Biofiltration in Drinking Water Treatment: Reduction of Membrane Fouling and Biodegradation of Organic Trace Contaminants

The goal of drinking water treatment is to produce and deliver safe water to the consumers. To achieve these objectives water treatment plants are designed based on the concept of the multibarrier approach which combines several drinking water treatment processes in order to increase the reliability of the system. The presence of pharmaceutically active compounds (PhACs), personal care products (PCPs) and endocrine disrupting compounds (EDCs) in drinking water sources is becoming a concern, because of chronic and indirect human exposure to contaminant mixtures at sub-therapeutic levels via drinking water consumption. Membrane filtration can be an efficient treatment process to remove microorganisms and/or trace organic contaminants from drinking water sources. However, membranes are confronted by a major limitation: membrane fouling. Fouled membranes suffer from a loss in performance either leading to a reduction in flux or a higher pressure requirement. Generally, membrane fouling increases the need for membrane maintenance measures such as backwashing and chemical cleaning which has a negative impact on the operating costs and membrane life time. Severe membrane fouling may even impact permeate quality and/or compromise membrane integrity. The aim of this study was to establish if biofiltration pretreatment without prior coagulation would be able to control membrane fouling in natural waters. The second objective investigated the removal of trace organic contaminants by individual treatment processes (i.e. biofiltration and membrane filtration). Parallel to this work, the presence and concentration of selected trace organic contaminants in Grand River (Ontario, Canada) were determined. The trace organic contaminants investigated included atrazine, carbamazepine, DEET, ibuprofen, naproxen, and nonylphenol. Direct biofiltration pretreatment (no coagulation) significantly reduced both reversible and irreversible fouling of ultrafiltration membranes. Results showed that the different degree of reduction of hydraulically reversible fouling was primarily attributed to the absolute concentration of a specific fraction of the dissolved organic matter (i.e. biopolymers) in the biofilter effluent (i.e. membrane feed). The study also suggests that the composition of biopolymers rather than their absolute concentration is important for the control of irreversible fouling. High pressure membranes such as nanofiltration membranes are also subjected to fouling. Results showed that biofiltration pretreatment was able to achieve fouling control but membrane characteristics (i.e. molecular weight cut off) influence the efficiency of the pretreatment. This study also showed that not only biopolymers but also humic substances and low molecular weight acids are being rejected by nanofiltration membranes. Selected trace organic contaminants were detected in Grand River water in the low ng/L range with detection frequencies between 48 to 100%. Seasonal occurrence patterns could be explained by compound use and possible degradation mechanisms. These results confirm the impact of human activities on the Grand River. This study showed that under the right conditions rapid biofiltration is capable of completely removing biodegradable emerging contaminants at ng/L concentrations. DEET, ibuprofen, and naproxen were biodegradable and therefore amenable to removal while carbamazepine and atrazine were recalcitrant. Factors such as empty bed contact time, influent concentration, and temperature influenced the biodegradation kinetics. Finally, both membrane and contaminant properties influenced the degree of rejection achieved by nanofiltration membranes. Results showed that steric hindrance and electrostatic repulsion were the major rejection mechanisms. Several benefits are associated with the use of direct biofiltration for drinking water treatment. These benefits include: the removal of easily biodegradable organic matter leading to biologically stable effluents; the removal of biodegradable trace organic contaminants contributing to the multibarrier approach; the absence of chemicals coagulation which is of advantage for operations in isolated areas; the simple operation and maintenance which is an advantage for locations with limited trained operators; and finally if used prior to membrane filtration biofiltration pretreatment can control membrane fouling

Variation of Legionella spp. with Lake Depth and Season in Two Norwegian Drinking Water Sources

In Norway, placement of the water treatment plant intake within the lake hypolimnion is considered a hygienic barrier against pathogens of fecal origin. It is unclear, however, whether this practice provides a barrier against opportunistic pathogens such as Legionella. In this study, water samples were collected at 10 m depth intervals near the drinking water intakes of two lakes. Legionella and one of their common hosts, Acanthamoeba spp., were quantified using culture-based assays (Legionella pneumophila only) and real-time quantitative PCR (qPCR). L. pneumophila and Acanthamoeba spp. were never detected by qPCR; Legionella spp., however, were present in all samples at concentrations ranging from 2.33 to 4.14 log10[copies/L] in lake A and from 2.69 to 4.27 log10[copies/L] in lake B. For most sampling months in both lakes, there was no significant difference between total bacteria and Legionella spp. concentrations at the intake depth versus those on the lake surface. The results of this limited investigation of two Norwegian water supplies suggest that placement of water treatment plant intakes within the hypolimnion may not afford a sufficient hygienic barrier against Legionella.publishedVersio

Screening for Obstructive Sleep Apnea in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance: Many adverse health outcomes are associated with obstructive sleep apnea (OSA). Objective: To review primary care-relevant evidence on screening adults for OSA, test accuracy, and treatment of OSA, to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, EMBASE, and trial registries through October 2015, references, and experts, with surveillance of the literature through October 5, 2016. Study Selection: English-language randomized clinical trials (RCTs); studies evaluating accuracy of screening questionnaires or prediction tools, diagnostic accuracy of portable monitors, or association between apnea-hypopnea index (AHI) and health outcomes among community-based participants. Data Extraction and Synthesis: Two investigators independently reviewed abstracts and full-text articles. When multiple similar studies were available, random-effects meta-analyses were conducted. Main Outcomes and Measures: Sensitivity, specificity, area under the curve (AUC), AHI, Epworth Sleepiness Scale (ESS) scores, blood pressure, mortality, cardiovascular events, motor vehicle crashes, quality of life, and harms. Results: A total of 110 studies were included (N = 46 188). No RCTs compared screening with no screening. In 2 studies (n = 702), the screening accuracy of the multivariable apnea prediction score followed by home portable monitor testing for detecting severe OSA syndrome (AHI ≥30 and ESS score >10) was AUC 0.80 (95% CI, 0.78 to 0.82) and 0.83 (95% CI, 0.77 to 0.90), respectively, but the studies oversampled high-risk participants and those with OSA and OSA syndrome. No studies prospectively evaluated screening tools to report calibration or clinical utility for improving health outcomes. Meta-analysis found that continuous positive airway pressure (CPAP) compared with sham was significantly associated with reduction of AHI (weighted mean difference [WMD], -33.8 [95% CI, -42.0 to -25.6]; 13 trials, 543 participants), excessive sleepiness assessed by ESS score (WMD, -2.0 [95% CI, -2.6 to -1.4]; 22 trials, 2721 participants), diurnal systolic blood pressure (WMD, -2.4 points [95% CI, -3.9 to -0.9]; 15 trials, 1190 participants), and diurnal diastolic blood pressure (WMD, -1.3 points [95% CI, -2.2 to -0.4]; 15 trials, 1190 participants). CPAP was associated with modest improvement in sleep-related quality of life (Cohen d, 0.28 [95% CI, 0.14 to 0.42]; 13 trials, 2325 participants). Mandibular advancement devices (MADs) and weight loss programs were also associated with reduced AHI and excessive sleepiness. Common adverse effects of CPAP and MADs included oral or nasal dryness, irritation, and pain, among others. In cohort studies, there was a consistent association between AHI and all-cause mortality. Conclusions and Relevance: There is uncertainty about the accuracy or clinical utility of all potential screening tools. Multiple treatments for OSA reduce AHI, ESS scores, and blood pressure. Trials of CPAP and other treatments have not established whether treatment reduces mortality or improves most other health outcomes, except for modest improvement in sleep-related quality of life

Vision Screening in Children Aged 6 Months to 5 Years: Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance: Preschool vision screening could allow detection and treatment of vision abnormalities during a critical developmental stage, preserving function and quality of life. Objective: To review the evidence on screening for and treatment of amblyopia, its risk factors, and refractive error in children aged 6 months to 5 years to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, CINAHL, and trial registries through June 2016; references; and experts, with surveillance of the literature through June 7, 2017. Study Selection: English-language randomized clinical trials (RCTs) or prospective cohort studies that evaluated screening, studies evaluating test accuracy, RCTs of treatment vs inactive controls, and cohort studies or case-control studies assessing harms. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Studies were not quantitatively pooled because of clinical and methodological heterogeneity. Main Outcomes and Measures: Visual acuity, amblyopia, school performance, functioning, quality of life, test accuracy, testability, and harms. Results: Forty studies were included (N = 34 709); 34 evaluated test accuracy. No RCTs compared screening with no screening, and no studies evaluated school performance, function, or quality of life. Studies directly assessing earlier or more intensive screening were limited by high attrition. Positive likelihood ratios were between 5 and 10 for amblyopia risk factors or nonamblyogenic refractive error in most studies of test accuracy and were greater than 10 in most studies evaluating combinations of clinical tests. Inability to cooperate may limit use of some tests in children younger than 3 years. Studies with low prevalence (75%). Among children with amblyopia risk factors (eg, strabismus or anisometropia), patching improved visual acuity of the amblyopic eye by a mean of less than 1 line on a standard chart after 5 to 12 weeks for children pretreated with glasses (2 RCTs, 240 participants); more children treated with patching than with no patching experienced improvement of at least 2 lines (45% vs 21%; P = .003; 1 RCT, 180 participants). Patching plus glasses improved visual acuity by about 1 line after 1 year (0.11 logMAR [95% CI, 0.05-0.17]) for children not pretreated with glasses (1 RCT, 177 participants). Glasses alone improved visual acuity by less than 1 line after 1 year (0.08 logMAR [95% CI, 0.02-0.15], 1 RCT, 177 participants). Conclusions and Relevance: Studies directly evaluating the effectiveness of screening were limited and do not establish whether vision screening in preschool children is better than no screening. Indirect evidence supports the utility of multiple screening tests for identifying preschool children at higher risk for vision problems and the effectiveness of some treatments for improving visual acuity outcomes

Primary Care Screening and Treatment for Latent Tuberculosis Infection in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force

Five to ten percent of individuals with latent tuberculosis infection (LTBI) progress to active tuberculosis (TB) disease. Identifying and treating LTBI is a key component of the strategy for reducing the burden of TB disease. To review the evidence about targeted screening and treatment for LTBI among adults in primary care settings to support the US Preventive Services Task Force in updating its 1996 recommendation. MEDLINE, Cochrane Library, and trial registries, searched through August 3, 2015; references from pertinent articles; and experts. Literature surveillance was conducted through May 31, 2016. English-language studies of LTBI screening, LTBI treatment with recommended pharmacotherapy, or accuracy of the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). Studies of individuals for whom LTBI screening and treatment is part of public health surveillance or disease management were excluded. Two investigators independently reviewed abstracts and full-text articles. When at least 3 similar studies were available, random-effects meta-analysis was used to generate pooled estimates of outcomes. Sensitivity, specificity, reliability, active TB disease, mortality, hepatotoxicity, and other harms. The review included 72 studies (n = 51 711). No studies evaluated benefits and harms of screening compared with no screening. Pooled estimates for sensitivity of the TST at both 5-mm and 10-mm induration thresholds were 0.79 (5-mm: 95% CI, 0.69-0.89 [8 studies, n = 803]; 10 mm: 95% CI, 0.71-0.87 [11 studies; n = 988]), and those for IGRAs ranged from 0.77 to 0.90 (57 studies; n = 4378). Pooled estimates for specificity of the TST at the 10-mm and 15-mm thresholds and for IGRAs ranged from 0.95 to 0.99 (34 studies; n = 23 853). A randomized clinical trial (RCT) of 24 weeks of isoniazid in individuals with pulmonary fibrotic lesions and LTBI (n = 27 830) found a reduction in absolute risk of active TB at 5 years from 1.4% to 0.5% (relative risk [RR], 0.35 [95% CI, 0.24-0.52]) and an increase in absolute risk for hepatoxicity from 0.1% to 0.5% (RR, 4.59 [95% CI, 2.03-10.39]) for 24 weeks of daily isoniazid compared with placebo. An RCT (n = 6886) found that 3 months of once-weekly rifapentine plus isoniazid was noninferior to 9 months of isoniazid alone for preventing active TB. The risk difference for hepatoxicity comparing isoniazid with rifampin ranged from 3% to 7%, with a pooled RR of 3.29 (95% CI, 1.72-6.28 [3 RCTs; n = 1327]). No studies evaluated the benefits and harms of screening compared with no screening. Both the TST and IGRAs are moderately sensitive and highly specific within countries with low TB burden. Treatment reduced the risk of active TB among the populations included in this review. Isoniazid is associated with higher rates of hepatotoxicity than placebo or rifampin

Management of diarrhea in patients with HER2-positive breast cancer treated with neratinib: A case series and summary of the literature

INTRODUCTION: Neratinib and neratinib-based combinations have demonstrated efficacy for treatment of human epidermal growth factor receptor 2-positive (HER2+) early-stage and metastatic breast cancers. However, diarrhea has been reported as a common adverse event leading to neratinib discontinuation. Results from the CONTROL trial suggest that proactive diarrhea management with antidiarrheal prophylaxis or dose escalation of neratinib from a lower starting dose to the full FDA-approved dose of 240 mg/day can reduce the incidence, duration, and severity of neratinib-associated diarrhea in patients with early-stage breast cancer. Dose escalation has been included in the FDA-approved label for both early-stage and metastatic HER2+ breast cancer since June 2021. CASE SERIES: This series of five cases details real-world clinical implementation of strategies for management of neratinib-induced diarrhea in patients with early-stage and metastatic HER2+ breast cancer, including a patient with a pre-existing gastrointestinal disorder. MANAGEMENT AND OUTCOME: In four of five cases, diarrhea was managed with neratinib dose escalation, and antidiarrheal prophylaxis with loperamide plus colestipol was used in the remaining case. Management of diarrhea allowed all patients to remain on therapy. DISCUSSION: This case series shows that neratinib-associated diarrhea can be managed effectively with neratinib dose escalation from a lower initial starting dose and/or prophylactic antidiarrheal medications in a real-world clinical setting. The findings highlight the importance of patient-provider communication in proactive management of adverse events. Widespread implementation of the strategies described here may improve adherence and thereby clinical outcomes for patients with HER2+ breast cancer treated with neratinib

Demonstrating the potential of salt tracer studies to improve Norwegian drinking water network models and water age estimates

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