Dietary intervention focused on phosphate intake in hemodialysis patients with hyperphosphoremia

BACKGROUND

Elevated serum phosphorus has been identified as a cardiovascular risk factor. This study aimed to assess the effectiveness of dietary intervention to reduce phosphorus intake and to improve the calcium-phosphorus metabolism in hemodialysis patients.

DESIGN

Patients were included in a 6-month, 2-group experimental study if their previous 3-month average serum phosphorus was over 5.5 mg/dl. Patients were allocated to intensive dietary intervention or usual dietary recommendations. The clinical end-points were the multivariate-adjusted change in serum phosphorus and the number of patients who achieved serum phosphorus levels of < 5.5 mg/dl and serum phosphorus levels of < 5 mg/dl.

RESULTS

80 dialysis patients completed the study, 41 in the experimental group and 39 in the control group. After 6 months, phosphorus intake (702 ± 168 vs. 872 ± 242 mg/24 h; p = 0.002) was lower in the experimental group than in the control group, with no inter-group differences in protein-caloric intake. Serum phosphorus decreased 1.67 mg/dl in the experimental group and 0.58 mg/dl in the control group (multivariate-adjusted difference 0.93 mg/ dl; 95% CI 0.34 - 1.52; p = 0.003). Serum phosphorus < 5.5 mg/dl and serum phosphorus < 5 mg/dl were attained more frequently in the experimental group (51 vs. 18%, p = 0.002 and 31.7 vs. 15.4%, p = 0.08 respectively).

CONCLUSIONS

Intensive dietary intervention focusing on phosphorus intake may be useful to reduce phosphorus retention and to improve calcium-phosphorus metabolism in hemodialysis patients.

Use of the vaccination register to evaluate influenza vaccine coverage in seniors in the 2010/11 influenza season, Navarre, Spain

People aged 65 and older have a high risk of suffering from complications of influenza, therefore it is recommended that they receive annual influenza vaccination. However, vaccination coverage falls far short of the target of 75%. In this study we use the vaccination register to evaluate the coverage of influenza vaccine in non-institutionalised persons aged 65 and over in Navarre, Spain, in the 2010/11 season (104,427 persons). Vaccination coverage was 58.6%, lower than the 62.7% coverage in the 2009/10 season. In the multivariate analysis, lower coverage was associated with being female, age under 80 or over 94 years, immigrant status and hospitalisation in the previous year. In contrast, persons with major chronic conditions, high level of dependence or those with more visits to the general practitioner in the previous year had higher vaccination coverage. Influenza vaccination in the previous season was a strong predictor of vaccination in the current season (odds ratio: 37.0, 95% confidence interval: 35.7–38.4). The vaccination register has been shown to be useful to monitor the coverage of influenza vaccination in seniors and may help guide strategies to improve coverage.

Score to identify the severity of adult patients with influenza A (H1N1) 2009 virus infection at hospital admission

The objective of this paper was to develop a prognostic index for severe complications among hospitalized patients with influenza A (H1N1) 2009 virus infection. We conducted a prospective observational cohort study of 618 inpatients with 2009 H1N1 virus infection admitted to 36 Spanish hospitals between July 2009 and February 2010. Risk factors evaluated included host-related factors and clinical data at admission. We developed a composite index of severe in-hospital complications (SIHC), which included: mortality, mechanical ventilation, septic shock, acute respiratory distress syndrome, and requirement for resuscitation maneuvers. Six factors were independently associated with SIHC: age >45 years, male sex, number of comorbidities, pneumonia, dyspnea, and confusion. From the β parameter obtained in the multivariate model, a weight was assigned to each factor to compute the individual influenza risk score. The score shows an area under the receiver operating characteristic (ROC) curve of 0.77. The SIHC rate was 1.9 % in the low-risk group, 10.3 % in the intermediate-risk group, and 29.6 % in the high-risk group. The odds ratio for complications was 21.8 for the high-risk group compared with the low-risk group. This easy-to-score influenza A (H1N1) 2009 virus infection risk index accurately stratifies patients hospitalized for H1N1 virus infection into low-, intermediate-, and high-risk groups for SIHC.

Structure of the β2-α2 loop and interspecies prion transmission

Prions are misfolded, aggregated conformers of the prion protein that can be transmitted between species. The precise determinants of interspecies transmission remain unclear, although structural similarity between the infectious prion and host prion protein is required for efficient conversion to the misfolded conformer. The β2-α2 loop region of endogenous prion protein, PrP(C), has been implicated in barriers to prion transmission. We recently discovered that conversion was efficient when incoming and host prion proteins had similar β2-α2 loop structures; however, the roles of primary vs. secondary structural homology could not be distinguished. Here we uncouple the effect of primary and secondary structural homology of the β2-α2 loop on prion conversion. We inoculated prions from animals having a disordered or an ordered β2-α2 loop into mice having a disordered loop or an ordered loop due to a single residue substitution (D167S). We found that prion conversion was driven by a homologous primary structure and occurred independently of a homologous secondary structure. Similarly, cell-free conversion using PrP(C) from mice with disordered or ordered loops and prions from 5 species correlated with primary but not secondary structural homology of the loop. Thus, our findings support a model in which efficient interspecies prion conversion is determined by small stretches of the primary sequence rather than the secondary structure of PrP.

Influenza outbreaks in nursing homes with high vaccination coverage in Navarre, Spain, 2011/12

In the 2011/12 season, three influenza outbreaks were studied in nursing homes with high vaccination coverage in Navarre, Spain. Attack rates ranged from 2.9% to 67%. Influenza A/Stockholm/18/2011(H3N2) virus strain was isolated from the three outbreaks. Vaccination should be complemented with other hygiene measures in nursing homes. Early detection of influenza outbreaks in nursing homes can aid in their control.

Influenza outbreaks in nursing homes with high vaccination coverage in Navarre, Spain, 2011/12

In the 2011/12 season, three influenza outbreaks were studied in nursing homes with high vaccination coverage in Navarre, Spain. Attack rates ranged from 2.9% to 67%. Influenza A/Stockholm/18/2011(H3N2) virus strain was isolated from the three outbreaks. Vaccination should be complemented with other hygiene measures in nursing homes. Early detection of influenza outbreaks in nursing homes can aid in their control.

Lipids, a missing link in prion propagation

Prion protein is considered to have an infectious ability by itself. However, in order to explain the main features of prion diseases, additional cofactors would be required. Sanghera et al. (in this issue of Chemistry and Biology) have found evidence that a ganglioside, GM1, is a ligand for the C-terminal region of prion protein.

Early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in Spain, 25 December 2011 to 19 February 2012

We present early estimates of influenza vaccine effectiveness (VE) in the population targeted for vaccination, during 25 December 2011 to 19 February 2012. The adjusted VE was 55% (95% CI: 3 to 79) against any type of influenza virus and 54% (95% CI: 1 to 79) against influenza A(H3N2) virus. This suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.

Early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in Spain, 25 December 2011 to 19 February 2012

We present early estimates of influenza vaccine effectiveness (VE) in the population targeted for vaccination, during 25 December 2011 to 19 February 2012. The adjusted VE was 55% (95% CI: 3 to 79) against any type of influenza virus and 54% (95% CI: 1 to 79) against influenza A(H3N2) virus. This suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.

Detection of PrPres in genetically susceptible fetuses from sheep with natural scrapie

Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and has rarely been studied. Recently, the use of the protein misfolding cyclic amplification technique (PMCA) has allowed prion detection in various tissues and excretions in which PrPres levels have been undetectable by traditional assays. The main goal of this study was to detect PrPres in fetal tissues and the amniotic fluid from natural scrapie infected ewes using the PMCA technique. Six fetuses from three infected pregnant ewes in an advanced clinical stage of the disease were included in the study. From each fetus, amniotic fluid, brain, spleen, ileo-cecal valve and retropharyngeal lymph node samples were collected and analyzed using Western blotting and PMCA. Although all samples were negative using Western blotting, PrPres was detected after in vitro amplification. Our results represent the first time the biochemical detection of prions in fetal tissues, suggesting that the in utero transmission of scrapie in natural infected sheep might be possible.

Effectiveness of trivalent seasonal and monovalent influenza A(H1N1)2009 vaccines in population with major chronic conditions of Navarre, Spain: 2010/11 mid-season analysis

We defined a cohort of people with major chronic conditions (152,585 subjects) in Navarre, Spain, using electronic records from physicians, to obtain 2010/11 mid-season estimates of influenza vaccine effectiveness. The adjusted estimates of the effectiveness of the 2010/11 trivalent influenza vaccine were 31% (95% confidence interval (CI): 20–40%) in preventing medically attended influenza-like illness, and 58% (95% CI: 11–80%) in preventing laboratory-confirmed influenza. Having received the monovalent influenza A(H1N1)2009 vaccine in the 2009/10 season had an independent preventive effect against medically attended influenza-like illness (17%, 95% CI: 1–30%), and having received both vaccines had 68% (95% CI: 23–87%) effectiveness in preventing laboratory-confirmed influenza.

Effectiveness of trivalent seasonal and monovalent influenza A(H1N1)2009 vaccines in population with major chronic conditions of Navarre, Spain: 2010/11 mid-season analysis

Binary file ES_Abstracts_Final_ECDC.txt matches

A molecular switch controls interspecies prion disease transmission in mice

Transmissible spongiform encephalopathies are lethal neurodegenerative disorders that present with aggregated forms of the cellular prion protein (PrPC), which are known as PrPSc. Prions from different species vary considerably in their transmissibility to xenogeneic hosts. The variable transmission barriers depend on sequence differences between incoming PrPSc and host PrPC and additionally, on strain-dependent conformational properties of PrPSc. The beta2-alpha2 loop region within PrPC varies substantially between species, with its structure being influenced by the residue types in the 2 amino acid sequence positions 170 (most commonly S or N) and 174 (N or T). In this study, we inoculated prions from 5 different species into transgenic mice expressing either disordered-loop or rigid-loop PrPC variants. Similar beta2-alpha2 loop structures correlated with efficient transmission, whereas dissimilar loops correlated with strong transmission barriers. We then classified literature data on cross-species transmission according to the 170S/N polymorphism. Transmission barriers were generally low between species with the same amino acid residue in position 170 and high between those with different residues. These findings point to a triggering role of the local beta2-alpha2 loop structure for prion transmissibility between different species.

Prion strain mutation determined by prion protein conformational compatibility and primary structure

Prions are infectious proteins composed of the abnormal disease-causing isoform PrPSc, which induces conformational conversion of the host-encoded normal cellular prion protein PrPC to additional PrPSc. The mechanism underlying prion strain mutation in the absence of nucleic acids remains unresolved. Additionally, the frequency of strains causing chronic wasting disease (CWD), a burgeoning prion epidemic of cervids, is unknown. Using susceptible transgenic mice, we identified two prevalent CWD strains with divergent biological properties but composed of PrPSc with indistinguishable biochemical characteristics. Although CWD transmissions indicated stable, independent strain propagation by elk PrPC, strain coexistence in the brains of deer and transgenic mice demonstrated unstable strain propagation by deer PrPC. The primary structures of deer and elk prion proteins differ at residue 226, which, in concert with PrPSc conformational compatibility, determines prion strain mutation in these cervids.

[Analysis of weekly mortality as a tool for the early detection of alerts in public health]

BACKGROUND

There is a growing interest in public health in monitoring indicators in real time that permit immediate action to be taken. The aim of this study is to evaluate the utility of the analysis of weekly mortality for the early detection of alerts in public health.

METHODS

We analysed the early reception of mortality (ERM) from five computerised civil registers in Navarre and gathered 70% of total mortality (TM) for the 2003-2007 period. We identified the weeks when mortality exceeded the threshold calculated on the basis of the five previous years. We analysed the correspondence of these excesses in mortality with flu levels of incidence and with high atmospheric temperatures.

RESULTS

The was moderate concordance between the alerts detected from the information proceeding from the ERM and TM sources (Kappa index 0.59; CI 95% 0.42-0.76). Both sources behaved analogously in the detection of excesses of mortality when these occurred in weeks of severe flu, with 13 and 12 alerts respectively. In relation to high temperatures, TM only generated alerts in the years when heat waves were declared, while ERM also generated them in other weeks which were hot but did not reach the heat wave threshold.

CONCLUSION

The early availability of results, the acceptable concordance between sources and the high percentage of excesses of mortality attributable to identified public health problems, show the potential utility of monitoring weekly mortality in epidemiological surveillance.

Estimating the impact of the 2009 influenza A(H1N1) pandemic on mortality in the elderly in Navarre, Spain

We analysed mortality among people aged 65 years or older in Navarre, Spain in 2009 and compared it with the mean for the same period of time in the previous three years. In the pandemic weeks 24 to 52 2009 we observed 4.9% more deaths than expected (p=0.0268). Excess mortality occurred during the circulation of seasonal influenza (8.0%, p=0.0367) and the first wave of pandemic influenza (9.9%, p=0.0079). In the second wave of pandemic influenza there was a non-significant excess of deaths (5.2%, p=0.1166). Surveillance of laboratory-confirmed severe influenza cases detected only one death in this age group.

Estimating the impact of the 2009 influenza A(H1N1) pandemic on mortality in the elderly in Navarre, Spain

We analysed mortality among people aged 65 years or older in Navarre, Spain in 2009 and compared it with the mean for the same period of time in the previous three years. In the pandemic weeks 24 to 52 2009 we observed 4.9% more deaths than expected (p=0.0268). Excess mortality occurred during the circulation of seasonal influenza (8.0%, p=0.0367) and the first wave of pandemic influenza (9.9%, p=0.0079). In the second wave of pandemic influenza there was a non-significant excess of deaths (5.2%, p=0.1166). Surveillance of laboratory-confirmed severe influenza cases detected only one death in this age group.

In vitro studies of the transmission barrier

Protein Misfolding Cyclic Amplification (PMCA) has proved to be an efficient method mimicking in vitro some of the fundamental steps involved in prion replication in vivo. Thus, it can be used to efficiently replicate a variety of prion strains/species. The in vitro generated prions possess key prion features, i.e., they are infectious in vivo and maintain their strain specificity. One of the big challenges is its use for studying prion transmission barriers. PMCA has been efficiently used for adapting different prion species through a range of species barriers; however its capacity for overcoming purportedly unbreakable species barriers compels us to adapt it in order to use it as a reliable technique. In addition, this in vitro method might be a crucial tool in evaluating the potential risks of different prion strains (natural or experimentally generated in vitro) to humans and animals.

[M. tuberculosis complex drug resistance in Navarre: differences between the local and immigrant populations]

BACKGROUND

Tuberculosis is an important public health problem, whose epidemiology in our country has changed in recent years due to the increase in the immigrant population. The aim of this article is to evaluate the frequency of resistance to the four principal antitubercular drugs in both the local and immigrant populations.

METHODS

A study was made of the antibiograms of 457 isolations of Mycobacterium tuberculosis carried out in the Hospital of Navarre in 2000-2007. The antibiograms were processed using the BACTEC460TB system.

RESULTS

Twenty six point three percent of the strains corresponded to immigrants, with a significant increase occurring over the period. The frequencies of resistances to the different antitubercular drugs in the local and immigrant populations respectively were: to at least one 5.6% vs 20.8% (p <0.001); to isoniazid 4.5% vs 14.2% (p <0.001); to streptomycin 2.4% vs 12.6% (p <0.001); to rifampicin 0.9% vs 5% (p <0.05); to ethambutol 0.3% vs 2.5% (p <0.05); and multiresistance 0.3% vs 2.5% (p <0.05).

CONCLUSION

There are significant differences between local and immigrant populations in the pattern of resistances of the strains isolated. The immigrant population, due to the high frequency with which resistance is shown to isoniazid, must be treated initially with a pattern of four drugs until the result of the biogram is available.

Changing epidemiology of invasive pneumococcal disease following increased coverage with the heptavalent conjugate vaccine in Navarre, Spain

The present study evaluated changes in the incidence of invasive pneumococcal disease (IPD) and the pattern of serotypes isolated in Navarre, Spain, after the introduction and increased coverage of the heptavalent pneumococcal conjugate vaccine (PCV7). All cases with isolation of pneumococcus from normally sterile bodily fluids were included. The incidence of IPD in children and adults was compared for the periods 2001-2002 and 2006-2007. By the end of 2002, only 11% of children aged <5 years had received any dose of PCV7, whereas, beginning in 2007, the proportion exceeded 50%. Among the cases of IPD aged <5 years, the percentage of those vaccinated increased from 7% during 2001-2002 to 53% during 2006-2007 (p <0.001). The incidence of IPD from PCV7-serotypes decreased by 85% in children <5 years (p <0.001), by 45% in the population aged 5-64 years (p 0.10) and by 68% in those >or=65 years (p 0.004). By contrast, the incidence of IPD from non-PCV7 serotypes increased by 40% overall (p 0.006). The incidence of IPD from all serotypes did not change significantly in children <5 years (from 83 to 72 per 100 000) or in the total population (from 15.8 to 16.3 per 100 000). The percentage of cases as a result of serotypes 7 and 19A increased significantly in both children and adults. No significant changes were seen in the clinical forms of IPD. The pattern of serotypes causing IPD has changed, in both children and adults, following the increased coverage of PCV7, although the incidence has been reduced only slightly.

Incidence of acute myocardial infarction in the Spanish epic cohort

BACKGROUND

There is some evidence that Mediterranean diet reduces risk of ischemic heart disease, and this is to be investigated in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). In this paper we present the incidence of acute myocardial infarction (AMI) in four EPIC Spanish cohorts.

METHOD

Incidence cases were ascertained in EPIC cohort during the follow up period (from recruitment to the end of 2004), by means of self-report questionnaires, hospital morbidity and mortality registries, and population AMI registries. Analysis was restricted to aged 45 to 74. The present study included data from 13,704 women and 19,410 men, after excluding a priori participants with prevalent AMI. Age standardized incidence rate for each cohort was estimated and compared with the available population rates.

RESULTS

The Median duration of follow-up was 9.3 years, yielding a total of 297,704 person-years. 391 men and 99 women presented AMI in the four cohorts studied. Age standardized AMI rates in men of the EPIC cohorts go from the lowest 302 (CI: 268-335) per 100.000 person-year of Gipuzkoa to the highest 330 (CI: 293-367) of Navarra. Women in Navarra presented the lowest AMI incidence with 60 (CI: 43-77) per 100,000 and the highest was observed in Murcia (114, CI: 91-137). The AMI incidence in all EPIC centres are close to the population incidence rates and in any case these are within the EPIC 95% CI.

CONCLUSIONS

The comparison of incidence in EPIC with population rates shows very good agreement for acute myocardial infarction.