Acquisition and cross-transmission of Staphylococcus aureus in European intensive care units

Objective. To study the acquisition and cross-transmission of Staphylococcus aureus in different intensive care units (ICUs). Methods. We performed a multicenter cohort study. Six ICUs in 6 countries participated. During a 3-month period at each ICU, all patients had nasal and perineal swab specimens obtained at ICU admission and during their stay. All S. aureus isolates that were collected were genotyped by spa typing and multilocus variable-number tandem-repeat analysis typing for cross-transmission analysis. A total of 629 patients were admitted to ICUs, and 224 of these patients were found to be colonized with S. aureus at least once during ICU stay (22% were found to be colonized with methicillin-resistant S. aureus [MRSA]). A total of 316 patients who had test results negative for S. aureus at ICU admission and had at least 1 follow-up swab sample obtained for culture were eligible for acquisition analysis. Results. A total of 45 patients acquired S. aureus during ICU stay (31 acquired methicillin-susceptible S. aureus [MSSA], and 14 acquired MRSA). Several factors that were believed to affect the rate of acquisition of S. aureus were analyzed in univariate and multivariate analyses, including the amount of hand disinfectant used, colonization pressure, number of beds per nurse, antibiotic use, length of stay, and ICU setting (private room versus open ICU treatment). Greater colonization pressure and a greater number of beds per nurse correlated with a higher rate of acquisition for both MSSA and MRSA. The type of ICU setting was related to MRSA acquisition only, and the amount of hand disinfectant used was related to MSSA acquisition only. In 18 (40%) of the cases of S. aureus acquisition, cross-transmission from another patient was possible. Conclusions. Colonization pressure, the number of beds per nurse, and the treatment of all patients in private rooms correlated with the number of S. aureus acquisitions on an ICU. The amount of hand disinfectant used was correlated with the number of cases of MSSA acquisition but not with the number of cases of MRSA acquisition. The number of cases of patient-to-patient cross-transmission was comparable for MSSA and MRSA.

Validity and reliability of the Spanish version of the DN4 (Douleur Neuropathique 4 questions) questionnaire for differential diagnosis of pain syndromes associated to a neuropathic or somatic component

BACKGROUND This study assesses the validity and reliability of the Spanish version of DN4 questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component (non-neuropathic pain, NNP). METHODS A study was conducted consisting of two phases: cultural adaptation into the Spanish language by means of conceptual equivalence, including forward and backward translations in duplicate and cognitive debriefing, and testing of psychometric properties in patients with NP (peripheral, central and mixed) and NNP. The analysis of psychometric properties included reliability (internal consistency, inter-rater agreement and test-retest reliability) and validity (ROC curve analysis, agreement with the reference diagnosis and determination of sensitivity, specificity, and positive and negative predictive values in different subsamples according to type of NP). RESULTS A sample of 164 subjects (99 women, 60.4%; age: 60.4 +/- 16.0 years), 94 (57.3%) with NP (36 with peripheral, 32 with central, and 26 with mixed pain) and 70 with NNP was enrolled. The questionnaire was reliable [Cronbach's alpha coefficient: 0.71, inter-rater agreement coefficient: 0.80 (0.71-0.89), and test-retest intra-class correlation coefficient: 0.95 (0.92-0.97)] and valid for a cut-off value > or = 4 points, which was the best value to discriminate between NP and NNP subjects. DISCUSSION This study, representing the first validation of the DN4 questionnaire into another language different than the original, not only supported its high discriminatory value for identification of neuropathic pain, but also provided supplemental psychometric validation (i.e. test-retest reliability, influence of educational level and pain intensity) and showed its validity in mixed pain syndromes.

Characterization of microevolution events in Mycobacterium tuberculosis strains involved in recent transmission clusters.

Under certain circumstances, it is possible to identify clonal variants of Mycobacterium tuberculosis infecting a single patient, probably as a result of subtle genetic rearrangements in part of the bacillary population. We systematically searched for these microevolution events in a different context, namely, recent transmission chains. We studied the clustered cases identified using a population-based universal molecular epidemiology strategy over a 5-year period. Clonal variants of the reference strain defining the cluster were found in 9 (12%) of the 74 clusters identified after the genotyping of 612 M. tuberculosis isolates by IS6110 restriction fragment length polymorphism analysis and mycobacterial interspersed repetitive units-variable-number tandem repeat typing. Clusters with microevolution events were epidemiologically supported and involved 4 to 9 cases diagnosed over a 1- to 5-year period. The IS6110 insertion sites from 16 representative isolates of reference and microevolved variants were mapped by ligation-mediated PCR in order to characterize the genetic background involved in microevolution. Both intragenic and intergenic IS6110 locations resulted from these microevolution events. Among those cases of IS6110 locations in intergenic regions which could have an effect on the regulation of adjacent genes, we identified the overexpression of cytochrome P450 in one microevolved variant using quantitative real-time reverse transcription-PCR. Our results help to define the frequency with which microevolution can be expected in M. tuberculosis transmission chains. They provide a snapshot of the genetic background of these subtle rearrangements and identify an event in which IS6110-mediated microevolution in an isogenic background has functional consequences.

Pneumocystis jirovecii transmission from immunocompetent carriers to infant.

We report a case of Pneumocystis jirovecii transmission from colonized grandparents to their infant granddaughter. Genotyping of P. jirovecii showed the same genotypes in samples from the infant and her grandparents. These findings support P. jirovecii transmission from immunocompetent carrier adults to a susceptible child.

Vertical Transmission of Pneumocystis jirovecii in Humans

This study is part of the project “Pneumocystis Pathogenomics: Unravelling the Colonization-to-Disease Shift,” a Coordination Action supported by the European Commission (ERANET PathoGenoMics). This study was partially supported by the Spanish Ministry of Health (FIS 03/1743). M.A.M.-C. and C.d.l.H. were supported by the Spanish Ministry of Health (FIS CP-04/217 and FIS CM-04/146).

Retest reliability of individual p3 topography assessed by high density electroencephalography.

BACKGROUND Some controversy remains about the potential applicability of cognitive potentials for evaluating the cerebral activity associated with cognitive capacity. A fundamental requirement is that these neurophysiological parameters show a high level of stability over time. Previous studies have shown that the reliability of diverse parameters of the P3 component (latency and amplitude) ranges between moderate and high. However, few studies have paid attention to the retest reliability of the P3 topography in groups or individuals. Considering that changes in P3 topography have been related to different pathologies and healthy aging, the main objective of this article was to evaluate in a longitudinal study (two sessions) the reliability of P3 topography in a group and at the individual level. RESULTS The correlation between sessions for P3 topography in the grand average of groups was high (r = 0.977, p<0.001). The within-subject correlation values ranged from 0.626 to 0.981 (mean: 0.888). In the between-subjects topography comparisons, the correlation was always lower for comparisons between different subjects than for within-subjects correlations in the first session but not in the second session. CONCLUSIONS The present study shows that P3 topography is highly reliable for group analysis (comprising the same subjects) in different sessions. The results also confirmed that retest reliability for individual P3 maps is suitable for follow-up studies for a particular subject. Moreover, P3 topography appears to be a specific marker considering that the between-subjects correlations were lower than the within-subject correlations. However, P3 topography appears more similar between subjects in the second session, demonstrating that is modulated by experience. Possible clinical applications of all these results are discussed.

Cuestiones controvertidas en evaluación económica (I): perspectiva y costes de intervenciones sanitarias.

Economic evaluation of health care interventions has experienced a strong growth over the past decade and is increasingly present as a support tool in the decisions making process on public funding of health services and pricing in European countries. A necessary element using them is that agents that perform economic evaluations have minimum rules with agreement on methodological aspects. Although there are methodological issues in which there is a high degree of consensus, there are others in which there is no such degree of agreement being closest to the normative field or have experienced significant methodological advances in recent years. In this first article of a series of three, we will discuss on the perspective of analysis and assessment of costs in economic evaluation of health interventions using the technique Metaplan. Finally, research lines are proposed to overcome the identified discrepancies.

Cuestiones controvertidas en evaluación económica (III). Intervenciones sanitarias en tres situaciones especiales: enfermedades raras, tratamientos al final de la vida y externalidades en las evaluaciones.

The development of the economic evaluation of health care interventions has become a support tool in making decisions on pricing and reimbursement of new health interventions. The increasingly extensive application of these techniques has led to the identification of particular situations in which, for various reasons, it may be reasonable to take into account special considerations when applying the general principles of economic evaluation. In this article, which closes a series of three, we will discuss, using the Metaplan technique, about the economic evaluation of health interventions in special situations such as rare diseases and end of life treatments, as well as consideration of externalities in assessments, finally pointing out some research areas to solve the main problems identified in these fields.