E. Siala

Les cultures sur milieu NNN dans le diagnostic biologique des leishmanioses

Cutaneous and visceral leishmaniasis (VL, CL) represent the most frequent vector-borne diseases in Tunisia. Their biological confirmation is necessary before the administration of restricting, expensive and toxic specific treatments. Retrospective evaluation of the contribution of Leishmania cultures on NNN medium in leishmaniasis diagnosis have been done using the data of 375 cultures concerning 214 CL cases and 125 VL cases consecutively recruited in Pasteur Institute of Tunisia between 1995 and 2007. The global sensitivity of the culture in the course of CL was of 68.2%. It was significantly higher during zoonotic CL (78.8%) compared to that during sporadic CL (54.9%); p<0.001. This difference is explained by the easier thrust in NNN medium of Leishmania (L.) major, the agent of zoonotic CL than that of L. infantum, particularly its zymodeme MON-24, agent of sporadic CL. In the course of VL, and in spite of the better sensitivity of bone marrow aspirates (BMA) culture (70.8%), the blood buffy-coat, which permit to avoid the trauma induced by BM aspiration gave promising results (58.2%), the difference being not significant. Besides, in the course of both CL and VL, the direct examination of smears is revealed more sensitive, respectively 89.7% and 93.4% (p<0.01 and p<0.01). Although, systematic cultures practise, in parallel with direct examination, is recommended. In fact, in addition of straightening out some diagnosis, 22 cases in our series, the culture provide the isolation and the isoenzymatic identification of the causative species and strains allowing a better comprehend of parasite life cycles and a disposing of important epidemiological data for suitable control measures. As known with all cultures, those of Leishmania are also exposed to the contamination problem, which reached 5.9% in our study. In conformity with previsions, the contamination concerned much more cutaneous samples (8.4%) than blood or BM ones (2.5%; p=0.015).

Caractérisation comparative des trois formes de leishmaniose cutanée endémiques en Tunisie

BACKGROUND The recent spread in the geographical distribution of the three forms of cutaneous leishmaniasis (CL) endemic in Tunisia has resulted in the coexistence of more than one species of Leishmania (L.) in some foci, rendering characterization on the basis of geographical criteria alone more difficult. The aim of the study was to establish clinical criteria associated with these noso-geographic forms, namely sporadic CL (SCL) due to L. infantum, zoonotic CL (ZCL) due to L. major and chronic CL (CCL) due to L. tropica. PATIENTS AND METHODS One hundred and twelve patients with biologically confirmed CL were involved in the study. Leishmania species was systematically identified by iso-enzyme analysis and/or PCR-RFLP. Details of the number, the location, the morphological aspect and the month of outbreak of the lesions were noted for each patient. RESULTS SCL lesions appeared later than ZCL lesions (53.8% of cases appeared from December onwards vs. 23.6%, P<0.001). ZCL lesions were often multiple (75%) and situated on the limbs (84.7%, P<0.001), whereas SCL lesions were single (92.3%, P<0.001) and located on the face (84.6%, P<0.001). CCL lesions were also single (78.6%) and located on the face (71.4%). The classical ulcerous presentation with scabs was mainly observed in ZCL patients (69.4%) and the erythematous presentation was described more frequently in SCL patients (75%; P<0.001). CONCLUSION The number, site, morphological aspect and month of outbreak of lesions could be considered as useful criteria that help differentiate between the three noso-geographical forms of CL prevailing in Tunisia. Such characterization is useful for the individual management of patients and for optimizing the combat against the disease.

Relapse of Plasmodium malariae malaria 20 years after living in an endemic area

INTRODUCTION Malaria has been eradicated in Tunisia since 1979. Although it continues to be evoked in the case of fever after travel to an endemic zone, its diagnosis is however difficult during relapses, notably when they are delayed. OBSERVATION A 50 year-old man having lived in Mauritania from 1978 to 1982 was hospitalized for interstitial pneumopathy and urarthritis. In spite of treatment with broad spectrum antibiotics, the fever accompanied by abundant sweating persisted. A thick blood drop and blood smear was requested and led to the diagnosis of Plasmodium malariae malaria. DISCUSSION This observation recalls the possibility of parasitic upsurge of some plasmodial species. It should prompt physicians to be careful and evoke malaria in the case of fever in subjects having stayed, even several years before, in an endemic zone. This would permit early diagnosis and treatment.Resume Introduction Une dissemination et une evolution grave d’une anguillulose sont possibles en cas d’immuno-depression. Observation Un homme de 52 ans ayant un lymphome T et traite par corticoides a developpe une anguillulose disseminee et une meningite a Enterococcus faecalis. Commentaires L’anguillulose disseminee est une manifestation d’hypervirulence du parasite favorisee par une immunodepression cellulaire. Une infection pulmonaire et meningee a germes intestinaux a ete diagnostiquee.

Dépistage de la toxoplasmose materno-foetale : étude des cas suivis à l’Institut Pasteur de Tunis (2007–2010)

Toxoplasmosis when occurring during pregnancy can be transmitted to the fetus and lead to congenital toxoplasmosis (CT). Therefore, pregnant women are a risk group, for which it is necessary to determine the serologic profile. The objective of this study is to determine the serologic profile of toxoplasmosis in pregnant women followed at the Parasitology Laboratory of the Pasteur Institute in Tunis, to establish the prevalence of toxoplasmic infections during pregnancy and the incidence of the CT, noting the difficulties faced in the interpretation of serological results. This is a retrospective study concerning 2833 toxoplasmic serologies practiced on 2070 pregnant women, followed at the Parasitology-Mycology Laboratory of the Pasteur Institute of Tunis, between 2007 and 2010. Serological diagnosis of toxoplasmosis was done by ELISA (Enzyme Linked Immunosorbent Assay) for the detection of Immunoglobulin (Ig) G and M and the study of toxoplasmosis IgG avidity. Prenatal diagnosis was performed for 58 women by amniotic fluid sampling. Toxoplasma gondii was detected by Polymerase Chain Reaction (PCR). At birth, the diagnosis of congenital toxoplasmosis was established based on serology. The toxoplasmic serologies carried out have shown that 45.6% of the pregnant women were formerly immunized while 49.6% had a negative serology. A toxoplasmosis primary infection acquired during pregnancy was detected in 79 cases (3.8%). Among them, 33% had a true seroconversion while 67% had a recent toxoplasmosis infection in view of the positivity of IgG and IgM on the first sample with a low index of avidity (IA). For 21 parturients whose serology showed the presence of IgG, IgM and an intermediate or high IA. Among the 58 parturients in whom prenatal diagnosis was performed, PCR was positive in four cases. After birth, six cases of congenital toxoplasmosis were detected by serology.

Tunisian Toxoplasma gondii strains genotyping by the use of AK69 marker

BackgroundClinical manifestation due to infection by Toxoplasma gondii is closely linked to the infecting strain of the parasite. Several genetic markers are available to determinate its genotype but few of them are able to discriminate between the three predominant lineages, namely types I, II and III. The number of markers decreases when atypical, recombinant/mixed genotypes need to be identified.FindingsIn our study, the contribution of sequence polymorphisms in the AK69 gene as typing markers for T. gondii was investigated for the first time in an epidemiological study. The coding region of the marker was amplified, sequenced and aligned for different Toxoplasma strains. The identified nucleotide polymorphism at 12 positions was able to highly discriminate between the different congenital toxoplasmosis Tunisian strains. Moreover the high detection sensitivity level of the marker enabled unambiguous identification of mixed/recombinant genotypes directly.ConclusionIt can be, thus, very useful for direct typing in areas where such genotypes are frequently encountered, mainly in the African continent.

Place de l’identification des leishmanies par la polymerase chain reaction – restriction fragment length polymerase dans l’étude de l’épidémiologie des leishmanioses cutanées en Tunisie

AIM Three forms of cutaneous leishmaniasis (CL) are endemic in Tunisia. The identification of the causative species is useful to complete epidemiological data and to manage the cases. The aim of this study is to assess PCR-RFLP technique in the identification of Leishmania species responsible of CL in Tunisia and to compare the results of this technique to those of isoenzyme analysis. PATIENTS AND METHODS Sixty-one CL lesions were sampled. Dermal samples were tested by culture on NNN medium and analyzed by PCR-RFLP assay targeting the ITS1 region of ribosomal DNA. Species identification was performed by both iso-enzymatic typing for positive cultures and analysis of restriction profiles after enzymatic digestion by HaeIII of the obtained amplicons. RESULTS Thirty-eight (62%) samples were positive by culture. The iso-enzymatic typing of 32 isolates identified 3 L. infantum, 23 L. major MON-25 and 6 L. tropica MON-8. Sixty samples were positive by PCR. The PCR-RFLP digestion profiles of the 56 PCR products identified 12 L. infantum, 38 L. major and 6 L. tropica. The results of both techniques were concordant in the 32 strains identified by both techniques. Species identification correlated with the geographical distribution of CL forms endemic in Tunisia. CONCLUSION Results of PCR-RFLP revealed highly concordant with those of isoenzyme electrophoresis. Thanks to its simplicity, rapidity and ability to be performed directly on biological samples, this technique appears as an interesting alternative for the identification of Leishmania strains responsible of CL in Tunisia.

La méfloquine prescrite pour les voyageurs tunisiens dans le cadre de la chimioprophylaxie antipaludique: observance et effets indésirables

Introduction : le paludisme est officiellement eradique en Tunisie depuis plus d’une trentaine d’annee. Cependant la prophylaxie reste indispensable, particulierement en cas de voyage en zone d’endemie. Methodes : il s’agit d’une etude retrospective concernant les tunisiens ayant sejourne dans un pays d’endemie palustre et pour lesquels une chimioprophylaxie antipaludique par la mefloquine a ete prescrite. Ces individus se sont presentes au laboratoire de Parasitologie de l’Institut Pasteur de Tunis durant la periode allant de 2011 a Aout 2016 pour recherche de Plasmodium dans le sang. Une fiche a ete remplie pour chaque patient precisant l’âge, la profession, le pays de sejour, l’observance a la mefloquine et ses eventuels effets indesirables (EI).

Le paludisme d’importation en Tunisie: bilan des cas diagnostiques à l’Institut Pasteur de Tunis (2008-2016)

Introduction : en Tunisie, l’incidence des cas de paludisme d’importation a augmente ces dernieres annees pour atteindre une moyenne de 80 cas par an. Par consequent, l’actualisation de l’epidemiologie de cette parasitose est fondamentale. L’objectif de cette etude etait de decrire les caracteristiques epidemiologiques des cas de paludisme d’importation diagnostiques a l’Institut Pasteur de Tunis. Methodes : etude retrospective ayant concerne 85 cas de paludisme diagnostiques entre janvier 2008 et septembre 2016 au laboratoire de parasitologie de l’Institut Pasteur de Tunis. Pour chaque individu, un questionnaire a ete rempli et un prelevement veineux sur anticoagulant a ete fait. Le diagnostic du paludisme a ete base sur la mise en evidence du parasite dans la goutte epaisse et/ou le frottis sanguin. Resultats : l’incidence annuelle moyenne des cas de paludisme diagnostiques a ete de 9 cas/an. Les etrangers ont represente 56,63% des cas et etaient principalement representes par les ressortissants originaires de l’Afrique sub-saharienne (85%). Nos patients avaient un âge median de 29 ans (±15,6). Dans 98,5% des cas, les contaminations ont eu lieu en Afrique sub-saharienne; principalement la Cote d’Ivoire (28,98%) et le Cameroun (13%). Quatorze cas (16,4%) etaient asymptomatiques depistes lors d’un controle systematique des etudiants originaires des zones d’endemie. Pour les sujets symptomatiques (83,5%), la fievre (87,32%) et les frissons (73,23%) etaient les signes les plus releves. Le delai median entre le debut de la symptomatologie et la confirmation diagnostique etait de 5 jours (±5,5). Plasmodium falciparum etait l’espece predominante (81,7%), suivie par Plasmodium ovale (12,94%). Dix-huit patients (21,17%) etaient porteurs de gametocytes. Conclusion : l’etude epidemiologique des cas de paludisme d’importation permettrait une meilleure prise en charge des malades et un controle du risque d’introduction de cette parasitose dans notre pays.

Dépistage de la toxoplasmose materno-foetale : étude des cas suivis à l’Institut Pasteur de Tunis (2007–2010)Toxoplasmosis mother-to-child screening: study of cases followed in the Pasteur Institute of Tunis (2007–2010)

Toxoplasmosis when occurring during pregnancy can be transmitted to the fetus and lead to congenital toxoplasmosis (CT). Therefore, pregnant women are a risk group, for which it is necessary to determine the serologic profile. The objective of this study is to determine the serologic profile of toxoplasmosis in pregnant women followed at the Parasitology Laboratory of the Pasteur Institute in Tunis, to establish the prevalence of toxoplasmic infections during pregnancy and the incidence of the CT, noting the difficulties faced in the interpretation of serological results. This is a retrospective study concerning 2833 toxoplasmic serologies practiced on 2070 pregnant women, followed at the Parasitology-Mycology Laboratory of the Pasteur Institute of Tunis, between 2007 and 2010. Serological diagnosis of toxoplasmosis was done by ELISA (Enzyme Linked Immunosorbent Assay) for the detection of Immunoglobulin (Ig) G and M and the study of toxoplasmosis IgG avidity. Prenatal diagnosis was performed for 58 women by amniotic fluid sampling. Toxoplasma gondii was detected by Polymerase Chain Reaction (PCR). At birth, the diagnosis of congenital toxoplasmosis was established based on serology. The toxoplasmic serologies carried out have shown that 45.6% of the pregnant women were formerly immunized while 49.6% had a negative serology. A toxoplasmosis primary infection acquired during pregnancy was detected in 79 cases (3.8%). Among them, 33% had a true seroconversion while 67% had a recent toxoplasmosis infection in view of the positivity of IgG and IgM on the first sample with a low index of avidity (IA). For 21 parturients whose serology showed the presence of IgG, IgM and an intermediate or high IA. Among the 58 parturients in whom prenatal diagnosis was performed, PCR was positive in four cases. After birth, six cases of congenital toxoplasmosis were detected by serology.

Évaluation et apport du test OptiMAL-IT ® dans le diagnostic du paludisme d'importation en Tunisie Evaluation and contribution of OptiMAL-IT ® test for the diagnosis of imported malaria in Tunisia

The rapid test OptiMAL-IT® was evaluated in the diagnosis and the screening of imported malaria in Tunisia in comparison with microscopic techniques. This prospective study focused on 500 individuals recruited from September 2010 to September 2012 in laboratory of Parasitology of Pasteur Institute of Tunis. They include 192 patients with clinical manifestations suggestive of malaria and 308 students originating from endemic areas. Microscopy of thick-and-thin blood smears and OptiMAL-IT® test were systematically performed on blood samples of all participants. Sixty individuals revealed infected by Plasmodium (12%). Positivity rates were respectively 20.3% in patients (44 cases) and 5.2% among asymptomatic students (16 cases) (p<0.01). The sensitivity and specificity of the OptiMAL-IT® test were respectively 88.6% and 100%. The concordance kappa was 0.92. The sensitivity and specificity during the screening of asymptomatic subjects were respectively 68.8% and 98.3% with a concordance of 0.67.