The Impact of Prior Season Vaccination on Subsequent Influenza Vaccine Effectiveness to Prevent Influenza-related Hospitalizations Over 4 Influenza Seasons in Canada

BACKGROUND

Recent studies have demonstrated the possibility of negative associations between prior influenza vaccines and subsequent influenza vaccine effectiveness (VE), depending on season and strain. We investigated this association over 4 consecutive influenza seasons (2011-2012 through 2014-2015) in Canada.

METHODS

Using a matched test-negative design, laboratory-confirmed influenza cases and matched test-negative controls admitted to hospitals were enrolled. Patients were stratified into 4 groups according to influenza vaccine history (not vaccinated current and prior season [referent], vaccinated prior season only, vaccinated current season only, and vaccinated both current and prior season). Conditional logistic regression was used to estimate VE; prior vaccine impact was assessed each season for overall effect and effect stratified by age (<65 years, ≥65 years) and type/subtype (A/H1N1, A/H3N2, influenza B).

RESULTS

Overall, mainly nonsignificant associations were observed. Trends of nonsignificant decreased VE among patients repeatedly vaccinated in both prior and current season relative to the current season only were observed in the A/H3N2-dominant seasons of 2012-2013 and 2014-2015. Conversely, in 2011-2012, during which B viruses circulated, and in 2013-2014, when A/H1N1 circulated, being vaccinated in both seasons tended to result in a high VE in the current season against the dominant circulating subtype.

CONCLUSIONS

Prior vaccine impact on subsequent VE among Canadian inpatients was mainly nonsignificant. Even in circumstances where we observed a trend of negative impact, being repeatedly vaccinated was still more effective than not receiving the current season's vaccine. These findings favor continuation of annual influenza vaccination recommendations, particularly in older adults.

CLINICAL TRIALS REGISTRATION

NCT01517191.

Validation of the Seegene RV15 multiplex PCR for the detection of influenza A subtypes and influenza B lineages during national influenza surveillance in hospitalized adults

Background. The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) has been performing active influenza surveillance since 2009 (ClinicalTrials.gov identifier: NCT01517191). Influenza A and B viruses are identified and characterized using real-time reverse-transcriptase polymerase chain reaction (RT-PCR), and multiplex testing has been performed on a subset of patients to identify other respiratory virus aetiologies. Since both methods can identify influenza A and B, a direct comparison was performed.Methods. Validated real-time RT-PCRs from the World Health Organization (WHO) to identify influenza A and B viruses, characterize influenza A viruses into the H1N1 or H3N2 subtypes and describe influenza B viruses belonging to the Yamagata or Victoria lineages. In a subset of patients, the Seeplex RV15 One-Step ACE Detection assay (RV15) kit was also used for the detection of other respiratory viruses.Results. In total, 1111 nasopharyngeal swabs were tested by RV15 and real-time RT-PCRs for influenza A and B identification and characterization. For influenza A, RV15 showed 98.0 % sensitivity, 100 % specificity and 99.7 % accuracy. The performance characteristics of RV15 were similar for influenza A subtypes H1N1 and H3N2. For influenza B, RV15 had 99.2 % sensitivity, 100 % specificity and 99.8 % accuracy, with similar assay performance being shown for both the Yamagata and Victoria lineages.Conclusions. Overall, the detection of circulating subtypes of influenza A and lineages of influenza B by RV15 was similar to detection by real-time RT-PCR. Multiplex testing with RV15 allows for a more comprehensive respiratory virus surveillance in hospitalized adults, without significantly compromising the reliability of influenza A or B virus detection.

What is the real number of Lyme disease cases in Canada?

BACKGROUND

Lyme disease is emerging in Canada due to expansion of the range of the tick vector Ixodes scapularis from the United States. National surveillance for human Lyme disease cases began in Canada in 2009. Reported numbers of cases increased from 144 cases in 2009 to 2025 in 2017. It has been claimed that few (< 10%) Lyme disease cases are reported associated with i) supposed under-diagnosis resulting from perceived inadequacies of serological testing for Lyme disease, ii) expectation that incidence in Canadian provinces and neighbouring US states should be similar, and iii) analysis of serological responses of dogs to the agent of Lyme disease, Borrelia burgdorferi. We argue that performance of serological testing for Lyme disease is well studied, and variations in test performance at different disease stages are accounted for in clinical diagnosis of Lyme disease, and in surveillance case definitions. Extensive surveillance for tick vectors has taken place in Canada providing a clear picture of the emergence of risk in the Canadian environment. This surveillance shows that the geographic scope of I. scapularis populations and Lyme disease risk is limited but increasing in Canada. The reported incidence of Lyme disease in Canada is consistent with this pattern of environmental risk, and the differences in Lyme disease incidence between US states and neighbouring Canadian provinces are consistent with geographic differences in environmental risk. Data on serological responses in dogs from Canada and the US are consistent with known differences in environmental risk, and in numbers of reported Lyme disease cases, between the US and Canada.

CONCLUSION

The high level of consistency in data from human case and tick surveillance, and data on serological responses in dogs, suggests that a high degree of under-reporting in Canada is unlikely. We speculate that approximately one third of cases are reported in regions of emergence of Lyme disease, although prospective studies are needed to fully quantify under-reporting. In the meantime, surveillance continues to identify and track the ongoing emergence of Lyme disease, and the risk to the public, in Canada.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Cardiac complications of congenital disorders of glycosylation (CDG): a systematic review of the literature

Congenital disorders of glycosylation (CDG) are inborn errors of metabolism due to protein and lipid hypoglycosylation. This rapidly growing family of genetic diseases comprises 103 CDG types, with a broad phenotypic diversity ranging from mild to severe poly-organ -system dysfunction. This literature review summarizes cardiac involvement, reported in 20% of CDG. CDG with cardiac involvement were divided according to the associated type of glycosylation: N-glycosylation, O-glycosylation, dolichol synthesis, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, COG complex, V-ATPase complex, and other glycosylation pathways. The aim of this review was to document and interpret the incidence of heart disease in CDG patients. Heart disorders were grouped into cardiomyopathies, structural defects, and arrhythmogenic disorders. This work may contribute to improved early management of cardiac complications in CDG.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Use of plasma human herpesvirus-8 viral load measurement: evaluation of practice in three UK HIV treatment centres

A retrospective audit of plasma human herpesvirus-8 (HHV-8) viral load testing was performed in three HIV treatment centres over 24 months. Reasons for testing (360 tests) were: symptoms of systemic inflammatory response syndrome (SIRS) (fever, lymphadenopathy and raised inflammatory markers); monitoring in known HHV-8 pathology other than Kaposi sarcoma (KS); investigation of known/suspected KS, and other/no reason. Of patients with multicentric Castleman disease (MCD), 14/16 (88%) had detectable plasma HHV-8, as did 27/45 (60%) with biopsy proven or clinically confirmed KS, and 6/19 (32%) with lymphoma. Neither of the two patients with MCD and no detectable HHV-8 had SIRS symptoms at the time of the test. There was wide variation between centres in the indications prompting HHV-8 testing, with a more conservative approach resulting in a higher proportion of positive results. Measuring plasma HHV-8 in the absence of SIRS symptoms, established HHV-8 disease monitoring, or confirmed/suspected KS is unlikely to yield detectable HHV-8 thus allowing potential cost savings.

240 PRECISE GENOME EDITING OF PDX1 BY DIRECT INJECTION OF TRANSCRIPTION ACTIVATOR-LIKE EFFECTOR NUCLEASES (TALENS) INTO PARTHENOGENETIC PIG EMBRYOS

Pancreatic and duodenal homeobox 1 (PDX1) is one of the transcription factors involved in pancreatic organogenesis and plays a critical role as an early lineage marker of pancreatic specification and β-cell differentiation. In mature pancreas, PDX1 regulates a large number of genes involved in maintaining β-cell identity and function. In mice and humans, its homozygous disruption results in pancreas agenesis, while heterozygous mutations have been associated with early-onset (MODY) and late-onset forms of Type II diabetes mellitus in humans. Knockout of the PDX1 gene in pigs may lead to the generation of an apancreatic phenotype, which in turn could allow the potential generation of an exogenic pancreas. Moreover, this could help to create a large animal model for human diabetes. We used transcription activator-like effector nucleases (TALEN) technology with the aim of studying the efficiency of precise editing by homologous recombination in parthenogenetically activated porcine embryos. Mature oocytes were activated by incubation in ionomycin (10 µM) for 20 min, followed by a 4-h incubation in DMAP (2 mM) + cytochalasin B (7.5 µg mL–1). Cytoplasmic injection was performed 14 h post-activation. Post injections, embryos were cultured for 6 days in NCSU23+BSA media at 38.5°C in a 5% CO2 atmosphere. We first evaluated the activity of a pair of TALENs targeting the functional domain of the PDX1 gene. Three concentrations of mRNA were microinjected (10, 20, and 40 ng µL–1) and blastocysts were analysed for non-homologous end-joining (NHEJ) by sequencing. The efficiency of indel mutations at the PDX1-target loci (either monoallelic or biallelic) was 34.5, 52.6, and 80.0% for the 10, 20, and 40 ng µL–1 concentrations, respectively. Next, we tested whether ssODNs (single-stranded oligodeoxynucleotide) coinjected with TALENs would permit precise homology direct repair (HDR) in porcine parthenotes. TALEN mRNA (40 ng µL–1) was coinjected with an ssODN donor template (50 ng µL–1) designed to incorporate a novel stop codon, HindIII restriction site, and a frame shift mutation. Cleavage and blastocyst rates were recorded at Days 2 and 6 of development, respectively, in the TALEN/ssODN injected group (n = 260 zygotes), buffer-injected embryos (n = 135 zygotes), and the non-injected group (n = 132 zygotes). Day 7 embryos were analysed for NHEJ and HDR by RFLP assay and Sanger sequencing after whole-genome amplification and PCR. Blastocyst rates were 15% (TALEN/ssODN-injected group), 27% (buffer-injected group), and 34% (non-injected group). A total of 30 blastocysts were analysed for HDR after whole-genome amplification. The majority of analysed blastocysts (28/30, 93%) were mutant. Among them, 10 (36%) incorporated the ssODN, from which 3 (30%) showed a KO genotype with a precise biallelic modification. We report here a highly efficient and precise TALEN-mediated gene knockout in swine embryos, which represents an alternative to cloning for phenotype evaluation of knockouts related to organogenesis.

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

BACKGROUND

There appears little consensus concerning protein requirements in phenylketonuria (PKU).

METHODS

A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics.

RESULTS

The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day).

CONCLUSIONS

The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014

Binary file ES_Abstracts_Final_ECDC.txt matches

Dietary management of urea cycle disorders: European practice

BACKGROUND

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries.

METHODS

Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets.

RESULTS

Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements.

CONCLUSIONS

Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required.

Dietary practices in pyridoxine non-responsive homocystinuria: a European survey

BACKGROUND

Within Europe, the management of pyridoxine (B6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice.

AIM

A comparison of dietetic management practices of patients with B6 non-responsive HCU in European centres.

METHODS

A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium).

RESULTS

181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n=119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n=62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and >16 years, 45 g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20 g; and >16 years, 38 g. Fifty-two percent (n=15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free l-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied.

CONCLUSION

In B6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines.

Organo-selenium-containing dental sealant inhibits bacterial biofilm

Oral bacteria, including Streptococcus mutans and Streptococcus salivarius, contribute to tooth decay and plaque formation; therefore, it is essential to develop strategies to prevent dental caries and plaque formation. We recently showed that organo-selenium compounds covalently attached to different biomaterials inhibited bacterial biofilms. Our current study investigates the efficacy of an organo-selenium dental sealant (SeLECT-Defense(TM) sealant) in inhibiting S. mutans and S. salivarius biofilm formation in vitro. The organo-selenium was synthesized and covalently attached to dental sealant material via standard polymer chemistry. By colony-forming unit (CFU) assay and confocal microscopy, SeLECT-Defense(TM) sealant was found to completely inhibit the development of S. mutans and S. salivarius biofilms. To assess the durability of the anti-biofilm effect, we soaked the SeLECT-Defense(TM) sealant in PBS for 2 mos at 37°C and found that the biofilm-inhibitory effect was not diminished after soaking. To determine if organo-selenium inhibits bacterial growth under the sealant, we placed SeLECT-Defense sealant over a lawn of S. mutans. In contrast to a control sealant, SeLECT-Defense(TM) sealant completely inhibited the growth of S. mutans. These results suggest that the inhibitory effect of SeLECT-Defense(TM) sealant against S. mutans and S. salivarius biofilms is very effective and durable.

Dietary management of urea cycle disorders: UK practice

BACKGROUND

There is no published data describing UK dietary management of urea cycle disorders (UCD). The present study describes dietary practices in UK inherited metabolic disorder (IMD) centres.

METHODS

Cross-sectional data from 16 IMD centres were collected by a questionnaire describing the management of UCD patients on prescribed protein-restricted diets.

RESULTS

One hundred and seventy-five patients [N-acetylglutamate synthase deficiency, n = 3; carbamoyl phosphate synthase deficiency (CPS), n = 8; ornithine transcarbamoylase deficiency (OTC), n = 75; citrullinaemia, n = 41; argininosuccinic aciduria (ASA), n = 36; arginase deficiency, n = 12] were reported; 70% (n = 123) aged 0-16 years; 30% (n = 52) >16 years. Prescribed median protein intake decreased with age (0-6 months: 2 g kg(-1) day(-1); 7-12 months: 1.6 g kg(-1) day(-1); 1-10 years: 1.3 g kg(-1) day(-1); 11-16 years: 0.9 g kg(-1) day(-1) and >16 years: 0.8 g kg(-1) day(-1)) with little variation between disorders. Adult protein prescription ranged 0.4-1.2 g kg(-1) day(-1) (40-60 g day(-1)). In the previous 2 years, 30% (n = 53) were given essential amino acid supplements (EAAs) (CPS, n = 2; OTC, n = 20; citrullinaemia, n = 15; ASA, n = 7; arginase deficiency, n = 9). EAAs were prescribed for low plasma quantitative essential amino acids (n = 13 centres); inadequate natural protein intake (n = 11) and poor metabolic control (n = 9). From diagnosis, one centre prescribed EAAs for all patients and one centre for severe defects only. Only 3% (n = 6) were given branch chain amino acid supplements. Enteral feeding tubes were used by 25% (n = 44) for feeds and 3% (n = 6) for medications. Oral energy supplements were prescribed in 17% (n = 30) of cases.

CONCLUSIONS

In the UK, protein restriction based on World Health Organization 'safe intakes of protein', is the principle dietary treatment for UCD. EAA supplements are prescribed mainly on clinical need. Multicentre collaborative research is required to define optimal dietary treatments.

Transient cortical blindness post angiography--a case report

A 56-year old female reported having had a fall two weeks prior to presentation. Computed Tomography (CT) scan showed an acute right-sided convexity subdural haematoma. A computed tomography angiogram revealed no vascular anomaly. One hour post procedure she had bilateral cortical blindness. Her vision subsequently was fully restored. A diagnosis of transient cortical blindness was made. Transient cortical blindness is a rare but recognized complication ofintra-arterial injection of iodinated contrast agents.

Complicated head trauma from machete wounds: the experience from a tertiary referral hospital in Jamaica

There have been limited reports on machete wounds to the cranium. This study was carried out to document the injury profile in a series of patients who have sustained cranial injuries from machete wounds in this setting. Between 1 January 1998 and 1 January 2008, demographic and clinical data were retrospectively collected from all patients treated with complicated head injuries from machete wounds with at least one of the following clinical or radiological features: a recorded Glasgow Coma Score < 8 at any point during admission; compound skull fractures; protruding brain matter; cerebrospinal fluid (CSF) leaks; intra-cranial bleeding; parenchymal contusions; lacerations and/or oedema. The data were analysed using the SPSS version 12.0. Of the 40 patients with complex injuries to the cranium, there was a 6:1 male preponderance with a mean age of 32.5 ± 13.7 years (Mean ± SD). The injuries included open skull fractures in all the 40 (100%) patients, depressed skull fractures in 20 (50%) patients, CSF leaks in 4 (10%) patients, protruding brain matter in 4 (10%) patients, cerebral contusions in 3 (7.5%) patients and extra cranial injuries in 16 (40%) patients. Tetanus prophylaxis and intravenous antibiotics were administered to all patients, and phenytoin was required in 16 (40%) cases. There were 37 (92%) patients requiring operative intervention at a mean of 10.4 h after presentation (SD ± 18.1; Median 6). The operative procedures included elevation of depressed fractures in 20 (54.1%) patients, dural repair in 10 (27.0%) patients and intra-cranial debridement in 7 (18.9%) patients. There were three deaths (7.5%), and seizures were recorded in 5 (12.5%) cases with no reports of infectious morbidity. Eighty percent of patients had a normal Glasgow outcome score on discharge. Complicated machete head trauma is uncommon at this health care facility in Jamaica. We achieved a satisfactory outcome with aggressive management consisting of prompt assessment of the extent of injury, appropriate antibiotics, anticonvulsants for those with seizures or cortical injury and early operation to decrease the risk of complications.

Experimental and finite element analysis of the mouse caudal vertebrae loading model: prediction of cortical and trabecular bone adaptation

In this study, we attempt to predict cortical and trabecular bone adaptation in the mouse caudal vertebrae loading model using knowledge of bone's local mechanical environment at the onset of loading. In a previous study, we demonstrated appreciable 25.9 and 11% increases in both trabecular and cortical bone volume density, respectively, when subjecting the fifth caudal vertebrae (C5) of C57BL/6 (B6) mice to an acute loading regime (amplitude of 8N, 3000 cycles, 10 Hz, 3 times a week for 4 weeks). We have also established a validated finite element (FE) model of the C5 vertebra using micro-computed tomography (micro-CT), which characterizes, in 3D, the micro-mechanical strains present in both cortical and trabecular compartments due to the applied loads. To investigate the relationship between load-induced bone adaptation and mechanical strains in-vivo and in-silico data sets were compared. Using data from the previous cross-sectional study, we divided cortical and trabecular compartments into 15 subregions and determined, for each region, a bone formation parameter ΔBV/BS (a cross-sectional measure of the bone volume added to cortical and trabecular surfaces following the described loading regime). Linear regression was then used to correlate mean regional values of ΔBV/BS with mean values of mechanical strains derived from the FE models which were similarly regionalized. The mechanical parameters investigated were strain energy density (SED), the orthogonal strains (e (x), e (y), e (z)) and the three shear strains (e (xy), e (yz), e (zx)). For cortical regions, regression analysis showed SED to correlate extremely well with ΔBV/BS (R (2) = 0.82) and e (z) (R (2) = 0.89). Furthermore, SED was found to predict expansion of the cortical shell correlating significantly with the regional percentage increases in cortical tissue volume (R (2) = 0.92), cortical marrow volume (R (2) = 0.91) and cortical thickness (R (2) = 0.56). For trabecular regions, FE parameters were found not to correlate with load-induced trabecular bone morphology. These results indicate that load-induced cortical morphology can be predicted from population data, whereas the prediction of trabecular morphology requires subject-specific micro- architecture.

NOD2 polymorphisms in clinical phenotypes of common variable immunodeficiency disorders

Common variable immunodeficiency disorders (CVIDs) are a heterogeneous group of diseases characterized by hypogammaglobulinaemia and consequent susceptibility to infection. CVID patients commonly develop a variety of additional manifestations for which the causative factors are not fully understood. Two such manifestations are granulomatous disease and enteropathy. Because the ability to predict complications would aid clinical management, we continue to search for possible disease modifier genes. NOD2 acts a microbial sensor and is involved in proinflammatory signalling. Particular mutations of the NOD2 gene are associated with Crohn's disease including gly908arg, leu1007finsc and arg702trp polymorphisms. We hypothesized that NOD2 polymorphisms may be a disease modifier gene towards an enteropathic or granulomatous phenotype within CVIDs. Sequence-specific primers returned genotypes for 285 CVID patients from centres across the United Kingdom and Europe. We present the frequencies of the different phenotypes of patients within our international cohort. Arg702trp polymorphisms were significantly less frequent than wild-type (WT) (P = 0·038) among international CVID patients with splenomegaly. Gly908arg polymorphisms were more prevalent than WT in UK patients with autoimmune disorders (P = 0·049) or enteropathy (P = 0·049). NOD2 polymorphisms were not more prevalent than WT in CVID patients with clinical phenotypes of granulomata. UK allele frequencies of 0·014, 0·056 and 0·026 were found for gly908arg, arg702trp and leu1007finsc NOD2 polymorphisms, respectively. These do not differ significantly from UK immunocompetent controls confirming, as expected, that in addition these NOD2 polymorphisms do not confer susceptibility to CVIDs per se.

Fluoroquinolone resistance in renal isolates of Mycobacterium tuberculosis

SETTING

Alberta, Canada, 1990-2003.

OBJECTIVE

Monotherapy of active tuberculosis (TB) promotes drug resistance. Given the common practice of empiric fluoroquinolone (FQ) therapy for urinary tract infections (UTI) and frequent delayed diagnosis of renal TB, we assessed urine Mycobacterium tuberculosis isolates for FQ resistance.

DESIGN

Retrospective study. Urine M. tuberculosis isolates underwent FQ susceptibility testing. Records were reviewed for evidence of FQ exposure and diagnostic delay.

RESULTS

Among 78 culture-positive renal TB patients between 1990 and 2003, initial isolates of M. tuberculosis were available from 74 (94.9%). Three (4.1%) were FQ-resistant. Previous FQ use was confirmed in nine cases (12.2%). FQ-exposed isolates were more likely than non-exposed isolates to be FQ-resistant (2/9, 22.2% vs. 1/65, 1.5%, P = 0.037). Among 41 cases (55.4%) with signs or symptoms of UTI, eight (19.5%) had previous FQ exposure, of which seven (87.5%) had delayed diagnosis. Only 15/33 (45.5%) UTI symptomatic cases without prior FQ exposure had delayed diagnosis (P = 0.050). In 2/8 (25%) UTI symptomatic cases with prior FQ exposure, the M. tuberculosis isolate was FQ-resistant.

CONCLUSION

FQ monotherapy of unsuspected renal TB may delay diagnosis and lead to FQ resistance.

Circulating levels of cobalt and chromium from metal-on-metal hip replacement are associated with CD8+ T-cell lymphopenia

We carried out a cross-sectional study with analysis of the demographic, clinical and laboratory characteristics of patients with metal-on-metal hip resurfacing, ceramic-on-ceramic and metal-on-polyethylene hip replacements. Our aim was to evaluate the relationship between metal-on-metal replacements, the levels of cobalt and chromium ions in whole blood and the absolute numbers of circulating lymphocytes. We recruited 164 patients (101 men and 63 women) with hip replacements, 106 with metal-on-metal hips and 58 with non-metal-on-metal hips, aged < 65 years, with a pre-operative diagnosis of osteoarthritis and no pre-existing immunological disorders. Laboratory-defined T-cell lymphopenia was present in 13 patients (15%) (CD8(+) lymphopenia) and 11 patients (13%) (CD3(+) lymphopenia) with unilateral metal-on-metal hips. There were significant differences in the absolute CD8(+) lymphocyte subset counts for the metal-on-metal groups compared with each control group (p-values ranging between 0.024 and 0.046). Statistical modelling with analysis of covariance using age, gender, type of hip replacement, smoking and circulating metal ion levels, showed that circulating levels of metal ions, especially cobalt, explained the variation in absolute lymphocyte counts for almost all lymphocyte subsets.

Risk factors for low BMD in healthy men age 50 years or older: a systematic review

SUMMARY

In this systematic review, we summarize risk factors for low bone mineral density and bone loss in healthy men age 50 years or older. Consistent risk factors were: age, smoking, low weight, physical/functional limitations, and previous fracture. Data specific to men has clinical and policy implications.

INTRODUCTION

Osteoporosis is a significant health care problem in men as well as women, yet the majority of evidence on diagnosis and management of osteoporosis is focused on postmenopausal women. The objective of this systematic review is to examine risk factors for low bone mineral density (BMD) and bone loss in healthy men age 50 years or older.

MATERIALS AND METHODS

A systematic search for observational studies was conducted in MEDLINE, Cochrane Database of Systematic Reviews, DARE, CENTRAL, CINAHL and Embase, Health STAR. The three main search concepts were bone density, densitometry, and risk factors. Trained reviewers assessed articles using a priori criteria.

RESULTS

Of 642 screened abstracts, 299 articles required a full review, and 25 remained in the final assessment. Consistent risk factors for low BMD/bone loss were: advancing age, smoking, and low weight/weight loss. Although less evidence was available, physical/functional limitations and prevalent fracture (after age 50) were also associated with low BMD/bone loss. The evidence was inconsistent or weak for physical activity, alcohol consumption, calcium intake, muscle strength, family history of fracture/osteoporosis, and height/height loss.

CONCLUSION

In this systematic review, we identified several risk factors for low BMD/bone loss in men that are measurable in primary practice.

Tuberculosis outbreak associated with a mosque: challenges of large scale contact tracing

In this report, we describe the investigation and management of an outbreak of TB associated with a mosque in Scotland, and consider the implications of large-scale TB contact tracing. In 2005, an Algerian man living in the north-east of Scotland was found to be sputum smear-positive for TB. Initial investigation identified three (18.8%) close contacts with active disease. Due to the high rate of transmission, contact tracing was extended to casual contacts of the index case at a mosque. No sub-group at highest risk of exposure could be defined at the mosque. Screening of mosque attendees identified two cases (0.53%), with a further two identified by review of existing cases and enhanced surveillance. Two additional cases were linked to the outbreak by genetic profile. Response to the screening exercise was initially poor, but after modification of the communication strategy, 438 people were offered screening with 86% attending. The investigation and management of a TB outbreak is challenging and requires a complex message about risk to be communicated. In a mosque setting, there were additional complexities that, to the best of our knowledge, have not been reported previously. It was crucial, in designing the communication strategy, to identify key individuals within the community to assist with tailoring the message to address risk perception and to help to deliver the message. Despite this, approximately 50% of those considered to have the highest exposure (adult males regularly attending Friday lunchtime prayer meetings) did not come forward for screening. The screening of casual contacts in this setting was complex and time-consuming with a low detection rate.

Tuberculosis outbreak associated with a mosque: challenges of large scale contact tracing

In this report, we describe the investigation and management of an outbreak of TB associated with a mosque in Scotland, and consider the implications of large-scale TB contact tracing. The screening of casual contacts in this setting was complex and time-consuming with a low detection rate.