Environmental and bioclimatic factors influencing yeasts and molds distribution along European shores

The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores applying a species distribution modelling approach. Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll-a concentration) downloaded from web databases. Analyses were performed by MaxEnt software. Results suggested a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.

Mycosands: Fungal diversity and abundance in beach sand and recreational waters - Relevance to human health

The goal of most studies published on sand contaminants is to gather and discuss knowledge to avoid faecal contamination of water by run-offs and tide-retractions. Other life forms in the sand, however, are seldom studied but always pointed out as relevant. The Mycosands initiative was created to generate data on fungi in beach sands and waters, of both coastal and freshwater inland bathing sites. A team of medical mycologists and water quality specialists explored the sand culturable mycobiota of 91 bathing sites, and water of 67 of these, spanning from the Atlantic to the Eastern Mediterranean coasts, including the Italian lakes and the Adriatic, Baltic, and Black Seas. Sydney (Australia) was also included in the study. Thirteen countries took part in the initiative. The present study considered several fungal parameters (all fungi, several species of the genus Aspergillus and Candida and the genera themselves, plus other yeasts, allergenic fungi, dematiaceous fungi and dermatophytes). The study considered four variables that the team expected would influence the results of the analytical parameters, such as coast or inland location, urban and non-urban sites, period of the year, geographical proximity and type of sediment. The genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp. and Cryptococcus spp. both in sand and in water. A site-blind median was found to be 89 Colony-Forming Units (CFU) of fungi per gram of sand in coastal and inland freshwaters, with variability between 0 and 6400 CFU/g. For freshwater sites, that number was 201.7 CFU/g (0, 6400 CFU/g (p = 0.01)) and for coastal sites was 76.7 CFU/g (0, 3497.5 CFU/g). For coastal waters and all waters, the median was 0 CFU/ml (0, 1592 CFU/ml) and for freshwaters 6.7 (0, 310.0) CFU/ml (p < 0.001). The results advocate that beaches should be monitored for fungi for safer use and better management.

Fungemia in the French department of Mayotte, Indian Ocean: A 10 years survey

OBJECTIVE

This study aimed at providing original data on fungemia in the Centre Hospitalier de Mayotte in terms of prevalence, epidemiological characteristics of infected patients, yeast species distribution and profile of in vitro antifungals susceptibility.

METHODS

A total of 223 positive blood cultures for yeasts were retrospectively reported during the period April 2010-April 2020.

RESULTS

Ninety-five episodes were identified corresponding to an incidence rate of 3.7 cases/100,000 inhabitants. The average age of patients was 33.5 years, and 63.3% patients were hospitalized in intensive care unit. The main co-morbidities were surgery in the 30 days prior to fungemia (27.8%), neoplasia (22.8%), parenteral nutrition (17.7%), diabetes (16.5%) and immunosuppressive medications (31.6%). Candida spp accounted for the majority of isolates (92.4%) with a predominance of non-albicans species (55.8% vs 33.7%), including C. albicans (33.7%), C. tropicalis (30.5%) and C. parapsilosis (20%). The antifungal susceptibility profiles did not differ from expected results for each species and did not change significantly over time.

DISCUSSION

Fungemia remain frequent hospital infections associated with high mortality in Mayotte. The vast majority of fungemia was due to Candida spp. Non-albicansCandida species reach half of the Candida isolates with a high percentage of C. tropicalis. Surprisingly, no case of candidemia due to C. glabrata were identified. The management of candidemia remains satisfactory and the treatment was adapted according to the international recommendations. However, the high susceptibility of Candida spp. isolates to fluconazole may invite to reconsider the use of this molecule as empirical and first-line treatment of candidemia in Mayotte.

Lyme borreliosis and other tick-borne diseases. Guidelines from the French scientific societies (II). Biological diagnosis, treatment, persistent symptoms after documented or suspected Lyme borreliosis

The serodiagnosis of Lyme borreliosis is based on a two-tier strategy: a screening test using an immunoenzymatic technique (ELISA), followed if positive by a confirmatory test with a western blot technique for its better specificity. Lyme serology has poor sensitivity (30-40%) for erythema migrans and should not be performed. The seroconversion occurs after approximately 6 weeks, with IgG detection (sensitivity and specificity both>90%). Serological follow-up is not recommended as therapeutic success is defined by clinical criteria only. For neuroborreliosis, it is recommended to simultaneously perform ELISA tests in samples of blood and cerebrospinal fluid to test for intrathecal synthesis of Lyme antibodies. Given the continuum between early localized and disseminated borreliosis, and the efficacy of doxycycline for the treatment of neuroborreliosis, doxycycline is preferred as the first-line regimen of erythema migrans (duration, 14 days; alternative: amoxicillin) and neuroborreliosis (duration, 14 days if early, 21 days if late; alternative: ceftriaxone). Treatment of articular manifestations of Lyme borreliosis is based on doxycycline, ceftriaxone, or amoxicillin for 28 days. Patients with persistent symptoms after appropriate treatment of Lyme borreliosis should not be prescribed repeated or prolonged antibacterial treatment. Some patients present with persistent and pleomorphic symptoms after documented or suspected Lyme borreliosis. Another condition is eventually diagnosed in 80% of them.

[Mycological and parasitological examinations in the management of lung infections]

Pulmonary parasitic diseases are rare whereas pulmonary fungal infections are increasing. The diversity of clinical presentations requires laboratory tests to confirm the diagnosis. Direct examination of lung samples and antibody detection are the basis of parasitological diagnosis. With regard to mycoses, the range of biological tests is broader. The conventional mycological examination allows identification of any type of fungus except Pneumocystis jirovecii. Its specificity is excellent but it lacks sensitivity. Detection of antibodies, antigens or nucleic acid complements the diagnostic tools. With regard to aspergillosis, there is a broad nosological set with variable prognosis. The choice of appropriate laboratory procedures depends on the clinical presentation and patient risk factors. The search for galactomannan antigen is effective and a new technique, "Lateral Flow Device", seems very promising. The detection of antibodies is also informative but various techniques are used. A good knowledge of the performance and limitations of these techniques allows targeted prescription. The use of PCR for the diagnosis of pulmonary fungal infections has limited indications. Biological and clinical co-operation is essential for the choice and interpretation of laboratory tests for parasitic or fungal pulmonary disease.

Antifungal therapy for patients with proven or suspected Candida peritonitis: Amarcand2, a prospective cohort study in French intensive care units

OBJECTIVE

The clinical characteristics and prognosis of patients treated for Candida peritonitis (CP) were compared according to the type of systemic antifungal therapy (SAT), empiric (EAF) or targeted (TAF) therapies, and the final diagnosis of infection.

METHODS

Patients in intensive care units (ICU) treated for CP were selected among the AmarCAND2 cohort, to compare patients receiving EAF for unconfirmed suspicion of CP (EAF/nonCP), to those with suspected secondarily confirmed CP (EAF/CP), or with primarily proven CP receiving TAF.

RESULTS

In all, 279 patients were evaluated (43.4% EAF/nonCP, 29.7% EAF/CP and 25.8% TAF patients). At SAT initiation, the severity of illness was similar among EAF/nonCP and EAF/CP patients, lower among TAF patients (median Simplified Acute Physiology Score II (SAPS II) 49 and 51 versus 35, respectively; p 0.001). Candida albicans was involved in 67%, Candida glabrata in 15.6%. All strains were susceptible to echinocandin; 84% to fluconazole. Echinocandin was administered to 51.2% EAF/nonCP, 49% EAF/CP and 40% TAF patients. At day 28, 72%, 76% and 75% of EAF/nonCP, EAF/CP and TAF patients, respectively, were alive. An increased mortality was observed in patients with a Sequential Organ Failure Assessment (SOFA) score <7 if SAT was delayed by ≥6 days (p 0.04). Healthcare-associated CP (OR 3.82, 95% CI 1.52-9.64, p 0.004), SOFA ≥8 at ICU admission (OR 2.61, 95% CI 1.08-6.34; p 0.03), and SAPS II ≥45 at SAT initiation (OR 5.08, 95% CI 1.04-12.67; p 0.001) impacted the 28-day mortality.

CONCLUSIONS

In summary, only 56.6% of ICU patients receiving SAT had CP. Most strains were susceptible to SAT. A similar 28-day mortality rate was observed among groups; the late administration of SAT significantly worsened the prognosis of patients with less severe CP.

Surveillance of leishmaniases in France, 1999 to 2012

Leishmaniasis is endemic in the south of France, where autochthonous disease is caused by Leishmania infantum, and affects both humans and dogs. The prevalence of canine leishmaniasis is between 3 and 66% depending on the region and the methods used. Human leishmaniases are also imported into France, mainly from French Guiana and North Africa. The surveillance of autochthonous and imported human leishmaniases is based on passive notification to the National Reference Centre for Leishmaniases (NRCL) created in 1998. Between 1999 and 2012, 317 autochthonous and 1,154 imported cases were notified to the NRCL. The average number of autochthonous cases notified per year was 22.6, mainly cases of visceral leishmaniasis (84.5%). All cases were infected in the south of France. Leishmaniasis incidence is 0.22 per 100,000 inhabitants in the endemic area. Imported cases were more frequent (annual mean of 82.4 cases) and consisted predominantly in cutaneous leishmaniasis (CL) cases (91%), essentially L. major CL imported from Maghreb and Sub-Saharan Africa, and L. guyanensis CL from French Guiana. This national notification system allowed a better understanding of the incidence and distribution of the disease; it is also useful to assess the temporal-spatial evolution of the disease in France, which appears relatively stable.

Surveillance of leishmaniases in France, 1999 to 2012

Leishmaniasis is endemic in the south of France, where autochthonous disease is caused by Leishmania infantum, and affects both humans and dogs. The prevalence of canine leishmaniasis is between 3 and 66% depending on the region and the methods used. Human leishmaniases are also imported into France, mainly from French Guiana and North Africa. The surveillance of autochthonous and imported human leishmaniases is based on passive notification to the National Reference Centre for Leishmaniases (NRCL) created in 1998. Between 1999 and 2012, 317 autochthonous and 1,154 imported cases were notified to the NRCL. The average number of autochthonous cases notified per year was 22.6, mainly cases of visceral leishmaniasis (84.5%). All cases were infected in the south of France. Leishmaniasis incidence is 0.22 per 100,000 inhabitants in the endemic area. Imported cases were more frequent (annual mean of 82.4 cases) and consisted predominantly in cutaneous leishmaniasis (CL) cases (91%), essentially L. major CL imported from Maghreb and Sub-Saharan Africa, and L. guyanensis CL from French Guiana. This national notification system allowed a better understanding of the incidence and distribution of the disease; it is also useful to assess the temporal-spatial evolution of the disease in France, which appears relatively stable.

[Internal and external quality controls for Elisa techniques of aspergillosis serodiagnosis: proposals of the group "sérodiagnostic fongique" of the Société française de mycologie médicale]

In the end of May 2012, a meeting of the group "sérodiagnostic fongique" of the "Société française de mycologie médicale" had concerned quality controls to use, in particular, in the follow-up of Elisa techniques. A preliminary investigation showed that the internal quality controls (CIQ), according to the terms defined by the accreditation, were not systematically used. In June, was published the new guide of the COFRAC SH-GTA-06 on quality controls, this text being applicable on July 1st, 2012. It incited the working group to formulate proposals on the choice of the CIQ for antigen and antibody Elisa in the aspergillosis serodiagnosis. Informations on the external evaluations of the quality (EEQ) have also been given to better define for what we can expect from it. All these controls will allow every laboratory to better master the used techniques and their conditions of realization. A strengthened dialogue between the users and the manufacturers should incite these last actors to improve the supplied kits. It will drive later to an improvement of the reliability of the results obtained by these techniques and their interest in the aspergillosis diagnosis.

Cost effectiveness of posaconazole in the prophylaxis of invasive fungal infections in acute leukaemia patients for the French healthcare system

BACKGROUND

Acute myeloblastic leukaemia (AML) patients are at high risk of suffering from invasive fungal infections (IFI). Posaconazole demonstrated higher efficacy than standard azole agents (SAA) in the prophylaxis of IFI in this population. The authors estimated the cost effectiveness of posaconazole versus SAA in France.

METHODS

A decision-tree model was developed to compare posaconazole with SAA with the results of a published clinical trial. Clinical events were modelled with chance nodes reflecting probabilities of IFI, IFI-related death, and death from other causes. Medical resource consumption and costs were obtained from results of the clinical trial and from a dedicated survey on the costs of treating IFI using a retrospective chart review design.

RESULTS

IFI treatment costs were estimated using medical files from 50 AML patients from six French centres, with a proven and probable IFI, who had been followed-up for 298 days on average. Direct costs directly related to IFI were estimated at €51,033, including extra costs of index hospitalisation, costs of antifungal therapy and additional hospitalisations related to IFI treatment. The model indicated that the healthcare costs for the posaconazole strategy were €5,223 (€2,697 for prophylaxis and €2,526 for IFI management), which was €859 less than the €6,083 in costs with SAA (€469 for prophylaxis and €5614 for IFI management). A sensitivity analysis indicated that there was an 80% probability that prophylaxis using the posaconazole strategy would be superior.

CONCLUSION

The findings from this analysis suggest that posaconazole use is a clinically and economically dominant strategy in the prophylaxis of IFI in AML patients, given the usual limits of economic models and the uncertainty of costs estimates.

Experimental evaluation of antifungal and antiseptic agents against Rhodotorula spp

We studied the susceptibility of 21 strains of Rhodotorula rubra and nine strains of R. glutinis to eight antifungals and tested eight antiseptic agents on one strain of R. rubra. The tested strains were susceptible to ketoconazole, 5-fluorocytosine, amphotericin B, and nystatin, intermediate to econazole and resistant to fluconazole, itraconazole and miconazole. After 5-min contact, six of the eight antiseptic agents tested showed a fungicidal activity on the tested R. rubra strain.

[Mycologic surveillance of the environment for preventive invasive aspergillosis. Proposals for standardization of the methodologies and implementation]

A MAJOR RISK: The infection of immunodepressed patients by Aspergillus-type fungi increases morbidity and mortality, particularly in hematology units or during solid organ transplantation. Although present diagnostic means benefit from the progress over the last years, they remain limited and chemoprophylaxis protocols have still not demonstrated significant efficacy. THE NEED FOR RECOMMENDATIONS: Today, the handling of environmental risks is the only strategy that has proved its efficacy and usefulness. On the basis of administrative recommendations and data from the literature, a multicentric and pluri-disciplinary task force, grouping clinicians, microbiologists and hygienists, has assessed different methods and has proposed recommendations for the standardization and optimization of fungal surveillance of the environment.

Virulence of Leishmania infantum is expressed as a clonal and dominant phenotype in experimental infections

Human Leishmania infantum infection results in a spectrum of clinical expressions ranging from cutaneous to either asymptomatic or fatal visceral disease. In this context, characterization of parasite virulence appears to be relevant as a biological marker of intrinsic parasitic factors that can affect the pathology of leishmaniasis. Since parasite populations in naturally infected hosts are likely to be composed of multiclonal associations, we first explored the biodiversity of parasite virulence at the intrastrain level in vitro and in vivo by using 11 clones isolated from three strains previously known to express different virulence phenotypes in mice. Subsequently, we studied the course of infection in mice inoculated simultaneously or successively with strains or clones showing various virulence phenotypes. Analysis of in vitro growth characteristics showed no differences among clones from the different parental strains. By contrast, in vivo experiments evidenced a marked intrastrain heterogeneity of virulence to mice. One out of five clones obtained from a virulent strain showed a typical virulence phenotype, while the remaining four clones had low-virulence profiles, as did the six clones isolated from two low-virulence strains. In mixed multiclonal infections, the virulence phenotype was expressed as a dominant character over the associated low-virulence clones. After a challenge with either a homologous or a heterologous strain or clone, virulence phenotypes were conserved and expressed as in naive mice independently from the preexisting population. These results strongly suggest that parasite virulence in L. infantum visceral leishmaniasis is clonal and dominant in nature.

Assessment of Leishmania promastigote growth in vitro by means of nucleoside hydrolase activity determination

Nucleoside hydrolases (NH) are involved in the purine salvage pathway of protozoan cells for the biosynthesis of nucleic acids. We developed a simple and reliable microassay based on N-ribohydrolase dosage using 4-nitrophenyl-beta-D-ribofuranoside (NPR) substrate for the quantification of Leishmania infantum. The free promastigote stage of L. infantum contains high amounts of NH capable of cleaving NPR, but the parasitic amastigote does not. The method allows reliable quantification of viable parasites over a wide range of concentrations (5 x 10(4) 2 x 10(8) parasites ml(-1)) in a single assay. No difference in NH activity was observed between various strains at equivalent concentrations and growth curves determined with NH dosage were similar to optical counts. Samples can be stored at -20 degrees C for weeks before use in this unique assay without significant loss of NH activity. The method is particularly simple and versatile and proves well adapted for the determination of growth characteristics and drug screening studies of L. infantum promastigotes in vitro.

Comparative performance of impactor air samplers for quantification of fungal contamination

The aim of this study was to assess the performance of different impactor air samplers for fungal spore collection in the hospital environment. Four recent impactor air samplers were selected: Samplair (AES, Combourg, France); Air Test Omega (LCB, France); Air Samplair Mas-100 (Merck, France); and BioImpactor 100-08 (AES). They were compared with one another at three different hospital sites with varying levels of contaminated air. No significant difference in the efficiency of spore recovery was found between Air Test Omega, Mas-100 and BioImpactor, whereas Samplair was significantly less efficient. BioImpactor was then selected to represent the three superior impactors and was compared with the single-stage Andersen disposable sampler and the Collectron MD8 air sampler (Sartorius, France) and the High Flow Air Sample (BioTest, France), which are based on filtration and centrifugation methods, respectively. No significant difference was observed in terms of spore recovery. On the basis of their performance, unit sampling cost, autonomy and simplicity of use, we conclude that Air Test Omega, Air Samplair Mas-100 and BioImpactor 100-08 are suitable for routine indoor evaluation of fungal contamination of air in hospitals.

Fungal contamination of food in hematology units

The prevalence of thermotolerant fungi on non-heat-sterilizable food was determined. Aspergillus spp. were noted in 100% of pepper and regular tea samples, 12 to 66% of fruits, 27% of herbal teas, and 20% of freeze-dried soup samples. All soft cheese samples were contaminated by Geotrichum and yeast (Candida norvegensis) but Candida albicans was never identified.

Evidence for determining parasitic factors in addition to host genetics and immune status in the outcome of murine Leishmania infantum visceral leishmaniasis

C.B-17 SCID and congenic BALB/C mice were used to examine Leishmania infantum strain pathogenicity independently of host genetic factors. While parasite loads were significantly higher in immunodeficient mice than in immunocompetent mice, the kinetics of infection during a long-term follow-up were similar, suggesting that intrinsic parasitic factors also influence the outcome of L. infantum infection.

Effects of immunosuppressive therapy on murine Leishmania infantum visceral leishmaniosis

We evaluated the effect of immunosuppressive therapy on the course of infection, the spleen cell immunophenotype and cytokine production during murine Leishmania infantum visceral leishmaniosis (VL). Rousseau et al. [1] recently reported that prolonged administration of dexamethasone induces limited reactivation of chronic murine visceral leishmaniosis, with no clear Th1-Th2 cytokine patterns. We found that another glucocorticoid, hydrocortisone acetate, had similar effects during acute visceral leishmaniosis, i.e. an increase in parasite burden in the spleen, but not the liver, of infected mice. A significant increase in parasite burden in both the liver and the spleen was only achieved when mice were treated with combined dexamethasone + pentoxifylline immunotherapy; increases in parasite burden were never associated with a specific spleen cell immunophenotype or a Th1-Th2 cytokine secretion profile.

[Treatment of visceral leishmaniasis: recent modalities]

AN ENDEMIC DISEASE: Visceral leishmaniasis is an endemic disease in 47 countries and continues to be a difficult therapeutic challenge. The emergence of Leishmania strains resistant to pentavalent antimony derivatives and the growing incidence of visceral leishmaniasis among AIDS patients in the Mediterranean area emphasizes the need for optimal therapeutic management. MORE EFFECTIVE STRATEGIES: During the last few years, alternatives to pentavalent antimony derivatives has disclosed the contribution of amphotericin B, more specifically of lipid formulations of amphotericin B, well tolerated and highly effective drugs [corrected]. Aminosidine, inhibitors of ergosterol synthesis, metronidazole, allupurinol, or miltefosine are also under evaluation. Results have been variable to date. NEW STRATEGIES: It is well demonstrated that the susceptibility of Leishmania to different drugs is species-dependent. Drugs should thus be chosen in accordance with the presumed species in an endemic zone. New strategies based on adapting therapy to the causal species of the parasite, multi-drug regimens, drug vectorization, or restoring immune function in association with secondary prophylaxis in immunodepressed subjects should provide more effective treatment and a lower relapse rate, particularly in patients co-infected with the human immunodeficiency virus.2

[Evolutive visceral malaria and hyperimmune palustral splenomegaly: a difficult distinction]

One case of hyperreactive malarial splenomegaly is reported for a Comores Island patient living in France and having thus lost his protective immunity. Plasmodium falciparum was detected in a bone marrow aspiration, whereas peripheral venous blood samples were negative. A three-month treatment of sulfadoxine + pyrimethamine was effective with a complete regression of splenomegaly and biological disorders.

Experimental evaluation of second-line oral treatments of visceral leishmaniasis caused by Leishmania infantum

In a murine model of Leishmania infantum visceral leishmaniasis, metronidazole, ketoconazole, fluconazole, itraconazole, and terbinafine were less effective than antimonial agents in reducing hepatic parasite load. Ketoconazole potentiated the effect of meglumine antimoniate reference therapy through its marked activity against spleen infection.

Changing patterns of disease and treatment of opportunistic parasitic infections in patients with AIDS

In the past 18 months, the significant effect of highly active antiretroviral therapy and immune reconstitution on the incidence of opportunistic protozoan infections, mainly cryptosporidiosis and microsporidiosis, has been demonstrated in HIV-infected patients. The major therapeutic advances of the past 18 months concern microsporidiosis, for which the efficacies of fumagillin and albendazole have been assessed against Enterocytozoon bieneusi and Encephalitozoon infections, respectively. The efficacy of macrolides is still uncertain for the treatment of cryptosporidiosis; however, promising results were obtained with nitazoxanide. The incidence of toxoplasmosis has markedly decreased as a result of the efficacy of specific prophylaxis, and visceral leishmaniasis is still considered as an emerging opportunistic disease during AIDS.

Influence of the host and parasite strain in a mouse model of visceral Leishmania infantum infection

We investigated the respective roles of the host and parasite strain in a murine model of visceral leishmaniasis. Balb/c and C57Bl/6 mice were selected for their respective 'non cure' and 'cure' haplotypes vis-a-vis Leishmania major. Mice were infected with 10(7) stationary-phase promastigotes of four strains of Leishmania infantum with different infection profiles in mice: visceralization or regulation, as established by Sulahian et al. (Sulahian et al. (1998) FEMS Immunol. Med. Microbiol. 17, 131-138). The infection was monitored by measuring parasite load in the liver and spleen on days 9, 22, 44 and 87 post-infection, using a sensitive microtitration technique. Similar profiles (visceralizing or regulating) were observed in the two mouse strains, suggesting a predominant role of the Leishmania strain in the visceralization process. The host response was assessed by analyzing the granulomatous response in the liver and by quantifying specific IgG, IgG1 and IgG2a as a marker of the Th1/Th2 immune response. A granulomatous response was observed in both strains of mice but was more pronounced with visceralizing strains of L. infantum and in C57Bl/6 mice compared to Balb/c mice. The kinetics of anti-Leishmania IgG antibody production was similar in all the groups, but the distribution of IgG1 and IgG2a isotypes was different between the two mouse strains: Balb/c mice had a predominantly Th2-like response whereas C57Bl/6 had a mixed Th1/Th2-like response. This study demonstrates the determining role of both the parasite and mouse strain in the outcome of L. infantum infection. The Th1/Th2 concept does not seem to explain susceptibility and resistance to infection in our model of visceral L. infantum infection, contrary to the L. major model.

Efficacy of aminosidine administered alone or in combination with meglumine antimoniate for the treatment of experimental visceral leishmaniasis caused by Leishmania infantum

BALB/c mice with an experimental visceral leishmaniasis produced by Leishmania infantum were treated with aminosidine sulphate alone or combined with meglumine antimoniate. Parasite burdens in the liver and spleen were determined by subculturings using a sensitive microtitration method. Treatments with aminosidine alone decreased the parasite burdens compared with those observed in the untreated mice, but were less efficacious than meglumine antimoniate. Aminosidine combined with meglumine antimoniate resulted in an increased efficacy compared with either drug given alone. However, these regimens were associated with toxicities and with persistence of hepatic and splenic leishmanial foci after drug administrations.

Activity of IFN-gamma in experimental Leishmania infantum murine visceral leishmaniasis

The effect of recombinant interferon-gamma (rIFN-gamma) on Leishmania infantum infection was investigated in vivo. BALB/c mice were injected intravenously (i.v.) with 10(7) promastigotes of Leishmania infantum. rIFN-gamma, 10(6) U given intraperitoneally (i.p.) daily on 3 consecutive days or 4 times on alternate days from day 7 (d7) post infection, had no detectable effect on the parasite burdens in liver, spleen, and lungs as compared to untreated mice. However rIFN-gamma enhanced the activity of Glucantime (50 mg/kg/d intraperitoneally for 7 days) in the liver and in the lungs. The additive effect of rIFN-gamma was still observed at day 30 post-infection, i.e. 15 days after cessation of therapy. By contrast the combination of the two drugs had no activity against splenic parasites.

Transmission of hepatitis C virus in allografted patients: use of viral genotyping as an epidemiological marker

One hundred and ninety-two allografted patients were tested for hepatitis C virus (HCV) RNA from 1992 to 1995 in Saint-Louis Hospital (Paris). They received blood products and intravenous immunoglobulins (IVIG) and more particularly Gammagard IVIG suspected of transmitting HCV (batches distributed in France between January 1993 and February 1994). The presence of serum HCV RNA was tested by polymerase chain reaction (PCR) in 86 patients who received Gammagard IVIG during the critical period and in 106 patients treated with IVIG other than the suspected batches of Gammagard (negative controls). HCV RNA positive sera were HCV genotyped. Ten out of 86 patients who received Gammagard IVIG during the exposed period vs 0 out of 106 negative controls were HCV RNA positive showing a higher prevalence of HCV infection in the exposed patients that in the negative controls (P = 0.001). The link between HCV transmission and IVIG infusion was reinforced by the high frequency of genotype 2b (70%) in the exposed patients because genotype 2b is an underrepresented subtype in France (< 1%).

Lipid formulations of amphotericin b in the treatment of experimental visceral leishmaniasis due to Leishmania infantum

Despite significant antileishmanial activity of amphotericin B (AmB) in vitro, the use of the deoxycholate formulation (Fungizone) is limited because of serious side effects. Lipid formulations of AmB have been proposed to reduce this toxicity. We compared the tolerance and efficacy of the conventional AmB prepared with deoxycholate, AmB emulsified in Intralipid 20%, amphotericin B lipid complex (Abelcet), and liposomal AmB (AmBisome) in a murine model of visceral leishmaniasis induced by Leishmania infantum. Control groups included untreated mice and mice treated with the pentavalent antimonial (Glucan-time). Balb/C mice were infected intravenously on day 0 with 10(7) promastigotes of L. infantum, then treated from days 7 to 17 (early treatment group) or from days 60 to 70 (delayed treatment group). Glucan-time was administered daily by intraperitoneal injection, whereas AmB formulations were administered intravenously on alternate days. On days 20, 60 and 120 in the early treatment group and 72 and 125 in the delayed treatment group, parasite burdens were determined in liver, spleen, and lungs by subculturing using a microtitration method. Abelcet (12 mg/kg) and AmBisome (12 mg/kg) completely eradicated the parasites from the tissues. Both of these lipid formulations enabled higher dosages to be tolerated, and were remarkably more effective than Fungizone (0.8 mg/kg) and AmB diluted in Intralipid 20% (1.2 mg/kg) in the treatment of murine visceral leishmaniasis due to L. infantum.

Therapy of visceral leishmaniasis due to Leishmania infantum: experimental assessment of efficacy of AmBisome

The tolerance and efficacy of amphotericin B (AmB) deoxycholate (Fungizone) were compared with those of liposomal AmB (AmBisome) in a murine model of visceral leishmaniasis induced by Leishmania infantum. Control groups consisted of untreated mice and mice treated with a pentavalent antimonial (Glucantime). BALB/c mice were infected intravenously on day 0 with 10(7) promastigotes of L. infantum and then treated from day 7 to 17 (early treatment group) or from day 60 to 70 (delayed treatment group). The pentavalent antimonial was administered daily by intraperitoneal injection, whereas AmB formulations were administered intravenously on alternate days. On days 20, 60, and 120 (early treatment group) and on days 72 and 125 (delayed treatment group), parasite burdens in the liver, spleen, and lungs were determined by subculturings using a microtitration method. A dose range study showed that administration of AmBisome at the well-tolerated doses of 5 or 50 mg/kg of body weight completely eradicated the parasites from the tissues. At 0.8 mg/kg, AmBisome proved more efficacious than AmB deoxycholate administered at the same dose. We also compared the levels of AmB deoxycholate and AmBisome in plasma and tissue. Mice treated with AmBisome had levels of AmB in tissue much higher than did AmB deoxycholate-treated mice with persistent detectable levels 14 weeks after treatment. These results seem to account for the remarkable efficacy of the liposomal formulation of AmB in the treatment of visceral leishmaniasis due to L. infantum.