Simultaneous occurrence of two new myxosporean species infecting the central nervous system of Hypopygus lepturus from Brazil.

This paper describes 2 new myxosporean species, Henneguya lepturus sp. nov. and Thelohanellus lepturus sp. nov., simultaneously infecting the brain and spinal cord of Hypopygus lepturus Hoedeman, 1962 (Teleostei, Hypopomidae) from the Brazilian Amazon (Roraima State). Several spherical cysts of varying dimensions (up to 135 µm) were microscopically observed. The myxospores of H. lepturus sp. nov. measured 25.8 µm in total length, having an ellipsoidal body (12.4 × 6.4 × 2.2 µm) and 2 equal tapering tails (13.4 µm in length). Each of the 2 pyriform polar capsules measured 4.4 × 1.6 µm and possessed a polar filament coiled in 8-9 turns. The myxospores of T. lepturus sp. nov. were pyriform, formed by 2 equal valves (17.7 × 9.1 × 4.3 µm) surrounding a single polar capsule (10.9 × 3.5 µm) that had a coiled polar filament with 13-16 turns and a binucleated sporoplasm that contained several circular sporoplasmosomes. Molecular analysis of the small subunit (SSU) rRNA gene sequences of these 2 species were in agreement with the taxonomic classification derived from the ultrastructure of the myxospores. Histopathology of the host tissue showed degradation of the myelinated axons surrounding the cysts of both species, with the hosts displaying behavioural changes and erratic movements when observed in an aquarium.

Eosinophilic meningitis caused by Angiostrongylus cantonensis: an emergent disease in Brazil.

Eosinophilic meningitis (EoM) is an acute disease that affects the central nervous system. It is primarily caused by infection with the nematode Angiostrongylus cantonensis. This infection was previously restricted to certain Asian countries and the Pacific Islands, but it was first reported in Brazil in 2007. Since then, intermediate and definitive hosts infected with A. cantonensis have been identified within the urban areas of many states in Brazil, including those in the northern, northeastern, southeastern and southern regions. The goals of this review are to draw the attention of the medical community and health centres to the emergence of EoM in Brazil, to compile information about several aspects of the human infection and mode of transmission and to provide a short protocol of procedures for the diagnosis of this disease.

Parasitoses with central nervous system involvement.

Most of the parasitoses manifest systemically, including the central nervous system (CNS). Among the most prevalent parasitoses in Central Europe (cysticercosis, toxocarosis, echinococcosis, and toxoplasmosis), cerebral involvement is well recognized and part of the clinical presentation, which cannot be neglected. CNS involvement results from invasion of larvae of these parasites via the blood stream or by direct migration into the CNS. Most frequently larvae reside within the cerebral parenchyma, but sometimes also within the ventricles, in the meningeas within cerebral aneurysms, or in the parenchyma of the spinal cord. Depending on the stage of their development, they cause a local defect or more widespread damage, such as encephalitis, ventriculitis, ependymitis, arachnoiditis, meningitis, myelitis, polyradiculitis, mechanical obstruction of the arterial or cerebrospinal fluid (CSF) flow, or vasculitis with appropriate clinical presentations. These include epilepsy, headache, impaired consciousness, orientation, cognition, focal neurological motor, sensory, or vegetative deficits, or visual impairment. CNS involvement is diagnosed on the clinical presentation, the epidemiological background, blood and CSF investigations, imaging studies, and sometimes biopsy. Treatment is based on various antihelminthic agents and, occasionally, surgery.

Parasitoses of the human central nervous system.

Cerebral involvement in parasitoses is an important clinical manifestation of most of the human parasitoses. Parasites that have been described to affect the central nervous system (CNS), either as the dominant or as a collateral feature, include cestodes (Taenia solium (neurocysticerciasis), Echinococcus granulosus (cerebral cystic echinococcosis), E. multilocularis (cerebral alveolar echinococcosis), Spirometra mansoni (neurosparganosis)), nematodes (Toxocara canis and T. cati (neurotoxocariasis), Trichinella spiralis (neurotrichinelliasis), Angiostrongylus cantonensis and A. costaricensis (neuroangiostrongyliasis), Gnathostoma spinigerum (gnathostomiasis)), trematodes (Schistosoma mansoni (cerebral bilharziosis), Paragonimus westermani (neuroparagonimiasis)), or protozoa (Toxoplasma gondii (neurotoxoplasmosis), Acanthamoeba spp. or Balamuthia mandrillaris (granulomatous amoebic encephalitis), Naegleria (primary amoebic meningo-encephalitis), Entamoeba histolytica (brain abscess), Plasmodium falciparum (cerebral malaria), Trypanosoma brucei gambiense/rhodesiense (sleeping sickness) or Trypanosoma cruzi (cerebral Chagas disease)). Adults or larvae of helminths or protozoa enter the CNS and cause meningitis, encephalitis, ventriculitis, myelitis, ischaemic stroke, bleeding, venous thrombosis or cerebral abscess, clinically manifesting as headache, epilepsy, weakness, cognitive decline, impaired consciousness, confusion, coma or focal neurological deficits. Diagnosis of cerebral parasitoses is dependent on the causative agent. Available diagnostic tools include clinical presentation, blood tests (eosinophilia, plasmodia in blood smear, antibodies against the parasite), cerebrospinal fluid (CSF) investigations, imaging findings and occasionally cerebral biopsy. Treatment relies on drugs and sometimes surgery. Outcome of cerebral parasitoses is highly variable, depending on the effect of drugs, whether they are self-limiting (e.g. Angiostrongylus costaricensis) or whether they remain undetected or asymptomatic, like 25% of neurocysticerciasis cases.

[HIV-associated neurocognitive disorders]. / Zaburzenia neuropoznawcze w przebiegu zakazenia wirusem HIV.

HIV infection is an important medical and social problem. In Poland, similarly to other countries, patients with HIV infections are mostly young people. Apart from typical immunologic pathologies, the HIV infection leads to some neurocognitive, motoric and behavioral disorders. The aim of this paper is to present the up-to-date knowledge of HIV-associated neurocognitive disorders (HAND).

Update on eosinophilic meningoencephalitis and its clinical relevance.

Eosinophilic meningoencephalitis is caused by a variety of helminthic infections. These worm-specific infections are named after the causative worm genera, the most common being angiostrongyliasis, gnathostomiasis, toxocariasis, cysticercosis, schistosomiasis, baylisascariasis, and paragonimiasis. Worm parasites enter an organism through ingestion of contaminated water or an intermediate host and can eventually affect the central nervous system (CNS). These infections are potentially serious events leading to sequelae or death, and diagnosis depends on currently limited molecular methods. Identification of parasites in fluids and tissues is rarely possible, while images and clinical examinations do not lead to a definitive diagnosis. Treatment usually requires the concomitant administration of corticoids and anthelminthic drugs, yet new compounds and their extensive and detailed clinical evaluation are much needed. Eosinophilia in fluids may be detected in other infectious and noninfectious conditions, such as neoplastic disease, drug use, and prosthesis reactions. Thus, distinctive identification of eosinophils in fluids is a necessary component in the etiologic diagnosis of CNS infections.

Parasitic diseases of the central nervous system.

Parasitic infections, though endemic to certain regions, have over time appeared in places far removed from their original sites of occurrence facilitated probably by the increase in world travel and the increasing migration of people from their native lands to other, often distant, countries. The frequency of occurrence of some of these diseases has also changed based on a variety of factors, including the presence of intermediate hosts, geographic locations, and climate. One factor that has significantly altered the epidemiology of parasitic diseases within the central nervous system (CNS) is the HIV pandemic. In this review of the pathology of parasitic infections that affect the CNS, each parasite is discussed in the sequence of epidemiology, life cycle, pathogenesis, and pathology.

[Descriptive epidemiology of extrapulmonary hydatid cysts: a report of 265 Tunisian cases]. / Profil epidémiologique descriptif des kystes hydatiques extra pulmonaires: a propos d'une série tunisienne de 265 cas.

BACKGROUND: Hydatidosis is a parasitic endemic disease in Tunisia. The liver and lung are the most common sites of involvement; however, it can develop anywhere in the body. AIM: The aim of the present study was to analyse the epidemiological features of extrapulmonary hydatid cysts and compare our results with those reported in literature. METHODS: A retrospective study of 265 extrapulmonary hydatid cysts collected over the 18-year period from 1990 to 2007 was undertaken. RESULTS: There were 101 male and 164 female patients (sex ratio M/F = 0.61) ranging in age from 2 to 84 years (mean age = 38.7). In our series, hydatid cysts involved mainly the kidney (24.1%), the central nervous system (22.6%), the liver (19.6%) and the spleen (11.3%). The other less frequent sites included the peritoneum (n = 9), heart (n = 9), bone (n = 6), adrenal gland (n = 4), epiploon (n = 4), orbit (n = 4), ovary (n = 3), prostate (n = 2), bladder (n = 2), breast (n = 2), Douglas' cul-de-sac (n = 2), diaphragm (n = 1), testis (n = 1), broad ligament (n = 1), mediastinum (n = 1), nasal cavity (n = 1), soft tissue (n = 1), abdominal wall (n = 1), parotid gland (n = 1), psoas muscle (n = 1), synovia (n = 1), thymus (n = 1) et le pancreas (n = 1). CONCLUSION: In contrast to literature, our results show that hydatid cysts of the kidney and of the central nervous system are more frequent than hepatic location which occupies the 3rd rank.

[Clinical analysis of 78 cases of parasitic encephalopathy].

OBJECTIVE: To investigate the epidemiology, clinical characteristics, therapeutic approaches and outcomes of parasitic encephalopathy. METHODS: A retrospective study was carried out to analyze 78 cases of parasitic encephalopathy in Huashan Hospital between June 2003 and June 2008. RESULTS: There were 52 male and 26 female patients with a mean age of (34.5+/-11.4) years. Among these patients, 32.1% (25/78) had a history of eating raw, neurocysticercosis accounted for 78.2% (61/78), cerebral sparganosis 15.4% (12/78), cerebral paragonimiasis 3.8% (3/78), and cerebral toxoplasmosis 2.6% (2/78). The common clinical features were epilepsy, headache, nausea, vomiting, vision and hearing loss, facial paralysis and mental retardation. Internal medical therapy resulted in an improvement in 69.2% of the patients. 7 out of 9 patients got improved or cured by combined surgical and internal medical treatment. 42 cases were diagnosed as parasitic encephalopathy while 36 cases (46.1%) were once misdiagnosed as other disorders. CONCLUSION: Parasitic encephalopathy is associated with a history of eating raw, with a high rate of misdiagnosis. Internal medicine combined with surgery is an effective way for the therapy.

Onchocerciasis-related epilepsy? Prospects at a time of uncertainty.

Epilepsy and onchocerciasis (river blindness) constitute serious public health problems in several tropical countries. There are four main mechanisms that might explain a relationship between these two diseases: (i) the presence of Onchocerca volvulus in the central nervous system; (ii) the pathogenicity of various O. volvulus strains; (iii) immunological mechanisms involving cross-reactive immunization or cytokine production during infection; and (iv) the triggering role of insomnia due to itching.

Parasitic diseases of the central nervous system: lessons for clinicians and policy makers.

Parasitic diseases of the central nervous system are associated with high mortality and morbidity, especially in resource-limited settings. The burden of these diseases is amplified as survivors are often left with neurologic sequelae affecting mobility, sensory organs, and cognitive functions, as well as seizures/epilepsy. These diseases inflict suffering by causing lifelong disabilities, reducing economic productivity, and causing social stigma. The complexity of parasitic life cycles and geographic specificities, as well as overlapping clinical manifestations in the host reflecting the diverse pathogenesis of parasites, can present diagnostic challenges. We herein provide an overview of these parasitic diseases and summarize clinical aspects, diagnosis, therapeutic strategies and recent milestones, and aspects related to prevention and control.

Seroprevalence of Helicobacter pylori among children in Sana'a, Yemen.

BACKGROUND: Helicobacter pylori infection is primarily acquired in early childhood. Its transmission routes are debated. The aims of this study were to determine the seroprevalence of anti-H. pylori immunoglobulin G (IgG) in Yemeni children under 10 years of age, the potential risk factors for contracting H. pylori infection and co-infection of H. pylori with intestinal parasites. METHODS: Enzyme-labeled immunosorbent assay was used to determine the H. pylori prevalence rate among 572 healthy volunteers aged less than 10 years. Formalin ether concentration methods were used to test the prevalence of intestinal parasites (intestinal roundworms and tapeworms). In addition, we interviewed participants regarding potential risk factors for contracting H. pylori infection. RESULTS: The seroprevalence of H. pylori antibodies was 9%. The prevalence according to age varied from 0% in children under 2 years to 12.5% in age group 9-10 years. There was a correlation between the amounts of positive antibodies and increasing age. The prevalence rate of H. pylori antibodies was also significantly associated with the practice of drinking water from reused plastic jerry cans, with poor mouth hygiene and with co-infection by intestinal parasites. CONCLUSION: The prevalence of H. pylori antibodies in Yemen among children under 10 years of age is higher than that reported from other regions for the same age groups. Yemen shares some but not all potential risk factors for H. pylori infection with countries in which similar socioeconomic conditions are found. A possible way of eliminating H. pylori from the population would be via public health measures, i.e. preventing the reuse of plastic jerry cans, and improving sanitation and the standard of living.

Central nervous system hydatidosis in Turkey: a cooperative study and literature survey analysis of 458 cases.

OBJECT: Hydatidosis is both a medical and an economic problem in Turkey. The aim of this study was to analyze central nervous system (CNS) involvement in this disease, the related problems the disease causes, and its diagnostic and therapeutic aspects. METHODS: The authors conducted an extensive literature survey of the subject, in which papers published by Turkish authors in international and domestic journals were carefully analyzed. In addition, the authors conducted a cooperative study in which data were gathered from 47 neurosurgery departments across the country. The purpose was to determine the current status of the disease in Turkey; thus, each unit was questioned about their experience over the past 5 years. Contrary to common belief, the incidence of hydatidosis has not decreased significantly in Turkey. However, computerized tomography and magnetic resonance imaging have tremendously increased diagnostic specificity. Incidences of morbidity and mortality have improved over time, according to the results of the cooperative study, although these changes are not statistically significant. This may be attributed to experience that has been gained and to more frequent use of chemotherapy, as reflected by the cooperative study data. The two statistically significant findings of that study were expanded use of chemotherapy in the management of hydatidosis, and a higher rate of extraneural involvement in the disease. The cooperative study revealed that chemotherapy was being used more often and that there was a wider range of indications for this treatment than previously reported. The higher rate of extraneural involvement was predictable because lesions in the CNS are typically secondary in this disease. With regard to the studies' findings on cases of spinal hydatid cysts, the authors found that administration of chemotherapeutic drugs was the only statistically significant parameter (t = 3.78, p < 0.05), with the rate of chemotherapy higher in the cooperative study. CONCLUSIONS: Morbidity, mortality, and recurrence rates of hydatidosis uncovered by the cooperative study and the literature survey were not statistically significant.

Cerebral hydatid cysts in children.

A parasitic tapeworm, called Taneia Echinococcus, causes hydatid disease. Hydatid disease is endemic in sheep and cattle-raising areas of the world. Hydatid disease of the central nervous system constitutes 2%-3% of all reported cases of hydatid cysts. In our institution, 23 children underwent surgery for intracranial hydatid cysts between 1979 and 1995. There were 14 boys and 9 girls, aged between 3 to 16 years (mean 8.8 years). Signs and symptoms were related to the site and size of the cyst. Headache and vomiting due to increased intracranial pressure were the most common presenting symptoms. A round cystic lesion without perifocal edema and rim enhancement is the characteristic appearance on a computed tomography (CT) scan. A magnetic resonance image visualizes cyst location better than CT. Associated systemic hydatidosis in four of our patients involved kidney, liver, lung, and liver and lung, respectively. Intact cyst removal was achieved in 14 patients. In three patients with infected or inflamed hydatid disease, the ruptured cyst capsule was totally resected. Aspiration and extirpation were performed in only one patient. Eleven patients were treated with chemotherapeutic agents such as albendazole or mebendazole due to cyst rupture during surgery or associated systemic hydatid disease. Hydatid disease can also be seen in Western countries because of travel and migration. Cerebral hydatid cyst should be kept in mind for the differential diagnosis of cystic lesions.

[Investigation of inpatient cases of food-borne parasitic encephalopathy].

OBJECTIVE: To investigate the clinical features of the patients with encephalopathy caused by food-borne parasites. METHODS: Questionnairing was carried out to collect and analyze clinical data of cerebral form of food-borne parasitic diseases in the hospital during the past five years. RESULTS: Among 190 discharged medical histories, 115 cases were valid for investigation, the number of males was 73, females 42, with a ratio of 1.74:1. Among these patients, 20.9% (24/115) had a history of eating raw meat. For discharge diagnosis, neurocysticercosis accounted for 92.2% (106/115), cerebral paragonimiasis 3.5% (4/115), sparganosis 2.6% (3/115), and angiostrongyliasis cantonensis and gnathostomiasis 0.9% (1/115) each. 13.9% (16/115) of the patients were hospitalized for three times or more. CONCLUSION: More attention should be paid to food-borne parasitic encephalopathy.

Overview of the effect and epidemiology of parasitic central nervous system infections in African children.

Infections of the central nervous system are a significant cause of neurologic dysfunction in resource-limited countries, especially in Africa. The prevalence is not known and is most likely underestimated because of the lack of access to accurate diagnostic screens. For children, the legacy of subsequent neurodisability, which affects those who survive, is a major cause of the burden of disease in Africa. Of the parasitic infections with unique effect in Africa, cerebral malaria, neurocysticercosis, human African trypanosomiasis, toxoplasmosis, and schistosomiasis are largely preventable conditions, which are rarely seen in resource-equipped settings. This article reviews the current understandings of these parasitic and other rarer infections, highlighting the specific challenges in relation to prevention, diagnosis, treatment, and the complications of coinfection.

Rickettsiae, protozoa, and opisthokonta/metazoa.

Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities.

Monitoring of parasitic cysts in the brains of a flock of sheep in Egypt.

Cerebral parasitic cysts constitute a major problem for livestock. Among these, coenurosis and toxoplasmosis are predominant. Here, a total number of 60 sheep obtained from a private farm in Suez province, Egypt, were examined postmortem to detect visible parasitic cysts, and microscopically to detect small-sized entities. Necropsy revealed bladder-like cysts measuring 0.5-6.5 cm in diameter that were filled with a translucent fluid containing a large number of protoscolices. Accordingly, the cysts were identified as the metacestode Coenurus cerebralis. Among the sheep examined, 11 animals (7 males and 4 females) (18.3%) were infected. Most of the cysts were located in the cerebral hemispheres, with numbers ranging from one to three per infected animal. The effect of the presence of cysts in the brain tissue was evaluated. Histopathologically, pseudocysts of the apicomplexan Toxoplasma gondii were found in two animals with no detectable inflammatory cell reactions. In conclusion, coenurosis and toxoplasmosis are serious parasitic problems that play a significant role in sheep management in Egypt, as a result of close contact between livestock and dogs and cats, which play a critical role in the life cycle of these parasites.

Epidemiology of central nervous system infection.

In cases of central nervous system infection, it is crucial for the neuroradiologist to provide an accurate differential diagnosis of the possible pathogens involved so that treating physicians can be aided in the choice of empiric therapy. This approach requires the radiologist to be aware of local epidemiology and have knowledge of infectious agents that are endemic to their area of practice. This article reviews and discusses the changing epidemiology of pathogens most often observed in meningitis, brain abscess, epidural abscess, postoperative infections, and human immunodeficiency virus infection.