Family case studies: absence of Pseudomonas aeruginosa transmission in bronchiectasis.

Two case reports show lack of Pseudomonas aeruginosa transmission, despite household contact, in non-cystic fibrosis bronchiectasis (NCFB). This supports evidence that in NCFB, P. aeruginosa is poorly transmitted. This affects management strategies. https://bit.ly/3PeOcHy.

An observational study of Pseudomonas aeruginosa in adult long-term ventilation.

Introduction: Pseudomonas aeruginosa increases morbidity and mortality in respiratory disease. To date the long-term ventilation population does not have clear guidelines regarding its management. Method: We undertook a retrospective observational study in a regional long-term ventilation population (837 patients). We defined the primary outcome as P. aeruginosa isolation. In addition positive cultures for copathogens (Serratia, Proteus species, Stenotrophomonas, Burkholderia cepacia complex and nontuberculous mycobacteria) were recorded. Logistic regression and odds ratios were calculated. Results: 17.6% of the cohort isolated P. aeruginosa, and this pathogen was cultured more frequently in patients with a tracheostomy (logistic regression coefficient 2.90, p≤0.0001) and cystic fibrosis/bronchiectasis (logistic regression coefficient 2.48, p≤0.0001). 6.3% of patients were ventilated via tracheostomy. In the P. aeruginosa positive cohort 46.9% of patients were treated with a long-term macrolide, 36.7% received a nebulised antibiotic and 21.1% received both. Tracheostomised P. aeruginosa positive patients received a nebulised antibiotic more frequently (OR 2.63, 95% CI 1.23-5.64, p=0.013). Copathogens were isolated in 33.3% of the P. aeruginosa cohort. In this cohort patients with a tracheostomy grew a copathogen more frequently than those without (OR 2.75, 95% CI 1.28-5.90). Conclusions: P. aeruginosa isolation is common within the adult long-term ventilation population and is significantly associated with tracheostomy, cystic fibrosis and bronchiectasis. Further research and international guidelines are needed to establish the prognostic impact of P. aeruginosa and to guide on antimicrobial management. The increased risk of P. aeruginosa should be considered when contemplating long-term ventilation via tracheostomy.

The effect of high-speed dental handpiece coolant delivery and design on aerosol and droplet production.

OBJECTIVES: High-speed dental instruments produce aerosol and droplets. The objective of this study was to evaluate aerosol and droplet production from a novel electric micromotor handpiece (without compressed air coolant) in real world clinical settings. METHODS: 10-minute upper incisor crown preparations were performed in triplicate in an open-plan clinic with mechanical ventilation providing 3.45 air changes per hour. A 1:5 ratio electric micromotor handpiece which allows water coolant without compressed air (Ti-Max Z95L, NSK) was used at three speeds: 60,000 (60 K), 120,000 (120 K), and 200,000 (200 K) revolutions per minute. Coolant solutions contained fluorescein sodium as a tracer (2.65 mmol L - 1). High-speed air-turbine positive control, and negative control conditions were conducted. Aerosol production was evaluated at 3 locations (0.5 m, 1.5 m, and 1.7 m) using: (1) an optical particle counter (OPC; 3016-IAQ, Lighthouse) to detect all aerosol; and (2) a liquid cyclone air sampler (BioSampler, SKC Ltd.) to detect aerosolised fluorescein, which was quantified by spectrofluorometric analysis. Settled droplets were detected by spectrofluorometric analysis of filter papers placed onto a rig across the open-plan clinic. RESULTS: Local (within treatment bay) settled droplet contamination was elevated above negative control for all conditions, with no difference between conditions. Settled droplet contamination was not detected above negative controls outside the treatment bay for any condition. Aerosol detection at 1.5 m and 1.7 m, was only increased for the air-turbine positive control condition. At 0.5 m, aerosol levels were highly elevated for the air-turbine, minimally elevated for 200 K and 120 K, and not elevated for 60 K. CONCLUSIONS: Electric micromotor handpieces which use water-jet coolant alone without compressed air produce localised (within treatment bay) droplet contamination, but are unlikely to produce aerosol contamination beyond the immediate treatment area (1.5 m), allowing them to be used safely in most open-plan clinic settings.

Evaluating contaminated dental aerosol and splatter in an open plan clinic environment: Implications for the COVID-19 pandemic.

OBJECTIVES: Identify splatter/aerosol distribution from dental procedures in an open plan clinic and explore aerosol settling time after dental procedures. METHODS: In two experimental designs using simulated dental procedures on a mannequin, fluorescein dye was introduced: (1) into the irrigation system of an air-turbine handpiece; (2) into the mannequin's mouth. Filter papers were placed in an open plan clinic to collect fluorescein. An 8-metre diameter rig was used to investigate aerosol settling time. Analysis was by fluorescence photography and spectrofluorometry. RESULTS: Contamination distribution varied across the clinic depending on conditions. Unmitigated procedures have the potential to deposit contamination at large distances. Medium volume dental suction (159 L/min air) reduced contamination in the procedural bay by 53%, and in other areas by 81-83%. Low volume suction (40 L/min air) was similar. Cross-ventilation reduced contamination in adjacent and distant areas by 80-89%. In the most realistic model (fluorescein in mouth, medium volume suction), samples in distant bays (≥5 m head-to-head chair distance) gave very low or zero readings (< 0.0016% of the fluorescein used during the procedure). Almost all (99.99%) of the splatter detected was retained within the procedural bay/walkway. After 10 min, very little additional aerosol settled. CONCLUSIONS: Cross-infection risk from dental procedures in an open plan clinic appears small when bays are ≥ 5 m apart. Dilution effects from instrument water spray were observed, and dental suction is of benefit. Most settled aerosol is detected within 10 min indicating environmental cleaning may be appropriate after this. CLINICAL SIGNIFICANCE: Aerosols produced by dental procedures have the potential to contaminate distant sites and the majority of settled aerosol is detectable after 10 min. Dental suction and ventilation have a substantial beneficial effect. Contamination is likely to be minimal in open plan clinics at distances of 5 m or more.

New developments in invasive fungal disease.

Invasive fungal infections continue to be a major cause of morbidity and mortality in immunocompromised or severely ill patients. This report highlights new research data presented at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy on invasive fungal disease and its treatment. A number of important clinical trials were reported, and there were also interesting presentations on the use of new diagnostic tools, further studies on therapeutic drug monitoring for azoles and updates on several of the emerging fungal pathogens.

Practical issues across the lifetime of heart failure.

Over the past 10-20 years there have been major changes in the management of heart failure, based on a robust evidence base from randomized clinical trials. This has led to improved outcome for patients but prognosis is still poor. Some of the challenges to provision of evidence-based care and new developments in heart failure therapy were discussed at the 2010 Annual Meeting of the British Society for Heart Failure. The conference theme was 'Practical issues across the lifetime of heart failure', with the 2-day conference covering a broad range of topics from diagnosis to end-of-life care.

Emerging resistance in Gram-negative pathogens and implications for clinical practice.

Infectious disease specialists and scientists attending the 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Boston (MA, USA), were updated on the current worldwide picture regarding different aspects of the use of antimicrobial agents and resistance.

Update on invasive fungal disease.

One of the highlights of the antifungal sessions at the ECCMID-ICC congress was the presentation of the first European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline for diagnostic and management for Candida diseases. Experts also discussed specific aspects of the management of invasive fungal disease in the intensive care unit and in hematological malignancy. Data from new clinical studies and from 'real life' experience of clinical use of antifungal therapy were also presented and discussed.

Carbapenems in the treatment of intra-abdominal infection. Report from the 20th European Congress of Clinical Microbiology and Infectious Diseases. Vienna, Austria, 10-13 April 2010.

The changing pattern of resistance to antibacterial agents was a major theme at the 20th European Congress of Clinical Microbiology and Infectious Diseases. This article highlights presentations on the increasing threat from multidrug-resistant Gram-negative pathogens, particularly extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae, which are limiting the choice of drug therapy for serious infections. Surveillance data suggest that carbapenem antibiotics are appropriate choices for the empiric treatment of intra-abdominal infection.