The role of bacterial colonization of ventilator circuit in development of ventilator-associated pneumonia: a prospective observational cohort study.

OBJECTIVES: Ventilator-associated pneumonia (VAP) is a significant cause of prolonged hospital stay and increased mortality in mechanically ventilated children. Studies of the relationship between bacterial colonization of ventilator circuits (VCs) and VAP are lacking. This study aimed to investigate the role of bacterial colonization of VCs in the development of VAP, and to provide evidence for preventing VAP. METHODS: Mechanically ventilated patients admitted to the paediatric intensive care unit of a teaching hospital in China from October 2018 to November 2019 were enrolled. Specimens were collected from the VC and the patient's lower respiratory tract (LRT) for bacterial culture. Paired bacteria isolated from the VC and the patient's LRT, where colonization of the VC preceded that of the LRT, were evaluated for relatedness using pulsed field gel electrophoresis (PFGE). RESULTS: A total of 114 patients were included; the incidence rate of VAP was 28.1% (32/114). A total of 1368 samples were collected from VCs; 16% had positive bacterial culture. There was no significant difference in bacterial colonization of VCs between VAP and non-VAP. In 13 patients, the LRT and VC were concurrently colonized with the same bacteria, where colonization of the VC occurred before colonization of the patient's LRT. PFGE results demonstrated high correlation between bacteria from the LRT and VC in 11 patients. Among 114 mechanically ventilated children, VAP caused by bacteria from the VC occurred in six patients, accounting for 18.8% (6/32) of the overall VAP rate in this study. DISCUSSION: Bacterial colonization of the VC is a significant cause of VAP development in mechanically ventilated children. Preventive strategies for early identification and decontamination measures for contaminated VC may play a key role in preventing VAP.

Controlled formation of biological tubule systems in extracellular matrix gels in vitro.

Organs such as the lung and the kidney are composed of epithelial and endothelial tubule-forming networks. To engineer such organs, it would be desirable to control the shape, spatial orientation and interconnectedness of the forming tubules. To study this, channels were formed in extracellular matrix (ECM) gels and were subsequently filled with Madin-Darby canine kidney epithelial cells or human microvascular endothelial cells. After 3-5 days, the epithelial cells self-assembled into tubular structures of up to 1 cm, with a lumen lined by a monolayer of polarized epithelial cells at 10 days. In contrast, endothelial cells assembled into tubules with multiple fine branches. We found that a complex pattern of tubular networks of significant length and regular anatomical shape was achieved by molding ECM gels through microfabricated grooved templates.

Effectiveness of public health interventions in food safety: a systematic review.

PURPOSE: To summarize evidence on the effectiveness of public health interventions regarding food safety at restaurants, institutions, homes and other community-based settings. METHOD: This systematic review of published and unpublished studies involved a comprehensive literature search, screening for relevance, quality assessment of relevant studies, data extraction and synthesis. RESULTS: The interventions identified in 15 studies included in this review were grouped into three categories: inspections, food handler training, and community-based education. The evidence suggests that: routine inspection (at least once per year) of food service premises is effective in reducing the risk of foodborne illness; food handler training can improve the knowledge and practices of food handlers; and selected community-based education programs can increase public knowledge of food safety. DISCUSSION: There is some evidence for the effectiveness of multiple public health interventions on food safety. Future research needs include evaluation of HACCP and community-based education programs.

A comprehensive evaluation of the 1993 city of Toronto smoking by-laws.

Effective January 1, 1993, the City of Toronto's two smoking by-laws--one regarding workplaces and another regarding public places--were replaced and amended respectively. Smoking is now prohibited in all workplaces (unless in a designated smoking area), and in at least 50% of eating areas in restaurants. Through a workplace telephone survey and restaurant inspection records, the implementation and enforcement of the by-laws were evaluated. Eighty-three per cent of the workplaces were completely smoke-free and 7% had restricted smoking to a designated area. A majority (76%) of the managers and owners were in favour of regulatory controls on smoking in workplaces. Eighty-six per cent of restaurants complied with requirements for a minimum 50% smoke-free area and signage, and nearly 4% of the sampled restaurants banned smoking throughout the entire premises even though this is not currently required.