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R Piarroux

Publications and source records attributed to R Piarroux.

At least 37 records · Page 2Linked to original sources
PubMed2001

Assessment of the epidemiological status of Echinococcus multilocularis in foxes in France using ELISA coprotests on fox faeces collected in the field.

The aim of this study was to estimate the relevance of Echinococcus multilocularis coproantigen detection in fox faeces collected in the field to identify different levels of endemicity for Echinococcus multilocularis on a large scale (n x 10 km(2)). Six study sites were selected in a high endemicity area and two study sites in a low endemicity area in eastern France on the basis of landscape composition. Sampling was undertaken in the winters of 1996-97, 1997-98 and 1998-99. At each site, (i) necropsy and intestine examination was undertaken on a sample of shot foxes (total number of foxes, 222), and (ii) fox faeces were collected in the field along road verges, and scored for degradation status (total number of faeces, 625). Fox faeces were also sampled in a control area (n=30) in western France in the summer of 1998. Intestines were examined according to the sedimentation method. Echinococcus multilocularis coproantigens were detected by using two ELISA tests: EM-ELISA and EmA9-ELISA. The necropsy prevalence in high and low endemicity areas was 63.3% and 19.4%, respectively, and the distribution of adult worms in the fox population was highly overdispersed (75.5% of the total biomass was harboured by 11.6% of foxes). Using the two ELISA tests, there was no difference in the detection of E. multilocularis coproantigens in field faeces, regardless of the degradation status. The medians of EM- and EmA9-ELISA OD values of field faeces in high endemicity area were significantly higher than in low endemicity area (P<0.001 for both ELISA). The distribution of EM-ELISA OD values in low endemicity area was significantly higher (P=0.002) than in the control area. Moreover, for the two ELISA, the observed ELISA OD value distributions in high endemicity area, low endemicity area and control area seemed representative of the distribution of adult worms in fox populations. These results indicate that E. multilocularis coproantigen detection in field faeces could serve for large-scale surveillance, as an alternative to necropsy.

Animals↗
PubMed2001

Role of molds in farmer's lung disease in Eastern France.

Farmer's lung disease (FLD) is common in the east of France. In the absence of the primary recognized FLD agent, Saccharopolyspora rectivirgula, its etiology remains unknown. A prospective case-control study was performed to find the etiology of FLD in this area. Eleven patients were matched with 11 healthy control farmers. Twenty-two urban subjects constituted the nonexposed control group. Microorganisms from cowshed air and fodder were identified and counted. The antigens of the microorganisms most frequently isolated at the 22 farms were used for serological tests. Farms of patients with FLD contained more Absidia corymbifera than those of healthy farmers (p < 0.05 in air, p < 0.01 in fodder). Electrosyneresis, performed with A. corymbifera somatic antigen, differentiated 9 of 11 patients with FLD from control subjects (p < 0.01). Other significant results were obtained with Eurotium amstelodami (p < 0.01) and Wallemia sebi (p < 0.05). In contrast, no significant results were obtained with the other seven antigens tested, including S. rectivirgula. Absidia corymbifera and, to a lesser degree, W. sebi or E. amstelodami are likely to be the main causes of FLD in this area. Modifications in working conditions over time could explain the emergence of these new contributing etiologies.

Adult↗
PubMed2001

Increased serum and salivary immunoglobulins against Candida albicans in HIV-infected patients with oral candidiasis.

The aim of this study was to explore anti-Candida albicans systemic and mucosal humoral responses against Candida virulence antigens such as somatic antigen and secreted aspartic proteases (Saps) in HIV-infected patients with oral candidiasis. Twenty-eight subjects were included in the study: 11 HIV-positive patients without oral candidiasis (group A), 6 HIV-positive patients with oral candidiasis (group B) and 11 HIV-negative healthy controls (group C). Total IgA, IgG and IgM concentrations and antibodies to C. albicans (somatic antigen, Sap1, Sap6) were measured in serum and saliva. We developed a time-resolved immunofluorometric assay with biotin and europium-labeled streptavidin for this purpose. Salivary total IgA, IgG and IgM concentrations were higher in group B. IgA, IgG and IgM anti-C. albicans antibodies (against somatic antigen, Sap1, Sap6) were higher in saliva and serum from patients from group B compared with patients from group A and controls. Our results suggest that, in oral candidiasis, HIV-infected patients have a high mucosal response, specifically directed against C. albicans virulence antigens, such as somatic antigen, Sap1 and Sap6.

AIDS-Related Opportunistic Infections↗
PubMed2000

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.

Animals↗
PubMed2000

Skin manifestations associated with toxocariasis: a case-control study.

BACKGROUND: Human toxocariasis is one of the most common zoonotic helminthiases. The recent development of sensitive and specific diagnostic laboratory tests has led to identify a large spectrum of diseases, including cutaneous diseases, induced by Toxocara infection. OBJECTIVE: The purpose of our study was to assess the risk of having a positive Toxocara ELISA test in patients with different cutaneous symptoms. METHODS: The diagnosis of toxocariasis was based on an ELISA test which was performed in 653 patients suffering from different skin conditions during a prospective case-control study. RESULTS: The excess of risk (adjusted odds ratio) of having a positive result in the Toxocara ELISA was statistically significant for 134 patients with urticaria (whatever the clinical presentation) and for 22 patients with prurigo compared to a control group (249 patients). No statistical excess of risk was observed for patients with atopic dermatitis, pruritus or non-atopic eczema. CONCLUSION: The authors conclude that patients suffering from urticaria or prurigo should be tested for Toxocara infection. Whether these patients should be treated with anthelminthic drugs remains to be determined in further studies.

Adolescent↗
PubMed1999

[Mediterranean visceral leishmaniasis: physiopathology].

INFANTILE LEISHMANIASIS: The protozoan parasites of the genus Leishmania are the causal agent of various diseases ranging from cutaneous lesions to fatal systemic diseases. In southern France, Leishmania infantum is an endemic species recognized as the causal agent of infantile leishmaniasis (Mediterranean visceral leishmaniasis). Little is known about the pathophysiology of the disease in humans, but models in mice may provide a new approach. INSECT VECTOR: Leishmania infantum are carried by sand flies. Antigenic modifications of the promastigote forms occur in these insects modifying lipophyosphoglycan (LPG) or glyocprotein gp63. Salivary gland lysates from the sand flies also enhance Leishmania infectivity. HUMAN INFESTATION: In humans, LPG and gp63 play a role in complement fixation, cell adhesion and resistance to complement-mediated lysis. Macrophage expression of class I and II major histocompatibility complex antigens is suppressed. T cells and interferon gamma are very important keys in the control of the parasite infection.

Adolescent↗
PubMed1999

[Treatment of infantile visceral leishmaniasis].

Visceral leishmaniasis is an endemic disease in the Mediterranean Basin. Children are one of the targets of the infection. Treatment usually requires parenteral injections of pentavalent antimony (Glucantime or Pentostam), but the high frequency of adverse events and the occurrence of primary or secondary resistance cases limit the use of these medications. Diamidines (Pentacarinat) or amphotericin B derivatives are alternatives to antimony. Unfortunately, pharmacokinetics and optimal dosage of diamidines are not well-known, and numerous adverse events are described. Liposomal preparations of amphotericin B enhance its efficiency and tolerance, and the duration of treatment may be reduced to 5 days. Moreover, primary resistance to amphotericin B is not described in immunocompetent children. Allopurinol associated with antimony seems no more efficient than antimony alone. Aminosidine is not evaluated.

Amphotericin B↗
PubMed1999

[Imported pediatric malaria in Marseille].

UNLABELLED: Imported malaria is frequently observed in pediatric practices within geographical areas which have a migrant population. MATERIAL AND METHODS: All the pediatric malaria cases of a university children's hospital (Marseilles, southern France) had been studied retrospectively. The period of the study was from January 1987 to December 1997. Inclusion criteria were based on clinical diagnosis criteria established by WHO. RESULTS: Three hundred and fifteen clinical cases were observed. Ninety-nine percent were confirmed by blood smears. Eighty-six percent of the patients came from the archipelago of the Comoro Islands in the Indian Ocean. Twenty percent were not given chemoprophylaxis, and 77% of the patients with chemoprophylaxis were not compliant. Fever (92%), splenomegaly (61%), vomiting and/or diarrhea (50%) were frequently observed. Neurological signs (23%), especially headaches (15%), were noted. The causative species was Plasmodium falciparum in 76%; coinfections with two species were observed in 9%. Halofantrine was commonly used for therapy (64%), but relapses were noted with this drug. No death was observed during the study. DISCUSSION: Imported pediatric malaria is rare in France. Clinical signs may lead to misdiagnosis when splenomegaly is not obvious, or when vomiting and/or diarrhea, cough or otitis occur. Diagnosis relies on blood smears. Curative medications are chloroquine or halofantrine, with special attention to heart troubles. Mefloquine is rarely used in children. Quinine is reserved for serious attacks. Concerning chimioprophylaxy, medical prescriptions should be adapted to the stay abroad, and patient compliance to medications could be improved.

Adolescent↗
PubMed1998

Pediatric visceral leishmaniasis in southern France.

PURPOSE: The purposes of this study were to describe the characteristics of pediatric visceral leishmaniasis in southern France and to evaluate a new scheme of therapy. METHODS: Hospital records of 59 children with visceral leishmaniasis were retrospectively reviewed. The period of the study was from 1981 to 1997. RESULTS: All children but one lived or had previously dwelled in the south of France. None was coinfected with human immunodeficiency virus or known to be immunocompromised. The mean age was 31 months; 10 children were younger than 1 year when admitted to the hospital. The male:female ratio was 0.73. Fever and splenomegaly were present in 90 and 100%, respectively. Anemia, leukopenia and thrombocytopenia were commonly observed, especially in the youngest patients. Hypergammaglobulinemia was noted in 64%. A biopsy sample of the bone marrow was always performed, but direct microscopic examination failed to identify Leishmania in 13 (22%) cases. In these patients specific serology and genomic amplification with polymerase chain reaction were useful tools for the diagnosis. All patients were initially treated with meglumine antimonate (Glucantime). Twenty-six (44%) patients receiving the drug experienced at least one adverse event during treatment. Treatment failure occurred in six children (10%), who were subsequently cured with liposomal amphotericin B. Three additional children were treated with liposomal amphotericin B. All the children were finally cured and no death was observed. CONCLUSION: Our experience suggests that liposomal amphotericin B is effective therapy for visceral leishmaniasis in children.

Amphotericin B↗
PubMed1997

In vitro and in vivo resistance of Leishmania infantum to meglumine antimoniate: a study of 37 strains collected from patients with visceral leishmaniasis.

Primary and secondary unresponsiveness to meglumine has long been described in human visceral leishmaniasis. However, no studies have been performed to elucidate if these therapeutic failures were due to strain variability in meglumine sensitivity or were related to host factors. We have studied the in vitro sensitivity of 37 strains of Leishmania infantum isolated from 23 patients (11 human immunodeficiency virus-infected and 12 immunocompetent patients) with visceral leishmaniasis. Sensitivity tests were performed by infecting murine macrophages with Leishmania parasites and culturing them in medium containing different concentrations of meglumine. For each test we calculated a 50% effective dose (ED50) corresponding to the meglumine concentration at which 50% of the Leishmania parasites survived. In vitro results were strongly correlated to immediate clinical outcome. All strains requiring an ED50 of >70 microg/ml were related to therapeutic failures, whereas all strains requiring an ED50 of <40 microg/ml corresponded to an initial efficiency of meglumine. Among those patients who were initially improved, relapses occurred in all immunocompromised patients and in most immunocompetent patients who had a short duration of treatment (15 days). Finally, we found that in vitro sensitivity of strains decreased progressively in relapsing patients treated with meglumine. Consequently, the physician may be encouraged to alternate meglumine with other treatments such as amphotericin B or pentamidine, especially in the case of relapsing patients.

Animals↗
PubMed1997

Rapid identification of causative species in patients with Old World leishmaniasis.

Conventional methods for the identification of species of Leishmania parasite causing infections have limitations. By using a DNA-based alternative, the present study tries to develop a new tool for this purpose. Thirty-three patients living in Marseilles (in the south of France) were suffering from visceral or cutaneous leishmaniasis. DNA of the parasite in clinical samples (bone marrow, peripheral blood, or skin) from these patients were amplified by PCR and were directly sequenced. The sequences observed were compared to these of 30 strains of the genus causing Old World leishmaniasis collected in Europe, Africa, or Asia. In the analysis of the sequences of the strains, two different sequence patterns for Leishmania infantum, one sequence for Leishmania donovani, one sequence for Leishmania major, two sequences for Leishmania tropica, and one sequence for Leishmania aethiopica were obtained. Four sequences were observed among the strains from the patients: one was similar to the sequence for the L. major strains, two were identical to the sequences for the L. infantum strains, and the last sequence was not observed within the strains but had a high degree of homology with the sequences of the L. infantum and L. donovani strains. The L. infantum strains from all immunocompetent patients had the same sequence. The L. infantum strains from immunodeficient patients suffering from visceral leishmaniasis had three different sequences. This fact might signify that some variants of L. infantum acquire pathogenicity exclusively in immunocompromised patients. To dispense with the sequencing step, a restriction assay with HaeIII was used. Some restriction patterns might support genetic exchanges in members of the genus Leishmania.

Adolescent↗
PubMed1996

[Resistance of Leishmania infantum to Glucantime: risk factors and therapeutic management].

BACKGROUND: Resistance to antimonial drugs is rarely observed in immunocompetent patients. CASE REPORT: A 1-year-old girl was admitted suffering from persistent fever. A diagnosis of visceral leishmaniasis was made. The patient was given two courses of meglumine antimoniate (Glucantime) (60 mg/kg/d for 15 days) and one course of 12 injections of pentamidine (4 mg/kg). She relapsed 8 months later and failed to respond to Glucantime. Immunological tests performed during the relapse showed a suppression of the T cell response to Leishmania antigen and no production of interferon gamma. The patient was then successfully given liposomal amphotericin B (3 mg/kg/d for 10 days). She was asymptomatic 9 months later and had acquired specific cellular immunity against Leishmania. CONCLUSION: Deficient cell-mediated immunity and interferon gamma production are some factors responsible for decreased sensitivity to antimonial drugs. The WHO recommendations treating visceral leishmaniasis with prolonged administration of Glucantime may prevent relapses. Liposomal amphotericin B could be an alternative treatment.

Animals↗