

Conclusions/Significance

In this small-sample, nonrandomized, retrospective exploratory study, some patients with cerebral sparganosis were responsive to long-term, high-dose praziquantel with an efficacy similar to that of surgical lesion removal. These findings increase the treatment flexibility for this serious infection.

Sparganosis is most prevalent in developing countries in East and Southeast Asia, probably because public health strategies have not prioritized its prevention. The plerocercoid larvae of Spirometra mansoni sometimes invade the brain parenchyma, resulting in cerebral sparganosis. In general, surgical removal of the larvae is considered a standard therapy for cerebral sparganosis. One alternative treatment for sparganosis is short-term, low-dose praziquantel, which has had limited success. However, the efficacy and safety of long-term, high-dose praziquantel treatment for cerebral sparganosis have not been explored. In this study, we evaluated the effectiveness of long-term, high-dose praziquantel for treatment of cerebral sparganosis in China. We conducted a retrospective exploratory study using routinely recorded data from 96 patients at three medical centers. Forty-two patients underwent surgical lesion removal, and the other 54 patients received long-term, high-dose praziquantel. Treatment of cerebral sparganosis by long-term, high-dose praziquantel showed an efficacy similar to that of surgical lesion removal with respect to the primary outcome (complete disappearance of the active lesions on cerebral magnetic resonance imaging). However, this was a small-sample, nonrandomized retrospective study, and the results should be further confirmed by a large-sample prospective study or other studies.

Identification of sparganosis based on next-generation sequencing

The incidence of sparganosis, a parasitic disease caused by plerocercoid larvae of the genus Spirometra, has gradually risen worldwide (especially in remote areas) in recent years. Pulmonary and pleural sparganosis, as well as other sites of infestation, including the subcutaneous tissues, the abdominal viscera, brain and eyes, has been reported. In clinical practice, due to the atypical signs and symptoms as well as limited laboratory approaches for the specific detection of sparganum, sparganosis is often misdiagnosed. In the present study, an 11-year-old girl visited the Department of Infectious Diseases in Shanghai Children's Medical Center for recurrent shoulder and chest pain and shortness of breath. Imaging tests demonstrated bilateral pleural and pericardial effusion, enlarged lymph nodes in front of the tracheal carina, and infection of the left lower lobe. Sparganum were not observed in the dissected soft tissue at the root of the right thigh with naked-eye and light microscopy examination. Histologic examination revealed granulomatous inflammation and tunnel-like necrosis with eosinophilic, neutrophilic and lymphocytic infiltration. Although the patient's serum was positive for sparganum antibodies, the diagnosis of sparganosis was not confirmed for more than three months. Ultimately, genomic DNA of Spirometra erinaceieuropaei was detected in the mass at the root of the right thigh using next-generation sequencing (NGS), confirming the diagnosis of sparganosis. The patient was treated with praziquantel (150 mg/kg/day) without recurrence after an eight-month follow-up. We present, for the first time, a study of human sparganosis diagnosed using NGS, which provided a clinically actionable diagnosis of a specific infectious disease from an uncommon pathogen.

Orbital sparganosis in an 8-year boy: a case report

Background

Sparganosis is one of the neglected but important food-borne parasitic zoonoses, with higher prevalence in Asian countries. The infection is commonly located in the subcutaneous tissue, brain, breast, and lung, but fewer reported infections involve the eye. Because the majority of patients with sparganosis are adults, it is likely to be missed in children.

Case presentation

An 8-year-old boy presented to our clinic complaining of a painless ocular mass in his right eye for 1 month. The boy had a history of eating frogs and frog poultice applications to his eyelids. The patient was checked for an elliptical mass near the medial wall of the right eye. Serodiagnosis testing was positive in an enzyme-linked immunosorbent assay. During surgical operation on the patient, calcified parasite eggs and foreign body granulomatous reaction were found using histological examination. Due to early detection and surgery, the patient fully recovered with no damage to his eyesight.

Conclusions

Although rare, ocular sparganosis should be suspected in a mass of the eye when there is a history of eating frogs and frog poultice applications on eyelids. Early surgical resection is important for a good prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0675-8) contains supplementary material, which is available to authorized users.

Case report: the first case of human infection by adult of SPIROMETRA ERINACEIEUROPAEI in VIETNAM

BACKGROUND

Tapeworms of the genus Spirometra include species whose larval stages can infect humans, causing a disease called sparganosis. Cases of human infection with adult worms are very rare and have been reported in Korea and China. Here we report the first case of human infection with an adult of Spirometra erinaceieuropaei in Vietnam.

CASE PRESENTATION

A 23-year-old male was admitted to 103 Military Hospital, Hanoi, Vietnam with fever, weight loss and epigastric discomfort. Preliminary diagnosis based on discovery of parasite eggs in his faeces incorrectly determined a fluke as the agent of the infection and praziquantel was prescribed. Two days later he passed out proglottids in his stool. The tapeworm was identified as Spirometra erinaceieuropaei using morphological and molecular tools.

CONCLUSION

This is the first case of human infection with adult worm of Spirometra erinaceieuropaei in Vietnam.

Clinical Manifestation of a Patient With Forehead Sparganosis

Human sparganosis is a parasite infection caused by the larva of a tapeworm of the genus Spirometra. Ocular, central nervous system, auricular, pulmonary, intraosseous, intraperitoneal, and subcutaneous manifestations of this infection in the neck or inguinal region have been described.The authors report the rare occurrence of cutaneous forehead sparganosis of a 19-year-old male who presented with a soft subcutaneous mass in the forehead, along with a related literature review.

The prevalence of helminth parasites in Pelophylax nigromaculatus (Anura: Ranidae) from Shanghai, China

Parasites are ubiquitous members of biotic communities. To investigate the infective status of helminth parasites in Pelophylax nigromaculatus from Shanghai, 90 frogs were collected from July 2013 to July 2014 and examined for the presence of internal parasites. Of these, 86.67% (78/90) of frogs were infected with parasites, the total helminth intensity within infected frogs ranged from 1 to 367, and the mean intensity was 28.49. The infection rates and intensities were 78.89% and 22.89 for trematodes, 50.00% and 5.24 for nematodes, 13.33% and 3.92 for cestodes, and 41.11% and 8.49 for acanthocephalas, respectively. The majority (60.04%) of parasites were parasitic in the intestine, followed by urinary bladder (24.8%) and lungs (7.38%). Based on morphological features, 13 different species of helminth, including 9 undetermined species, were identified. The infective status of different species was significantly different. The most prevalent species were Diplodiscus nigromaculati (64.44%), Diplodiscus sp. (37.78%), Pomphorhynchus sp. (35.56%), Strongyloides sp. (33.33%). The mean infection intensity of Diplorchis nigromaculatus (139.25) was higher than the others' species ranged from 3.57-14.63. This is the first reported discovery of Pomphorhynchus sp. (Pomphorhynchidae Yamaguti, 1939) in frogs from China. These data provide the foundation for further analyses of parasites in this and other species of amphibians.

Parasitism by larval tapeworms genus Spirometra in South American amphibians and reptiles: new records from Brazil and Uruguay, and a review of current knowledge in the region

Spargana are plerocercoid larvae of cestode tapeworms of the genus Spirometra, Family Diphyllobothriidae, parasitic to frogs, reptiles, birds and mammals. This parasitic disease in humans can be transmitted through the use and consumption of amphibians and reptiles. The available knowledge about Spirometra in South America is scarce, and there are only a few reports on the occurrence of sparganum in amphibians and reptiles, many of them published in old papers not easily available to researchers. In this work we present a review on this topic, provide new records in two species of amphibians and 7 species of reptiles from Brazil and Uruguay respectively. We also summarize current knowledge of Spirometra in the continent, along with an updated of host taxonomy. We could gather from the literature a total of 15 studies about amphibian and reptile hosts, published between 1850 and 2016, corresponding to 43 case reports, mostly from Brazil (29) and Uruguay (8), Argentina (3), Peru (2), and Venezuela (1); the majority of them related to reptiles (five lizards and 26 snake species), and 14 corresponded to amphibians (9 anurans). Plerocercoid larvae were located in different organs of the hosts, such as subcutaneous tissue, coelomic cavity, peritoneum, and musculature. The importance of amphibians and reptiles in the transmission of the disease to humans in South America is discussed. Relevant issues to be studied in the near future are the taxonomic characterization of Spirometra in the region and the biological risk of reptile meat for aboriginal and other rural communities.

Seroprevalence of Sparganosis in Rural Communities of Northern Tanzania

In this study, the seroprevalence of sparganosis and its relationship with sociodemographic factors in northern Tanzania have been assessed. A total of 216 serum samples from two rural districts, Monduli and Babati, were tested for sparganosis using an enzyme-linked immunosorbent assay. The seroprevalence of anti-sparganum IgG antibodies was 62.5% (95% confidence interval [CI] = 56.1–68.9) in all age groups. There were significant associations between district (relative risk [RR] = 1.95, 95% CI = 1.42–2.69), education (RR = 1.40, 95% CI = 1.15–1.70), and pet ownership with seropositivity (RR = 1.48, 95% CI = 1.02–2.16) based on univariate analysis. However, only the district was significantly associated with seropositivity (odds ratio = 4.20, 95% CI = 1.89–9.32) in binary logistic regression analysis. Providing health education to people residing in sparganosis-endemic areas is likely to improve the efficacy of preventative measures and reduce human disease burden.

The phylogenetic diversity of Spirometra erinaceieuropaei isolates from southwest China revealed by multi genes

The larval plerocercoid of Spirometra erinaceieuropaei can parasitize humans, causing a serious food borne parasitic zoonosis known as sparganosis. Sparganosis have increased in China in recent years. In this study, the prevalence of sparganum infection in wild frogs in 9 geographical areas in southwest China was firstly investigated. Of 276 caught frogs, 55 frogs were found to be infected with sparganum. Then, the population genetic structure of these sparganum isolates was explored based on four molecular markers (cytb, cox1, rrnS and 28S rDNA D1). Highly genetic diversity and the genetic differentiation among sparganum isolates from different sites were revealed in the DNA polymorphism analyses. Both the phylogenetic inference and the analysis of the median-joining network supported two clades in the southwest S. erinaceieuropaei population. However, none demographic population expansion of the southwest S. erinaceieuropaei population was observed in the neutrality test, mismatch distribution analysis and Bayesian skyline plot analysis. Finally, the phylogenetic diversity of S. erinaceieuropaei from eastern, central, southern and southwest China was analyzed, the result suggested that Chinese S. erinaceieuropaei population should be divided into two groups (Group I and Group II), and they started to divergence in the middle Pliocene.

Human sparganosis, a neglected food borne zoonosis

Human sparganosis is a food borne zoonosis caused by the plerocercoid larvae (spargana) of various diphyllobothroid tapeworms of the genus Spirometra. Human infections are acquired by ingesting the raw or undercooked meat of snakes or frogs, drinking untreated water, or using raw flesh in traditional poultices. More than 1600 cases of sparganosis have been documented worldwide, mostly in east and southeast Asia. Sporadic cases have been reported in South America, Europe, and Africa, and several cases have been described in travellers returning from endemic regions. Epidemiological data suggest that the increased effect of sparganosis on human health is because of greater consumption of raw meat of freshwater frogs and snakes. This Review provides information about the Spirometra parasites and their lifecycles, summarises clinical features, diagnosis, and treatment of human sparganosis, and describes geographical distribution and infection characteristics of Spirometra parasites in host animals.

Zoonotic helminths parasites in the digestive tract of feral dogs and cats in Guangxi, China

BACKGROUND

In Guangxi, a province of southern China, an important number of dogs and cats roam freely in rural settings, and the presence of these animals in proximity of people may represent a risk of parasitic zoonoses. The objective of the present study was to investigate the presence and identify gastrointestinal helminths in feral carnivores in Guangxi province. Therefore, post mortem examination was performed in 40 dogs and in 39 cats.

RESULTS

The Gastrointestinal helminths were found in all the necropsied dogs and in 37 out of 39 cats. Fifteen species were identified including 7 trematodes, 3 cestodes and 5 nematodes. Most of them may be responsible for zoonotic infections.

CONCLUSIONS

Major zoonotic gastrointestinal helminths, including liver and intestinal flukes, Toxocara spp., and Ancylostoma spp., are present in feral dogs and cats in Guangxi, and may represent a significant risk for public health.

Differential diagnosis of a carcinoma of the maxillary sinus that resembles a sparganum infection: A case report

Primary malignant tumors of the maxillary sinuses are rare. The present study reports the case of a maxillary sinus adenocarcinoma that was misdiagnosed as a frog sparganum infection, and discusses the differential diagnosis between the two diseases. The patient was ultimately diagnosed with a carcinoma of the left maxillary sinus that presented as a progressive mass in the left eye and the maxillary sinus. Eosinophilic infiltration was observed in the subcutaneous tissue, and the patient had experienced previous exposure to undercooked frog. Although an anti-sparganum ELISA was performed and the results were negative, a sparganosis infection was initially diagnosed. However, following the application of anti-sparganosis treatment, no improvements were observed. Histological examination of an orbital mass resection revealed an adenocarcinoma with bone metastases. To the best of our knowledge, the present study is the first to report a maxillary sinus carcinoma misdiagnosed as sparganosis. Therefore, the findings of the current study should be considered in the differential diagnosis between a carcinoma of the maxillary sinus and sparganosis. Avoidance of misdiagnosis at an early stage is crucial for effective diagnosis and treatment of sinonasal malignancies.

The genome of the sparganosis tapeworm Spirometra erinaceieuropaei isolated from the biopsy of a migrating brain lesion

BACKGROUND

Sparganosis is an infection with a larval Diphyllobothriidea tapeworm. From a rare cerebral case presented at a clinic in the UK, DNA was recovered from a biopsy sample and used to determine the causative species as Spirometra erinaceieuropaei through sequencing of the cox1 gene. From the same DNA, we have produced a draft genome, the first of its kind for this species, and used it to perform a comparative genomics analysis and to investigate known and potential tapeworm drug targets in this tapeworm.

RESULTS

The 1.26 Gb draft genome of S. erinaceieuropaei is currently the largest reported for any flatworm. Through investigation of β-tubulin genes, we predict that S. erinaceieuropaei larvae are insensitive to the tapeworm drug albendazole. We find that many putative tapeworm drug targets are also present in S. erinaceieuropaei, allowing possible cross application of new drugs. In comparison to other sequenced tapeworm species we observe expansion of protease classes, and of Kuntiz-type protease inhibitors. Expanded gene families in this tapeworm also include those that are involved in processes that add post-translational diversity to the protein landscape, intracellular transport, transcriptional regulation and detoxification.

CONCLUSIONS

The S. erinaceieuropaei genome begins to give us insight into an order of tapeworms previously uncharacterized at the genome-wide level. From a single clinical case we have begun to sketch a picture of the characteristics of these organisms. Finally, our work represents a significant technological achievement as we present a draft genome sequence of a rare tapeworm, and from a small amount of starting material.

Characterization of Spirometra erinaceieuropaei Plerocercoid Cysteine Protease and Potential Application for Serodiagnosis of Sparganosis

Background

Sparganosis is a neglected but important food-borne parasitic zoonosis. Clinical diagnosis of sparganosis is difficult because there are no specific manifestations. ELISA using plerocercoid crude or excretory–secretory (ES) antigens has high sensitivity but has cross-reactions with other helminthiases. The aim of this study was to characterize Spirometra erinaceieuropaei cysteine protease (SeCP) and to evaluate its potential application for serodiagnosis of sparganosis.

Methodology/Principal Findings

The full length SeCP gene was cloned, and recombinant SeCP (rSeCP) was expressed and purified. Western blotting showed that rSeCP was recognized by the serum of sparganum-infected mice, and anti-rSeCP serum recognized the native SeCP protein of plerocercoid crude or ES antigens. Expression of SeCP was observed at plerocercoid stages but not at the adult and egg stages. Immunolocalization identified SeCP in plerocercoid tegument and parenchymal tissue. The rSeCP had CP activity, and the optimum pH and temperature were 5.5 and 37°C, respectively. Enzymatic activity was significantly inhibited by E-64. rSeCP functions to degrade different proteins and the function was inhibited by anti-rSeCP serum and E-64. Immunization of mice with rSeCP induced Th2-predominant immune responses and anti-rSeCP antibodies had the potential capabilities to kill plerocercoids in an ADCC assay. The sensitivity of rSeCP-ELISA and ES antigen ELISA was 100% when performed on sera of patients with sparganosis. The specificity of rSeCP-ELISA and ES antigen ELISA was 98.22% (166/169) and 87.57% (148/169), respectively (P<0.05).

Conclusions

The rSeCP had the CP enzymatic activity and SeCP seems to be important for the survival of plerocercoids in host. The rSeCP is a potential diagnostic antigen for sparganosis.

Sparganosis is a neglected tropical disease; its diagnosis is difficult and it is often misdiagnosed. ELISA using the crude or ES antigens of plerocercoids cross reacts with other helminthiases. Cysteine protease is a type of hydrolase and plays important roles in the development and survival of parasites; it has been used for diagnostic markers and vaccine targets for some parasitic diseases. In this study, a 36 kDa Spirometra erinaceieuropaei cysteine protease (SeCP) was expressed and purified. The results showed that SeCP was a plerocercoid stage-specific protein located in the teguments and parenchymal tissue. The rSeCP had cysteine protease activity and functioned to degrade host proteins. Vaccination of mice with rSeCP induced high levels of IgG1 and anti-rSeCP antibodies with the ability to kill plerocercoids in an ADCC assay. The rSeCP had a high sensitivity and specificity for detecting anti-plerocercoid antibodies, and could be used as a potential antigen for serodiagnosis of sparganosis.

Sparganosis presenting as pericardial effusion and lung lesions

We herein report a rare form of sparganosis in a 29-year-old man presenting with pericardial effusion and lung lesions. The diagnosis was confirmed by the patient's history of eating inadequately cooked snake, significant elevated eosinophils in the peripheral blood and pericardial effusion, and marked positive reactions against Sparganum mansoni antigen in the serum. After two consecutive doses of praziquantel treatment, the patient's symptoms and laboratory and imaging findings were improved. Both specific antibody detection and follow-up of the patient's eosinophils, serum antibody, and imaging changes are important for sparganosis diagnosis, particularly in cases without a subcutaneous lump or mass.

Scrotal sparganosis mimicking scrotal teratoma in an infant: a case report and literature review

Sparganosis is an infection with a parasitic tapeworm larva that occurs by eating infected foods or drinking contaminated water. The larvae can migrate to a tissue or muscle in the chest, abdominal wall, extremities, eyes, brain, urinary tract, pleura, pericardium, spinal canal, or scrotum. Herein, we report a 5-month old infant with scrotal sparganosis who was initially suspected to have a scrotal inflammatory mass with a history of applying raw frog meat into the umbilicus. Preoperative ultrasound examinations and computed tomography (CT) scanning misdiagnosed the mass as a scrotal teratoma. The scrotal mass was surgically removed, and the histopathology proved it to be scrotal sparganosis. This case displays the youngest patient ever reported with scrotal sparganosis, and the first description of CT characteristics of scrotal sparganosis. A detailed medical history is necessary for patients with scrotal masses suspected of sparganosis. In addition, ultrasound and CT examinations are helpful to rule out other causes of a scrotal mass.

Development of a rapid diagnostic kit that uses an immunochromatographic device to detect antibodies in human sparganosis

A diagnostic kit using an immunochromatographic device was developed to replace the time-consuming immunodiagnostic methods for human sparganosis. The kit was found to be faster and easier to use than an enzyme-linked immunosorbent assay (ELISA) and showed higher sensitivity and specificity. It will be useful for the laboratory diagnosis of hospitalized cases of sparganosis.

Pulmonary sparganosis mansoni: a case report from a non-endemic region

Sparganosis mansoni is a parasitic disease caused by the larva of Spirometra mansoni. It occurs worldwide, but only a few patients show pulmonary involvement. Here, we present a case of pulmonary sparganosis mansoni in a non-endemic region. A 32-year-old Chinese woman presented with intermittent bloody phlegm, peripheral blood eosinophilia, and migratory patch shadows in both lungs. She had been misdiagnosed with eosinophilic pneumonia. She had a history of eating raw frogs, and the sparganum mansoni antibody was positive in both her blood and bronchoalveolar lavage fluid. Several sparganum mansoni were found in a frog sample that the patient provided. Consequently, she was diagnosed with pulmonary sparganosis mansoni. After two oral courses of praziquantel were administered, her symptoms and radiological lesions improved significantly. To our knowledge, this is the first case of pulmonary sparganosis mansoni occuring in Shanghai. Oral praziquantel is effective for the treatment of sparganosis mansoni, although its course of therapy may need to be repeated.

Diagnostic efficacy of a recombinant cysteine protease of Spirometra erinacei larvae for serodiagnosis of sparganosis

The mature domain of a cysteine protease of Spirometra erinacei plerocercoid larva (i.e., sparganum) was expressed in Escherichia coli, and its value as an antigen for the serodiagnosis of sparganosis was investigated. The recombinant protein (rSepCp-1) has the molecular weight of 23.4 kDa, and strongly reacted with the sparganum positive human or mice sera but not with negative sera by immunoblotting. ELISA with rSepCp-1 protein or sparganum crude antigen (SeC) was evaluated for the serodiagnosis of sparganosis using patient's sera. The sensitivity and specificity of ELISA using rSepCp-1 protein were 95.0% (19/20) and 99.1% (111/112), respectively. In contrast, the sensitivity and specificity of ELISA with SeC were 100% (20/20) and 96.4% (108/112), respectively. Moreover, in experimentally infected mice, the sensitivity and specificity of both ELISA assays were 100% for the detection of anti-sparganum IgG. It is suggested that the rSepCp-1 protein-based ELISA could provide a highly sensitive and specific assay for the diagnosis of sparganosis.

Retrospective epidemiological analysis of sparganosis in mainland China from 1959 to 2012

In this study, epidemiological factors of sparganosis cases reported in mainland China from 1959 to December 2012 were analysed. A total of 1061 valid cases were distributed throughout most of the provinces of mainland China, with most cases occurring in Southern and Eastern China. The average age of patients was 29 years (range 0–80 years). Modes of transmission to humans were via contact (54·6%), mainly by application of frog meat as a poultice, foodborne (33·8%), mainly through ingesting frogs or snakes, and waterborne (11·5%) through drinking raw water. The tissue/organs involved were subcutaneous/muscle (43·1%), eyes (31·0%), central nervous system (CNS) (17·9%), urogenital system (3·9%) and visceral organs (3·2%). Obvious differences existed in main risk factors for different areas. Close correlation was found between tissue/organs and risk factors. Main modes of transmission changed during the past decades, from contact (83·8% pre-1979) to foodborne (63·9% post-2000). The tissue/organs involved also changed at the same time. Cases involving eyes fell from 50·0% pre-1979 to 8·3% post-2000, and cases involving CNS increased from 0% pre-1979 to 47·8% post-2000. These results illustrate that China is one of the main epidemic countries of sparganosis in the world. Consumption of frog/snake meat was the main risk factor, although application of frog flesh as a poultice was the main risk factor before 2000. Sparganosis has become one of the neglected but important foodborne/waterborne parasitic diseases in mainland China.