Decreased mortality among patients with catheter-related bloodstream infections at Catalan hospitals (2010-2019).

BACKGROUND: The incidence of catheter-related bloodstream infections (CRBSIs) has fallen over the last decade, especially in intensive care units (ICUs). AIM: To assess the existence of concomitant trends in outcomes and to analyse the current risk factors for mortality. METHODS: A multicentre retrospective cohort study was conducted at 24 Catalan hospitals participating in the Surveillance of healthcare-associated infections in Catalonia (VINCat). All hospital-acquired CRBSI episodes diagnosed from January 2010 to December 2019 were included. A common protocol including epidemiological, clinical, and microbiological data was prospectively completed. Mortality at 30 days after bacteraemia onset was analysed using the Cox regression model. FINDINGS: Over the study period, 4795 episodes of CRBSI were diagnosed. Among them, 75% were acquired in conventional wards and central venous catheters were the most frequently involved (61%). The 30-day mortality rate was 13.8%, presenting a significant downward trend over the study period: from 17.9% in 2010 to 10.6% in 2019 (hazard ratio (HR): 0.95; 95% confidence interval (CI): 0.92-0.98). The multivariate analysis identified age (HR: 1.03; 95% CI: 1.02-1.04), femoral catheter (1.78; 1.33-2.38), medical ward acquisition (2.07; 1.62-2.65), ICU acquisition (3.45; 2.7-4.41), S. aureus (1.59; 1.27-1.99) and Candida sp. (2.19; 1.64-2.94) as risk factors for mortality, whereas the mortality rate associated with episodes originating in peripheral catheters was significantly lower (0.69; 0.54-0.88). CONCLUSION: Mortality associated with CRBSI has fallen in recent years but remains high. Intervention programmes should focus especially on ICUs and medical wards, where incidence and mortality rates are highest.

Dense Ge nanocrystals embedded in TiO2 with exponentially increased photoconduction by field effect.

Si and Ge nanocrystals in oxides are of a large interest for photo-effect applications due to the fine-tuning of the optical bandgap by quantum confinement in nanocrystals. In this work, dense Ge nanocrystals suitable for enhanced photoconduction were fabricated from 60% Ge in TiO2 amorphous layers by low temperature rapid thermal annealing at 550 °C. An exponential increase of the photocurrent with the applied voltage was observed in coplanar structure of Ge nanocrystals composite films deposited on oxidized Si wafers. The behaviour was explained by field effect control of the Fermi level at the Ge nanocrystals-TiO2 layer/substrate interfaces. The blue-shift of the absorption gap from bulk Ge value to 1.14 eV was evidenced in both photocurrent spectra and optical reflection-transmission experiments, in good agreement with quantum confinement induced bandgap broadening in Ge nanocrystal with sizes of about 5 nm as found from HRTEM and XRD investigations. A nonmonotonic spectral dependence of the refractive index is associated to the Ge nanocrystals formation. The nanocrystal morphology is also in good agreement with the Coulomb gap hopping mechanism of T-1/2 -type explaining the temperature dependence of the dark conduction.

Predictive factors for early- and late-onset surgical site infections in patients undergoing elective colorectal surgery. A multicentre, prospective, cohort study.

BACKGROUND: Surgical site infections (SSIs) are the leading cause of healthcare-associated infections in acute care hospitals in Europe. However, the risk factors for the development of early-onset (EO) and late-onset (LO) SSI have not been elucidated. AIM: This study investigated the predictive factors for EO-SSI and LO-SSI in a large cohort of patients undergoing colorectal surgery. METHODS: We prospectively followed-up adult patients undergoing elective colorectal surgery in 10 hospitals (2011-2014). Patients were divided into three groups: EO-SSI, LO-SSI, or no infection (no-SSI). The cut-off defining EO-SSI and LO-SSI was seven days (median time to SSI development). Different predictive factors for EO-SSI and LO-SSI were analysed, comparing each group with the no-SSI patients. FINDINGS: Of 3701 patients, 320 (8.6%) and 349 (9.4%) developed EO-SSI and LO-SSI, respectively. The rest had no-SSI. Patients with EO-SSI were mostly males, had colon surgery and developed organ-space SSI whereas LO-SSI patients frequently received chemotherapy or radiotherapy and had incisional SSI. Male sex (odds ratio (OR): 1.92; P < 0.001), American Society of Anesthesiologists' physical status >2 (OR: 1.51; P = 0.01), administration of mechanical bowel preparation (OR: 0.7; P = 0.03) and stoma creation (OR: 1.95; P < 0.001) predicted EO-SSI whereas rectal surgery (OR: 1.43; P = 0.03), prolonged surgery (OR: 1.4; P = 0.03) and previous chemotherapy (OR: 1.8; P = 0.03) predicted LO-SSI. CONCLUSION: We found distinctive predictive factors for the development of SSI before and after seven days following elective colorectal surgery. These factors could help establish specific preventive measures in each group.

Preliminary study on serum paraoxonase-1 status and chemokine (C-C motif) ligand 2 in hospitalized elderly patients with catheter-associated asymptomatic bacteriuria.

Urinary tract infections (UTI) are common among elderly patients in residential care facilities, as well as in the hospital setting. Identifying new biochemical markers of UTI is an active line of research since UTI management is resource intensive. Paraoxonase-1 (PON1) forms part of the patient's immune system, the response-to-injury and inflammation. Our study sought to evaluate alterations in inflammation-related paraoxonase-1 (PON1) and chemokine (C-C motif) ligand 2 (CCL2) in patients with an indwelling catheter to assess their potential usefulness as biomarkers of infection. Patients (n = 142) who had had the urinary catheter removed and 100 healthy volunteers were recruited. In all participants we measured serum PON1 activity, PON1 concentration, CCL2, procalcitonin and C-reactive protein (CRP). Results indicated that patients had higher CCL2, CRP and procalcitonin concentrations than the control group, and lower paraoxonase activity. There were no significant differences in PON1 concentrations. When comparing the diagnostic accuracy of CRP, procalcitonin, CCL2 and the PON1-related variables in discriminating between patients with and those without UTI, we found a considerable degree of overlap between groups, i.e., a low diagnostic accuracy. However, there were significant inverse logarithmic correlations between serum paraoxonase activity and the number of days the urinary catheter had been in situ. Our results suggest that measurement of these biochemical variables may be useful in investigating complications of long-term use of these devices and help to improve the economic and clinical investment required in the management of the often-associated infection.

Effectiveness of sequential intravenous-to-oral antibiotic switch therapy in hospitalized patients with gram-positive infection: the SEQUENCE cohort study.

Switching from intravenous to oral antibiotic therapy may improve inpatient management and reduce hospital stays and the complications of intravenous treatment. We aimed to assess the effectiveness of intravenous-to-oral antibiotic switch therapy and an early discharge algorithm in hospitalized patients with gram-positive infection. We performed a prospective cohort study with a retrospective comparison cohort, recruited from eight tertiary, acute-care Spanish referral hospitals. All patients included had culture-confirmed methicillin-resistant gram-positive infection, or methicillin-susceptible gram-positive infection and beta-lactam allergy and had received intravenous treatment with glycopeptides, lipopeptides, or linezolid. The study comprised two cohorts: the prospective cohort to assess the effectiveness of a sequential intravenous-to-oral antibiotic switch algorithm and early discharge, and a retrospective cohort in which the algorithm had not been applied, used as the comparator. A total of 247 evaluable patients were included; 115 in the prospective and 132 in the retrospective cohort. Forty-five retrospective patients (34 %) were not changed to oral antibiotics, and 87 (66 %) were changed to oral antibiotics without following the proposed algorithm. The duration of hospitalization was significantly shorter in the prospective cohort compared to the retrospective group that did not switch to oral drugs (16.7 ± 18.7 vs 23 ± 13.4 days, P < 0.001). No differences were observed regarding the incidence of catheter-related bacteraemia (4.4 % vs 2.6 %, P = 0.621). Our results suggest that an intravenous-to-oral antibiotic switch strategy is effective for reducing the length of hospital stay in selected hospitalized patients with gram-positive infection.