F. Makni

Pathogenic free-living amoebae: Epidemiology and clinical review

Free-living amoebae are widely distributed in soil and water. Small number of them was implicated in human disease: Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris and Sappinia diploidea. Some of the infections were opportunistic, occurring mainly in immunocompromised hosts (Acanthamoeba and Balamuthia encephalitis) while others are non opportunistic (Acanthamoeba keratitis, Naegleria meningoencephalitis and some cases of Balamuthia encephalitis). Although, the number of infections caused by these amoebae is low, their diagnosis was still difficult to confirm and so there was a higher mortality, particularly, associated with encephalitis. In this review, we present some information about epidemiology, ecology and the types of diseases caused by these pathogens amoebae.

Epidemiology of dermatophytoses in Sfax, Tunisia.

The distribution of dermatophytes varies in different countries and geographical areas depending on several factors. To determine the frequency of aetiological agents and the clinical variants of dermatophytoses, we carried out a study between 1998 and 2007. Out of 25 432 subjects suspected to have superficial mycoses, 9960 (39.2%) were affected with dermatophytoses; 14957 positive samples were obtained. The mean age was 35.7 years (range: 21 days to 97 years). Sex ratio was 0.9. Our patients were from urban regions in 81.9% of cases. The most common type of infection was onychomycosis (30.3%), followed by tinea pedis (24.8%), intertrigo (21.7%), tinea corporis (11.4%) and tinea capitis (9.6%). Fifteen patients had generalised dermatophytosis. Hadida and Schousboe disease was diagnosed in one case with lethal evolution. The most isolated dermatophyte was Trichophyton rubrum (74.5%), followed by T. violaceum (7.9%), T. mentagrophytes (7.5%), Microsporum canis (3.8%), Epidermophyton floccosum (0.7%) and T. verrucosum (0.54%). Other species were occasionally isolated: T. schoenleinii, T. tonsurans, M. audouinii and M. ferrugineum. The prevalence of dermatophytoses remains high in our country (996 cases/year). Trichophyton rubrum is the predominant causal agent. However, zoophilic agents become more prevalent. Epidemiological surveys are an essential tool for developing strategies for infection control.

Microsatellite Typing To Trace Aspergillus flavus Infections in a Hematology Unit

ABSTRACT Assessing the relatedness of strains isolated from patients and their environment is instrumental in documenting the source of preventable health care-associated life-threatening Aspergillus flavus human infection clusters. The present study aimed at identifying and selecting suitable microsatellite markers for A. flavus typing. This typing scheme was then applied to investigate the A. flavus epidemiology within a hematology unit in Sfax, Tunisia. Use of a combination of five markers made it possible to discern clusters of isolates and to substantiate the genetic diversity of A. flavus within clusters. Isolates from Tunisia and Marseille, France, displayed distinct haplotypes, indicating a highly significant geographical structuring of A. flavus. The typing of clinical and environmental A. flavus isolates in a hematology unit provided insights into its hospital epidemiology. From a heterogeneous genetic background, a cluster indicative of a clonal propagation episode within the unit could be identified. In two patients with invasive aspergillosis, the same genotype was found in clinical and environmental isolates, indicating hospital-acquired colonization and infection. In further studies, this novel microsatellite typing scheme might be instrumental in illuminating important epidemiological issues about A. flavus population genetics or epidemiology, including tracing the sources and routes of transmission.

Invasive aspergillosis: epidemiology and environmental study in haematology patients (Sfax, Tunisia)

Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Preventive measures are important to control IA because diagnosis is difficult and the outcome of treatment is poor. We prospectively examined the environmental contamination by Aspergillus and other fungal species and evaluated the prevalence of invasive aspergillosis in the protect unit of haematology. A three‐year prospective study (December 2004–September 2007) was carried out in the department of haematology of Hedi Chaker Hospital. Suspected invasive aspergillosis cases were reviewed and classified as proven, probable and possible invasive aspergillosis using the EORTC criteria. During the study period, we collected weekly environmental samples (patient’s rooms, tables and acclimatisers) and clinical samples from each patient (nasal, expectoration and auricular). Among 105 neutropenic patients, 16 had probable and 13 had possible IA. A total of 1680 clinical samples were collected and A. flavus was most frequently isolated (79.2%). Analysis of 690 environmental samples revealed that Penicillium (44%) was the most frequent followed by Cladosporium (20%), Aspergillus spp. (18%) and Alternaria (13%). The PCR‐sequencing of 30 A. flavus isolates detected from clinical and environmental samples confirmed the mycological identification. Our findings underline the importance of environmental surveillance and strict application of preventive measures.

Comparison of PCR-ELISA and Real-Time PCR for invasive aspergillosis diagnosis in patients with hematological malignancies

This study aimed at comparing a real-time PCR assay and a PCR-ELISA assay of both serum and bronchoalveolar lavage (BAL) samples for the diagnosis of invasive aspergillosis (IA) in patients with hematological malignancies. Using a nested case-control design, 163 patients at risk were prospectively monitored and PCR assays were performed on frozen aliquots of 459 sera which were prospectively sampled twice weekly and 42 BAL specimens sampled from 43 probable and one proven IA cases and 47 matched controls. The data from three patients classified as possible IA were excluded from the nested case-control study. The sensitivity of real-time PCR and PCR-ELISA assays in serum was 73% and 86%, respectively and specificity was 100% for both. In BAL, sensitivity was 64% for real-time PCR, 71% for PCR-ELISA and 86% for Galactomannan antigen (GMA) assays with specificities of 96%, 96%, and 93%, respectively. While slightly less sensitive, the real time-PCR assay was highly specific and considerably faster and more workable than PCR-ELISA. Combining real-time PCR and GMA detection for both serum and BAL samples enhances routine laboratory IA diagnosis.

Candida dubliniensis: first identification in Sfax hospital, Tunisia

Candida dubliniensis, a newly described fungal pathogen associated mainly to immunocompromised host’s infection, is phenotypically closely related to C. albicans. In this study, we report for the first time, isolation and identification, in Tunisia, of 14 isolates of C. dubliniensis from 12 human immunodeficiency virus‐negative patients hospitalised in the intensive care unit (ICU) at Habib Bourguiba Sfax Hospital. Our study was firstly based on the failure to grow at 45 °C. This presumptive identification was completed by other tests: chlamydospore production, culture on Candiselect4 (Bio‐Rad) and the commercial test Bichro‐Dubli fumouze®, which specifically identify C. dubliniensis. The confirmation of the discrimination between both species was performed by PCR, targeting the hyphal wall protein (HWP1) gene. The recovery of C. dublinensis by routine laboratory diagnosis is recommended for elucidating the epidemiology of this novel pathogen.

Phtiriase ciliaire de l’enfant. Diagnostic et traitement

Introduction La phtiriase ciliaire est une blepharite a phtirius pubis. Il s’agit d’une ectoparasitose qui s’observe plus frequemment chez l’adulte. Une atteinte pubienne lui est habituellement associee. Elle est cependant rare chez l’enfant. Le but de cette etude est de rapporter quatre observations de phtiriase ciliaire infantile. Patients et methodes Quatre enfants se sont presentes pour prurit palpebral et rougeur oculaire. L’examen a la lampe a fente a permis de constater une irritation du bord libre palpebral et la presence de petits parasites solidement ancres le long des cils et des lentes accrochees a la base des cils. Une enquete au sein de l’entourage a ete menee et un examen parasitologique a ete realise. Resultats L’examen parasitologique a permis d’identifier les formes adultes et les lentes de phtirius. Les resultats de l’enquete au sein de l’entourage a permis de determiner la voie de contamination. Il s’agit d’une transmission par la literie. Une extraction du parasite a la pince est tentee, mais elle a ete tres douloureuse. Un traitement a base d’oxyde jaune de mercure 1 % a ete instaure chez deux patients, les deux autres ont ete traites par vaseline pommade en raison d’une irritation palpebrale tres importante. L’evolution a ete favorable chez tous les patients. Discussion Dans ce travail, nous discutons des modes de contamination de phtirus pubis chez l’enfant. En fait, la localisation ciliaire chez l’enfant est secondaire a une contamination au contact d’un adulte porteur de phtiriase pubienne. La transmission peut se faire suite a des sevices sexuels ou par le biais de vetements ou de literie infectes. Le diagnostic clinique de phtiriase ciliaire est confirme par l’examen parasitologique. Differentes therapeutiques ont ete proposees. Un traitement mecanique doit etre realise, mais il est rarement suffisant et il faut souvent l’associer a un traitement chimique (malathion a 1%, oxyde de mercure a 1 %, fluoresceine a 20 %…) ou physique (cryotherapie, laser argon). Conclusion La blepharite a phtirus pubis est de diagnostic facile et necessite la mise en route d’une enquete de l’entourage afin de detecter la source de contamination et de prevenir les reinfestations.

Clinical utility and prognostic value of galactomannan in neutropenic patients with invasive aspergillosis

UNLABELLED Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients. Delayed diagnosis and therapy may lead to poor outcomes. AIMS The objective of this study was to assess the performance characteristics of the galactomannan (GM) assay in serum and bronchoalveolar lavage specimens for the diagnosis of IA in neutropenic patients with hematological malignancies. We also evaluated the prognostic outcome. PATIENTS AND METHODS A total of 1198 serum samples and 42 BAL from 235 neutropenic patients were tested with a GM elisa platelia test. We used Cox modeling of time to 6- and 12-week mortality for GM level at the time of diagnosis (GM0) and GM decay in the week following diagnosis in proven and probable IA patients with more than two GM values. RESULTS There were three proven, 55 probable, and four possible cases of IA. The sensitivity and specificity of the GM test were 96.8% and 82.4% respectively. In BAL samples, sensitivity was 86% and the specificity 93%. BAL GM was more sensitive than microscopy (22.2%) and BAL culture (38.9%). Among patients with proven/probable IA, serum and BAL GM were in agreement for 92.8% of paired samples. The hazard ratio (HR) of GM0 and 1-week GM decay per unit increase in Aspergillus enzyme immunoassay (EIA) was 1.044 (95% CI, 0.738 to 1.476) and 0.709 (95% CI, 0.236 to 2.130) respectively. CONCLUSION We found good correlation between the GM0 and GM decay combination and outcome of IA patients. The GM is a useful tool for diagnosis and monitoring of IA.

Invasive fungal infections in renal transplant recipients: About 11 cases

UNLABELLED Invasive fungal infections are a major complication and an important cause of morbidity and mortality among solid organ transplant recipients. Their diagnosis is difficult and their prognosis is often pejorative. OBJECTIVE The aim of this study was to report the cases of invasive fungal infections in renal transplant recipients in Habib Bourguiba Sfax university hospital and to identify the main fungal agents. MATERIALS AND METHODS It is a retrospective study of invasive fungal infections in renal transplant recipient reported in our hospital from January 1995 to February 2013. RESULTS Invasive fungal infections were diagnosed in 11 cases (3.4%) among 321 renal transplant recipients. These infections included four cases of pneumocystosis, two cases of candidiasis, two cases of aspergillosis, two cases of cryptococcosis and one case of mucormycosis. There were six men and five women. The mean age was 37 years. The infection was late in 63% of cases (>3 months after transplantation). The prolonged corticosteroid and immunosuppressive therapy were the main risk factors (100%) followed by renal failure (45%), graft rejection (45%), broad spectrum antibiotics (45%), CMV infection (36%), neutropenia (36%) and dialysis (18%). The evolution under treatment was favourable only in two cases (18%). CONCLUSION Invasive fungal infections are not common among kidney transplant recipients. However, they remain an important cause of morbidity and mortality in this group of patients. Prevention, early diagnosis and appropriate management are necessary to improve prognosis and reduce mortality rate.

Ethnic and socio-cultural specificities in Tunisia have no impact on the prevalence of anti-Saccharomyces cerevisiae antibodies in Crohn's disease patients, their relatives or associated clinical factors.

Background. In Western Europe and the USA, the presence of anti-Saccharomyces cerevisiae antibodies (ASCAs) in Crohns disease (CD) patients and their healthy relatives suggests that ASCAs may be influenced by genetic and/or environmental factors. Objectives. To assess the prevalence of ASCAs in Tunisian patients with CD or ulcerative colitis (UC), and unaffected family members, in relation to clinical phenotype. Patients and methods. Seventy-seven patients (39 CD, 38 UC), 66 healthy relatives of CD patients, 16 relatives of UC patients and 70 healthy controls were studied. ASCAs were quantified with a new isotype-specific ELISA test involving an antigenic extract from S. cerevisiae strain W303 and by the original test which detects total immunoglobulins against S. cerevisiae Su1 mannan. Results. The specificity of the two tests was identical (91%). The isotype-specific ASCA W303 test was more sensitive than the ASCA Su1 test for immunoglobulin detection, but some CD patients were positive only with this latter test. A high percentage of patients with CD (72%) and their unaffected family members (35%) were ASCA-positive in contrast to UC patients (16%) and their relatives (0%) and controls (8.6%). ASCAs were shown to be independent of rural or urban living, disease activity, but were associated with ileal location. The antigen of S. cerevisiae strain W303 discriminated patients depending on age at onset or location of the disease. Conclusion. This study confirms the antigenic heterogeneity of S. cerevisiae strains in their ability to detect ASCA. It suggests that ASCAs are markers of immunoregulatory disturbance in CD, independently of ethnic/cultural differences between Europe, the USA and North Africa.