Systematic survey of clonal complexity in tuberculosis at a populational level and detailed characterization of the isolates involved.

Clonally complex infections by Mycobacterium tuberculosis are progressively more accepted. Studies of their dimension in epidemiological scenarios where the infective pressure is not high are scarce. Our study systematically searched for clonally complex infections (mixed infections by more than one strain and simultaneous presence of clonal variants) by applying mycobacterial interspersed repetitive-unit (MIRU)-variable-number tandem-repeat (VNTR) analysis to M. tuberculosis isolates from two population-based samples of respiratory (703 cases) and respiratory-extrapulmonary (R+E) tuberculosis (TB) cases (71 cases) in a context of moderate TB incidence. Clonally complex infections were found in 11 (1.6%) of the respiratory TB cases and in 10 (14.1%) of those with R+E TB. Among the 21 cases with clonally complex TB, 9 were infected by 2 independent strains and the remaining 12 showed the simultaneous presence of 2 to 3 clonal variants. For the 10 R+E TB cases with clonally complex infections, compartmentalization (different compositions of strains/clonal variants in independent infected sites) was found in 9 of them. All the strains/clonal variants were also genotyped by IS6110-based restriction fragment length polymorphism analysis, which split two MIRU-defined clonal variants, although in general, it showed a lower discriminatory power to identify the clonal heterogeneity revealed by MIRU-VNTR analysis. The comparative analysis of IS6110 insertion sites between coinfecting clonal variants showed differences in the genes coding for a cutinase, a PPE family protein, and two conserved hypothetical proteins. Diagnostic delay, existence of previous TB, risk for overexposure, and clustered/orphan status of the involved strains were analyzed to propose possible explanations for the cases with clonally complex infections. Our study characterizes in detail all the clonally complex infections by M. tuberculosis found in a systematic survey and contributes to the characterization that these phenomena can be found to an extent higher than expected, even in an unselected population-based sample lacking high infective pressure.

QoS online routing and MPLS multilevel protection: a survey

A survey of MPLS protection methods and their utilization in combination with online routing methods is presented in this article. Usually, fault management methods pre-establish backup paths to recover traffic after a failure. In addition, MPLS allows the creation of different backup types, and hence MPLS is a suitable method to support traffic-engineered networks. In this article, an introduction of several label switch path backup types and their pros and cons are pointed out. The creation of an LSP involves a routing phase, which should include QoS aspects. In a similar way, to achieve a reliable network the LSP backups must also be routed by a QoS routing method. When LSP creation requests arrive one by one (a dynamic network scenario), online routing methods are applied. The relationship between MPLS fault management and QoS online routing methods is unavoidable, in particular during the creation of LSP backups. Both aspects are discussed in this article. Several ideas on how these actual technologies could be applied together are presented and compared

A survey addressing the fundamental matrix estimation problem

Epipolar geometry is a key point in computer vision and the fundamental matrix estimation is the only way to compute it. This article surveys several methods of fundamental matrix estimation which have been classified into linear methods, iterative methods and robust methods. All of these methods have been programmed and their accuracy analysed using real images. A summary, accompanied with experimental results, is given

Assessing the Precision of Compositional Data in a Stratified Double Stage Cluster Sample: Application to the Swiss Earnings Structure Survey

Precision of released figures is not only an important quality feature of official statistics,it is also essential for a good understanding of the data. In this paper we show a casestudy of how precision could be conveyed if the multivariate nature of data has to betaken into account. In the official release of the Swiss earnings structure survey, the totalsalary is broken down into several wage components. We follow Aitchison's approachfor the analysis of compositional data, which is based on logratios of components. Wefirst present diferent multivariate analyses of the compositional data whereby the wagecomponents are broken down by economic activity classes. Then we propose a numberof ways to assess precision

Prevalence and Clinical Characteristics of HIV Type 1-Infected Patients Receiving Dialysis in Spain: Results of a Spanish Survey in 2006: GESIDA 48/05 Study

End-stage renal diseases (ESRD) are becoming more frequent in HIV-infected patients. In Europe there is little information about HIV-infected patients on dialysis. A cross-sectional multicenter survey in 328 Spanish dialysis units was conducted in 2006. Information from 14,876 patients in dialysis was obtained (81.6% of the Spanish dialysis population). Eighty-one were HIV infected (0.54%; 95% CI, 0.43-0.67), 60 were on hemodialysis, and 21 were on peritoneal dialysis. The mean (range) age was 45 (28-73) years. Seventy-two percent were men and 33% were former drug users. The mean (range) time of HIV infection was 11 (1-27) years and time on dialysis was 4.6 (0.4-25) years. ESRD was due to glomerulonephritis (36%) and diabetes (15%). HIV-associated nephropathy was not reported. Eighty-five percent were on HAART, 76.5% had a CD4 T cell count above 200 cells, and 73% had undetectable viral load. Thirty-nine percent of patients met criteria for inclusion on the renal transplant (RT) waiting list but only 12% were included. Sixty-one percent had HCV coinfection. HCV-coinfected patients had a longer history of HIV, more previous AIDS events, parenteral transmission as the most common risk factor for acquiring HIV infection, and less access to the RT waiting list (p < 0.05). The prevalence of HIV infection in Spanish dialysis units in 2006 was 0.54% HCV coinfection was very frequent (61%) and the percentage of patients included on the Spanish RT waiting list was low (12%).

Effects of Interviewer Experience on Components of Nonresponse in the European Social Survey

We analyze interviewer related nonresponse differences in face-to-face surveys distinguishing three types of interviewers: those who have previous experience with the same high standard cross-sectional survey ("experienced"), those who were chosen by the survey agency to complete refusal conversions ("seniors"), and usual interviewers. The nonresponse components are obtaining household contact, target person contact, and target person cooperation. In addition we examine if interviewer homogeneity with respect to these components is different across the three interviewer groups. Data come from the European Social Survey (ESS) contact forms from four countries which participated during the three rounds 2002/04/06 and used the same survey agency that in turn used to some extent the same interviewers. To analyze interviewer effects, we use discrete two-level models. We find some evidence of better performance by both senior and experienced interviewers and indications of greater homogeneity for nonresponse components, especially for those that contain room for improvement. Surprisingly, the senior interviewers do not outperform those experienced. We conclude that survey agencies should make more efforts to decrease the comparatively high interviewer turnover.

A comparative evaluation of endemic and non-endemic region of visceral leishmaniasis (Kala-azar) in India with ground survey and space technology

In visceral leishmaniasis, phlebotomine vectors are targets for control measures. Understanding the ecosystem of the vectors is a prerequisite for creating these control measures. This study endeavours to delineate the suitable locations of Phlebotomus argentipes with relation to environmental characteristics between endemic and non-endemic districts in India. A cross-sectional survey was conducted on 25 villages in each district. Environmental data were obtained through remote sensing images and vector density was measured using a CDC light trap. Simple linear regression analysis was used to measure the association between climatic parameters and vector density. Using factor analysis, the relationship between land cover classes and P. argentipes density among the villages in both districts was investigated. The results of the regression analysis indicated that indoor temperature and relative humidity are the best predictors for P. argentipes distribution. Factor analysis confirmed breeding preferences for P. argentipes by landscape element. Minimum Normalised Difference Vegetation Index, marshy land and orchard/settlement produced high loading in an endemic region, whereas water bodies and dense forest were preferred in non-endemic sites. Soil properties between the two districts were studied and indicated that soil pH and moisture content is higher in endemic sites compared to non-endemic sites. The present study should be utilised to make critical decisions for vector surveillance and controlling Kala-azar disease vectors.

Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR). Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT) (n = 51) and by both techniques (n = 47). PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.

Difficulties associated with out-patient management of drug abusers by general practitioners. A cross sectional survey of general practitioners with and without methadone patients in Switzerland

Résumé de l'article Contexte : En Suisse, les médecins de premier recours traitent la plupart des patients dépendants aux opiacés méthadone en tant que traitement de substitution. Méthode : Nous avons étudié les difficultés rencontrées dans la prise en charge des patients toxicodépendants en envoyant par poste un questionnaire d'enquête. Nous avons envoyé ce questionnaire à tous les médecins de premier recours de Suisse Romande prescrivant de la méthadone (556 médecins). Nous avons envoyé un autre questionnaire, plus court, à des médecins de premier recours du Canton de Vaud qui ne prescrivent pas de méthadone. Résultats : le taux de réponse global est de 63,3 %. La plus haute dose de méthadone donnée par les médecins de premier recours est de 120,4 mg/j (moyenne). Questionnés au sujet de l'aide qu'ils désireraient recevoir face à ces patients, les médecins de premier recours avec patients substitués par méthadone ont mentionné premièrement l'importance d'un meilleur remboursement des services prodigués. Les autres éléments demandés ont été une meilleure formation, de meilleures connaissances des pathologies psychiatriques et des groupes de discussion de cas cliniques. Les médecins sans patients sous méthadone refusent de traiter ces patients surtout pour des raisons émotionnelles et relationnelles. En conclusion : les médecins acceptant des patients sous méthadone rencontrent des difficultés relationnelles et émotionnelles. Ils désirent un meilleur remboursement pour les services prodigués.

A survey strategy for human respiratory syncytial virus detection among haematopoietic stem cell transplant patients: epidemiological and methodological analysis

Human respiratory syncytial virus (HRSV) causes severe infections among children and immunocompromised patients. We compared HRSV infections among Haematopoietic Stem Cell Transplant program (HSCT) patients and children using direct immunofluorescence (DFA), point-of-care RSV Bio Easy® and a polymerase chain reaction (PCR) assay. Overall, 102 samples from HSCT patients and 128 from children obtained positivity rate of 18.6% and 14.1% respectively. PCR sensitivity was highest mainly on samples collected after five days of symptoms onset. A combination of both DFA and reverse transcriptase-PCR methods for HSCT high-risk patients is the best diagnostic flow for HRSV diagnosis among these patients.

After-hours paediatric telephone triage and advice : the Neuchâtel experience

Résumé Introduction : Plusieurs études américaines et australiennes ont décrit des systèmes de tri téléphonique des urgences pédiatriques. En Europe, les services publics d'urgences pédiatriques ont peu de données épidémiologiques sur lesquelles s'appuyer pour répondre à la demande de soins. Depuis 1996, le département de pédiatrie de l'hôpital Pourtalès, Neuchâtel, offre, en dehors des heures ouvrables, mi tri téléphonique infirmier gratuit. Le présent travail analyse : 1) la situation suisse de l'offre en tri téléphonique infirmier pour les urgences pédiatriques ; 2) une partie des données épidémiologiques de l'expérience neuchâteloise. Méthode : 1) Un questionnaire a été envoyé aux 35 services d'urgences pédiatriques publics de Suisse pour Savoir si un tel tri était utilisé ; 2) une analyse rétrospective de tous les appels reçus, consignés sur fiches standardisées, en 1997 et 2000 a été menée. Résultats : 1) La majorité des services (27/35) ont effectivement un système de tri infirmier. Peu offrent une formation spécifique pour ce travail (14/27) ; 2) Au total, 7870 appels ont été analysés (3242 en 1997; 4628 en 2000, ± 43%). En semaine, la majorité ont été reçus entre 18h et 23h et le week-end en milieu de matinée. Septante-cinq % des appels ont concerné des enfants de 5 ans ou moins. La fièvre, les otalgies et la toux ont représenté 42% des plaintes. Vingt-sept % des appels ont été pris en charge uniquement par les conseils infirmiers, 15 % ont été transmis à l'interne de garde et 50% ont conduit à un rendez-vous dans le service le jour même. Conclusion : Nos données peuvent aider d'autres services d'urgences pédiatriques à planifier au mieux la mise en place d'un tel système de tri téléphonique. Abstract Delivery of paediatric primary care by call centres has emerged as a satisfactory system. It been reported in the literature in the United States and Australia. European public-funded paediatric emergency departments (ED) have little epidemiological data to rely on to match the demand in care. Since 1996, we have run a free nurse-led after-hours paediatric telephone triage and advice (TTA) system, To determine wether other Swiss public paediatric departments practiced formal TTA, we conducted a nation-wide postal survey. To delineate who used our call centre and for what reasons, we embarked on a retrospective study of ail the 1997/2000 calls. Most of the units run a TTA (27/35) but few specifically train their staff (14/27). A 43% increase in call numbers was seen between 1997 (3242) and 2000 (4628). During week-days, most of the calls were between 6 and 11 pm and at weekends, a mid morning activity peak was seen. Some 75% of calls were for children aged 5 years or less. Fever, earache and cough accounted for 42% of the main complaints. Of all calls, 27% were dealt by nurses' advice only. About 15% of the calls were transferred to the on-call resident. About 50% led to a same day ED appointment. Conclusion: Nurse-led paediatric telephone triage and advice is common in Switzerland where training seems to be irregular. Our data can help units to better plan an eventual paediatric telephone triage and advice service. After-hours; Paediatric; Telephone advice; Telephone triage

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.