Longitudinal Cavity Mode Referenced Spline Tuning for Widely Tunable MG-Y Branch Semiconductor Laser

This paper presents a novel method for wavelength-continuous tuning of a MG-Y-Branch Laser that possesses an intrinsic self-calibration capability. The method utilizes the measured characteristic output power pattern caused by the internal longitudinal cavity modes of the laser device to calibrate a set of cubical spline curves. The spline curves are then used to generate the tuning currents for the two reflector sections and the phase section of the laser from an intermediate tuning control parameter. A calibration function maps the desired laser wavelength to the intermediate tuning parameter, thus enabling continuous tuning with high accuracy

Assessment of varicella vaccine effectiveness in Germany: a time-series approach

A multivariate time-series regression model was developed in order to describe the 2005-2008 age-specific time-course of varicella sentinel surveillance data following the introduction of a varicella childhood vaccination programme in Germany. This ecological approach allows the assessment of vaccine effectiveness under field conditions by relating vaccine coverage in cohorts of 24-month-old children to the mean number of cases per reporting unit in the sentinel network. For the 1-2 years age group, which is directly affected by the vaccination programme, a one-dose vaccine effectiveness of 83·2% (95% CI 80·2-85·7) was estimated which corresponds to previous approaches assessing varicella vaccine effectiveness in the field in the US

Gastrointestinal pathogens detected by multiplex nucleic acid amplification testing in stools of pediatric patients and patients returning from the tropics

Background: Gastrointestinal infections are caused by a broad spectrum of pathogens. Conventional diagnostic procedures are resource and time consuming due to single pathogen testing, often in different laboratories. Method: We analyzed 312 consecutive stool samples from pediatric patients (n=127) with gastroenteritis or from adult travelers returning from the tropics with suspected parasite infestation (n=185) using commercial multiplex nucleic acid amplification testing (NAT) (xTAG gastrointestinal pathogen panel, Luminex) covering 15 diarrhea-causing pathogens. The results of the positive samples and a representative number of negative samples were compared to standard methods, including NAT, direct antigen detection (DAD), bacterial culture and microscopy. Results: Of the 185 samples from adult travelers, 21 (11%) were multiplexNAT-positive, with enterotoxigenic Escherichia coli (4%) being the predominant pathogen. Microscopic examination revealed Blastocystis hominis in 23% not covered by the panel. MultiplexNAT scored positive in 66 pediatric samples (52%), with rotavirus (27%) being the most prevalent. All adenovirus-, rotavirus-, Clostridium difficile- and Cryptosporidium-positive samples were confirmed in external laboratories, but only 40% of norovirus- and 29% of Giardia-positive samples. Analysis of frozen specimens by bacterial culture showed the highest discrepancies with the multiplexNAT. Conclusion: Our study demonstrates broad detection of relevant gastroenteritis pathogens by multiplexNAT with a short turnaround time. This is important for diagnosis, infection control and empiric management of gastroenteritis patients, but may be selectively complemented by bacterial culture and resistance testing

Update of the Swiss guidelines on post-treatment Lyme disease syndrome.

Lyme borreliosis is caused by Borrelia burgdorferi sensu lato infection, which responds well to antibiotic therapy in the overwhelming majority of cases. However, despite adequate antibiotic treatment some patients report persisting symptoms which are commonly summarised as post-treatment Lyme disease syndrome (PTLDS). In 2005, the Swiss Society of Infectious Diseases published a case definition for PTLDS. We aimed to review the scientific literature with a special emphasis on the last 10 years, questioning whether the definitions from 2005 are still valid in the light of current knowledge. Furthermore, we describe the clinical history of infection with Borrelia burgdorferi sensu lato, the estimated prevalence of PTLDS, the possible pathogenesis of PTLDS, and treatment options with an emphasis on clinical studies. In summary, we were unable to find a scientific reason for modification of the PTLDS definitions published in 2005. Thus, the diagnostic criteria remain unchanged, namely documented clinical and laboratory evidence of previous infection with B. burgdorferi, a completed course of appropriate antibiotic therapy, symptoms including fatigue, arthralgia, myalgia, cognitive dysfunction or radicular pain persisting for >6 months, a plausible timely association between documented B. burgdorferi infection and onset of symptoms (i.e., persistent or recurrent symptoms that began within 6 months of completion of a recommended antibiotic therapy for early or late Lyme borreliosis), and exclusion of other somatic or psychiatric causes of symptoms. The main therapeutic options remain cognitive behavioural therapy and low-impact aerobic exercise programmes. Growing and unequivocal evidence confirms that prolonged or repeated antibiotic therapy for PTLDS is not beneficial, but potentially harmful and therefore contraindicated. The Guidelines of the Swiss Society of Infectious Diseases offer an evidence based, diagnostic and therapeutic framework for physicians caring for patients suffering from presumptive PTLDS in Switzerland

Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods--particularly in patients with prior antibiotic treatment--and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time

Heart transplantation as salvage therapy for progressive prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis (MRSE)

Background: Prosthetic valve endocarditis (PVE) has the highest in-hospital mortality among all cases of infective endocarditis (IE), it is estimated at about 40 %. Orthotopic heart transplantation (OHT) as a measure of last resort, may be considered in selected cases where repeated surgical procedures and conservative efforts have failed to eradicate persistent or recurrent IE. Only few clinical data are available regarding this rare indication for OHT, since active IE has traditionally been considered as a contraindication for OHT. Case presentation: We report on a 55 year old male patient who underwent prosthetic valve replacement with a mechanical valved conduit ten years ago and developed now persistent PVE with severe complications due to methicillin-resistant Staphylococcus epidermidis (MRSE). Repeated surgical procedures and conservative efforts have failed to eradicate the pathogen. Regarding the lack of curative options, salvage OHT was discussed as a measure of last resort. 28 months after the first diagnosis of PVE, the patient was successfully transplanted and is now doing well under close follow-up (6 months post-OHT). Conclusions: PVE remains a challenging condition regarding diagnosis and treatment. The presented case underscores the urgent need for an integrated and multidisciplinary approach to patients with suspected and definitive IE - especially in PVE. OHT might be a feasible measure of last resort in selected patients with IE. Our case report adds published clinical experience to this rarely performed procedure and consolidates previous findings

First AMBER/VLTI observations of hot massive stars

AMBER is the first near infrared focal instrument of the VLTI. It combines three telescopes and produces spectrally resolved interferometric measures. This paper discusses some preliminary results of the first scientific observations of AMBER with three Unit Telescopes at medium (1500) and high (12000) spectral resolution. We derive a first set of constraints on the structure of the circumstellar material around the Wolf Rayet Gamma2 Velorum and the LBV Eta Carinae

Varicella susceptibility and transmission dynamics in Slovenia

<p>Abstract</p> <p>Background</p> <p>A cross-sectional, age-stratified study was conducted to determine varicella-zoster seroprevalence and force of infection in Slovenia.</p> <p>Methods</p> <p>3689 serum samples were tested for VZV IgG antibodies with an enzyme immunoassay. Semiparametric and parametric modelling were used to estimate the force of infection.</p> <p>Results</p> <p>Overall, 85.6% of serum samples were seropositive. Age-specific prevalence rose rapidly in preschool children and over 90% of 8 years old tested positive for VZV. However, 2.8% of serum samples among women of childbearing age were seronegative. Semiparametric modelling yielded force of infection estimates of 0.182 (95% CI 0.158-0.206), 0.367 (95% CI 0.285-0.448) and 0.008 (95% CI 0.0-0.032) for age groups 0.5- < 6, 6-11 and ≥12 years, respectively, and 0.175 (95% CI 0.147-0.202), 0.391 (95% CI 0.303-0.480) and 0.025 (95% CI 0.003-0.046) for age groups 0.5- < 5, 5-9 and ≥10 years, respectively.</p> <p>Conclusions</p> <p>Regardless of the age grouping used, the highest transmission occurred in children in their first years of school.</p