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.

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.

[HIV-associated neurocognitive disorders]

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).

[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.

[Descriptive epidemiology of extrapulmonary hydatid cysts: a report of 265 Tunisian cases]

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.

[Parasitic and fungal neuroinfections at the Infectious Diseases Clinic in Fann Teaching Hospital in Dakar]

OBJECTIVES

This retrospective study was carried out to describe the epidemiological, clinical and aetiological profile of parasitic and fungal neuroinfections at the Infectious Diseases Clinic in Fann Teaching Hospital in Dakar.

PATIENTS AND METHODS

Data were collected for analysis from patients files recorded from January 1, 2001 to December 31, 2003.

RESULTS

We found 126 cases of parasitic and fungal neuroinfections, representing 62% of the total of neuroinfections cases (126/203) and 27% of cerebro-meningeal diseases encountered at the clinic during the study period (126/470). Sex ratio M/F was 1.7 and the mean age of patients was 32 years +/- 14.4. Thirty seven patients (30%) were HIV seropositive. Aetiologies were represented by cerebral malaria (85 cases), neuromeningeal cryptococcosis (37 cases) and toxoplasmosis (4 cases). The overall case fatality rate was 38% (48 deaths/126). The fatality rate varied according to aetiologies: 27% in cerebral malaria, and 59.5% in neuromeningeal cryptococcosis that was found mainly among HIV positive patients (34 cases/37).

CONCLUSION

These results give evidence of the frequency and the gravity of the adult's cerebral malaria in Dakar, but also the growing place of the neuromeningeal cryptococcosis in the neuromeningeal opportunist pathology of HIV positive patients.

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.

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.

Review of epidemiological studies searching for a relationship between onchocerciasis and epilepsy

A review and a meta-analysis of the available epidemiological literature for evidence of an association between onchocerciasis infection and epilepsy were carried out. We used EMBASE (1974-2002), MEDLINE (1966-2002), and PASCAL (1987-2002) databases and relevant journals and bibliographies. We limited our analysis to the epidemiological studies, where the status regarding onchocerciasis infection and epilepsy was available for each subject. Nine African studies were included. The common relative risk estimated by the random-effects model was 1.21 (95% CI 0.99-1.47; p = 0.06). The meta-analysis did not show any difference according to the onchocerciasis endemicity level and the African areas. Our results do not allow to conclude for an association between Onchocerca volvulus infection and epilepsy. However, the results are nearly significant. Further research is needed in this neglected subject, in particular for the better understanding of the neurological pathogenicity in onchocerciasis.

[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.

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.