The increased incidence of Mycoplasma pneumoniae in France in 2011 was polyclonal, mainly involving M. pneumoniae type 1 strains.

An increased incidence of Mycoplasma pneumoniae infections was reported in 2011 in two cities in France, Bordeaux and Caen. Two complementary molecular typing methods, PCR-RFLP on adhesin P1 and multilocus variable number tandem repeat analysis (MLVA), were used to determine whether this phenomenon was clonal. In 2011, the percentage of M. pneumoniae-positive patients doubled in both cities compared with 2010. Macrolide resistance remained stable at 8.3% of patients. Eighteen MLVA types were identified among 94 M. pneumoniae-positive specimens, demonstrating that the phenomenon was multiclonal. Types P, J, U, X and E were the most frequent and 81.6% of the strains were adhesin P1 type 1.

[Molecular diagnosis of respiratory enterovirus infections: Use of PCR and molecular identification for a best approach of the main circulating strains during 2008]. / Diagnostic moléculaire des infections respiratoires à entérovirus : apport de la PCR et du génotypage pour une meilleure approche de la circulation des souches en Basse-Normandie au cours de l'année 2008.

UNLABELLED: The PCR assays are currently used in diagnosis of enterovirus (EV) meningitis. Nevertheless, the use of molecular diagnosis of EV should be investigated in respiratory tract infections (RTI). OBJECTIVES: To perform enterovirus molecular diagnostic tools, PCR and genotyping, in nasal samples for diagnostic and epidemiologic purposes. METHODS: During 2008, 3612 nasal specimen (NS) were studied by IFD and MRC5 culture. Next, we realised successively viral isolation on HuH7 culture (for NS negative by IFD assay) and a duplex PCR enterovirus-rhinovirus for the 816 HuH7 positive supernatants. Furthermore, 327 NS collected from neonates were systematically tested by a real-time RT-PCR. This assay was used in routine for EV diagnosis setting in cerebrospinal fluid. Enterovirus genotyping was then performed for the 68 positive supernatants. RESULTS: Thirty-five NS (0.97%) were positive for EV by culture (MRC5). A combination of both PCR assays, PEVRV and PEV, allowed an additional identification of 41 EV, eight EV-RV and 12 RV, increasing the number of positive to 96 NS (2.6%). Among the neonates, 32 NS (11.3%) were positive for EV by PEV. Of the 98 NS tested by the two PCR assays (PEV and PEVRV), 27 were positive and we detected 10 EV, five EV-RV and 12 RV. From January to December 2008, the circulation of EV showed the usual peak in June-July when a small outbreak of aseptic meningitis occurred and an additional autumnal peak corresponding to respiratory tract infections. Five main serotypes were isolated: 19 EV68 (29.7%), 12 CB3 (18.7%), nine E3 (14,1%), six CA9 (9.4%) and six CB1 (9.4%); the 19 EV68 were isolated in October-November and 17/19 (89.5%) of positive patients were hospitalised for severe respiratory diseases. CONCLUSION: The use of molecular screening techniques (PCR assays and genotyping) on nasal samples collected from patients with respiratory infections allowed a prospective, effective and precise identification of circulating strains.

[Mycoplasma pneumoniae and Chlamydophila pneumoniae coinfection in severe pneumoniae among a hospitalized child with respiratory distress: what are the best diagnostic tools for an optimal care?]. / Coinfection à Mycoplasma pneumoniae et Chlamydophila pneumoniae chez un enfant hospitalisé pour une pneumonie sévère avec détresse respiratoire: choix des outils diagnostiques pour une prise en charge optimale.

The role for Mycoplasma pneumoniae and Chlamydophila pneumoniae in lower and upper respiratory tract infections in childhood increased by use of specialised diagnostic techniques, more and more performant for the early diagnosis of these infections. However, the prevalence of M. pneumoniae and C. pneumoniae as a cause of severe pneumoniae among hospitalized children has been rarely described. We report a case of M. pneumoniae et C. pneumoniae coinfection in a 10-year-old child hospitalized with a respiratory distress.

[Hepatitis C virus screening: performances characteristics of a commercial automated chemiluminescent microparticle immunoassay (CMIA-ARCHITECT anti-HCV)]. / Dépistage de l'hépatite C: performances analytiques d'une trousse commerciale automatisée (CMIA-ARCHITECT anti-VHC).

OBJECTIVES: In spite of improvement of the third-generation enzyme immunoassay (EIA) for screening HCV antibodies, some non-specific reactions persist. With commercialisation of a new chemiluminescence microparticle immunoassay (CMIA), we assessed the specificity of 2 assays providing by Abbott Diagnostics: CMIA-ARCHITECT anti-HCV and MEIA-AxSYM HCV 3.0 for qualitative detection of HCV antibodies in serum sample of patients collected in CHU of Caen. PATIENTS AND METHODS: Anti-HCV results of 9753 serum samples tested by MEIA-AxSYM V.3 (2004), 6135 tested by CMIA-ARCHITECT1 (April to December 2005) and 5598 tested by CMIA-ARCHITECT2 (February to August 2006) were retrospectively analysed. Prevalences were calculated according to S/C ratio. The serum samples with an average S/C ratio from 1 to 2 for CMIA-ARCHITECT2 were confirmed with an immunoblot assay (Chiron RIBA HCV 3.0 SIA). RESULTS: The CMIA-ARCHITECT assays showed a strong discrimination between negative and positive samples. We observed a tiny distribution of negative results. The percentage of "low positive" was respectively 1.26% for the MEIA-AxSYM, 0.68% for the CMIA-ARCHITECT1 and 0.36% for the CMIA-ARCHITECT2. Thirty-three of 54 (61%) samples yielding S/C ratio between 1 and 2 in the initial screening analysis with the CMIA-ARCHITECT1 were tested negative with CMIA-ARCHITECT2. Among the 21 remaining, 62% of RIBA results were interpretable. CONCLUSION: CMIA-ARCHITECT assays improve the anti-HCV screening with a decrease of low-positive reactivity. However, low-positive results persist for which it is difficult to distinguish false-positive from low titer of antibodies. Supplemental assays such as immunoblot can be recommended in particularly context to more improve specificity and HCV-RNA detection should exclude a seroconversion.

[Mycoplasma pneumoniae infections: retrospective study in Basse-Normandie, 1997-2005. Epidemiology--diagnostic utility of serology and PCR for a rapid diagnostic]. / Infections à Mycoplasma pneumoniae: étude rétrospective en Basse-Normandie de 1997 à 2005. Epidémiologie--Place de la sérologie et de la PCR pour le diagnostic.

OBJECTIVES: The objective of this study was to evaluate the epidemiology of Mycoplasma pneumoniae (Mpn) infections in Basse-Normandie by a retrospective analysis of serological and PCR data, and to confirm the diagnostic utility of PCR and serology. METHODS: From 1997 to August 2005, 6156 serum samples and 6123 respiratory tract samples were collected from hospitalised patients and evaluated for the diagnosis of Mpn infection by PCR, serological assays, or by the two tests. During the epidemic period (2004-2005), the results of 1489 patients were analysed. RESULTS: Over the 9-y period, the seroprevalence was 40,4% and we reported on 525 cases with serologically or/and PCR proven Mpn infection, according a cyclic pattern spaced out 7 years. During the epidemic period, the seroprevalence increased to 50,2% and the rate of infections was 8.3%. The analysis of the 124 cases of Mpn infection showed typical epidemiological characteristics: a peak of incidence among the children and young adults, a summer-winter pattern and some coinfections with viral strains. For diagnosis of Mpn infection, the comparison of PCR and serological assays among 36 patients showed a concordance of only 41.7%. CONCLUSION: Mpn infections were endemic and outbreaks were observed according cyclic pattern with a high incidence specially in the children. Sensitive and specific tests were now available for early and reliable diagnosis. In children, the combination of the PCR on nasopharyngeal samples and the IgM EIA serology test were recommended. In adults, the PCR was privilegiated.

Development of three multiplex RT-PCR assays for the detection of 12 respiratory RNA viruses.

Three multiplex hemi-nested RT-PCR assays were developed to detect simultaneously 12 RNA respiratory viruses: influenza viruses A, B and C, human respiratory syncytial virus (hRSV), human metapneumovirus (hMPV), parainfluenza virus types 1-4 (PIV-1, -2, -3 and -4), human coronavirus OC43 and 229E (HCoV) and rhinovirus (hRV). An internal amplification control was included in one of the RT-PCR assays. The RT-PCR multiplex 1 and the hemi-nested multiplex 1 detected 1 and 0.1 TCID50 of RSV A, respectively, and 0.01 and 0.001 TCID50 of influenza virus A/H3N2, respectively. Two hundred and three nasal aspirates from hospitalised children were retrospectively tested in comparison with two conventional methods: direct immunofluorescence assay and viral isolation technique. Almost all samples (89/91) that were positive by immunofluorescence assay and/or viral isolation technique were detected by the multiplex assay. This method also detected an additional 85 viruses and 33 co-infections. The overall sensitivity (98%), rapidity and enhanced efficiency of these multiplex hemi-nested RT-PCR assays suggest that they would be a significant improvement over conventional methods for the detection of a broad spectrum of respiratory viruses.