Neuroschistosomiasis due to Schistosoma mansoni: a review of pathogenesis, clinical syndromes and diagnostic approaches

Pediatric Spinal Neuroschistosomiasis in Yemen: An Overlooked Dilemma in an Endemic Region

BACKGROUND

Neurological involvement in schistosomiasis presents a significant and serious complication. While the disease is generally considered treatable during the early stages, the rarity of this condition often leads to delays in diagnosis and treatment. This study aims to report the clinical characteristics of pediatric patients with spinal neuroschistosomiasis (NS) in an endemic area to the disease.

METHODS

A retrospective cross-sectional review was conducted at Althora General Hospital in Ibb, Yemen, from January 2016 to January 2021. The study examined confirmed pediatric cases of spinal NS, analyzing their clinical characteristics, laboratory and radiological data, treatment approaches, and complications.

RESULTS

The study identified 10 cases of spinal NS with a mean age of 10.1± 3.2 years. The majority (90%) were male and from rural areas, all with a history of freshwater exposure, a known risk factor for schistosomiasis. The average time from presentation to treatment was 33.4± 45.6 days (7-150 days). Common symptoms observed in all patients were bladder dysfunction and paresthesia (100%). Intestinal dysfunction was prevalent in 90% of cases, while 80% exhibited limb weakness or inability to walk. The diagnosis was confirmed through cerebrospinal fluid (CSF) serology in 80% of cases, and stool and urine exams yielded positive results in 90% and 30% of cases, respectively. Magnetic Resonance Imaging findings revealed medullary lesions in 50% of cases, cauda equina lesions in 20%, and multiple lesions in 30%. All patients received oral praziquantel and high-dose steroids for at least three days as part of their initial treatment. During the average follow-up period of 5.6±1.7 months, one patient experienced lower extremity paraplegia, while two cases (20%) showed partial improvement with residual deficits including urinary and fecal incontinence. Complete resolution of symptoms was achieved in seven cases (70%).

CONCLUSION

Schistosomiasis should be considered in pediatric patients with myeloradicular manifestations, especially in endemic areas. Early identification can be achieved through history, prompt imaging, and CSF serology. In the absence of immediate test results, expert-guided presumptive therapy should be considered to minimize neurological complications.

Encephalic Schistosoma japonicum resembles brainstem neoplasm: Case report and literature review

Encephalic schistosomiasis is a rare and severe parasitic disease which manifests as granuloma formation around ectopic eggs that migrate to the brain. We present a rare case of a pseudotumoral form of Schistosoma japonicum in the brainstem that was initially misidentified as a malignant tumor. The patient presented with intermittent headaches, diplopia, and left limb weakness. Neurological examination revealed hypoesthesia of the left lower limb, limitation of right eye abduction, and decreased muscle strength of the left upper limb. The cerebrospinal fluid tested positive for antibodies against S. japonicum. After standard treatment for schistosomiasis, the patient achieved complete remission. This case highlights that encephalic schistosomiasis can occur in the brainstem and resemble a neoplasm on magnetic resonance imaging. Once diagnosed, however, complete remission is achievable by non-invasive medical treatment.

Neuro-schistosomiasis with palm tree contrast enhancement pattern, a report of three cases, and review of literature

We describe three cases of neuroschistosomiasis, two cases with cerebral schistosomiasis due to Schistosoma japonicum, with multiple pseudotumoral lesions presented with seizures and hemiparesis respectively, and a spinal cord conus medullaris schistosomiasis due to Schistosoma mansoni presented with conus medullaris syndrome. In the two cases with cerebral schistosomiasis imaging with CT revealed multiple areas of brain edema, and gyriform calcifications in both cerebral hemispheres, which suggested cerebral parasitemia, chronic venous hypertension, multifocal cerebral vascular malformation, or a forme fruste Sturge Weber syndrome. Further MRI revealed corresponding blooming, T2W (weighted) -FLAIR (fluid attenuated inversion recovery) ibright signal intensity and enhancing lesions. In the third case with spinal cord involvement MRI revealed signal abnormality on T1W and T2W images with patchy and punctate post i.v. contrast enhancement of the conus medullaris. Excision biopsy and histopathological examination were undertaken for the first brain case and spinal cord case and showed multiple schistosomal granulomas in different evolution phases. In the second brain case, the diagnosis was suggested based on our experience with prior cases, positive laboratory tests, and urinary bladder wall biopsy. Neuroschistosomiasis must be considered in the differential diagnosis of multiple cerebral calcifications, and multiple nodular and linear like lesions with characteristic arborized enhancement pattern, especially for patients coming from endemic areas for Schistosomiasis.

Structure determination and analyses of the GAPDH from the parasite Schistosoma mansoni, the first one from a platyhelminth

The enzyme Glyceraldehyde-3-Phosphate Dehydrogenase from Schistosoma mansoni (SmGAPDH) is characterized as a therapeutical target for schistosomiasis. In this context, we report here the experimental structure, structural analyses and comparisons of SmGAPDH, the first one from a Platyhelminth. The enzyme was expressed, purified and assayed for crystallization, what allowed the obtainment of crystals of sufficient quality to collect X-ray diffraction data up to 2.51 Å resolution. SmGAPDH is the only GAPDH to present the sequence NNR (its residues 114-116) which leads to (especially R116) a hydrogen bond network that possibly reflects on the flexibility of residues to interact with the adenine part of NAD⁺, speculated to be important for differential drug design.

Intramedullary spinal schistosomiasis in a child with acute myelopathy: A case report

Background:

Neuroschistosomiasis is defined as an infection of the nervous system caused by Schistosoma mansoni. Neuroschistosomiasis is an important differential diagnostic consideration in pediatric patients presenting with myelopathy. Surgical excision combined with antiparasitic drugs typically provides a satisfactory outcome and often results in neurological recovery.

Case Description:

A 4-year-old child presented with acute and progressive myelopathy. A thoracolumbar magnetic resonance image revealed a T12-L2 conus medullaris mass that was isointense on T1 and hyperintense on T2 (with an extensive syringomyelia at the thoracic spinal cord) and showed enhanced heterogeneity with gadolinium. The lesion was excised through T12-L2 laminotomy. Intraoperatively, the tumor appeared reddish and infiltrative. The frozen section suggested a granulomatous process, while the final pathology confirmed conus medullaris schistosomiasis.

Conclusion:

Schistosomal myeloradiculopathy should be considered among the different diagnosis in children presenting with lower thoracic region, conus medullaris, and/or cauda equina infiltrative spinal masses.

Spinal neuroschistosomiasis caused by Schistoma mansoni: cases reported in two brothers

Background

Spinal neuroschistosomiasis (SN) is one of the most severe clinical presentations of schistosomiasis infection and an ectopic form of the disease caused by any species of Schistosoma. In Brazil, all cases of this clinical manifestation are related to Schistosoma mansoni, the only species present in the country. Although many cases have been reported in various endemic areas in Brazil, this is the first time in the literature that SN is described in two brothers.

Case presentation

Two cases of SN were accidentally diagnosed during an epidemiological survey in an urban area endemic for schistosomiasis transmission. Both patients complained of low back pain and muscle weakness in the lower limbs. Sphincter dysfunction and various degrees of paresthesia were also reported. The patients’ disease was classified as hepato-intestinal stage schistosomiasis mansoni at the onset of the chronic form. A positive parasitological stool test for S. mansoni, clinical evidence of myeloradicular damage and exclusion of other causes of damage were the basic criteria for diagnosis. After treatment with praziquantel and corticosteroid, the patients presented an improvement in symptoms, although some complaints persisted.

Conclusions

It is important to consider SN when patients come from areas endemic for transmission of schistosomiasis mansoni. Clinical physicians and neurologists should consider this diagnostic hypothesis, because recovery from neurological injuries is directly related to early treatment. As, described here in two brothers, a genetic predisposition may be related to neurological involvement. Primary care physicians should thus try to evaluate family members and close relatives in order to arrive at prompt schistosomiasis diagnosis in asymptomatic individuals and propose treatment in an attempt to avoid progression to SN.

Does physical exercise influence in the development of neuroeschistosomiasis?

Neuroschistosomiasis is a severe form of presentation of schistosomiasis in which Schistosoma spp. affects the central nervous system. This is the first study performed to analyze whether there is any relationship between physical effort and the appearance of neuroschistosomiasis, through clinical, molecular and immunological evaluations. An experimental controlled study using 64 male Balb/c inbred mice divided into four groups according to presence or absence of S. mansoni infection and submitted to physical effort or resting was conducted. Thirteen weeks after exercise training, S. mansoni DNA was detected in the brain or spinal cord in about 30% of the infected animals moreover, only S. mansoni-positive samples showed positive labeling for S. mansoni antigens in the brain or spinal cord, with a striking reaction inside the microglia. However, the behavioral tests did not show any clinical symptoms of neuroschistosomiasis in animals submitted to physical effort or in resting. In animals with S. mansoni-positive DNA, immunohistochemical data revealed astrogliosis and microgliosis, elevated IL-10 levels and decreased TNF-α expression. This study demonstrated that isometric exercise does not promote neuroschistosomiasis, furthermore, ectopic forms of schistosomiasis in the central nervous system were largely asymptomatic and exhibited a Th2 immune response profile. More experimental studies are necessary in order to characterize the pathological process of experimental neuroschistosomiasis.

Cerebral schistosomiasis: Case series from Qatar

Schistosomiasis is the third most widespread devastating parasitic disease worldwide and has a high mortality burden. Neuroschistosomiasis is one of the rare and most severe clinical presentations of the disease. It is caused by granuloma formation around eggs that lodge in the central nervous system, with Schistosoma japonicum usually causing most reported cerebral disease. Three unusual presentations of schistosomiasis in Qatar are described herein. The three patients were young males who presented with seizures and tumor-like lesions on brain imaging. The diagnosis was confirmed by biopsy, which showed necrotizing granulomas containing Schistosoma eggs. These cases raise awareness of neuroschistosomiasis as a potential cause of tumor-like brain lesions in migrants and returning travelers from endemic areas.

PREVENTING THE SPREAD OF SCHISTOSOMIASIS IN GHANA: POSSIBLE OUTCOMES OF INTEGRATED OPTIMAL CONTROL STRATEGIES

The goal of a future free from schistosomiasis in Ghana can be achieved through integrated strategies, targeting simultaneously several stages of the life cycle of the schistosome parasite. In this paper, the transmission of schistosomiasis is modeled as a multi-scale 12-dimensional system of ODEs that includes vector-host and within-host dynamics of infection. An explicit expression for the basic reproduction number [Formula: see text] is obtained via the next generation method, this expression being interpreted in biological terms, as well as in terms of reproductive numbers for each type of interaction involved. After discussing the stability of the disease-free equilibrium and the existence and uniqueness of the endemic equilibrium, the Center Manifold Theory is used to show that for values of [Formula: see text] larger than 1, but close to 1, the unique endemic equilibrium is locally asymptotically stable. A sensitivity analysis indicates that [Formula: see text] is most sensitive to the natural death rate of the vector population, while numerical simulations of optimal control strategies reveal that the most effective strategy for the control and possible elimination of schistosomiasis should combine sanitary measures (access to safe water, improved sanitation and hygiene education), large-scale treatment of infected population and vector control measures (via the use of molluscicides), for a significant amount of time.

Delayed presentation of cerebral schistosomiasis presenting as a tumor-like brain lesion

Schistosomiasis is the second most common parasitic infection worldwide. North America is a nonendemic area. However, there are occasional case reports among travelers and immigrants from endemic regions. We describe a case of a 55-year-old Canadian woman who presented with first episode of seizure. Her magnetic resonance imaging scan revealed a mass-like lesion involving the left anterior temporal lobe. The lesion showed T1 hypo- and T2 hyperintense with perilesional brain edema. On post-gadolinium-enhanced T1-weighted sequence, the lesion showed multiple small nodular and linear enhancements, also called an "arborized" appearance. Initially, the lesion was thought to be a malignant tumor. She underwent left anterior temporal lobe resection. Histologic examination showed parasitic eggs with a characteristic lateral spine consistent with Schistosoma mansoni infection. Upon subsequent questioning, it was revealed that the patient lived in Ghana from the ages of 8-10 years and she visited Ghana again 10 years prior for two weeks. She recalled swimming in beaches and rivers. Latent disease, as in this case with presentation, many years or decades after presumed exposure is rare but has been reported. Characteristic magnetic resonance imaging findings may suggest the diagnosis and facilitate noninvasive work-up.

Immunological Profile in Individuals with Schistosomal Myeloradiculopathy

BACKGROUND

Schistosomal myeloradiculopathy (SMR) is the most serious ectopic presentation of Schistosoma mansoni infection. The pathogenesis occurs mainly via the host inflammatory response to the eggs of the parasite that are stuck in the central nervous system, and the diagnosis is generally made by the exclusion of other neurological diseases.

OBJECTIVE

We aimed to evaluate the immune status of SMR patients and to identify a marker for SMR diagnosis.

METHODS

We enrolled 15 patients with a presumptive diagnosis of SMR, and the control groups included 17 patients with myelopathy associated with human T cell lymphotropic virus type 1 (HTLV-1) and 11 with other neurological disorders. The determination of soluble egg antigen-specific IgE and the levels of cytokines from Th1, Th2, Th17 and T-regulatory cell profiles and the chemokines MIP-1a and RANTES were measured in the cerebrospinal fluid (CSF) and serum using an ELISA technique.

RESULTS

We observed that SMR leads to an increase in IgE levels in the CSF compared to serum, and the levels of IL-13 and MIP-1α were significantly higher in the CSF and serum of the SMR patients than in the patients with HTLV-1-associated myelopathy. The levels of MIP-1α and RANTES were higher in the CSF than in the serum of the SMR group. The ratio between levels of IL-13, MIP-1α and RANTES over IL-10 was positive in the CSF of the SMR patients.

CONCLUSIONS

These results indicate that S. mansoni-specific IgE in the CSF is a promising marker for the diagnosis of SMR and that the cytokines and chemokines associated with the Th2 profile may be important factors in the immunopathogenesis of SMR.

Bacterial, Fungal, and Parasitic Infections of the Central Nervous System: Radiologic-Pathologic Correlation and Historical Perspectives

Despite remarkable progress in prevention and treatment, infectious diseases affecting the central nervous system remain an important source of morbidity and mortality, particularly in less-developed countries and in immunocompromised persons. Bacterial, fungal, and parasitic pathogens are derived from living organisms and affect the brain, spinal cord, or meninges. Infections due to these pathogens are associated with a variety of neuroimaging patterns that can be appreciated at magnetic resonance imaging in most cases. Bacterial infections, most often due to Streptococcus, Haemophilus, and Neisseria species, cause significant meningitis, whereas the less common cerebritis and subsequent abscess formation have well-documented progression, with increasingly prominent altered signal intensity and corresponding contrast enhancement. Atypical bacterial infections are characterized by the development of a granulomatous response, classically seen in tuberculosis, in which the tuberculoma is the most common parenchymal form of the disease; spirochetal and rickettsial diseases are less common. Fungal infections predominate in immunocompromised hosts and are caused by yeasts, molds, and dimorphic fungi. Cryptococcal meningitis is the most common fungal infection, whereas candidiasis is the most common nosocomial infection. Mucormycosis and aspergillosis are characterized by angioinvasiveness and are associated with high morbidity and mortality among immunocompromised patients. In terms of potential exposure in the worldwide population, parasitic infections, including neurocysticercosis, toxoplasmosis, echinococcosis, malaria, and schistosomiasis, are the greatest threat. Rare amebic infections are noteworthy for their extreme virulence and high mortality. The objective of this article is to highlight the characteristic neuroimaging manifestations of bacterial, fungal, and parasitic diseases, with emphasis on radiologic-pathologic correlation and historical perspectives.

Spinal neuroschistosomiasis

We report a 20-year-old woman with a diagnosis of spinal neuroschistosomiasis that was confirmed histologically. Magnetic resonance imaging demonstrated an expanded, oedematous conus with intrinsic heterogeneous enhancement, which was initially thought to be a neoplastic lesion. This case demonstrates an alternative diagnosis to oncological lesions of the spinal cord which should be considered in patients who have recently travelled to endemic areas.

Biochemical and Parasitological Studies on the Effect of hUCB-Selected CD34(+) Progenitor/Stem Cells in Mice Infected with Schistosoma mansoni

Background and Objectives:

Placenta and blood that remained in the umbilical cord is routinely available as a discarded tissue after deliveries and it is free of any legal, moral, ethical or religious objections, providing a high number of multipotent CD34⁺ progenitor and stem cells. Using ex vivo isolated CD34⁺ cells from human umbilical cord blood (hUCB) have emerged as promising candidates to treat various diseases, including exogenous pathogenic infections. We have expanded to build a rational approach to study the effect of CD34⁺ cells after damaged liver tissues by the devastating human parasitic flatworm Schistosoma mansoni.

Methods and Results:

Experimental studies were conducted in the Department of Zoology, Faculty of Science and Departments of Parasitology and Physiology, Faculty of Medicine, SCU, Egypt. We have studied the impact of ex vivo preparation of CD34⁺ cells from hUCB on S. mansoni-induced liver fibrosis de novo, and treated for shorter and longer periods in vivo. Ova count, ALT and albumin were measured at specific time interval and histopathological examination of liver was conducted to confirm the biochemical results. The data obtained were statistically analyzed by ANOVA between groups. It was found that the administration of CD34⁺ cells have modestly reduced liver damage; reduced the S. mansoni infection associated elevation in serum levels of ALT; significantly improved serum levels of albumin and reduced egg granuloma diameter in the livers.

Conclusions:

We demonstrated that CD34⁺ cells can markedly ameliorated liver fibrosis in vivo and may be beneficial for therapy to recover organ structure and/or function of S. mansoni-infected mice.

Prevention and control of schistosomiasis: a current perspective

Schistosomiasis is a neglected tropical disease that ranks second only to malaria in terms of human suffering in the tropics and subtropics. Five species are known to infect man and there are currently over 240 million people infected worldwide. The cornerstone of control to date has been mass drug administration with 40 mg/kg of praziquantel but there are problems with this approach. Human and bovine vaccines are in various stages of development. Integrated control, targeting the life cycle, is the only approach that will lead to sustainability and future elimination.

Medullary schistosomiasis

Background:

Schistosomal infestation of the central nervous system is a rare cause of cord compression, although a predominant one in endemic areas.

Case Description:

A 38-year-old male, native of Ivory Coast, with a history of 1 month of progressive paraparesis, neurogenic bladder, diminished deep tendon reflexes of the lower limbs, and sensory level. The magnetic resonance imaging (MRI) showed a medullary lesion at D4-D5 level, suggestive of an intramedullary tumor. Laminotomy of D3 to D5 and excision of a grayish white lesion according to a preliminary histopathologic review suggestive of a high grade glioma. Definitive histopathology review established the diagnosis of medullary schistosomiasis.

Conclusion:

Schistosomal myeloradiculopathy should be considered in patients presenting with cord compression or features of transverse myelitis, especially in patients from endemic areas or low social economic settlements.

Neuroschistosomiasis mansoni: literature review and guidelines

BACKGROUND

Schistosomiasis is a tropical disease caused by worms of the genus Schistosoma. It is endemic in the Caribbean Islands, the middle east, eastern Asia, South America, and Africa. In nonendemic areas, physicians should be aware of this condition in travelers returning from endemic areas and in immigrants. The main disease-causing species are Schistosoma haematobium, Schistosoma mansoni, and Schistosoma japonicum. Neuroschistosomiasis is an ectopic form of the disease that is mainly associated with S. japonicum infection. Involvement of the central nervous system (CNS) in S. mansoni infection is neglected and underestimated. Neuroschistosomiasis mansoni can be classified into cerebral, spinal, and encephalomyelitic forms in the course of an acute or chronic infection.

REVIEW SUMMARY

We review the CNS involvement by S. mansoni infection with an emphasis on life cycle, epidemiology, pathophysiology and immunology, clinical manifestations, diagnostic criteria, differential diagnosis, current treatment guidelines, and prognosis.

CONCLUSIONS

Although an underreported CNS infection, found mainly in underdeveloped countries, neuroschistosomiasis mansoni still causes significant incapacity and morbidity. Hence, neurologists should become familiar with this infection worldwide and include it in the differential diagnosis of CNS involvement in travelers returning from endemic areas and in immigrants.

Schistosomiasis of the nervous system

Schistosomiasis is a parasitic disease caused by blood flukes of the genus Schistosoma. Currently 200 million people worldwide are infected. Neurological manifestations are a result of the inflammatory response of the host to egg deposition in the brain and spinal cord and is usually seen in patients with recent infection with no evidence of systemic illness. Cerebral and cerebellar disease can result in headache, seizure, and increased intracranial pressure. Cerebral schistosomiasis is more common in Schistosoma japonicum, but increasing cases due to Schistosoma mansoni are being reported in the literature. Other complications of cerebral schistosomiasis include delirium, loss of consciousness, visual field impairment, focal motor deficits, and ataxia. Myelopathy is the most common neurological manifestation of Schistosoma mansoni and the conus medullaris and cauda equine are the most common sites of involvement. Severe disease can result in flaccid paraplegia with areflexia, sphincter dysfunction, and sensory disturbance. Early recognition and prompt treatment are essential when physicians are faced with schistosomiasis involving the central nervous system. Schistosomicidal drugs, such as praziquantel, steroids and surgery, are the mainstay of therapy for this severe form of schistosomiasis.

Brain magnetic resonance imaging findings in young patients with hepatosplenic schistosomiasis mansoni without overt symptoms

The purpose of this study was to describe the brain magnetic resonance imaging (MRI) findings in young patients with hepatosplenic schistosomiasis mansoni without overt neurologic manifestations. This study included 34 young persons (age range = 9-25 years) with hepatosplenic schistosomiasis mansoni who had been previously treated. Patients were scanned on a 1.5-T system that included multiplanar pre-contrast and post-contrast sequences, and reports were completed by two radiologists after a consensus review. Twenty (58.8%) patients had MRI signal changes that were believed to be related to schistosomiasis mansoni. Twelve of the 20 patients had small focal hyperintensities on T2WI in the cerebral white matter, and eight patients had symmetric hyperintense basal ganglia on T1WI. There was a high frequency of brain MRI signal abnormalities in this series. Although not specific, these findings may be related to schistosomiasis.

Neuroschistosomiasis due to Schistosoma haematobium presenting as spinal cord tumor

Schistosomiasis is rarely encountered in the United States, but immigration and travel to endemic areas make it important to know its various presentations to improve diagnosis and treatment. We present our experience with a child with Schistosoma haematobium pseudotumor, initially diagnosed as a cord neoplasm.

Cerebral neuroschistosomiasis: a rare clinical presentation and review of the literature

The symptomatic presentation of cerebral schistosomiasis is uncommon. The case of a 25-year-old woman from Equatorial Guinea with headache and seizures secondary to cerebral neuroschistosomiasis, as confirmed by histopathological examination and microbiological study, is presented. A review of the literature on this subject is also provided.

Panorganismal metabolic response modeling of an experimental Echinostoma caproni infection in the mouse

Metabolic profiling of host tissues and biofluids during parasitic infections can reveal new biomarker information and aid the elucidation of mechanisms of disease. The multicompartmental metabolic effects of an experimental Echinostoma caproni infection have been characterized in 12 outbred female mice infected orally with 30 E. caproni metacercariae each, using a further 12 uninfected animals as a control group. Mice were killed 36 days postinfection and brain, intestine (colon, ileum, jejeunum), kidney, liver, and spleen were removed. Metabolic profiles of tissue samples were measured using high-resolution magic angle spinning (1)H NMR spectroscopy and biofluids measured by applying conventional (1)H NMR spectroscopy. Spectral data were analyzed via principal component analysis, partial least-squares-derived methods and hierarchical projection analyses. Infection-induced metabolic changes in the tissues were correlated with altered metabolite concentrations in the biofluids (urine, plasma, fecal water) using hierarchical modeling and correlation analyses. Metabolic descriptors of infection were identified in liver, renal cortex, intestinal tissues but not in spleen, brain or renal medulla. The main physiological change observed in the mouse was malabsorption in the small intestine, which was evidenced by decreased levels of various amino acids in the ileum, for example, alanine, taurine, glutamine, and branched chain amino acids. Furthermore, altered gut microbial activity or composition was reflected by increased levels of trimethylamine in the colon. Our modeling approach facilitated in-depth appraisal of the covariation of the metabolic profiles of different biological matrices and found that urine and plasma most closely reflected changes in ileal compartments. In conclusion, an E. caproni infection not only results in direct localized (ileum and jejenum) effects, but also causes remote metabolic changes (colon and several peripheral organs), and therefore describes the panorganismal metabolic response of the infection.

Clinical characterization of neuroschistosomiasis due to Schistosoma mansoni and its treatment

The involvement of the central nervous system (CNS) by Schistosoma mansoni may or may not cause clinical manifestations. When symptomatic, neuroschistosomiasis mansoni (NSM) is one of the most severe presentations of this infection. The neurological manifestations are due to numerous granulomas grouped in confined areas of the spinal cord or the brain. Considering the symptomatic form, myelopathy is far more frequent than the cerebral disease. Spinal cord NSM presents as a low cord syndrome of acute/subacute progression usually associated with involvement of the cauda esquina roots. Lower limbs pain, weakness and sensory disturbance, and autonomic dysfunctions, particularly bladder dysfunction, are often present. Cerebrospinal fluid (CSF) examination generally shows an inflammatory pattern with or without eosinophils and/or IgG against schistosomal antigens. Magnetic resonance imaging (MRI) demonstrates signs of inflammatory myelopathy. Cerebral NSM presents as a slow-expanding intracranial tumor-like lesion. Its clinical manifestations are variable and depend on the increased intracranial pressure and on the site of the lesion. The diagnosis of spinal cord NSM is based on clinical evidence whereas the cerebral disease is usually diagnosed by biopsy of the nervous tissue. There is no consensus on the treatment of NSM. We discuss the literature data on this topic, and suggest a therapeutic approach based on our experience with 69 spinal cord NSM patients who have been followed up by a long period of time. Outcome is largely dependent on early treatment, particularly in the medullar disorder, and is better in cerebral NSM.

The effect of the number of stool samples on the observed prevalence and the infection intensity with Schistosoma mansoni among a population in an area of low transmission

Examination of faecal material by Kato Katz (KK) technique is a widely used approach for the diagnosis of intestinal schistosomiasis, particularly in epidemiological surveys. However, this technique lacks diagnostic sensitivity in individuals with low infection intensity or in low endemic areas. In the total population (TP) of 1265 individuals prevalence and infection intensity were established by examining two KK slides. A representative subset of 305 individuals, denominated experimental group (EG), was defined to assess the comparative advantage of an increased sampling effort using the KK technique. In addition stools of the participants of the EG were examined by the formol ether centrifugation technique. The proportion of all positive stool examinations detected by both methods among the experimental group served as reference value for prevalence (diagnostic 'gold' standard). Prevalence of schistosomiasis among TP based on two KK slides was 12.5%. Prevalence among the EG varied from 13.8%, based on one KK slide, over 27.2 based on 10 KK slides of three stool samples to 35.4% as value for the diagnostic 'gold' standard. The comparison of values for prevalence, stratified by age, revealed significant elevated numbers for all age groups, and interestingly, an extension of the highest prevalence levels until an age of 50 years. The overall infection intensity in eggs per gram (epg), calculated as geometric mean, was 83 epg for the TP based on one KK slide, 78 epg for the GE based on one KK slide and 28 epg based on 10 KK slides of three stool samples. In summary our data demonstrate that control programmes based on the examination of a single KK slide, as it is the case in Brazil, tend to underestimate significantly the prevalence and overestimate infection intensity. This applies especially for low endemic areas, where the efficacy and cost-effectiveness of such programmes become questionable. Our data also indicate that the possible solution of this problem lies in targeted mass treatment including age groups with the highest proportions of those infected. This will give high sensitivity together with sustainability and suitability under field conditions.

Intramedullary schistosomiasis presenting in an adolescent with prolonged intermittent back pain

A 14-year-old boy traveling from Guinea presented with a 2-month history of stable lower back pain. His neurologic examination was significant only for mild weakness in the distal lower extremities. He manifested peripheral eosinophilia, and magnetic resonance imagining revealed enlargement of the caudal aspect of the spinal cord and conus. A presumptive diagnosis of spinal schistosomiasis was rendered, and appropriate medication was administered before obtaining positive serology results. The patient's signs rapidly resolved. Spinal schistosomiasis should be considered in the differential diagnosis of any child with back pain and an appropriate travel history.