Impact of stagnation and sampling volume on water microbial quality monitoring in large buildings

Microbial drinking water quality can be altered in large buildings, especially after stagnation. In this study, bacterial profiles were generated according to the stagnation time and the volume of water collected at the tap. Successive volumes of cold and hot water were sampled after controlled stagnation periods. Bacterial profiles revealed an important decline (> 2 log) in culturable cells in the first 500 mL sampled from the hot and cold water systems, with a steep decline in the first 15 mL. The strong exponential correlation (R2 >/= 0.97) between the culturable cell counts in water and the pipe surface-to-volume ratio suggests the biofilm as the main contributor to the rapid increase in suspended culturable cells measured after a short stagnation of one-hour. Results evidence the contribution of the high surface-to-volume ratio at the point of use and the impact of short stagnation times on the increased bacterial load observed. Simple faucets with minimal internal surface area should be preferred to minimize surface area. Sampling protocol, including sampling volume and prior stagnation, was also shown to impact the resulting culturable cell concentration by more than 1000-fold. Sampling a smaller volume on first draw after stagnation will help maximize recovery of bacteria

Investigative approach to improve hot water system hydraulics through temperature monitoring to reduce building environmental quality hazard associated to Legionella

Several countries have promulgated control measures and design guidelines to limit the proliferation of Legionella within hot water distribution systems (HWDS). However, there is little information on how to assess and improve existing HWDS unable to maintain water temperatures >= 55 degrees C throughout the system. A 50-year old hot water system of a 10 story hospital was investigated in terms of temperature distribution and Legionella pneumophila prevalence. Concentrations of L. pneumophila were correlated with the maximum temperature reached at the tap, with a significant decrease observed at T >= 55 degrees C. Continuous temperature and flow monitoring was performed on the overall HWDS, characterizing the principal and secondary horizontal return loops for all 9 wings, and detailed investigations of the secondary vertical return loops was completed in Wing 3. Results indicated the system inability to systematically maintain desired operating temperatures of 55 degrees C. The deficient hydraulic distribution was the root cause of the poor temperature maintenance throughout the secondary loops, but defective devices were also identified as playing an important role in sectorial temperature failure. A simple stepwise investigative approach was developed to identify hydraulic deficiencies. The implementation of flow restrictions on identified recirculation loops and increased pumping efficiency was conducted within a short period of 2 months, with no major system upgrade. These corrective measures resulted in a balanced system with increased flow velocities (>0.2 m/s). As a result, the proportion of taps achieving 55 degrees C within 2 min increased from 11% to 74% and L. pneumophila prevalence decreased from 93.1% to 46.1% after 4 weeks. (C) 2016 The Authors. Published by Elsevier Ltd

Safety and antitumor activity of pembrolizumab in patients with estrogen receptor–positive/human epidermal growth factor receptor 2–negative advanced breast cancer

Purpose: We investigated the safety and antitumor activity of the anti-programmed death 1 monoclonal antibody pembrolizumab in patients with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2(-)) advanced breast cancer with programmed death ligand 1-positive (PD-L1-positive) tumors in the phase Ib open-label, multicohort KEYNOTE-028 (NCT02054806) study. Patients and Methods: Patients with ER+/HER2(-)advanced breast cancer with PD-L1-positive tumors (combined positive score >= 1) received pembrolizumab (10 mg/kg every 2 weeks) up to 2 years or until confirmed progression/intolerable toxicity. Primary endpoints were safety and overall response rate (ORR), based on Response Evaluation Criteria in Solid Tumors, version 1 (RECIST v1.1) as assessed by investigator review. Results: Between April 2014 and January 2015, 25 patients were enrolled. Median number of prior therapies for breast cancer, including endocrine agents, was 9 (range, 3-15). Median follow-up was 9.7 months (range, 0.7-31.8 months). Three patients experienced partial response (PR) and none experienced complete response (CR), resulting in an ORR of 12.0% (95% CI, 2.5%-31.2%); 16% of patients had stable disease (SD) and clinical benefit rate (CR + PR + [SD for >= 24 weeks]) was 20% (95% CI, 7-41). Median duration of response was 12.0 months (range, 7.4-15.9 months). The incidence of treatment-related adverse events was 64%; nausea (20%) and fatigue (12%) were most common and were predominantly grade 1/2. No treatment-related discontinuations or deaths occurred. Conclusions: Pembrolizumab was well tolerated with modest but durable overall response in certain patients with previously treated, advanced, PD-L1-positive, ER+/HER2(-) breast cancer. (C) 2018 AAC