A multistate investigation of health care-associated Burkholderia cepacia complex infections related to liquid docusate sodium contamination, January-October 2016

BACKGROUND

Outbreaks of health care-associated infections (HAIs) caused by Burkholderia cepacia complex (Bcc) have been associated with medical devices and water-based products. Water is the most common raw ingredient in nonsterile liquid drugs, and the significance of organisms recovered from microbiologic testing during manufacturing is assessed using a risk-based approach. This incident demonstrates that lapses in manufacturing practices and quality control of nonsterile liquid drugs can have serious unintended consequences.

METHODS

An epidemiologic and laboratory investigation of clusters of Bcc HAIs that occurred among critically ill, hospitalized, adult and pediatric patients was performed between January 1, 2016, and October 31, 2016.

RESULTS

One hundred and eight case patients with Bcc infections at a variety of body sites were identified in 12 states. Two distinct strains of Bcc were obtained from patient clinical cultures. These strains were found to be indistinguishable or closely related to 2 strains of Bcc obtained from cultures of water used in the production of liquid docusate, and product that had been released to the market by manufacturer X.

CONCLUSIONS

This investigation highlights the ability of bacteria present in nonsterile, liquid drugs to cause infections or colonization among susceptible patients. Prompt reporting and thorough investigation of potentially related infections may assist public health officials in identifying and removing contaminated products from the market when lapses in manufacturing occur.

Detecting Local Zika Virus Transmission in the Continental United States: A Comparison of Surveillance Strategies

Introduction:

The 2015-2017 Zika virus (ZIKV) epidemic in the Americas has driven efforts to strengthen surveillance systems and to develop interventions, testing, and travel recommendations. In the continental U.S. and Hawaii, where limited transmission has been observed, detecting local transmission is a key public health objective. We assessed the effectiveness of three general surveillance strategies for this situation: testing all pregnant women twice during pregnancy, testing blood donations, and testing symptomatic people who seek medical care in an emergency department (ED).

Methods:

We developed a simulation model for each surveillance strategy and simulated different transmission scenarios with varying population sizes and infection rates. We then calculated the probability of detecting transmission, the number of tests needed, and the number of false positive test results.

Results:

The probability of detecting ZIKV transmission was highest for testing ED patients with Zika symptoms, followed by pregnant women and blood donors, in that order. The magnitude of the difference in probability of detection between strategies depended on the incidence of infection. Testing ED patients required fewer tests and resulted in fewer false positives than surveillance among pregnant women. The optimal strategy identified was to test ED patients with at least two Zika virus disease symptoms. This case definition resulted in a high probability of detection with relatively few tests and false positives.

Discussion:

In the continental U.S. and Hawaii, where local ZIKV transmission is rare, optimizing the probability of detecting infections while minimizing resource usage is particularly important. Local surveillance strategies will be influenced by existing public health system infrastructure, but should also consider the effectiveness of different approaches. This analysis demonstrated differences across strategies and indicated that testing symptomatic ED patients is generally a more efficient strategy for detecting transmission than routine testing of pregnant women or blood donors.

Update: Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure - United States (Including U.S. Territories), July 2017

CDC has updated the interim guidance for U.S. health care providers caring for pregnant women with possible Zika virus exposure in response to 1) declining prevalence of Zika virus disease in the World Health Organization's Region of the Americas (Americas) and 2) emerging evidence indicating prolonged detection of Zika virus immunoglobulin M (IgM) antibodies. Zika virus cases were first reported in the Americas during 2015-2016; however, the incidence of Zika virus disease has since declined. As the prevalence of Zika virus disease declines, the likelihood of false-positive test results increases. In addition, emerging epidemiologic and laboratory data indicate that, as is the case with other flaviviruses, Zika virus IgM antibodies can persist beyond 12 weeks after infection. Therefore, IgM test results cannot always reliably distinguish between an infection that occurred during the current pregnancy and one that occurred before the current pregnancy, particularly for women with possible Zika virus exposure before the current pregnancy. These limitations should be considered when counseling pregnant women about the risks and benefits of testing for Zika virus infection during pregnancy. This updated guidance emphasizes a shared decision-making model for testing and screening pregnant women, one in which patients and providers work together to make decisions about testing and care plans based on patient preferences and values, clinical judgment, and a balanced assessment of risks and expected outcomes.

Scaling of the Quantum Anomalous Hall Effect as an Indicator of Axion Electrodynamics

We report on the scaling behavior of V-doped (Bi,Sb)_{2}Te_{3} samples in the quantum anomalous Hall regime for samples of various thickness. While previous quantum anomalous Hall measurements showed the same scaling as expected from a two-dimensional integer quantum Hall state, we observe a dimensional crossover to three spatial dimensions as a function of layer thickness. In the limit of a sufficiently thick layer, we find scaling behavior matching the flow diagram of two parallel conducting topological surface states of a three-dimensional topological insulator each featuring a fractional shift of 1/2e^{2}/h in the flow diagram Hall conductivity, while we recover the expected integer quantum Hall behavior for thinner layers. This constitutes the observation of a distinct type of quantum anomalous Hall effect, resulting from 1/2e^{2}/h Hall conductance quantization of three-dimensional topological insulator surface states, in an experiment which does not require decomposition of the signal to separate the contribution of two surfaces. This provides a possible experimental link between quantum Hall physics and axion electrodynamics.

Vital Signs: Update on Zika Virus-Associated Birth Defects and Evaluation of All U.S. Infants with Congenital Zika Virus Exposure - U.S. Zika Pregnancy Registry, 2016

Background

In collaboration with state, tribal, local, and territorial health departments, CDC established the U.S. Zika Pregnancy Registry (USZPR) in early 2016 to monitor pregnant women with laboratory evidence of possible recent Zika virus infection and their infants.

Methods

This report includes an analysis of completed pregnancies (which include live births and pregnancy losses, regardless of gestational age) in the 50 U.S. states and the District of Columbia (DC) with laboratory evidence of possible recent Zika virus infection reported to the USZPR from January 15 to December 27, 2016. Birth defects potentially associated with Zika virus infection during pregnancy include brain abnormalities and/or microcephaly, eye abnormalities, other consequences of central nervous system dysfunction, and neural tube defects and other early brain malformations.

Results

During the analysis period, 1,297 pregnant women in 44 states were reported to the USZPR. Zika virus–associated birth defects were reported for 51 (5%) of the 972 fetuses/infants from completed pregnancies with laboratory evidence of possible recent Zika virus infection (95% confidence interval [CI] = 4%–7%); the proportion was higher when restricted to pregnancies with laboratory-confirmed Zika virus infection (24/250 completed pregnancies [10%, 95% CI = 7%–14%]). Birth defects were reported in 15% (95% CI = 8%–26%) of fetuses/infants of completed pregnancies with confirmed Zika virus infection in the first trimester. Among 895 liveborn infants from pregnancies with possible recent Zika virus infection, postnatal neuroimaging was reported for 221 (25%), and Zika virus testing of at least one infant specimen was reported for 585 (65%).

Conclusions and Implications for Public Health Practice

These findings highlight why pregnant women should avoid Zika virus exposure. Because the full clinical spectrum of congenital Zika virus infection is not yet known, all infants born to women with laboratory evidence of possible recent Zika virus infection during pregnancy should receive postnatal neuroimaging and Zika virus testing in addition to a comprehensive newborn physical exam and hearing screen. Identification and follow-up care of infants born to women with laboratory evidence of possible recent Zika virus infection during pregnancy and infants with possible congenital Zika virus infection can ensure that appropriate clinical services are available.

Infection Prevention and Control for Ebola in Health Care Settings - West Africa and United States

The 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa underscores the need for health care infection prevention and control (IPC) practices to be implemented properly and consistently to interrupt transmission of pathogens in health care settings to patients and health care workers. Training and assessing IPC practices in general health care facilities not designated as Ebola treatment units or centers became a priority for CDC as the number of Ebola virus transmissions among health care workers in West Africa began to affect the West African health care system and increasingly more persons became infected. CDC and partners developed policies, procedures, and training materials tailored to the affected countries. Safety training courses were also provided to U.S. health care workers intending to work with Ebola patients in West Africa. As the Ebola epidemic continued in West Africa, the possibility that patients with Ebola could be identified and treated in the United States became more realistic. In response, CDC, other federal components (e.g., Office of the Assistant Secretary for Preparedness and Response) and public health partners focused on health care worker training and preparedness for U.S. health care facilities. CDC used the input from these partners to develop guidelines on IPC for hospitalized patients with known or suspected Ebola, which was updated based on feedback from partners who provided care for Ebola patients in the United States. Strengthening and sustaining IPC helps health care systems be better prepared to prevent and respond to current and future infectious disease threats.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Notes from the Field: Probable Mucormycosis Among Adult Solid Organ Transplant Recipients at an Acute Care Hospital - Pennsylvania, 2014-2015

On September 17, 2015, the Pennsylvania Department of Health (PADOH) notified CDC of a cluster of three potentially health care-associated mucormycete infections that occurred among solid organ transplant recipients during a 12-month period at hospital A. On September 18, hospital B reported that it had identified an additional transplant recipient with mucormycosis. Hospitals A and B are part of the same health care system and are connected by a pedestrian bridge. PADOH requested CDC's assistance with an on-site investigation, which started on September 22, to identify possible sources of infection and prevent additional infections.

Kinetic limitation of chemical ordering in Bi2Te3-x Se x layers grown by molecular beam epitaxy

We study the chemical ordering in Bi2Te3-x Se x grown by molecular beam epitaxy on Si substrates. We produce films in the full composition range from x = 0 to 3, and determine their material properties using energy dispersive x-ray spectroscopy, x-ray diffraction and Raman spectroscopy. By fitting the parameters of a kinetic growth model to these results, we obtain a consistent description of growth at a microscopic level. Our main finding is that despite the incorporation of Se in the central layer being much more probable than that of Te, the formation of a fully ordered Te-Bi-Se-Bi-Te layer is prevented by kinetic of the growth process. Indeed, the Se concentration in the central layer of Bi2Te2Se1 reaches a maximum of only ≈ 75% even under ideal growth conditions. A second finding of our work is that the intensity ratio of the 0 0 12 and 0 0 6 x-ray reflections serves as an experimentally accessible quantitative measure of the degree of ordering in these films.

Correction: Synthesis and crystal structure of a new hexagonal perovskite 7H-Ba7Li1.75Mn3.5O15.75 with Mn(4+)/Mn(5+) charge distribution

Correction for ‘Synthesis and crystal structure of a new hexagonal perovskite 7H-Ba₇Li_1.75Mn_3.5O_15.75 with Mn⁴⁺/Mn⁵⁺ charge distribution’ by N. V. Tarakina et al., Dalton Trans., 2015, DOI: 10.1039/c5dt01528f.

Synthesis and crystal structure of a new hexagonal perovskite 7H-Ba7Li1.75Mn3.5O15.75 with Mn(4+)/Mn(5+) charge distribution

Ba7Li1.75Mn3.5O15.75 is a new hexagonal perovskite whose crystal structure has elements typical for the layered hexagonal perovskites and quasi-one-dimensional oxides, hence representing a new polytype. It has been synthesized via a solid-state microwave route. The crystal structure was solved using a combination of X-ray and neutron diffraction data, which show that Ba7Li1.75Mn3.5O15.75 crystallizes in a hexagonal unit cell with parameters a = 5.66274(2) Å and c = 16.7467(1) Å (V = 465.063(4) Å(3)), with one formula unit, and can be described as columns of face-shared octahedra occupied by Mn(4+) and Li(+) cations and vacancies along the c axis separated in the ab plane by barium atoms. Every sixth layer, the coordination of Mn(5+) and Li(+) changes to tetrahedral. Additional local ordering of manganese and lithium atoms among cationic sites leading to the formation of a rhombohedral supercell has been observed by scanning transmission electron microscopy.

Magneto-optics of massive dirac fermions in bulk Bi2Se3

We report on magneto-optical studies of Bi2Se3, a representative member of the 3D topological insulator family. Its electronic states in bulk are shown to be well described by a simple Dirac-type Hamiltonian for massive particles with only two parameters: the fundamental band gap and the band velocity. In a magnetic field, this model implies a unique property-spin splitting equal to twice the cyclotron energy: Es=2Ec. This explains the extensive magnetotransport studies concluding a fortuitous degeneracy of the spin and orbital split Landau levels in this material. The Es=2Ec match differentiates the massive Dirac electrons in bulk Bi2Se3 from those in quantum electrodynamics, for which Es=Ec always holds.

Outbreak of Carbapenem-Resistant Klebsiella pneumoniae in Puerto Rico Associated with a Novel Carbapenemase Variant

Background.

Carbapenem-resistantKlebsiella pneumoniae(CRKP) is resistant to almost all antimicrobial agents, and CRKP infections are associated with substantial morbidity and mortality.

Objective.

To describe an outbreak of CRKP in Puerto Rico, determine risk factors for CRKP acquisition, and detail the successful measures taken to control the outbreak.

Design.

Two case-control studies.

Setting.

A 328-bed tertiary care teaching hospital.

Patients.

Twenty-six CRKP case patients identified during the outbreak period of February through September 2008, 26 randomly selected uninfected control patients, and 26 randomly selected control patients with carbapenem-susceptibleK. pneumoniae(CSKP) hospitalized during the same period.

Methods.

We performed active case finding, including retrospective review of the hospital's microbiology database and prospective perirectal surveillance culture sampling in high-risk units. Case patients were compared with each control group while controlling for time at risk. We sequenced theblaKPCgene with polymerase chain reaction for 7 outbreak isolates and subtyped these isolates with pulsed-field gel electrophoresis.

Results.

In matched, multivariable analysis, the presence of wounds (hazard ratio, 19.0 [95% confidence interval {CI}, 2.5-142.0]) was associated with CRKP compared with noK. pneumoniae.Transfer between units (adjusted odds ratio [OR], 7.5 [95% CI, 1.8-31.1]), surgery (adjusted OR, 4.0 [95% CI, 1.0-15.7]), and wounds (adjusted OR, 4.9 [95% CI, 1.1-21.8]) were independent risk factors for CRKP compared to CSKP. A novelK. pneumoniaecarbapenemase variant (KPC-8) was present in 5 isolates. Implementation of active surveillance for CRKP colonization and cohorting of CRKP patients rapidly controlled the outbreak.

Conclusions.

Enhanced surveillance for CRKP colonization and intensified infection control measures that include limiting the physical distribution of patients can reduce CRKP transmission during an outbreak.

Strategies to prevent catheter-associated urinary tract infections in acute care hospitals: 2014 update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their catheter-associated urinary tract infection (CAUTI) prevention efforts. This document updates “Strategies to Prevent Catheter-Associated Urinary Tract Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA). the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Fabrication of magnetic artificial atoms

We have fabricated gated vertical quantum dots made from a II-VI semiconductor heterostructure containing a paramagnetic quantum well. The absence of a known Schottky gate metal compatible with ZnSe based material precludes the traditional method of using a self-aligning shadow evaporated gate. Instead, we make use of a multi-step electron beam lithography process to surround a pillar with an insulating dielectric and gate. This process allows for the processing of dots with diameters down to 250 nm. Preliminary transport data confirming the magnetic nature of the resulting artificial atom are presented.

Diffusion thermopower of (Ga,Mn)As/GaAs tunnel junctions

We report the observation of tunneling anisotropic magnetothermopower, a voltage response to a temperature difference across an interface between a normal and a magnetic semiconductor. The resulting voltage is related to the energy derivative of the density of states in the magnetic material, and thus has a strongly anisotropic response to the direction of magnetization in the material. The effect will have relevance to the operation of semiconductor spintronic devices, and may indeed already play a role in correctly interpreting the details of some earlier spin injection studies.

Investigation of a group A streptococcal outbreak among residents of a long-term acute care hospital

BACKGROUND

In January 2008, a long-term acute care hospital (LTACH) in New Mexico reported a cluster of severe group A Streptococcus (GAS) infections.

METHODS

We defined a case as illness in a patient in the LTACH from 1 October 2007 through 3 February 2008 from whom GAS was isolated from a usually sterile site or with illness consistent with GAS infection and GAS isolated from a nonsterile site. To identify carriers, we swabbed the oropharynx and skin lesions of patients and staff. We observed facility procedures to assess possible transmission routes and adherence to infection control practices. We also conducted a case-control study to identify risk factors for infection with use of asymptomatic patients who were noncarriers as control subjects.

RESULTS

We identified 11 case patients and 11 carriers (8 patients and 3 staff). No carriers became case patients. Significant risk factors for infection in univariate analysis included sharing a room with an infected or colonized patient (6 [55%] of 11 case patients vs 3 [8%] of 39 control subjects), undergoing wound debridement (64% vs 13%), and receiving negative pressure wound therapy (73% vs 33%). Having an infected or colonized roommate remained associated with case patients in multivariable analysis (odds ratio, 15.3; 95% confidence interval, 2.5-110.9). Suboptimal infection control practices were widespread.

CONCLUSIONS

This large outbreak of GAS infection was the first reported in an LTACH, a setting that contains a highly susceptible patient population. Widespread infection control lapses likely allowed continued transmission. Similar to the situation in other care settings, appropriate infection control and case cohorting may help prevent and control outbreaks of GAS infection in LTACHs.

Fully electrical read-write device out of a ferromagnetic semiconductor

We report the realization of a read-write device out of the ferromagnetic semiconductor (Ga,Mn)As as the first step to a fundamentally new information processing paradigm. Writing the magnetic state is achieved by current-induced switching and readout of the state is done by the means of the tunneling anisotropic magnetoresistance effect. This 1 bit demonstrator device can be used to design an electrically programmable memory and logic device.

Photoinduced Barkhausen effect in the ferromagnetic semiconductor (Ga,Mn)As

Magnetization of ferromagnetic materials commonly occurs via random jumps of domain walls between pinning sites, a phenomenon known as the Barkhausen effect. Using strongly focused light pulses of appropriate power and duration we demonstrate the ability to selectively activate single jumps in the domain wall propagation in (Ga,Mn)As, manifesting itself as a discrete photoinduced domain wall creep as a function of illumination time. The propagation velocity can be increased over 7 orders of magnitude varying the illumination power density and the magnetic field.

Independent magnetization behavior of a ferromagnetic metal-semiconductor hybrid system

We report the discovery of an effect where two ferromagnetic materials, one semiconductor [(Ga,Mn)As] and one metal (Permalloy), can be directly deposited on each other and still switch their magnetization independently. We use this independent magnetization behavior to create various resistance states dependent on the magnetization direction of the individual layers. At zero magnetic field a two layer device can reach up to four nonvolatile resistance states.

Complete restriction of fluoroquinolone use to control an outbreak of Clostridium difficile infection at a community hospital

OBJECTIVE

To review the effect of interventions, including a complete restriction in the use of fluoroquinolones (FQs), used to control an outbreak of hospital-onset Clostridium difficile infection (HO-CDI) caused primarily by the epidemic North American pulsed-field gel electrophoresis type 1 strain.

DESIGN

Retrospective cohort and case-control study of all episodes of HO-CDI both before and after 2 interventions.

SETTING

Community hospital; January 1, 2005, through March 31, 2007. Interventions. Complete, 5-month, facility-wide restriction of fluoroquinolone use, during which a change in the environmental-services contractor occurred.

RESULTS

During a 27-month period, 319 episodes of HO-CDI occurred. The hospital-wide mean defined daily doses of antimicrobials decreased 22% after restricting FQ use, primarily because of a 66% decrease in the use of FQs. The interventions were also associated with a significant change in the HO-CDI incidence trends and with an absolute decrease of 22% in HO-CDI cases caused by the epidemic strain (from 66% before the intervention period to 44% during and after the intervention period; P=.02). Univariate analysis revealed that case patients with HO-CDI due to the epidemic strain were more likely than control patients, who did not have diarrhea, to receive a FQ, whereas case patients with HO-CDI due to a nonepidemic strain were not. However, FQ use was not significantly associated with HO-CDI in multivariable analysis.

CONCLUSIONS

An outbreak of epidemic-strain HO-CDI was controlled at a community hospital after an overall decrease in antimicrobial use, primarily because of a restriction of FQ use and a change in environmental-services contractors. The restriction of FQ use may be useful as an adjunct control measure in a healthcare facilities during outbreaks of epidemic-strain HO-CDI.

Nonthermal photocoercivity effect in a low-doped (Ga,Mn)As ferromagnetic semiconductor

We report a photoinduced change of the coercive field, i.e., a photocoercivity effect (PCE), under very low intensity illumination of a low-doped (Ga,Mn)As ferromagnetic semiconductor. We find a strong correlation between the PCE and the sample resistivity. Spatially resolved dynamics of the magnetization reversal rule out any role of thermal heating in the origin of this PCE, and we propose a mechanism based on the light-induced lowering of the domain wall pinning energy. The PCE is local and reversible, allowing writing and erasing of magnetic images using light.

Infections associated with haemophagocytic syndrome

Haemophagocytic syndrome or haemophagocytic lymphohistiocytosis is a rare disease that is often fatal despite treatment. Haemophagocytic syndrome is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of lymphocytes or histiocytes with uncontrolled haemophagocytosis and cytokine overproduction. The syndrome is characterised by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyperferritinaemia. Haemophagocytic syndrome can be either primary, with a genetic aetiology, or secondary, associated with malignancies, autoimmune diseases, or infections. Infections associated with haemophagocytic syndrome are most frequently caused by viruses, particularly Epstein-Barr virus (EBV). We present a case of EBV-associated haemophagocytic syndrome in a young adult with no known immunosuppression. We briefly review haemophagocytic syndrome and then discuss its associated infections, particularly EBV and other herpes viruses, HIV, influenza, parvovirus, and hepatitis viruses, as well as bacterial, fungal, and parasitic organisms.

Control of magnetic anisotropy in (Ga,Mn)as by lithography-induced strain relaxation

We report control of magnetic anisotropy in epitaxial (Ga,Mn)As by anisotropic strain relaxation in patterned structures. The strain in the structures is characterized using reciprocal space mapping by x-ray techniques. The magnetic anisotropy before patterning of the layer, which shows biaxial easy axes along [100] and [010], is replaced by a hard axis in the direction of large elastic strain relaxation and a uniaxial easy axis in the direction where pseudomorphic conditions are retained.

Magnetization-switched metal-insulator transition in a (Ga,Mn)as tunnel device

We observe the occurrence of an Efros-Shklovskii gap in (Ga,Mn)As based tunnel junctions. The occurrence of the gap is controlled by the extent of the hole wave function on the Mn acceptor atoms. Using k.p-type calculations we show that this extent depends crucially on the direction of the magnetization in the (Ga,Mn)As (which has two almost equivalent easy axes). This implies one can reversibly tune the system into the insulating or metallic state by changing the magnetization.

Remanent zero field spin splitting of self-assembled quantum dots in a paramagnetic host

We report on the observation of a finite spin splitting at zero magnetic field in resonant tunneling experiments on CdSe self-assembled quantum dots in a (Zn,Be,Mn)Se barrier. This is remarkable since bulk II-VI dilute magnetic semiconductors are paramagnets. Our experiment may be viewed as tunneling through a single magnetic polaron, where the carriers contained inside the dot act to mediate an effective ferromagnetic interaction between Mn ions in their vicinity. The effect is observable up to relatively high temperatures, which we tentatively ascribe to a feedback mechanism with the electrical current, previously predicted theoretically.

General practice critical incident reviews of patient suicides: benefits, barriers, costs, and family participation

AIM

To explore the feasibility of holding critical incident reviews (CIRs) after patient suicides in general practice and their ability to change practice.

METHODS

Thirteen practices were invited to conduct a facilitated CIR on 18 current patient suicides. Next of kin views were sought. All staff attending a CIR were interviewed after the review.

RESULTS

Ten practices reviewed 12 deaths. Twenty six staff attended reviews; all were interviewed. Next of kin contributed to six reviews; only one criticised care. Changes following the reviews included steps to improve internal communication and bereavement support to set up internal CIRs and review prescribing policies. Communications between practices and other agencies were clarified.

CONCLUSION

Practices were willing to hold CIRs and appreciated the potential positive value but need reassurance that they will not be blamed for suicides, and that the cost in time and resources will be recognised.

Very large tunneling anisotropic magnetoresistance of a (Ga,Mn)As/GaAs/(Ga,Mn)As stack

We report the discovery of a very large tunneling anisotropic magnetoresistance in an epitaxially grown (Ga,Mn)As/GaAs/(Ga,Mn)As structure. The key novel spintronics features of this effect are as follows: (i) both normal and inverted spin-valve-like signals; (ii) a large nonhysteretic magnetoresistance for magnetic fields perpendicular to the interfaces; (iii) magnetization orientations for extremal resistance are, in general, not aligned with the magnetic easy and hard axis; (iv) enormous amplification of the effect at low bias and temperatures.

Tunneling anisotropic magnetoresistance: a spin-valve-like tunnel magnetoresistance using a single magnetic layer

We introduce a new class of spintronic devices in which a spin-valve-like effect results from strong spin-orbit coupling in a single ferromagnetic layer rather than from injection and detection of a spin-polarized current by two coupled ferromagnets. The effect is observed in a normal-metal-insulator-ferromagnetic-semiconductor tunneling device. This behavior is caused by the interplay of the anisotropic density of states in (Ga,Mn)As with respect to the magnetization direction and the two-step magnetization reversal process in this material.

Spin injection in the nonlinear regime: band bending effects

We report on electrical spin-injection measurements into a nonmagnetic semiconductor in the nonlinear regime. For voltage drops across the interface larger than a few mV the spin-injection efficiency decreases strongly. The effect is caused by repopulation of the minority spin level in the magnetic semiconductor due to band bending at the interface.

Very large magnetoresistance in lateral ferromagnetic (Ga,Mn)as wires with nanoconstrictions

We have fabricated (Ga,Mn)As nanostructures in which domain walls can be pinned by sub-10 nm constrictions. Controlled by shape anisotropy, we can switch the regions on either side of the constriction to either parallel or antiparallel magnetization. All samples exhibit a positive magnetoresistance, consistent with domain-wall trapping. For metallic samples, we find a magnetoresistance up to 8%, which can be understood from spin accumulation. In samples where, due to depletion at the constriction, a tunnel barrier is formed, we observe a magnetoresistance of up to 2000%.

Voltage-controlled spin selection in a magnetic resonant tunneling diode

We have fabricated all II-VI semiconductor resonant tunneling diodes based on the (Zn,Mn,Be)Se material system, containing dilute magnetic material in the quantum well, and studied their current-voltage characteristics. When subjected to an external magnetic field the resulting spin splitting of the levels in the quantum well leads to a splitting of the transmission resonance into two separate peaks. This is interpreted as evidence of tunneling transport through spin polarized levels, and could be the first step towards a voltage controlled spin filter.

Large magnetoresistance effect due to spin injection into a nonmagnetic semiconductor

A novel magnetoresistance effect, due to the injection of a spin-polarized electron current from a dilute magnetic into a nonmagnetic semiconductor, is presented. The effect results from the suppression of a spin channel in the nonmagnetic semiconductor and can theoretically yield a positive magnetoresistance of 100%, when the spin flip length in the nonmagnetic semiconductor is sufficiently large. Experimentally, our devices exhibit up to 25% magnetoresistance.

Observational study of effect of patient centredness and positive approach on outcomes of general practice consultations

OBJECTIVE

To measure patients' perceptions of patient centredness and the relation of these perceptions to outcomes.

DESIGN

Observational study using questionnaires.

SETTING

Three general practices.

PARTICIPANTS

865 consecutive patients attending the practices.

MAIN OUTCOME MEASURES

Patients' enablement, satisfaction, and burden of symptoms.

RESULTS

Factor analysis identified five components. These were communication and partnership (a sympathetic doctor interested in patients' worries and expectations and who discusses and agrees the problem and treatment, Cronbach's alpha=0.96); personal relationship (a doctor who knows the patient and their emotional needs, alpha=0.89); health promotion (alpha=0.87); positive approach (being definite about the problem and when it would settle, alpha=0.84); and interest in effect on patient's life (alpha=0.89). Satisfaction was related to communication and partnership (adjusted beta=19.1; 95% confidence interval 17.7 to 20.7) and a positive approach (4.28; 2.96 to 5.60). Enablement was greater with interest in the effect on life (0.55; 0.25 to 0.86), health promotion (0.57; 0.30 to 0.85), and a positive approach (0.82; 0.52 to 1.11). A positive approach was also associated with reduced symptom burden at one month (beta=-0.25; -0.41 to -0.10). Referrals were fewer if patients felt they had a personal relationship with their doctor (odds ratio 0.70; 0.54 to 0.90).

CONCLUSIONS

Components of patients' perceptions can be measured reliably and predict different outcomes. If doctors don't provide a positive, patient centred approach patients will be less satisfied, less enabled, and may have greater symptom burden and higher rates of referral.