SARS-CoV-2 contact tracing among disadvantaged populations during epidemic intervals should be a priority strategy: results from a pilot experiment in Barcelona.

OBJECTIVES: The aim of this study was to trace contacts of coronavirus disease 2019 (COVID-19) hospitalised patients and determine the risk factors of infection in urban areas. STUDY DESIGN: Longitudinal analysis of contacts identified from index cases. METHODS: A contact tracing study was carried out in the Northern Metropolitan area of Barcelona, Spain, during the inter-epidemic lapse of May to July 2020, a period of low SARS-CoV-2 incidence. Index cases were notified from the referral hospital. Contacts were traced and followed up for 14 days. Reverse transcription polymerase chain reaction was performed on day 0 and day 14 for contacts. RESULTS: In total, 368 contacts were identified from 81 index cases (median of seven contacts per index case), from which 308 were traced successfully. The median age of contacts was 28 years, 62% (223 of 368) were men. During the follow-up period, 100 contacts tested positive for COVID-19 (32.5% [95% confidence interval {CI} = 27.3-38.0]), with a secondary infection rate of 48.3% (95% CI = 40.8-55.9) among housemates. Clusters of index and respective contacts tended to aggregate within disadvantaged neighbourhoods (P < 0.001), and non-national index cases (N = 28, 34.1%) resulted in higher secondary infection rates compared with nationals (51.0% [95% CI = 41.0-60.9] vs 22.3% [95% CI = 16.8-28.8]; P < 0.001). CONCLUSIONS: Disadvantaged communities experience a disproportionate burden of COVID-19 and may act as infection reservoirs. Contact tracing with a cross-cutting approach among these communities is required, especially during inter-epidemic periods.

Multiscale design of cell-free biologically active architectural structures.

Cell-free protein expression systems are here combined with 3D-printed structures to study the challenges and opportunities as biofabrication enters the spaces of architecture and design. Harnessing large-scale additive manufacturing of biological materials, we examined the addition of cell-free protein expression systems ("TXTL" i.e., biological transcription-translation machinery without the use of living cells) to printed structures. This allowed us to consider programmable, living-like, responsive systems for product design and indoor architectural applications. This emergent, pluripotent technology offers exciting potential in support of health, resource optimization, and reduction of energy use in the built environment, setting a new path to interactivity with mechanical, optical, and (bio) chemical properties throughout structures. We propose a roadmap towards creating healthier, functional and more durable systems by deploying a multiscale platform containing biologically-active components encapsulated within biopolymer lattices operating at three design scales: (i) supporting cell-free protein expression in a biopolymer matrix (microscale), (ii) varying material properties of porosity and strength within two-dimensional lattices to support biological and structural functions (mesoscale), and (iii) obtaining folded indoor surfaces that are structurally sound at the meter scale and biologically active (we label that regime macroscale). We embedded commercially available cell-free protein expression systems within silk fibroin and sodium alginate biopolymer matrices and used green fluorescent protein as the reporter to confirm their compatibility. We demonstrate mechanical attachment of freeze-dried bioactive pellets into printed foldable fibrous biopolymer lattices showing the first steps towards modular multiscale fabrication of large structures with biologically active zones. Our results discuss challenges to experimental setup affecting expression levels and show the potential of robust cell-free protein-expressing biosites within custom-printed structures at scales relevant to everyday consumer products and human habitats.

Incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infection in European hospitals: the COMBACTE-NET ARTHR-IS multi-centre study.

BACKGROUND: The aim of this study was to estimate the incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infections (SA-PJI) after primary hip and knee arthroplasty in European centres. METHODS: This study was conducted in patients who underwent primary hip and knee arthroplasty in 19 European hospitals between 2014 and 2016. The global incidence of PJI and SA-PJI was calculated. The associated disease burden was measured indirectly as infection-related mortality plus loss of function. For healthcare utilization, number and duration of hospitalizations, number and type of surgical procedures, duration of antibiotic treatments, and number of outpatient visits were collected. Subgroup and regression analyses were used to evaluate the impact of SA-PJI on healthcare utilization, controlling for confounding variables. RESULTS: The incidence of PJI caused by any micro-organism was 1.41%, and 0.40% for SA-PJI. Among SA-PJI, 20.7% were due to MRSA with substantial regional differences, and were more frequent in partial hip arthroplasty (PHA). Related deaths and loss of function occurred in 7.0% and 10.2% of SA-PJI cases, respectively, and were higher in patients with PHA. Compared with patients without PJI, patients with SA-PJI had a mean of 1.4 more readmissions, 25.1 more days of hospitalization, underwent 1.8 more surgical procedures, and had 5.4 more outpatient visits, controlling for confounding variables. Healthcare utilization was higher in patients who failed surgical treatment of SA-PJI. CONCLUSIONS: This study confirmed that the SA-PJI burden is high, especially in PHA, and provided a solid basis for planning interventions to prevent SA-PJI.

The Impact of Culturing the Organ Preservation Fluid on Solid Organ Transplantation: A Prospective Multicenter Cohort Study.

BACKGROUND: We analyzed the prevalence, etiology, and risk factors of culture-positive preservation fluid and their impact on the management of solid organ transplant recipients. METHODS: From July 2015 to March 2017, 622 episodes of adult solid organ transplants at 7 university hospitals in Spain were prospectively included in the study. RESULTS: The prevalence of culture-positive preservation fluid was 62.5% (389/622). Nevertheless, in only 25.2% (98/389) of the cases were the isolates considered "high risk" for pathogenicity. After applying a multivariate regression analysis, advanced donor age was the main associated factor for having culture-positive preservation fluid for high-risk microorganisms. Preemptive antibiotic therapy was given to 19.8% (77/389) of the cases. The incidence rate of preservation fluid-related infection was 1.3% (5 recipients); none of these patients had received preemptive therapy. Solid organ transplant (SOT) recipients with high-risk culture-positive preservation fluid receiving preemptive antibiotic therapy presented both a lower cumulative incidence of infection and a lower rate of acute rejection and graft loss compared with those who did not have high-risk culture-positive preservation fluid. After adjusting for age, sex, type of transplant, and prior graft rejection, preemptive antibiotic therapy remained a significant protective factor for 90-day infection. CONCLUSIONS: The routine culture of preservation fluid may be considered a tool that provides information about the contamination of the transplanted organ. Preemptive therapy for SOT recipients with high-risk culture-positive preservation fluid may be useful to avoid preservation fluid-related infections and improve the outcomes of infection, graft loss, and graft rejection in transplant patients.

Factors influencing mortality in solid organ transplant recipients with bloodstream infection.

Although bloodstream infection (BSI) is a major cause of mortality after solid organ transplantation, information regarding its prognostic factors is scarce. To identify risk factors for 30-day mortality in solid organ transplant (SOT) recipients with BSI, we prospectively recorded all episodes of BSI occurring in adult SOT recipients from January 2007 to October 2014 at a university hospital. We identified 361 consecutive episodes of BSI involving 246 patients. The 30-day case-fatality rate from the onset of BSI was 11.4%. Factors independently associated with 30-day mortality in a logistic regression analysis were shock at presentation (OR 13.658; 95% CI 5.985-31.168), acute graft rejection in the previous 6 months (OR 3.681; 95% CI 1.059-12.795), and a platelet count of <50,000 × 10(9)/L (OR 3.070; 95% CI 1.173-8.038). Kidney recipients were the patients with the best prognosis (OR 0.375; 95% CI 0.156-0.900). Our findings may help to identify SOT recipients with BSI who are at the highest risk of death.

Traumatic optic neuropathy: to treat or not to treat? Report of two cases.

CASE REPORTS: We present two cases of blunt ocular trauma with clinical findings and complementary tests compatible with traumatic optic neuropathy (TON), and progression to sectorial optic atrophy. DISCUSSION: TON have an essentially clinical diagnosis, and in the last few years has been treated with high doses of intravenous steroids, based on weak evidence of the benefit of the steroids in cases of medular trauma. Nevertheless, subsequent studies have concluded that there is a relatively high proportion of cases in all series with spontaneous visual recovery, and there was no convincing evidence of a benefit of steroids compared to observation only.