Haemophilus influenzae serotype B (Hib) seroprevalence in England and Wales in 2009.

A national seroprevalence study was performed to determine the prevalence of Haemophilus influenzae type b (Hib) antibodies in England and Wales in 2009, when Hib disease incidence was the lowest ever recorded. A total of 2,693 anonymised residual sera from routine diagnostic testing submitted by participating National Health Service hospital laboratories were tested for Hib anti-polyribosyl-ribitol phosphate (PRP) IgG antibodies using a fluorescent bead assay. Median anti-PRP IgG concentrations were highest in toddlers aged 1­4 years (2.65 µg/ml), followed by children aged 5­9 years (1.95 µg/ml). Antibody concentrations were significantly lower after this age, but were still significantly higher among 10­19 year-olds (0.54 µg/ml) compared with adults aged >20 years (0.16 µg/ ml; p<0.0001). Half of the adults (51%) did not have Hib antibody concentrations ≥0.15 µg/ml, the level considered to confer short-term protection. Thus, the current excellent Hib control appears to be the result of high anti-PRP antibody concentrations in children aged up to 10 years, achieved through the various childhood vaccination campaigns offering booster immunisation. The lack of seroprotection in adults emphasises the importance of maintaining control of the disease and, most probably carriage, in children, therefore raising the question as to whether long-term routine boosting of either pre-school children or adolescents may be required.

[Amniocentesis trainer: development of a cheap and reproducible new training model]. / Simulateur d'amniocentèse : intérêts et développement d'un nouveau modèle reproductible et économique.

Amniocentesis is the most common invasive procedure for prenatal diagnosis. It is essential to master this sampling technique prior to performing more complex ultrasound-guided interventions (cordocentesis, drain insertion). Training is a challenge because of the risks associated with the procedure, as well as the impact on the patient's anxiety. An amniocentesis simulator allows for safe training and repeats interventions, thus accelerating the learning curve, and also allows for periodic evaluation of proficiency. We present here a new, simple, and cost-effective amniotrainer model that reproduces real life conditions, using chicken breast and condoms filled with water.

[Chorionic villus sampling training method]. / Technique d'apprentissage de la biopsie de trophoblaste.

OBJECTIVES: Chorionic villus sampling (CVS) in the first trimester of pregnancy has become a major tool in prenatal diagnosis. To increase the safety of CVS during training period, we have built a "BT-Trainer". MATERIALS AND METHODS: A medical device has been developed which simulates the in vivo procedure with the various layers to cross. The stratum of the layer and the accessibility of the placenta can modulate the level difficulty. CONCLUSION: Traditional strategies for clinical teaching are often insufficient and trainees may fail to achieve competence in even basic procedural skills. We present herein an easy and reproducible model of "BT-Trainer" which allows a safe and repeatable training. Efficacy of this model is currently under evaluation in a teaching program. This trainer could help gynaecologists in order to learn gradually and safely the technique and to enhance their skills and coordination.

Investigation of different group A immunoassays following one dose of meningococcal group A conjugate vaccine or A/C polysaccharide vaccine in adults.

A double-blind, randomized, controlled phase I study to assess the safety, immunogenicity, and antibody persistence of a new group A conjugate vaccine (PsA-TT) in volunteers aged 18 to 35 years was previously performed. Subjects received one dose of either the PsA-TT conjugate vaccine, meningococcal A/C polysaccharide vaccine (PsA/C), or tetanus toxoid vaccine. The conjugate vaccine was shown to be safe and immunogenic as demonstrated by a standardized group A-specific immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and by a serum bactericidal antibody (SBA) assay using rabbit complement (rSBA). This report details further analysis of the sera using four additional immunologic assays to investigate the relationship between the different immunoassays. The immunoassays used were an SBA assay that used human complement (hSBA), a group A-specific IgG multiplexed bead assay, and two opsonophagocytic antibody (OPA) assays which used two different methodologies. For each vaccine group, geometric mean concentrations or geometric mean titers were determined for all assays before and 4, 24, and 48 weeks after vaccination. Pearson's correlation coefficients were used to assess the relationship between the six assays using data from all available visits. An excellent correlation was observed between the group A-specific IgG concentrations obtained by ELISA and those obtained by the multiplexed bead assay. hSBA and rSBA titers correlated moderately, although proportions of subjects with putatively protective titers and those demonstrating a > or = 4-fold rise were similar. The two OPA methods correlated weakly and achieved only a low correlation with the other immunoassays. The correlation between hSBA and group A-specific IgG was higher for the PsA-TT group than for the PsA/C group.

Competitive inhibition flow analysis assay for the non-culture-based detection and serotyping of pneumococcal capsular polysaccharide.

Traditional confirmation procedures for the identification of a pneumococcal serotype require an isolate. Non-culture-based confirmation protocols are available. Some of these confirm only the presence of pneumococci, and others are capable of identifying a limited number of serotypes. The increased use of pneumococcal polysaccharide and conjugate vaccines, especially in high-risk patient groups, and the likely increase in the number of serotypes included in future versions of the conjugate vaccines have necessitated the need for improved enhanced surveillance in order to assess their impact on public health. Since 2006, a multiplexed assay has been used at the Health Protection Agency of the United Kingdom for the detection of 14 pneumococcal serotypes which requires pneumococcal serotype-specific monoclonal antibodies (MAbs). We have developed a microsphere competitive inhibition method capable of detecting 23 pneumococcal capsular polysaccharide serotypes in cerebrospinal fluid (CSF) and urine and serotyping pneumococcal suspensions, utilizing an international reference serum, 89-SF. The assay was shown to be reproducible and specific for homologous polysaccharide. Validation of the assay was performed with a selection of MAbs specific for pneumococcal capsular polysaccharide serotypes, which confirmed the specificity of the assay. Analysis of pneumolysin PCR-positive CSF samples in the competitive inhibition assay determined a serotype for 89% of the samples. The assay developed here is well suited to large-scale epidemiologic studies because the assay is simple, robust, and rapid and utilizes readily available resources.