Diagnostic du paludisme severe : comparaison de la technique de PCR en temps reel versus microscopie; a Kinshasa; Republique Democratique du Congo

Contexte : Le controle du paludisme depend de la rapidite et de la qualite d'un diagnostic correct. En depit de sa sensibilite diagnostique superieure a la microscopie; l'usage de la PCR n'est limite a ce jour qu'a quelques laboratoires specialises. Cette etude a evalue la performance de la PCR en temps reel pour le diagnostic du paludisme comparee a la microscopie.Methodes : Deux cent-treize lames portant des gouttes epaisses ont ete aleatoirement selectionnees du service pediatrique d'une clinique de Kinshasa. Une identification des Plasmodiums par microscopie et par PCR en temps reel specifique aux especes plasmodiales; basee sur de l'ADN extrait a partir des gouttes epaisses; a ete realisee. La performance de la PCR en temps reel et l'accord avec la microscopie ont ete evalues a l'aide du test Kappa de Cohen et en calculant la specificite et la sensibilite.Resultats : Le P. falciparum a ete retrouve sur 184/213 echantillons (86;3%); parmi lesquels une infection mixte. La PCR en temps reel a par contre decele 202 (94;8%) echantillons positifs a P. falciparum dont 3 infections mixtes. Ses resultats etaient en accord avec ceux de la microscopie pour 195 (91;5%) echantillons. La sensibilite de la microscopie; comparee a la PCR etait de 91;09% et sa specificite de 100%.Conclusion : Meme en utilisant les gouttes epaisses comme source d'ADN plasmodial; la PCR en temps reel demeure plus sensible que la microscopie et plus precise pour la detection des infections mixtes. Qouique non encore de pratique routiniere dans les pays en voie de developpement; la tecnique de PCR en temps reel peut tirer un net interet dans les etudes epidemiologiques evaluant la chimioresistance de P. falciparum ou pour l'identification des especes plasmodiales

Human cytomegalovirus and primary intracranial tumours: frequency of tumour infection and lack of correlation with systemic immune anti-viral responses.

AIMS: Human cytomegalovirus (HCMV) is a ubiquitous beta human herpesvirus able to influence infected cell survival and proliferation and to modulate the host immune response. As there is accumulating evidence that HCMV is detected in primary intracranial astrocytic tumours, in this study we looked for the presence of HCMV in intracranial tumours and tried to correlate this eventual presence with the anti-HCMV systemic immunoreactivity and with the detection of HCMV in peripheral blood. METHODS: In this study, we analysed 43 glioblastomas (GBM), 14 oligodendrogliomas (OL) and 20 meningiomas (MG) by immunofluorescence (IF) targeting HCMV immediate early antigen (IE1) and by nested PCR (nPCR) amplifying HCMV glycoprotein B (gB). RESULTS: Detection of IE1 by IF showed the presence of HCMV in 70% of GBM, 57% of OL and 85% of MG, in contrast to gB nPCR, which detected HCMV in only 50% of GBM, 38% of OL and 46% of MG. Unexpectedly, HCMV DNA and antigens were detected within GBM, OL and MG of patients that exhibit negative viral serology. More surprisingly, PCR on the peripheral blood did not detect HCMV in patients with a HCMV-positive tumour. CONCLUSIONS: Our results are in agreement with previous observations demonstrating HCMV in glial tumours and highlight the presence of HCMV in meningiomas. We also showed that anti-HCMV specific systemic immunoreactivity and detection of HCMV in peripheral blood are not predictive of HCMV presence in primary intracranial tumours.

Prevalence and spread of extended-spectrum ß-lactamase-producing Enterobacteriaceae in Ngaoundere, Cameroon.

During April 2010 and June 2010, 334 Enterobacteriaceae isolates from 590 participants (outpatients, inpatients, inpatient carers, hospital workers and members of their households) were collected from faecal samples. Based on ß-lactamase pattern, origin of strains and the relationship between participants, 44 isolates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae were selected from 44 participants (in Ngaoundere Protestant Hospital and Ngaoundere Regional Hospital, Cameroon). To determine the relatedness of bacterial strains, these isolates were fingerprinted using the automated, repetitive-sequenced-based PCR-based DiversiLab system. Subsequently, E. coli isolates that had undergone DiversiLab analysis were examined with respect to their phylogenetic group and detection of the ST131 clone to shed light on the epidemiology of these isolates in the Ngaoundere hospitals. The prevalence of faecal carriage of ESBL-producing Enterobacteriaceae among the study participants was 54.06%. According to participant groups, the prevalence of faecal carriage was also high (outpatients 45%; inpatients 67%; inpatient carers 57%; hospital workers 44%; and members of their households 46%). Analysis of the molecular epidemiology of ESBL-producing E. coli and K. pneumoniae showed a close relationship of the isolates between related and non-related individuals. In addition, DiversiLab results of E. coli identified four related isolates (4/22) from cluster III belonging to the epidemiologically important clone ST131. Our results highlight the importance of outpatients, inpatients, their carers, hospital workers and their families as reservoirs of ESBL-producing Enterobacteriaceae.

Extended-spectrum ß-lactamase-producing Enterobacteriaceae in Cameroonian hospitals.

Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae have been described worldwide, but there are few reports on the carriage of these bacteria in Cameroon. In order to investigate the types of ESBLs and to analyse some risk factors associated with ESBL carriage, faecal samples were collected between 3 January and 3 April 2009 from hospitalised patients at Yaounde Central Hospital and at two hospitals in Ngaoundere, Cameroon. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production using the double-disk synergy test. Polymerase chain reaction (PCR) and DNA sequencing were performed in order to find out the different types of ESBL genes in presumptive ESBL-positive isolates. During the study period, a total of 121 different patients were screened for ESBL carriage. The prevalence among these patients whose faecal samples were found to contain ESBL-producers was 55.3 % (67/121). According to a univariate analysis, hospitalisation during the previous year was found to be associated with ESBL carriage. Of the 71 bacteria isolated, Escherichia coli was predominant and represented 48 % of all isolates. ESBL characterisation revealed two types of ESBLs, CTX-M-15 (96 %) and SHV-12 (4 %). The present study emphasises the importance of screening for ESBLs in laboratories in African countries. The monitoring and detection of ESBL-producing bacteria are important in the setting up of appropriate treatment of patients and to ensure effective infection control efforts.