[Mansonelliasis identified by a cervicovaginal smear at the university hospital center of Bobo-Dioulasso (Burkina Faso)]. / Frottis cervicovaginal révélant une mansonellose au centre hospitalier universitaire de Bobo-Dioulasso, Burkina Faso

INTRODUCTION: Mansonella perstans is a genus of filaria that is often asymptomatic or responsible for unspecific symptoms. M. perstans microfilariae are uncommon on cervicovaginal smears. CASE: We report the case of a woman with pruritis and eosinophilia. Microfilariae of M. perstans were observed on both cervicovaginal and blood smears. The patient was successfully treated with a combined single dose of 400 mg of albendazole and ivermectin (150 µg/kg). CONCLUSION: We described here an atypical and rare localization of M. perstans. The routine examination of cervicovaginal smears of women admitted to Bobo-Dioulasso Hospital for screening of cervical neoplasia should allow us to determine the frequency of this parasitosis and propose appropriate treatment.

[Sciatica after return from Mali: case report of schistosomal myelopathy]. / Sciatique au retour du Mali.

INTRODUCTION: In spite of the high prevalence of schistosomiasis in Mali, few cases involving neurological complications have been described. The purpose of this report is to present a case associated medullary complications. CASE REPORT: A 29-year-old man was hospitalized for low back pain and difficulty in walking linked to dysesthesia. Five months earlier the patient had been trreated for schistosomiasis contracted during a trip to Dogon region of Mali. Based on radiological and laboratory findings and previous clinical history, the difinitive diagnosis was schistosomal myelopathy. DISCUSSION/CONCLUSION: Neuroschistosomiasis is a rare but serious complication of the schistosomiasis that can only be made after complete parasite identification and careful differential diagnosis. Treatment with antiparasitic agents in association with corticosteroids is mandatory but must only be initiated in state stage of the parasitic infection, i.e., after maturation of larvae into adults.

Hydrocephalus and racemose cysticercosis: surgical alternative by endoscopic third ventriculostomy.

BACKGROUND AND PURPOSE: Hydrocephalus is a frequent and potentially serious complication of neurocysticercosis. Its treatment often requires ventricular shunting. The complication rate is high due to obstruction or material infection, which may justify endoscopic third ventriculostomy (ETV). OBSERVATION: We report a case of obstructive hydrocephalus in a 46-year-old man in the context of racemose cysticercosis, presenting with headaches and transient disorders of consciousness. Imaging showed cystic lesions of the cisterna magna, responsible for hydrocephalus which was treated effectively by ETV. Treatment with albendazole decreased the volume of the cisterna magna cysts. RESULTS: The patient was followed for 6 years after ETV with no recurrence of hydrocephalus despite two more symptomatic episodes of the disease with extension of the cysts into the lumen of the fourth ventricle and into the perispinal subarachnoid spaces, effectively treated by albendazole each time. CONCLUSIONS: Treatment of obstructive hydrocephalus secondary to cerebral racemose cysticercosis by ETV seems to be an effective and safety technique. The role of ETV should be evaluated in this indication.

Aspergillus fumigatus causes in vitro electrophysiological and morphological modifications in human nasal epithelial cells.

The role of the airway epithelium in the development of invasive aspergillosis in immunocompromised hosts has rarely been studied although patients at risk for this infection frequently have epithelial damage. We developed an in vitro model of primary culture of human nasal epithelial cells (HNEC) in air-liquid interface, which allows epithelial cell differentiation and mimics in vivo airway epithelium. We subsequently tested 7-day and 24-hour Aspergillus fumigatus filtrates on the apical side of HNEC to know whether A. fumigatus, the main species responsible for invasive aspergillosis, produces specific damage to the epithelial cells. The results were compared with those obtained with non-pathogenic filamentous fungi. Seven-day culture filtrates of A. fumigatus and Penicillium chrysogenum induced electrophysiological modifications whatever the fungus tested. In contrast, only 24-hour A. fumigatus filtrates induced a specific decrease in transepithelial resistance, hyperpolarization of the epithelium, and cytoplasmic vacuolization of HNEC compared with both A. niger and Penicillium chrysogenum. The inhibition of the A. fumigatus effects with amiloride suggests that the 24-hour fungal filtrate acts through sodium channels of HNEC. These early modifications of the epithelial cells could facilitate colonization of the airways by A. fumigatus. To know whether the molecules involved are specific to A. fumigatus or simply produced more rapidly than by other filamentous fungi warrants further investigation. In this perspective, the primary culture of HNEC represents a suitable model to study the interactions between airway epithelial cells and A. fumigatus.

Immunodiagnosis of Echinococcus infections: confirmatory testing and species differentiation by a new commercial Western Blot.

The Echinococcus Western Blot IgG (LDBIO Diagnostics, Lyon, France), using a whole larval antigen from Echinococcus multilocularis, was evaluated for serodiagnosis and differentiation between two human parasitic infections of worldwide importance: cystic echinococcosis, due to Echinococcus granulosus, and alveolar echinococcosis, due to E. multilocularis. Fifty and 61 serum samples from patients with cystic and alveolar echinococcosis, respectively, were used for assessing diagnostic sensitivity. The sensitivity of the assay was compared with those of screening tests used for these applications. Sera used for assessing cross-reactivities were from 154 patients with other diseases, either parasitic or not. The assay allowed the detection of serum immunoglobulin G antibodies in 97% of Echinococcus-infected patients. It had a higher sensitivity than screening assays for the detection for each echinococcosis. The assay allowed us to correctly distinguish between E. granulosus- and E. multilocularis-infected patients in 76% of cases. It did not allow us to distinguish active from inactive forms of both echinococcoses. The occurrence of cross-reactivities with neurocysticercosis indicates the necessity for retesting sera with species-specific antigens, for rare patients with neurologic disorders. This study shows the usefulness of the commercially available Echinococcus Western Blot IgG for the serological confirmation of human echinococcosis.

[Alveolar echinococcosis: a dreadful orphan disease]. / L'échinococcose alvéolaire. Une redoutable orpheline.

A WIDESPREAD DISEASE: Significant progress in screening for alveolar echinococcosis has reduced the number of new cases observed in Europe. Health education and serodetection campaigns have allowed earlier diagnosis and more effective treatment. The disease cannot however be totally eradicated due to the widespread wild reservoirs, sometimes even in the center of large cities. THERAPEUTICS: Early diagnosed and treatment can inhibit the inevitable progression observed after clinical manifestations appear. Drugs can block disease progression and surgical excision can be most effective. Inversely, the hopes raised by liver transplantation in patients with advanced stage disease have not been fulfilled due to the more or less late-onset metastasis favored by immunosuppressive treatments. PERSPECTIVES: There has been considerable progress in our knowledge of this parasite disease, particularly in improved diagnostic techniques. They have also demonstrated that humans are poor hosts for the parasite which is often spontaneously ejected. We are beginning to better understand the mechanisms of this spontaneous cure. Practical consequences would be a definition of receptive patient profiles or "vaccine" or immunotherapeutic procedures.

Secondary alveolar echinococcosis in lymphotoxin-alpha and tumour necrosis factor-alpha deficient mice: exacerbation of Echinococcus multilocularis larval growth is associated with cellular changes in the periparasitic granuloma.

The availability of mice carrying a deletion of LT-alpha and tumour necrosis factor (TNF)-alpha genes enabled us to investigate the role of the TNF during alveolar echinococcosis. We compared the growth rate of Echinococcus multilocularis in LT-alphaTNF-alpha +/+ mice to that of mice having either no or only one LT-alphaTNF-alpha functionnal allele. LT-alphaTNF-alpha -/- mice harboured a significantly higher parasite burden than did the other two populations at 5, 10, and 15 weeks of infection, and they did not survive thereafter. Liver metacestodes removed from these mice were alive and the dehydrogenase activities of peritoneal metacestodes were decreased. Liver lesions regressed in most wild-type mice. Indeed, dead parasites were cordoned by granulomas containing numerous macrophages and lymphocytes leading to focal liver fibrosis at an early stage of infection. In contrast, most of LT-alphaTNF-alpha -/- mice harboured metacestodes interspersed with leucocytes, realising purulent abscesses with secondary extensive irregular fibrosis at a late stage of infection. Heterozygous mice had behavioural characteristics intermediate between homozygous mutants and wild-type mice. Levels of E. multilocularis-specific delayed-type hypersensitivity and serum antibodies were slightly decreased in LT-alphaTNF-alpha -/- mice. This study shows that TNF-alpha and/or LT-alpha genes play an essential role in the immune protection mechanisms against E. multilocularis at the site of infection.

Echinococcus multilocularis infection in mice: in vivo treatment with a low dose of IFN-gamma decreases metacestode growth and liver fibrogenesis.

As no antiparasitic drug is definitively efficient in patients with alveolar echinococcosis, the effects of exogenous IFN-gamma on murine Echinococcus multilocularis infection were assessed with regards to the parasite burden, parasite-specific immune responses, and the urinary level of the collagen cross-link pyridinolines. They were analyzed after 3-week treatments with 1 or 5 micrograms of IFN-gamma per day twice a week. The treatment with 1 microgram transiently reduced the liver metacestode load, and the metastase weight as far as 6 weeks after the end of treatment. It slightly increased Th 1-type T cell responses and reduced the excretion of pyridinolines. These results should encourage further study to assess whether the decrease in liver fibrosis leads to an improvement of the efficacy of albendazole therapy. In contrast, the treatment with 5 micrograms increased the liver metacestode load and was less efficient than that with 1 microgram in decreasing pyridinoline excretion. These results incitate to follow up carefully patients with alveolar echinococcosis who are treated with IFN-gamma.

[Alveolar echinococcosis in the French province of Ardennes: isolated case or new focus?]. / L'échinococcose alvéolaire dans le département français des Ardennes: cas isolés ou nouveau foyer?

The first three autochthonous cases of alveolar echinococcosis were diagnosed in the Ardennes area (France). This is the most occidental localization of this disease in Northern Europe. The authors discuss these cases with an epidemiological regard. They are looking for relationships with natural parasitic cycle in the neighbouring country Belgium and their consequences on local public health in the future.

Echinococcus multilocularis: relationship between susceptibility/resistance and liver fibrogenesis in experimental mice.

To analyze collagen and other matrix protein deposits in experimental alveolar echinococcosis as well as the expression of lysyl oxidase, the enzyme that initiates the first steps in the pyridinoline cross-linking of collagen, and to establish a relationship between resistance/susceptibility to Echinococcus multilocularis larval growth and fibrogenesis, we compared AKR/J mice (susceptible to E. multilocularis infection) with NMRI mice (resistant hosts) in this study. Collagen deposits in the lesions were evaluated using a colorimetric method; the nature of matrix proteins involved in the periparasitic fibrosis and lysyl oxidase expression were assessed using immunostaining on tissue sections. The results obtained in this sequential study confirm that fibrogenesis is an important aspect of the host immune reaction against parasitic development and that both the extent and the course of matrix protein deposition differ in the liver of susceptible and resistant mice, respectively. The long-lasting expression of alpha-actin and lysyl oxidase by host cells in NMRI mice suggests that in this resistant strain, fibrosis was not only more developed but also more highly cross-linked and, thus, less sensitive to collagenases than in susceptible mice. A very strong expression of lysyl oxidase by parasitic cells was observed in both strains of mice; the observation that E. multilocularis itself has a role in lysyl oxidase cross-linking of host collagens can be hypothesized and would be a new example of parasite-host interplay.

In vivo treatment with recombinant IL-12 protects C57BL/6J mice against secondary alveolar echinococcosis.

Using an experimental model of hepatic Echinococcus multilocularis infection in C57BL/6J mice, intraperitoneal administration of 0.8 microgram of recombinant IL-12 to mice with an established infection was shown to reduce the parasite burden as soon as two weeks after the end of treatment. At that time, in vitro Echinococcus multilocularis-induced spleen T cell proliferative responses as well as IFN-gamma and IL-5 production were higher in IL-12 treated mice than in untreated mice. Administration of 0.8 microgram of IL-12 at the time of infection was shown to be without effect on the parasite establishment. However, this treatment greatly inhibited the subsequent metacestode development. Indeed, ten weeks after infection, it induced a complete healing in 37.5% of mice. At that time, the development of metastases was inhibited in 68.75% of IL-12-treated mice. This reduction of parasite burden was mainly associated with a strong proliferation of spleen cells to E. multilocularis antigen and with a high IFN-gamma production. Altogether, our results show that IL-12 is of crucial importance in inhibiting the larval growth after the metacestode establishment in the liver and suggest that this cytokine could be of potential value in the treatment of human alveolar echinococcosis.

Intestinal and systemic humoral immunological events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs.

The aim of the study was to investigate the systemic and, for the first time, the intestinal humoral events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs. Thirty-one mice were divided into three groups; W-2, W-8 and control group. Each mouse of the W-2 and W-8 groups was orally infected with 1,500 E. multilocularis eggs, two weeks and eight weeks before sacrifice respectively. Control group mice received phosphate buffer saline. Measurement of anti-E. multilocularis and non-specific IgG, IgA and IgM, and of a transudation marker, albumin, were performed in serum and intestinal washings by a time-resolved immunofluorometric assay. These results were complemented by microscopic examination of the intestinal mucosa. This infection model is well-suited to the study of mucosal immunity during alveolar echinococcosis. It showed a major specific intestinal response in the early stage of the disease whereas the systemic response predominated later in the disease. Histopathological studies and calculation of the relative coefficient of excretion of Ig also confirmed that the presence of the parasite, even during a short period, was responsible for a local immunological and inflammatory response and for a change in mucosal permeability. Mucosal immunity could thus play a role in tolerance induction against E. multilocularis that could be a prerequisite for the subsequent development of the larvae in the liver, and for the occurrence of the parasitic disease, alveolar echinococcosis.

Lack of H-2 gene influence on mouse susceptibility to secondary alveolar echinococcosis.

To determine whether the development of hepatic Echinococcus multilocularis infection is influenced by major histocompatibility-linked genes, metacestode growth and host immune responses were compared in 4 C57BL/10 congenic murine strains of H-2b, H-2d, H-2k and H-2q haplotypes. Although the H-2q strain appeared slightly more resistant than the other strains, the 4 strains of mice developed comparable spleen cell proliferative response and Th1/Th2 cytokine production at 13 weeks p.i. A kinetic analysis, performed in 2 of these congenic strains, showed a similar pattern of parasite growth in these mice and failed to detect any significant difference in the production of parasite-specific IgM, IgG1 and IgG2, antibodies. Consequently, this study indicates that the control of secondary alveolar echinococcosis is not H-2 gene-linked.

Secondary Echinococcus multilocularis infection in A/J mice: delayed metacestode development is associated with Th1 cytokine production.

The course of Echinococcus multilocularis infection was studied in four different strains of mice after intrahepatic inoculation of a metacestode homogenate. Among these strains of mice, A/J and BALB/c mice were characterized, respectively, as the most resistant and susceptible strains. Although there was no significant difference between the mean surface of hepatic metacestodes of these two strains of mice at any examination time, 13 weeks after infection, the mean metastatic burden of A/J mice was significantly lower than that of BALB/c mice. Moreover, at this time, some BALB/c mice spontaneously died from their infection whereas all A/J mice remained in good health. The relative resistance of A/J mice to parasite development was associated with a strong and sustained in vitro spleen cell proliferative response to a crude E. multilocularis extract as well as with a high parasite-induced production of IFN-gamma and IL-2. The susceptibility of BALB/c mice was on the contrary associated with a high IL-4 production. Interestingly, the parasite extract also stimulated a significant IL-4 production by spleen cells of uninfected susceptible BALB/c mice, but not by control A/J mouse spleen cells. Altogether, these results suggest that the relative resistance of A/J mice to E. multilocularis growth is associated with the development of T cell responses characterized by the production of high levels of Th1 cytokines.

Characterization of T-cell immune responses of Echinococcus multilocularis-infected C57BL/6J mice.

Specific and non-specific parasite-induced changes in lymphocyte responses were analysed in C57/BL/6J mice after intrahepatic infection with Echinococcus multilocularis. Spleen cells harvested at selected times after infection were in vitro stimulated with mitogens or a crude soluble parasite extract (EmAg) at an optimized dose. Cell proliferative responses to Con-A were not modified by the infection over the first 22 weeks. In contrast, LPS-induced responses were decreased from the 13th week. A strong CD4+ proliferative T-cell response to the parasitic extract of infected mouse spleen cells was observed at the early stage of infection. This response then progressively decreased but remained significantly higher than that of control mice until the 19th week of infection. Cytokine production was investigated after in vitro EmAg stimulation of spleen cells. IFN-gamma, IL-2, IL-5 were produced within the first weeks after infection whereas the detection of IL-10 was slightly delayed. Thus, the promotion of the disease does not appear associated with the expansion of one rather than another T-cell subset in C57BL/6J mice. A general immunosuppression affecting both mitogenic and parasite-specific T-cell responses was observed at the end of the infection.

Development of an injectable formulation of albendazole and in vivo evaluation of its efficacy against Echinococcus multilocularis metacestode.

The loading of poly (D, L-lactide) nanoparticles with ABZ has led us to evaluate the potential of this new colloidal drug delivery system against E. multilocularis, using a murine model of hepatic alveolar echinococcosis. ABZ-loaded nanoparticles had a monodisperse size distribution between 100 and 150 nm. The efficiency of drug loading to nanoparticles was over 97%. In vitro, at an ABZ concentration of 1.0 microgram ml-1, the formulation had no toxicity for peritoneal macrophages harvested from uninfected mice. In vivo, the ABZ-loaded nanoparticles exhibited no signs of toxicity at any of the doses tested. Intravenous injections of 6 mg kg-1 of bound ABZ to infected mice had an equivalent antiparasitic effect on the metacestode growth to that of a treatment with 1500 mg kg-1 of orally administered free ABZ. The parasite hepatic superficial size as well as the peritoneal metastatic burden was significantly reduced by these 2 courses of treatment, as compared to those of untreated mice. Our results should encourage further study in order to explain the absence of dose-dependent efficacy of ABZ-loaded nanoparticles demonstrated in the present study.

Covalent cross-linking of liver collagen by pyridinoline increases in the course of experimental alveolar echinococcosis.

We report that covalent cross-linking of collagen molecules by pyridinoline increases significantly in liver in a murine model of alveolar echinococcosis. The highest amount of pyridinoline per collagen molecule (up to 3.5 fold the control values) is found in liver parasitic lesions. It is also increased, but to a far lesser extent, at distance from the fibrotic areas, in macroscopically normal zones of the liver, suggesting that the increase in mature collagen cross-linking occurring in the fibrogenesis due to Echinococcus multilocularis infection involves the whole liver. The comparison of these data with those we have obtained in another parasitic disease, murine schistosomiasis leading to a milder liver fibrosis, largely reversible following chemotherapy, supports a relationship between the liver pyridinoline level and the severity of liver fibrosis. Pyridinoline could be a tissular marker of chronic liver fibrosis in parasitic diseases.

In vitro quantitative assessment of Echinococcus multilocularis metacestode viability after in vivo and in vitro maintenance.

The aim of this study was to apply the enzymatic MTT (3,5 dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide--formazan colorimetry for quantifying the viability of Echinococcus multilocularis whole cysts, after maintenance in vivo or in vitro. The enzymatic activities of young cysts freshly removed from rodents were linearly correlated with the parasite cyst weight. A comparative evaluation of the MTT assay and the in vitro viability assessments showed that the number of animals used for drug-screening purposes would be reduced by 35.8%. In this way, the use of different parasite samples removed from the same host is required, because of their different ages and their subsequent different abilities to reduce MTT. Cysts removed from mice exhibited higher colorimetric values than those removed from jirds. Thus, small entire cysts obtained from mice were maintained in the CMRL 1066 culture medium. Their enzymatic activities were evaluated at different times. The results indicate that, in such conditions, the optimal period of time for testing the effect of drugs against the metacestodes is limited to the 10 days following their transfer from mouse to culture flasks. The MTT assay encourages further studies to improve the viability of the whole cysts in vitro, using other standardizable culture conditions.