M. Gari-Toussaint

Use of the leishmanin skin test and Western blot analysis for epidemiological studies in visceral leishmaniasis areas: experience in a highly endemic focus in Alpes-Maritimes (France)

Fifty unselected subjects living in Alpes-Maritimes, France, a high risk area for visceral leishmaniasis due to Leishmania infantum, were examined simultaneously by the leishmanin skin test and the Western blot technique in 1993; 32% and 38%, respectively, gave a positive reaction. The concordance of the 2 methods was 82%. Thus, in this high risk area, a large proportion of inhabitants had been exposed to the parasite. The use of these 2 tests should permit the detection of potential cases of reactivated leishmaniasis in prospective follow-up investigations.

A century of leishmaniasis in Alpes-Maritimes, France.

Health decision-makers working in Africa often need to act for millions of people over large geographical areas on little and uncertain information. Spatial statistical modelling and Bayesian inference have now been used to quantify the uncertainty in the predictions of a regional, environmental risk map for Loa loa (a map that is currently being used as an essential decision tool by the African Programme for Onchocerciasis Control). The methodology allows the expression of the probability that, given the data, a particular location does or does not exceed a predefined high-risk threshold for which a change in strategy for the delivery of the antihelmintic ivermectin is required.

Human visceral leishmaniasis in Alpes-Maritimes, France: epidemiological characteristics for the period 1985–1992

In 8 years (1985-1992), 65 cases of human visceral leishmaniasis (HVL) have been diagnosed in the department of Alpes-Maritimes, France, 56 of them having been infected locally. The annual frequency has increased from 3 cases in 1985 to 15 cases in 1992. There is a low rate of paediatric cases (29%) and a predominance of males among adult cases (85%). Since 1986, 19 cases of co-infection with Leishmania and human immunodeficiency virus 1 have been reported, corresponding to 40% of adult cases and to 30% of the total cases. The frequency of co-infections is stable at about 3 per annum. Isoenzymatic identification of the strains isolated from patients confirmed Leishmania infantum zymodeme MON-1 as responsible for most if not all HVL in the department of Alpes-Maritimes; 42 of the 44 strains isolated belonged to that zymodeme.

Detection by Western blot of four antigens characterizing acute clinical leishmaniasis due to Leishmania infantum

Western blot analysis of sera from 32 patients with acute clinical leishmaniasis due to Leishmania infantum showed the simultaneous presence of antibodies against 4 antigens with molecular masses of 18, 21, 23, 31 kDa. The simultaneous presence of these 4 antigens was specific to the clinical disease and it was not detected in 47 sera from asymptomatic individuals living in the leishmaniasis endemic area of Alpes-Maritimes (southern France) or in 37 sera from patients with other protozoan infections.

Usefulness of molecular biology performed with formaldehyde-fixed paraffin embedded tissue for the diagnosis of combined pulmonary invasive mucormycosis and aspergillosis in an immunocompromised patient

Immunocompromised patients who develop invasive filamentous mycotic infections can be efficiently treated if rapid identification of the causative fungus is obtained. We report a case of fatal necrotic pneumonia caused by combined pulmonary invasive mucormycosis and aspergillosis in a 66 year-old renal transplant recipient. Aspergillus was first identified during the course of the disease by cytological examination and culture (A. fumigatus) of bronchoalveolar fluid. Hyphae of Mucorales (Rhizopus microsporus) were subsequently identified by culture of a tissue specimen taken from the left inferior pulmonary lobe, which was surgically resected two days before the patient died. Histological analysis of the lung parenchyma showed the association of two different filamentous mycoses for which the morphological features were evocative of aspergillosis and mucormycosis. However, the definitive identification of the associative infection was made by polymerase chain reaction (PCR) performed on deparaffinized tissue sections using specific primers for aspergillosis and mucormycosis. This case demonstrates that discrepancies between histological, cytological and mycological analyses can occur in cases of combined mycotic infection. In this regard, it shows that PCR on selected paraffin blocks is a very powerful method for making or confirming the association of different filamentous mycoses and that this method should be made available to pathology laboratories.

Usefulness of frozen section in rhinocerebral mucormycosis diagnosis and management

Aims: Rhinocerebral mucormycosis (RCM) is a well‐described fulminant fungal infection that presents acutely in patients with ketoacidosis and immunosuppression. Very early diagnosis, established with the demonstration of characterised hyphae in tissues, greatly improves the prognosis of RCM. In this regard, the specificity and the sensitivity of frozen section for the diagnosis and the surgical debridement of RCM were evaluated in this study. Methods and results: Frozen section was performed for the diagnosis (six of seven cases) and surgical treatment (three of seven cases) of RCM. In all cases, diagnosis was made by frozen section and confirmed by histological examination. Frozen section allowed radical surgical excision of infected tissue. In all cases, invasive, broad‐based non‐septated hyphae with branching at right angles were well demonstrated on toluidine blue staining. Cultures were positive for Rhizopus oryzae in three of seven cases. Outcome was favourable for five of seven patients and two patients died after the diagnosis. Conclusions: Frozen section is a specific and sensitive method to make both a quick initial diagnosis of RCM and to successfully eradicate the tissue infected by organisms belonging to the order Mucorales.

Detection of Pneumocystis jirovecii by Quantitative PCR To Differentiate Colonization and Pneumonia in Immunocompromised HIV-Positive and HIV-Negative Patients

ABSTRACT Pneumocystis jirovecii pneumonia (PCP) is an acute and life-threatening lung disease caused by the fungus Pneumocystis jirovecii. The presentation of PCP in HIV-positive patients is well-known and consists of a triad of dyspnea, fever, and cough, whereas the presentation of PCP in HIV-negative patients is atypical and consists of a sudden outbreak, O2 desaturation, and a rapid lethal outcome without therapy. Despite the availability of direct and indirect identification methods, the diagnosis of PCP remains difficult. The cycle threshold (CT ) values obtained by quantitative PCR (qPCR) allow estimation of the fungal burden. The more elevated that the fungal burden is, the higher the probability that the diagnosis is pneumonia. The purposes of the present study were to evaluate the CT values to differentiate colonization and pneumonia in a population of immunocompromised patients overall and patients stratified on the basis of their HIV infection status. Testing of bronchoalveolar lavage (BAL) fluid samples from the whole population of qPCR-positive patients showed a mean CT value for patients with PCP of 28 (95% confidence interval [CI], 26 to 30) and a mean CT value for colonized patients of 35 (95% CI, 34 to 36) (P < 10−3). For the subgroup of HIV-positive patients, we demonstrated that a CT value below 27 excluded colonization and a CT value above 30 excluded PCP with a specificity of 100% and a sensitivity of 80%, respectively. In the subgroup of HIV-negative patients, we demonstrated that a CT value below 31 excluded colonization and a CT value above 35 excluded PCP with a specificity of 80% and a sensitivity of 80%, respectively. Thus, qPCR of BAL fluid samples is an important tool for the differentiation of colonization and pneumonia in P. jirovecii-infected immunocompromised patients and patients stratified on the basis of HIV infection status with different CT values.

Adjuvant corticosteroid therapy in 2 children with hepatosplenic candidiasis-related IRIS.

First described in HIV-infected patients who recently initiated highly active antiretroviral therapy, the immune reconstitution inflammatory syndrome (IRIS) is best characterized as a collection of inflammatory disorders triggered by rapid resolution of immunosuppression. Treatment of IRIS is a clinical challenge due to the variety of clinical presentations and the presence of multiple pathogens capable of causing the syndrome. Hepatosplenic candidiasis, an uncommon form of invasive Candida species infection, was recently suggested to belong to the spectrum of fungus-related IRIS. We report 2 cases of probable hepatosplenic candidiasis according to the guidelines of the European Organization for Research and Treatment of Cancer and the Mycosis Study Group, occurring in pediatric patients with acute leukemia during rapid neutrophil recovery after cytotoxic chemotherapy. In both cases, abdominal computed tomography scan revealed multiple hepatic micronodules, and liver biopsy showed nonspecific granulomatous lesions. Hepatosplenic candidiasis symptoms (fever, nausea and vomiting, abdominal pain) resolved within 2 days after adjunction of corticosteroid therapy to antifungal treatment. Inflammatory markers and related radiologic abnormalities decreased or disappeared within 1 month. Recovery of neutrophil count in a context of hepatosplenic candidiasis may result in a heightened inflammatory response. Corticosteroid therapy in this setting is associated with prompt resolution of the symptoms.

Surveillance mycologique de l’eau pour la prévention des mycoses invasives dans les établissements de santé : Propositions de standardisation des méthodologies

OBJECTIVES The aims of this study were to assess the risk of fungal infections related to the water supply in several hospitals and to clarify the appropriate methodology in order to standardize the technical conditions of the controls and develop guidelines. It was conducted in 10 university hospital centers across the country from February 2004 through March 2005. METHOD A preliminary study allowed us to optimize the mycological analysis. The study was conducted under the same conditions as for bacteriological controls: water filtration through a cellulose acetate membrane cultured on agar. Departments with the highest patient risk were selected, including hematology, organ transplantation, and burn units. We selected 98 sites and sampled both water and water-related surfaces at each: three one-liter water samples (the first flow, cold and hot water) and two or three surface samples (inside the tap, pommel of the shower and siphon). At each site, a form was filled to specify its location in the unit, any water treatment (chlorine or other), filtering, and temperature. Water from taps equipped with sterilized filtration was sampled without the filter. RESULTS There was a significant difference (p=0.039) in the number of positive cultures between the three types of water sampled: hot water (>50 degrees C) was colonized less often than first flow or cold water. Only 4% of the hot-water samples had positive cultures, compared to the 52% of the cold-water samples. Except in two hospitals with generalized contamination of the water pipes (one with Exophiala spp and the other with Fusarium spp), colonization was usually slight. Cold water was more colonized than hot water, but 79% of the samples yielded fewer than 5CFU/L. Dematiaceous hyphomycetes were isolated; Aspergillus spp were rare. The number of CFU in surface samples (that is, biofilms) was higher (mean=15 CFU per sample) but surfaces were positive less often than water (13% compared with 43% of all water samples). Sampling from siphons was productive more often than from taps (23%), but the molds isolated differed from those in the related water. Relations to bacterial flora and P. aeruginosa were also studied, together with the effects of chemical treatment. CONCLUSION Current regulations require only bacteriological survey. The absence of knowledge about the threshold of contamination at which there is a risk of nosocomial invasive fungal infections makes it difficult to impose routine monitoring. Mycological surveys of water are required during hospital renovation, plumbing work, pipe maintenance and when air samples are negative during nosocomial infection investigations.

[Prevention of fungal infections related to the water supply in French hospitals: proposal for standardization of methods].

OBJECTIVES The aims of this study were to assess the risk of fungal infections related to the water supply in several hospitals and to clarify the appropriate methodology in order to standardize the technical conditions of the controls and develop guidelines. It was conducted in 10 university hospital centers across the country from February 2004 through March 2005. METHOD A preliminary study allowed us to optimize the mycological analysis. The study was conducted under the same conditions as for bacteriological controls: water filtration through a cellulose acetate membrane cultured on agar. Departments with the highest patient risk were selected, including hematology, organ transplantation, and burn units. We selected 98 sites and sampled both water and water-related surfaces at each: three one-liter water samples (the first flow, cold and hot water) and two or three surface samples (inside the tap, pommel of the shower and siphon). At each site, a form was filled to specify its location in the unit, any water treatment (chlorine or other), filtering, and temperature. Water from taps equipped with sterilized filtration was sampled without the filter. RESULTS There was a significant difference (p=0.039) in the number of positive cultures between the three types of water sampled: hot water (>50 degrees C) was colonized less often than first flow or cold water. Only 4% of the hot-water samples had positive cultures, compared to the 52% of the cold-water samples. Except in two hospitals with generalized contamination of the water pipes (one with Exophiala spp and the other with Fusarium spp), colonization was usually slight. Cold water was more colonized than hot water, but 79% of the samples yielded fewer than 5CFU/L. Dematiaceous hyphomycetes were isolated; Aspergillus spp were rare. The number of CFU in surface samples (that is, biofilms) was higher (mean=15 CFU per sample) but surfaces were positive less often than water (13% compared with 43% of all water samples). Sampling from siphons was productive more often than from taps (23%), but the molds isolated differed from those in the related water. Relations to bacterial flora and P. aeruginosa were also studied, together with the effects of chemical treatment. CONCLUSION Current regulations require only bacteriological survey. The absence of knowledge about the threshold of contamination at which there is a risk of nosocomial invasive fungal infections makes it difficult to impose routine monitoring. Mycological surveys of water are required during hospital renovation, plumbing work, pipe maintenance and when air samples are negative during nosocomial infection investigations.