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.

[Efficacy of albendazole for treatment of mice infected with Sparganum mansoni].

In order to observe the efficacy of albendazole for the treatment of mice infected with Sparganum mansoni, a total of 72 mice were divided into 8 groups (9 mice each), each mouse was orally infected with 5 plerocercoid. At one week after infection, groups A-C were treated with a 7-day course of albendazole (1700, 2500, and 3300 mg/kg, twice daily), and sacrificed at 1 week post-treatment; groups E-G were treated with the second course of albendazole with the same dosage at 1 week interval after the first course, and sacrificed at 1 week after the second course; the groups D and H were used as control for A-C and E-G, respectively. After the infected mice were sacrificed, the mean number of worms recovered was observed and worm reduction rate was determined. When treating with one course of albendazole at 1 week post infection, the worm reduction rate in groups A-C was 20.0%, 20.0% and 24.9%, respectively (chi2 = 0.351, P > 0.05). After treatment with two courses of albendazole, the worm reduction rate in groups E-G was 22.3%, 36.4% and 31.9% (chi2 = 1.812, P > 0.05). The difference of the worm reduction rate in the infected mice treated with 1 and 2 courses of albendazole showed no statistical significance (P > 0.05). The results indicated albendazole has no obvious efficacy for treating sparganosis in mice.

[A case of Sparganum mansoni infection induced by eating live frogs].

A case of Sparganum mansoni infection induced by having live frogs in other city was reported in Nantong City, Jiangsu Province. The patient was treated with praziquantel and the effect was satisfactory.

Proliferative sparganosis in a dog.

CASE DESCRIPTION: A 21-month-old spayed female Border Collie was examined because of progressive right forelimb lameness, signs of pain, and subcutaneous edema. The dog lived in a fenced yard in Tampa, Fla, that contained a small area of marshy terrain. CLINICAL FINDINGS: The subcutis and intermuscular fascia contained multiple cystic cavities filled with larval cestodes (plerocercoids or spargana) and cloudy red fluid. Parasites were identified morphologically and by DNA sequence analysis as pseudophyllidean cestodes, most likely Sparganum proliferum. The dog developed a progressively worsening fever, dyspnea, mature neutrophilia, and hypoproteinemia. Septic pleuritis and peritonitis complicated the later stages of the disease. TREATMENT AND OUTCOME: Treatment with praziquantel, fenbendazole, and nitazoxanide failed to control the proliferation and dissemination of larval cestodes. The dog was euthanatized after 133 days of treatment. At necropsy, numerous parasitic tissue cysts were present in the subcutis and intermuscular fascia; these cysts were most abundant in the soft tissues of the forelimbs and cervical musculature. The pleural and peritoneal cavities contained multiple larval cestodes and were characterized by neutrophilic inflammation and secondary bacterial infection. CLINICAL RELEVANCE: Findings indicated that clinical signs associated with proliferative sparganosis in dogs may be rapidly progressive and that the condition may be refractory to antiparasitic treatment. Veterinarians should be aware of this zoonotic, water-borne agent.

A 78 kDa glucose-regulated protein gene of Spirometra erinacei plerocercoid induced by chemical and physiological stresses.

To adapt to different environmental conditions between poikilothermic and homeothermic hosts, the plerocercoid of Spirometra erinacei (sparganum) might express a variety of biologically active molecules. We have identified a 78 kDa glucose-regulated protein of the sparganum (SpGrp78) by differential display of mRNA, employing RNAs each from sparganum adjusted at 9 degrees C and 37 degrees C. A full-length cDNA of 2148 bp encodes for a protein of 651 amino acids with a predicted molecular mass of 71 610 Da and shares molecular characteristics with heat-shock protein 70, including a putative ATP binding site, signal peptide cleavage site and endoplasmic reticulum retention signal. Phylogenetic analysis revealed that SpGrp78 was mostly related to those of Echinococcus multilocularis and E. granulosus. Expression of SpGrp78 mRNA increased approximately 7-fold by inhibition of glycosylation by tunicamycin, 2-fold by temperature-shift from 9 degrees C to 37 degrees C and slightly by pH-shift to 4.0 or 5.5. These results suggested that induction of SpGrp78 mRNA is related to the functional role of SpGrp78 as a molecular chaperone when the parasite adapts to a new host environment.

[Infectivity of the sparganum treated by praziquantel, gamma-irradiation and mechanical cutting].

An experimental study was performed to observe the infectivity of sparganum (plerocercoid of Spirometra erinacei) treated by praziquantel, gamma-irradiation and mechanical cutting. The spargana were obtained from the naturally infected European grass snake, Rhabdophis tigrina, or from the experimentally infected mice. A total of 83 mice (ICR strain) were divided into 3 experimental groups by the source of the damage, fed each with 5 spargana, and sacrificed 1 month later for worm recovery. In the praziquantel group, the worms were incubated in the concentration of 10 micrograms/ml (control: Tyrode for 4 hours) for 0.5, 1, 2 and 4 hours at 36 degrees C, and fed to mice. The recovery rate from mice in praziquantel group was not different from that (80%) of control group and in the range of 76-100%. In the gamma-irradiation group, the worms were irradiated by 10-1000 Gy with Cs137. The average recovery rates of 69-100% were not different from that of control up to 100 Gy. The rate was 56% under 150 Gy, and 5% by 1000 Gy. In the mechanical cutting group, the worms were cut at 0.5, 1, 2 and 3 mm from the anterior end of the scolex. The average recovery rates in each group were 70-90% and that of control was 90%. The present finding suggests that the sparganum be highly resistant to praziquantel, gamma-irradiation and mechanical cutting. The vitality center of the sparganum must be at the anterior end of its scolex.